Digital camera

• US 4,286,849 A
• Filed: 02/06/1979
• Issued: 09/01/1981
• Est. Priority Date: 02/09/1978
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Shimizu, Masami, Aizawa, Hiroshi, Uchidoi, Masanori, Date, Nobuaki
• Primary Examiner(s): Gellner, Michael L.
• Application Number:
  US06/009,806
• Time in Patent Office: 938 Days
• Field of Search: 354/23 D, 354/36, 354/37, 354/38, 354/217, 354/289
• US Class Current: 396/239
• CPC Class Codes: G03B 7/097 for control of both exposure time and aperture

Abstract

A digital camera with five automatic exposure modes is provided with corresponding individual cards upon selective insertion into the camera to effect the operation of either or both of the shutter and diaphragm in accordance with the digital output of a computer through logic selection circuits as the mode information on the inserted card is read into a binary coded decimal counter controlling operation of the logic circuits. When the card is absent from the camera, a first controlling push button for sequential display of the modes is rendered effective to pass a pulse train to the counter so that upon release of the button, the current mode displayed can be set. The card further includes information relating to the determination of whether or not to give a sound warning signal which occurs, in one embodiment, when the film nears the terminal end of footage. In another embodiment, the buzzer is utilized to assist in releasing not only a first but also an additional three buttons for setting exposure factors and a number of film frames available just after a desired symbol or digital value appears in the display as they are sequentially presented.

Claims

1. An automatic exposure control apparatus for a camera comprising:

(a) light measuring means for producing an electrical signal proportional to the level of brightness of an object being photographed;

(b) exposure factor setting means for producing electrical signals proportional to preset values of exposure factors;

(c) exposure value computing means responsive to the electrical signals from said light measuring and said factor setting means for producing an output;

(d) shutter control means;

(e) diaphragm control means;

(f) exposure mode selecting means responsive to first and second switch signals for directing the output of said computing means to either of said shutter control means and said diaphragm control means, respectively; and

(g) signal forming means having terminals receptive of one of a number of different mode setting members upon reading of information on said mode setting member for producing either one of said first and second signals to be applied to said mode selecting means.

2. An apparatus according to claim 1, wherein said mode selecting means comprises a first gate circuit which is enabled by said first switch signal so that the output of said computing means is directed to said shutter control means, and a second gate circuit which is enabled by said second switch signal so that the output of said computing means is directed to said diaphragm control means.

3. An apparatus according to claim 2, wherein said exposure factor setting means comprises a first setting means for setting film sensitivity, a second setting means for setting shutter time or diaphragm aperture and a pulse generator, said first setting means having a first counter for counting a pulse train from said pulse generator, and said second setting means having a second counter for counting the pulse train from said pulse generator.

4. An apparatus according to claim 3, wherein said first setting element has a first switch connected between said first counter and said pulse generator, and said second setting element has a second switch connected between said second counter and said pulse generator.

5. An apparatus according to claim 4, further including warning means for producing a warning signal each time one pulse is applied to said first or second counter.

6. An apparatus according to claim 4, further including display means responsive to the outputs of said first and second counters for displaying the set values of exposure factors.

7. An apparatus according to claim 1, further including:

(a) pulse generating means;

(b) a first switch accessible from the outside of the camera housing for setting a maximum possible number of film frames;

(c) a first counter cooperative with said first switch for counting a pulse train from said pulse generating means in order to set said number;

(d) a second counter cooperative with an internal mechanism of said camera for advancing one count each time one frame has been exposed;

(e) comparing means for comparing the outputs of said first and second counters with each other upon attainment of a predetermined relationship for producing a warning signal; and

(f) warning means for converting said warning signal to an audible or visible signal.

8. An apparatus according to claim 7, further including a second switch cooperative with a back cover of said camera and operating upon opening of said cover to reset said first and second counters.

9. An automatic exposure control apparatus for a camera including:

(a) light measuring means for producing an electrical signal proportional to the object brightness level;

(b) exposure factor setting means for producing electrical signals proportional to the set values of exposure factors, said means being associated with correcting means responsive to a switch signal for producing an electrical signal proportional to a corrected value of exposure factor;

(c) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output;

(d) shutter control means;

(e) diaphragm control means;

(f) exposure mode selecting means for directing the output of said computing means to either one of said shutter control and said diaphragm control means, said means comprising a first gate circuit which is enabled by a first switch signal so that the output of said computing means is applied to said shutter control means, and a second gate circuit which is enabled by a second switch signal so that the output of said computing means is applied to said diaphragm control means;

(g) first detecting means for detecting whether or not the output of said first gate circuit is outside a dynamic range of said shutter control means and for producing an actuating signal to be applied to said correcting means when the output of said first gate circuit is outside the dynamic range;

(h) second detecting means for detecting whether or not the output of said second gate circuit is outside a dynamic range of said diaphragm control means and for producing an actuating signal to be applied to said correcting means when the output of said second gate circuit is outside the dynamic range; and

(i) signal forming means for producing first and second switch signals for controlling the operation of said mode selecting means, said means having terminals receptive of one of a number of different mode setting members upon reading of information on said mode setting member for applying either of said first and second signals to said mode selecting means.

10. An apparatus according to claim 9, further including gate means interposed between said mode selecting means and said signal forming means and wherein said signal forming means produces one of four signals, namely, a shutter preselection signal, a shutter preselection magic signal, a diaphragm preselection signal and a diaphragm preselection magic signal, so that when said signal forming means produces either of said shutter preselection signal and said shutter preselection magic signal, said gate means produces said second switch signal, while when said signal forming means produces either of said diaphragm preselection signal and said diaphragm preselection magic signal, said gate means produces said first switch signal.

11. An apparatus according to claim 10, wherein said first detecting means is actuated when a first counter produces said diaphragm preselection magic signal, and said second detecting means is actuated when a second counter produces said shutter preselection magic signal.

12. An apparatus according to claim 9, further including:

(a) pulse generating means for producing a pulse train;

(b) a first switch accessible from the outside of the camera housing for setting a maximum possible number of film frames;

(c) a first counter cooperative with said first switch for counting the pulse train in order to set said number;

(d) a second counter cooperative with an internal mechanism of said camera for advancing one count each time one frame has been exposed;

(e) comparing means for comparing the outputs of said first and second counters with each other upon attainment of a predetermined relationship to produce a warning signal; and

(f) warning means for converting said warning signal to an audible or visible signal.

13. An apparatus according to claim 12, further including a second switch cooperative with a back cover of said camera and operating upon opening of said cover to reset said first and second counters.

14. An apparatus according to claim 12, further including a second switch cooperative with a back cover of said camera and operating upon opening of said cover to reset said first and second counters.

15. An automatic exposure control apparatus for a camera including:

(a) light measuring means for producing an electrical signal proportional to the brightness level of an object being photographed;

(b) exposure factor setting means having;

(1) pulse generating means for producing a pulse train;

(2) a first counter for counting the pulse train from said generating means to set a desired value of exposure factor;

(3) a first switch connected between said generating means and said first counter; and

(4) a second counter responsive to a control signal for correcting the set value of exposure factor;

(c) exposure value computing means responsive to the outputs of said light measuring means and said second counter for producing an output;

(d) shutter control means;

(e) diaphragm control means;

(f) exposure mode selecting means for directing the output of said computing means to either one of said shutter control means and said diaphragm control means, said means including a first gate circuit which is enabled by either one of first and second switch signals so that the output of said computing means is applied to said shutter control means, and a second gate circuit which is enabled by either one of third and fourth switch signals so that the output of said computing means is applied to said diaphragm control means;

(g) first detecting means rendered operative by said second signal when it is detected that the output of said first gate circuit is outside the dynamic range of said shutter control means to produce an actuating signal which is applied to said second counter.

(h) second detecting means rendered operative by said fourth signal when it is detected that the output of said second gate circuit is outside the dynamic range of said shutter control means to produce an actuating signal which is applied to said second counter; and

(i) a third counter having input terminals receptive of information of one of a number of different mode setting members and responsive to the reading of the information on the selected member for producing one of said first, second, third and fourth signals for controlling operation of said mode selecting means.

16. An apparatus according to claim 15, further including warning means for producing a warning signal each time one pulse is applied to said second counter.

17. An apparatus according to claim 15, further including display means responsive to the outputs of said second and third counters for displaying the set mode and the preset value of the exposure factor.

18. An automatic exposure control apparatus for a camera including:

(a) light measuring means for producing an electrical signal proportional to the object brightness level;

(b) exposure factor setting means for producing electrical signals proportional to the preset values of exposure factors;

(c) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output;

(d) shutter control means;

(e) diaphragm control means;

(f) exposure mode selecting means responsive to first and second signals for directing the output of said computing means to either of said shutter and said diaphragm control means and responsive to a third signal for directing the output of said computing means to both said shutter and said diaphragm control means; and

(g) signal forming means having input terminals receptive of information on one of a number of different mode setting members and responsive to insertion of the mode setting member into said camera for producing one of said first, second and third signals which are applied to said exposure mode selecting means.

19. An apparatus according to claim 18, wherein said mode selecting means includes a first gate circuit which is enabled by said first signal so that the output of said computing means is applied to said shutter control means, a second gate circuit which is enabled by said second signal so that the output of said computing means is applied to said diaphragm control means, and a third gate circuit which is enabled by said third signal so that the output of said computing means is applied to both said diaphragm control means and said shutter control means.

20. An apparatus according to claim 19, wherein said exposure factor setting means includes a first setting element for setting film sensitivity, a second setting element for setting a preselected exposure factor and a pulse generating source for producing a pulse train, said first and second setting elements having first and second counters, respectively, for counting the pulse train.

21. An apparatus according to claim 20, wherein said first setting element has a first switch connected between said first counter and said pulse generating means, and said second setting element has a second switch connected between said second counter and said pulse generating means.

22. An apparatus according to claim 21, wherein said exposure value computing means has a first computing section responsive to the outputs of said light measuring means and said first and second counters for producing a first output which is applied to said first and second gate circuits and has a second computing section responsive to the outputs of said light measuring means and said first counter for producing a second output which is applied to said third gate circuit.

23. An apparatus according to claim 21, further including display means responsive to the outputs of said first and second counters for displaying the set mode and the preset values of exposure factors.

24. An apparatus according to claim 18, further including:

(a) pulse generating means for producing a pulse train;

(b) a first switch accessible from the outside of the camera housing for setting a maximum possible number of film frames;

(c) a first counter cooperative with said first switch for counting the pulse train from said pulse generating means in order to set said number;

(d) a second counter cooperative with an internal mechanism of said camera for advancing one count each time one frame has been exposed;

(e) comparing means for comparing the outputs of said first and second counters with each other and, upon attainment of a predetermined relationship between them, producing a warning signal; and

(f) warning means for converting said warning signal to an audible or visible signal.

25. An apparatus according to claim 24, further including a second switch cooperative with a back cover of said camera and operating upon opening of said cover to reset said first and second counters.

26. An automatic exposure control apparatus for a camera including:

(a) light measuring means for producing an electrical signal proportional to the brightness level of an object being photographed;

(b) exposure factor setting means for producing electrical signals proportional to the set values of exposure factors, said means being associated with correcting means responsive to a control signal for producing an electrical signal proportional to a corrected value of exposure factor;

(c) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output;

(d) shutter control means;

(e) diaphragm control means;

(f) exposure mode selecting means for directing the output of said computing means to either or both of said shutter and said diaphragm control means, said means including a first gate circuit which is enabled by a first switch signal so that the output of said computing means is applied to said shutter control means, a second gate circuit which is enabled by a second switch signal so that the output of said computing means is applied to said diaphragm control means, and a third gate circuit which is enabled by a third switch signal so that the output of said computing means is applied to both said shutter and said diaphragm control circuits;

(g) first detecting means for detecting whether or not the output of said first gate circuit is outside the dynamic range of said shutter control means and, when such output is outside the dynamic range, for producing an actuating signal which is applied to said correcting means;

(h) second detecting means for detecting whether or not the output of said second gate circuit is outside a dynamic range of said diaphragm control means and, when such output is outside the dynamic range, for producing an actuating signal which is applied to said correcting means;

(i) signal forming means having a mode information reader arranged upon selective reception of a number of different mode setting members from the outside of the camera housing for producing one of said first, second and third signals which is applied to said mode selecting means.

27. An apparatus according to claim 26, further including gate means interposed between said mode selecting means and said signal forming means and wherein said signal forming means produces one of five signals, namely, a shutter preselection signal, a shutter preselection magic signal, a diaphragm preselection signal, a diaphragm preselection magic signal and a program signal so that, when said signal forming means produces either of said shutter preselection signal and said shutter preselection magic signals, said gate means produces said second switch signal;

when said signal forming means produces either of said diaphragm preselection signal and said diaphragm preselection magic signal, said gate means produces said first switch signal; and

when said signal forming means produces said program signal, said gate means produces said third signal.

28. An apparatus according to claim 27, further including a first counter for producing said diaphragm preselection magic signal which actuates said first detecting means, and a second counter for producing said shutter preselection magic signal which actuates said second detecting means.

29. An apparatus according to claim 26, further including:

(a) pulse generating means for producing a pulse train;

(b) a first switch accessible from the outside of the camera housing for setting a maximum possible number of film frames;

(c) a first counter cooperative with said first switch for counting the pulse train in order to set said number;

(d) a second counter cooperative with an internal mechanism of said camera for advancing one count each time one frame has been exposed;

(e) comparing means for comparing the outputs of said first and second counters with each other upon attainment of a predetermined relationship for producing a warning signal; and

(f) warning means for converting said warning signal to an audible or visible signal.

30. An automatic exposure control apparatus for a camera including:

(A) light measuring means having;

(a) photosensitive means for producing an electrical signal proportional to the brightness level of an object being photographed; and

(b) analog-to-digital converting means for converting the analog signal of said photosensitive means to a digital signal;

(B) pulse generating means for producing a pulse train;

(C) exposure factor setting means having;

(a) a first switch accessible from the outside of the camera housing for use in setting an exposure factor;

(b) a second switch accessible from the outside of the camera housing for use in setting film sensitivity;

(c) a first counter for setting the exposure factor, said first counter counting the pulse train in response to actuation of said first switch;

(d) a second counter for setting the film sensitivity, said second counter counting the pulse train in response to actuation of said second switch; and

(e) a third counter which is provided for a setting value altering purpose and is receptive of the output of said first counter, said third counter being arranged to alter the count output of the first counter by counting oscillation pulses produced by said pulse generating means while a detecting signal is being applied thereto;

(D) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output in digital form, said means having;

(a) first computing means for digitally computing the outputs of said analog-to-digital converting means, said first counter and said second counter; and

(b) second computing means for digitally computing the outputs of said analog-to-digital converting means and said second counter;

(E) shutter control means;

(F) diaphragm control means;

(G) exposure mode selecting means having;

(a) a first gate circuit enabled by either of first and second signals to apply the output of said first computing means to said shutter control means;

(b) a second gate circuit enabled by either of third and fourth signals to apply the output of said first computing means to said diaphragm control means; and

(c) a third gate circuit enabled by a fifth signal to apply the output of said second computing means to both said shutter and said diaphragm control means;

(H) first detecting means rendered operative by said second signal when the output of said first gate circuit is outside the dynamic range of said shutter control means for producing an actuating signal which is applied to said third counter;

(I) second detecting means rendered operative by said fourth signal when the output of said second gate circuit is outside the dynamic range of said diaphragm control means for producing an actuating signal which is applied to said third counter; and

(J) a fourth counter having a mode information reader arranged upon selective reception of a number of different mode setting members from the outside of the camera housing for producing one of said first, second, third and fourth signals.

31. An apparatus according to claim 30, further including warning means for producing a warning signal each time one pulse is applied to said first and second counters.

32. An apparatus according to claim 30, further including display means for displaying the preset value of exposure factor and the selected mode based on the outputs of said first, second and fourth counters.

33. An automatic exposure control apparatus for a camera including:

(A) light measuring means for producing an electrical signal proportional to the brightness level of an object being photographed;

(B) exposure factor setting means for producing electrical signals proportional to the preset values of exposure factors;

(C) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output;

(D) shutter control means;

(E) diaphragm control means;

(F) exposure mode selecting means responsive to a first signal for directing the output of said computing means to said shutter control means and responsive to a second signal for directing the output of said computing means to said diaphragm control means;

(G) pulse generating means for producing a pulse train;

(H) a first counter for counting the pulse train for producing either one of said first and said second signals depending upon the number of pulses counted; and

(I) a first switch accessible from the outside of the camera, said first switch being arranged to cause a number of pulses corresponding to the switching operation time of the first switch to be applied to said first counter and to cause the first counter to produce either the first signal or the second signal thereof according to the count value of the first counter.

34. An apparatus according to claim 33, wherein said mode selecting means has a first gate circuit which is enabled by said first signal so that the output of said computing means is applied to said shutter control means, and a second gate circuit which is enabled by said second signal so that the output of said computing means is applied to said diaphragm control means.

35. An apparatus according to claim 34, wherein said exposure factor setting means has a first setting member for setting film sensitivity and a second setting member for setting a preselected exposure factor, said first setting member having a second counter for counting the pulse train and said second setting members having a third counter for counting the pulse train.

36. An apparatus according to claim 35, wherein said first setting member has a second switch connected between said pulse generator and said second counter, and said second setting member has a third switch connected between said pulse generator and said third counter.

37. An apparatus according to claim 36, further including warning means for producing a warning signal each time one pulse is applied to said first, second and third counters.

38. An apparatus according to claim 36, further including display means responsive to the outputs of said first, second and third counters for displaying the set mode and the preset values of exposure factors.

39. An apparatus according to claim 33, further including:

(a) a second switch accessible from the outside of the camera housing to set a maximum possible number of frames of the used film;

(b) a second counter connected through said second switch to said pulse generating means upon actuation of said second switch to count the pulse train in order to set that number;

(c) a third counter cooperative with an internal mechanism of the camera for advancing one count each time one exposure has been completed;

(d) comparing means for comparing the outputs of said second and third counters when the difference therebetween attains a predetermined value for producing a warning signal; and

(e) warning means for converting said warning signal to an audible or visible signal.

40. An apparatus according to claim 39, further including a third switch cooperative with a back cover of the camera and operating upon opening of said back cover to reset said second and third counters.

41. An automatic exposure control apparatus for a camera including:

(A) light measuring means for producing an electrical signal proportional to the brightness level of an object being photographed;

(B) exposure factor setting means for producing electrical signals proportional to the preset values of exposure factors;

(C) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output;

(D) shutter control means;

(E) diaphragm control means;

(F) exposure mode selecting means responsive to a first signal for directing the output of said computing means to said shutter control means and responsive to a second signal for directing the output of said computing means to said diaphragm control means;

(G) pulse generating means for producing a pulse train;

(H) a first counter for counting the pulse train for producing either one of said first and said second signals depending upon the number of pulses counted; and

(I) a first switch accessible from the outside of the camera, said first switch being arranged to cause a number of pulses corresponding to the switching operation time of the first switch to be applied to said first counter and to cause the first counter to produce either the first signal or the second signal thereof according to the count value of the first counter; and

wherein said first counter has a trigger terminal connected to the output of said pulse generating means, and has input terminals receptive of mode information supplied from the outside of the camera with selection of one of a number of different mode setting members, so that when the mode member is loaded, a signal representative of the selected load is applied to said first counter and the reception of the pulse train at the trigger terminal of said counter is inhibited, while said first counter applies either one of said first and second signals to said mode selecting means depending upon the input signal at the input terminals thereof.

42. An automatic exposure control apparatus for a camera including:

(A) light measuring means for producing an electrical signal proportional to the object brightness level.

(B) exposure factor setting means for producing electrical signals proportional to the preset values of exposure factors, said means being associated with correcting means responsive to a control signal for producing an electrical signal proportional to a corrected value of exposure factor;

(C) exposure value computing means responsive to the output of said light measuring means and said exposure factor setting means for producing an output;

(D) shutter control means;

(E) diaphragm control means;

(F) exposure mode selecting means for directing the output of said computing means to either one of said shutter and said diaphragm control means, said means having a first gate circuit which is enabled by a first signal so that the output of said computing means is applied to said shutter control means, and a second gate circuit which is enabled by a second signal so that the output of said computing means is applied to said diaphragm control means;

(G) first detecting means for detecting whether or not the output of said first gate circuit is outside the dynamic range of said shutter control means and, when such output is outside the dynamic range, for producing the signal which is applied to said correcting means;

(H) second detecting means for detecting whether or not the output of said second gate circuit is outside the dynamic range of said diaphragm control means and, when such output is outside the dynamic range, for producing the signal which is applied to the correcting means;

(I) pulse generating means for producing a pulse train;

(J) a first counter for counting the pulse train for producing either one of said first and second signals dependent upon the number of pulses counted; and

(K) a first switch accessible from the outside of the camera, said first switch being arranged to cause a number of pulses corresponding to the switching operation time of the first switch to be applied to said first counter and to cause the first counter to produce either the first signal or the second signal thereof according to the count value of the first counter.

43. An apparatus according to claim 42, further including gate means interposed between said first counter and said mode selecting means, and wherein said first counter produces one of four signals, namely, a shutter preselection signal, a shutter preselection magic signal, a diaphragm preselection signal and a diaphragm preselection magic signal, so that when said first counter produces either one of said shutter preselection signal and said shutter preselection magic signal, said gate means produces the second signal which is applied to said mode selecting means, while when said first counter produces either one of said diaphragm preselection signal and said diaphragm preselection magic signal, said gate means produces the first signal which is applied to said mode selecting means.

44. An apparatus according to claim 42, wherein said first detecting means is rendered operative when said first counter produces said diaphragm preselection magic signal, and said second detecting means is rendered operative when said first counter produces said shutter preselection magic signal.

45. An apparatus according to claim 42, further including:

(a) a second switch for use in setting a maximum possible number of frames of the used film accessible from the outside of the camera housing;

(b) a second counter connected through said second switch to said pulse generating means upon actuation of said second switch to count the pulse train in order to set that number;

(c) a third counter cooperative with an internal mechanism of the camera for advancing one count each time one frame has been exposed;

(d) comparing means for comparing the outputs of said second and third counters with each other when the difference therebetween attains a predetermined value for producing a warning signal; and

(e) warning means for converting said warning signal to an audible or visible signal.

46. An apparatus according to claim 45, further including a third switch cooperative with a back cover of the camera and operating upon opening of the back cover to reset said second and third counters.

47. An automatic exposure control apparatus for a camera including:

(A) light measuring means for producing an electrical signal proportional to the object brightness level;

(B) exposure factor setting means for producing electrical signals proportional to the preset values of exposure factors, said means being associated with correcting means responsive to a control signal for producing an electrical signal proportional to a corrected value of exposure factor;

(C) exposure value computing means responsive to the output of said light measuring means and said exposure factor setting means for producing an output;

(D) shutter control means;

(E) diaphragm control means;

(F) exposure mode selecting means for directing the output of said computing means to either one of said shutter and said diaphragm control means, said means having a first gate circuit which is enabled by a first signal so that the output of said computing means is applied to said shutter control means, and a second gate circuit which is enabled by a second signal so that the output of said computing means is applied to said diaphragm control means;

(G) first detecting means for detecting whether or not the output of said first gate circuit is outside the dynamic range of said shutter control means and, when such output is outside the dynamic range, for producing the signal which is applied to said correcting means;

(H) second detecting means for detecting whether or not the output of said second gate circuit is outside the dynamic range of said diaphragm control means and, when such output is outside the dynamic range, for producing the signal which is applied to the correcting means;

(I) pulse generating means for producing a pulse train;

(J) a first counter for counting the pulse train for producing either one of said first and second signals dependent upon the number of pulses counted; and

(K) a first switch accessible from the outside of the camera, said first switch being arranged to cause a number of pulses corresponding to the switching operation time of the first switch to be applied to said first counter and to cause the first counter to produce either the first signal or the second signal thereof according to the count value of the first counter; and

wherein said first counter has a trigger terminal connected to the output of said pulse generating means and has input terminals receptive of mode information supplied from the outside of the camera with selection of one of a number of different mode setting members, so that when the mode setting member is loaded, a signal representative of the selected mode is applied to said first counter so that the reception of the pulse train at the trigger terminal of said first counter is inhibited, while said first counter applies either one of said first and second signals to said mode selecting means depending upon the input signal at the input terminals thereof.

48. An automatic exposure control apparatus for a camera including:

(A) light measuring means for producing an electrical signal proportional to the brightness level of an object being photographed;

(B) pulse generating means for producing a pulse train;

(C) exposure factor setting means having;

(1) a first switch accessible from outside of the camera housing for use in setting an exposure factor;

(2) a first counter for setting a value of the exposure factor, said first counter being arranged to receive and count a number of pulses corresponding to the switching operation time of said first switch applied thereto from said pulse generating means; and

(3) a second counter which is provided for a setting value changing purpose and is receptive of the count output of said first counter, said second counter being arranged to alter the count output of the first counter by counting oscillation pulses produced by said pulse generating means while a detecting signal is being applied thereto;

(D) exposure value computing means responsive to the outputs of said light measuring means and said second counter;

(E) shutter control means;

(F) diaphragm control means;

(G) exposure mode selecting means for directing the output of said computing means to either one of said shutter and said diaphragm control means, said means having a first gate circuit which is enabled by one of first and second signals so that the output of said computing means is applied to said shutter control means, and a second gate circuit which is enabled by one of third and fourth signals so that the output of said computing means is applied to said diaphragm control means;

(H) first detecting means rendered operative by said second signal to detect whether or not the output of said first gate circuit is outside the dynamic range of said shutter control means and, when such output is outside the range of the dynamic range, producing an actuating signal which is applied to said second counter;

(I) second detecting means rendered operative by said fourth signal to detect whether or not the output of said second gate circuit is outside the dynamic range of said diaphragm control means and, when such output is outside the dynamic range, for producing an actuating signal which is applied to said second counter;

(J) a second switch accessible from the outside of the camera housing for use in setting a mode; and

(K) a third counter arranged to receive and count a number of pulses which corresponds to the switching operation time of generating means, said third counter being further arranged to apply one of the first, second, third and fourth signals to said exposure mode selecting means according to the count value obtained at the third counter.

49. An apparatus according to claim 48, further including warning means for producing a warning signal each time one pulse is applied to said first and third counters.

50. An apparatus according to claim 48, further including display means responsive to the outputs of said first and third counters for displaying the selected mode and the preset value of exposure factor.

51. An automatic exposure control apparatus for a camera including:

(A) light measuring means for producing an electrical signal proportional to the brightness level of an object being photographed;

(B) exposure factor setting means for producing electrical signals proportional to the preset values of exposure factors;

(C) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output;

(D) shutter control means;

(E) diaphragm control means;

(F) exposure mode selecting means for directing the output of said computing means to either or both said shutter and said diaphragm control means, said means responsive to a first signal directing the output of said computing means to said shutter control means, responsive to a second signal directing the output of said computing means to said diaphragm control means, and responsive to a third signal directing the output of said computing means to both said shutter and said diaphragm control means;

(G) pulse generating means for producing a pulse train;

(H) a first counter for counting the pulse train for producing one of said first, second and third signals which is applied to said exposure mode selecting means depending upon the number of pulses counted; and

(I) a first switch accessible from the outside of the camera, said first switch being arranged to cause a number of pulses corresponding to the switching operation time of the first switch to be applied to said first counter and to cause the first counter to produce one of the first, second and third signals according to the count value obtained at the first counter.

52. An apparatus according to claim 51, wherein said exposure mode selecting means has a first gate circuit which is enabled by said first signal so that the output of said computing means is applied to said shutter control means, a second gate circuit which is enabled by said second signal so that the output of said computing means is applied to said diaphragm control means, and a third gate circuit which is enabled by said third signal so that the output of said computing means is applied to both said shutter and said diaphragm control means.

53. An apparatus according to claim 52, wherein said exposure factor setting means has a first setting member for setting film sensitivity, and a second setting member for setting a preselected exposure factor, said first setting member having a second counter for counting the pulse train;

and said second setting member having a third counter for counting the pulse train.

54. An apparatus according to claim 53, wherein said first setting member has a second switch connected between said pulse generating means and said second counter, and said second setting member has a third switch connected between said pulse generating means and said third counter.

55. An apparatus according to claim 54, wherein said exposure value computing means has a first computing member for computing the outputs of said light measuring means, said second and third counters for producing an output which is applied to said first and second gate circuits, and a second computing member for computing the outputs of said light measuring means and said second counter for producing an output which is applied to said third gate circuit.

56. An apparatus according to claim 54, further including display means responsive to the outputs of said first, second and third counters for displaying the selected mode and the preset values of exposure factors.

57. An apparatus according to claim 51, further including:

(a) a second switch accessible from the outside of the camera housing for use in setting a maximum possible number of frames of the used film;

(b) a second counter connected through said second switch to said pulse generating means upon actuation of said second switch to count the pulse train in order to set that number;

(c) a third counter cooperative with an internal mechanism of the camera to advance one count each time one frame has been exposed;

(d) comparing means for comparing the outputs of said second and third counters with each other upon attainment of the difference therebetween to a predetermined value for producing an output signal;

(e) warning means for converting said output signal of said comparing means to an audible or visible signal.

58. An apparatus according to claim 57, further including a third switch cooperative with a back cover of the camera housing and operating upon opening of said cover to reset said second and third counters.

59. An automatic exposure control apparatus for a camera including:

(A) light measuring means for producing an electrical signal proportional to the brightness level of an object being photographed;

60. (B) exposure factor setting means for producing electrical signals proportional to the preset value of exposure factors;

64. An apparatus according to claim 60, further including gate means interposed between said first counter and said mode selecting means, and wherein said first counter responsive to signals applied to input terminals thereof produces one of five signals, namely, a shutter preselection signal, a shutter preselection magic signal, a diaphragm preselection signal, a diaphragm preselection magic signal, and a program signal, so that when said first counter produces one of said shutter preselection signal and said shutter preselection magic signal, said gate means produces said first signal;

when said first counter produces one of said diaphragm preselection signal and said diaphragm preselection magic signal, said gate means produces said second signal; and

when said first counter produces the program signal, said gate means produces said third signal.

66. An apparatus according to claim 60, further including:

(a) a second switch accessible from the outside of the camera housing for use in setting a maximum possible number of frames of the used film;

(b) a second counter connected through said second switch to said pulse generating means upon actuation of said second switch to count the pulse train in order to set that number;

(c) a third counter for advancing one count each time one frame has been exposed;

(d) comparing means for comparing the outputs of said second and third counters with each other when the difference therebetween attains a predetermined value for producing a warning signal; and

(e) warning means for converting said warning signal to an audible or visible signal.

70. An apparatus according to claim 66, further including warning means for producing a warning signal each time one pulse is applied to one of said first, second and fourth counters.

71. An apparatus according to claim 66, further including display means responsive to the outputs of said first, second and fourth counters for displaying the selected mode and the preset values of exposure factors.

61. (C) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output;

(D) shutter control means;

(E) diaphragm control means;

(F) exposure mode selecting means for directing the output of said computing means to either or both said shutter and said diaphragm contol means, said means responsive to a first signal directing the output of said computing means to said shutter control means, responsive to a second signal directing the output of said computing means to said diaphragm control means, and responsive to a third signal directing the output of said computing means to both said shutter and said diaphragm control means;

(G) pulse generating means for producing a pulse train;

(H) a first counter for counting the pulse train for producing one of said first, second and third signals which is applied to said exposure mode selecting means depending upon the number of pulses counted; and

(I) a first switch accessible from the outside of the camera, said first switch being arranged to cause a number of pulses corresponding to the switching operation time of the first switch to be applied to said first counter and to cause the first counter to produce one of the first, second and third signals according to the count value obtained at the first counter;

wherein said first counter has a trigger terminal connected to the output of said pulse generating means, and has input terminals receptive of mode information supplied from the outside of the camera housing with selection of one of a number of different mode setting members so that when the mode setting member is loaded, a signal representative of the selected mode is applied to said first counter so that the reception of the pulse train at the trigger terminal of said counter is inhibited, while said first counter applies either one of said first, second and third signals to said mode selecting means depending upon the input signal at the input terminals thereof.

65. An apparatus according to claim 61, wherein said first detecting means is rendered operative when said first counter produces said diaphragm preselection magic signal, and said second detecting means is rendered operative when said first counter produces said shutter preselection magic signal.

62. An atuomatic exposure control apparatus for a camera including:

(A) light measuring means for producing an electrical signal proportional to the brightness level of an object being photographed;

(B) exposure factor setting means for producing electrical signals proportional to the preset values of exposure factors, said means being associated with correcting means for correcting the preset values of exposure factors in response to a control signal;

(C) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output;

(D) shutter control means;

63. (E) diaphragm control means;

(F) exposure mode selecting means for directing the output of said computing means to either or both said shutter and said diaphragm control means, said means having a first gate circuit which is enabled by a first signal so that the output of said computing means is applied to said shutter control means, a second gate circuit which is enabled by a second signal so that the output of said computing means is applied to said diaphragm control means, and a third gate circuit which is enabled by a third signal so that the output of said computing means is applied to both said shutter and said diaphragm control means;

(G) first detecting means for detecting whether or not the output of said first gate circuit is outside the dynamic range of said shutter control means and, when such signal exceeds the dynamic range, producing an actuating signal which is applied to said correcting means;

(H) second detecting means for detecting whether or not the output of said second gate circuit is outside the dynamic range of said diaphragm control means and, when such signal is outside the dynamic range, producing an actuating signal which is applied to said correcting means;

(I) pulse generating means for producing a pulse train;

(J) a first counter connected to the output of said pulse generating means for producing one of said first, second and third signals which is applied to said mode selecting means depending upon the number of pulses counted; and

(K) a first switch accessible from the outside of the camera, said first switch being arranged to cause a number of pulses corresponding to the switching operation time of the first switch to be applied to said first counter and to cause the first counter to produce one of the first, second and third signals according to the count value obtained at the first counter.

67. An apparatus according to claim 63, further including a third switch cooperative with a back cover of the camera housing and operating upon opening of said cover to reset said second and third counters.

68. An automatic exposure control apparatus for a camera including:

(A) light measuring means for producing an electrical signal proportional to the brightness level of an object being photographed;

(B) exposure factor setting means for producing electrical signals proportional to the preset values of exposure factors, said means being associated with correcting means for correcting the preset values of exposure factors in response to a control signal;

(C) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output;

(D) shutter control means;

(E) diaphragm control means;

(F) exposure mode selecting means for directing the output of said computing means to either or both said shutter and said diaphragm control means, said means having a first gate circuit which is enabled by a first signal so that the output of said computing means is applied to said shutter control means, a second gate circuit which is enabled by a second signal so that the output of said computing means is applied to said diaphragm control means, and a third gate circuit which is enabled by a third signal so that the output of said computing means is applied to both said shutter and said diaphragm control means;

(G) first detecting means for detecting whether or not the output of said first gate circuit is outside the dynamic range of said shutter control means and, when such signal exceeds the dynamic range, producing an actuating signal which is applied to said correcting means;

(H) second detecting means for detecting whether or not the output of said second gate circuit is outside the dynamic range of said diaphragm control means and, when such signal is outside the dynamic range, producing an actuation signal which is applied to said correcting means;

(I) pulse generating means for producing a pulse train;

(J) a first counter connected to the output of said pulse generating means for producing one of said first, second and third signals which is applied to said mode selecting means depending upon the number of pulses counted; and

(K) a first switch accessible from the outside of the camera, said first switch being arranged to cause a number of pulses corresponding to the switching operation time of the first switch to be applied to said first counter and to cause the first counter to produce one of the first, second and third signals according to the count value obtained at the first counter; and

wherein said first counter has a trigger terminal connected to the output of said pulse generating means, and has input terminals receptive of mode information supplied from the outside of the camera with the selection of one of a number of different mode setting members, so that when the mode setting member is loaded, a signal representative of the selected mode is applied to said first counter to that the reception of the pulse train at the trigger terminal of said counter is inhibited, while said first counter applies either one of said first, second and third signals to said mode selecting means depending upon the input signal at the input terminals thereof.

69. An automatic exposure control apparatus for a camera including:

(A) light measuring means having;

(a) a photosensitive element for producing an electrical signal proportional to the brightness level of an object being photographed; and

(b) analog-to-digital converting means for converting the analog signal of said photosensitive element to a digital signal;

(B) pulse generating means for producing a pulse train;

(C) exposure factor setting means having;

(a) a first switch accessible from the outside of the camera housing for use in setting a preselected exposure factor;

(b) a second switch accessible from the outside of the camera housing for use in setting film sensitivity;

(c) a first counter for setting an exposure value, said first counter being arranged to have a number of pulses corresponding to the switching operation time of said first switch applied thereto from said pulse generating means and to count the pulses thus applied;

(d) a second counter for setting a film sensitivity value, said second counter being arranged to have a number of pulses corresponding to the switching operation time of said second switch applied thereto from said pulse generating means and to count the pulses thus applied; and

(e) a third counter which is provided for an exposure setting value altering purpose and is receptive of the output of said first counter, said third counter being arranged to alter the count output of the first counter by counting oscillation pulses produced by said pulse generating means while a detecting signal is being applied thereto;

(D) exposure value computing means responsive to the outputs of said light measuring means and said exposure factor setting means for producing an output in digital form, said means having;

(a) a first computing member for digitally computing the outputs of said analog-to-digital converting means, said first counter and said second counter; and

(b) a second computing member for digitally computing the outputs of said analog-to-digital converting means and said second counter;

(E) shutter control means;

(F) diaphragm control means;

(G) exposure mode selecting means having;

(a) a first gate circuit enabled by either one of first and second signals to direct the output of said first computing means to said shutter control means; and

(b) a second gate circuit enabled by either one of third or fourth signals to direct the output of said first computing means to said diaphragm control means; and

(c) a third gate circuit enabled by a fifth signal to direct the output of said second computing member to both said shutter and said diaphragm control means;

(H) first detecting means rendered operative by said second signal to detect whether or not the output of said first gate circuit is outside the dynamic range of said shutter control means and, when such output is outside the dynamic range, producing a detecting signal which is applied to said third counter;

(I) second detecting means rendered operative by said fourth signal to detect whether or not the output of said second gate circuit is outside the dynamic range of said diaphragm control means and, when such output is outside the dynamic range, producing a detecting signal which is applied to said third counter;

(J) a third switch accessible from the outside of the camera housing for use in setting a mode; and

(K) a fourth counter arranged to receive and count a number of pulses which corresponds to the switching operation time of said third switch and are applied thereto from the pulse generating means, said fourth counter being further arranged to apply one of the first, second, third, fourth and fifth signals to said exposure mode selecting means according to the count value obtained at the fourth counter;