Camera with exposure control device

• US 4,165,929 A
• Filed: 12/12/1977
• Issued: 08/28/1979
• Est. Priority Date: 11/30/1974
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Shimizu, Masami, Ito, Tadashi, Ito, Fumio, Yamamichi, Masayoshi, Mashimo, Yukio, Murakami, Hiroyashu
• Primary Examiner(s): Adams, Russell E.
• Application Number:
  US05/859,694
• Time in Patent Office: 624 Days
• Field of Search: 354/26, 354/28, 354/29, 354/36, 354/37, 354/38
• US Class Current: 396/238
• CPC Class Codes: G03B 7/087 for control of both exposure time and aperture
• CPC Class Codes: G03B 7/089 for storage of exposure value in mirror reflex cameras

Abstract

An automatic camera being simple in handling and composition and provided with an accessory selectively mounted on the camera body or with an aperture value setting information device mounted on the camera body, so that the camera operation may select either the shutter time priority mode or the aperture value priority mode.

Claims

1. A camera which can select a shutter time priority photographing mode or an aperture priority photographing mode and can exchange its lenses, comprising:

a. shutter means;

b. shutter time setting means which can be set manually for generating an electrical signal corresponding to the set shutter time;

c. shutter control means which is electrically connected to the shutter time setting means for generating signal to control the operation of the shutter means;

d. aperture means having an aperture and aperture presetting means for determining the opening of the aperture;

e. means for measuring the light transmitted through a photographing lens of fully open aperture, wherein said means generates an electrical signal corresponding to the light transmitted through the photographing lens;

f. aperture value setting means which can be set independently of the shutter time setting means and has a transducing means for generating an electrical signal corresponding to an aperture value;

g. aperture control means which is electrically connected to the aperture value setting means for generating a signal to control the operation of the aperture means;

h. proper exposure amount detecting circuit means selectively and electrically connected either with the shutter time setting means or the aperture value setting means, wherein said means can be selectively connected either with the shutter control means or the aperture control means for producing a combination information output signal of the shutter value and the aperture value for giving a proper exposure in accordance with the light measuring means; and

i. photographic mode effecting means which is electrically connected to the shutter control means and the aperture control means and is arranged to effectuate a setting value set through said shutter time setting means or said aperture value setting means according to a photographic mode selecting action performed.

2. A camera system according to claim 1, wherein the proper exposure amount detecting circuit means further includes an operation circuit means for setting additional photographic parameters than the shutter time information and the aperture value information and being connected to the light measuring circuit for producing combined information of the shutter time and the aperture value for obtaining the proper exposure amount.

3. A camera system in accordance with claim 1, wherein the photographic mode effecting means comprises at least one selecting means connectable with the shutter control means and the aperture control means, said selecting means selectively connecting either the shutter time setting operation input means to the shutter control means or the aperture value setting operation input means to the aperture control means.

4. A camera system according to claim 1, wherein the shutter control means and the aperture control means respectively comprise an operational device means connected respectively and functionally to the shutter time setting operation input means and to the aperture value setting operation input means for producing respectively the shutter time information and the aperture value information for obtaining the proper exposure.

5. A camera system according to claim 4, wherein the proper exposure amount detecting means further comprises a memory means connected to the output terminal of the operation circuit.

6. A camera system according to claim 5, wherein the memory means is a condenser.

7. A camera system according to claim 5, wherein the memory means is a digital counter.

8. A camera system according to claim 4, wherein the effecting means includes at least a selecting switch being selectively connected to the output terminal of the operation means or to the shutter time setting means and the aperture value setting means, whereby in accordance with the selected priority mode the value set on the shutter time setting means or the aperture value setting means with priority and the output value of the operation means are selectively connected to either the shutter control means or the aperture control means.

9. A camera system comprising:

a camera having;

a. a shutter,

b. shutter control means functionally connected with the above mentioned shutter for controlling the opening time of the above mentioned shutter means,

c. aperture means for controlling the exposure amount in cooperation with the above mentioned shutter means,

d. aperture control means having an input for receiving an electrical signal corresponding to said aperture means setting value for providing aperture setting values to said aperture means,

e. shutter time setting operation input means having a transducing means for forming an electrical signal corresponding to a setting value functionally engageable with the shutter control means for controlling the above mentioned shutter means during the opening time corresponding to the set operation value,

f. proper exposure amount detecting means selectively connectable either with the shutter control means or the aperture control means for producing a combination information output of the shutter time and the aperture value for providing a proper exposure in accordance with the brightness of the object to be photographed; and

g. an accessory unit selectively disengageable with the camera body, and,

h. aperture value setting operation input means having another transducing means for forming an electrical signal corresponding to an aperture setting value, said accessory unit being provided with manually operable control means for setting an aperture independently of said shutter time setting operation input means,

i. coupling means for operatively connecting said aperture value setting input means with said input of aperture control means,

j. photographic mode effecting means selectively effectuating with either one of the shutter control means for the aperture control means so as to effectuate the input set value from the setting input means, whereby the photographic mode due to the selective setting operation by means of the photographic mode selecting means is effectuated by means of the photographic mode effecting means so as to make the photography with the selected mode possible.

10. A camera system according to claim 9, wherein the proper exposure amount detecting means further includes:

a. a light measuring circuit providing a light transducing means for receiving the light from the object to be photographed, and

b. operation circuit means for setting other set photographic information that the shutter time information and the aperture value information and being connected to the above-mentioned light measuring unit so as to produce a combination information of the shutter time and the aperture value for obtaining the proper exposure amount.

11. A camera system in accordance with claim 9, wherein the mode effectuating means comprises at least one selecting means connectable to the shutter control means and the aperture control means, said selecting means selectively connecting the shutter time setting operation input means to the shutter control means or the aperture value setting operation input means to the aperture control means.

12. A camera system according to claim 9, wherein the shutter control means and the aperture control means respectively comprise an operation device means connected respectively and functionally to the shutter time setting operation input means and to the aperture value setting operation input means for producing respectively the shutter time information and the aperture value information for obtaining the proper exposure.

13. A camera system according to claim 9, wherein the proper exposure amount detecting means further comprises a memory means, said means being connected to the output terminal of the operation circuit.

14. A camera system according to claim 13, wherein the memory means is a condenser.

15. A camera system according to claim 13, wherein the memory means is a digital counter.

16. A camera system according to claim 12, wherein the effecting means comprises at least a selecting switch selectively connected to the output terminal of the abovementioned operation means or to the shutter time setting operation input means and the aperture value setting operation input means, whereby in accordance with the selected priority mode the value set by the shutter time setting operation input means or the aperture value setting operation input means with priority and the output value of the operation means are selectively connected to either the shutter control means or the aperture control means.

17. A camera system comprising:

(A) aperture value setting means which is attachable to and detachable from a camera body, said means having transducing means which produces an electrical signal; and

(B) a camera body which permits attachment thereto and detachment therefrom of said aperture value setting means, said camera body having;

a. shutter means;

b. shutter time setting means which can be set manually for generating an electrical signal corresponding to the set shutter time;

c. shutter control means which is electrically connected to the shutter time setting means for generating a signal to control operation of said shutter means;

d. aperture means having an aperture and aperture presetting means for determining the opening of the aperture;

e. means measuring the light transmitted through a photographing lens of fully open aperture, wherein said means generates an electrical signal corresponding to the light transmitted through the photographing lens;

f. memory means which receives information of the brightness of an object to be photographed obtained through said photographing lens when the aperture of said lens is fully open, said memory means being arranged to store exposure information corresponding to said brightness information;

g. an aperture value operation circuit which receives output signals of said memory means and said shutter time setting means to compute and produce aperture value information based upon said brightness information;

h. a shutter time value operation circuit arranged to compute and produce a shutter time value based upon the output of said memory means and information on manual aperture setting received from said aperture value setting means;

i. aperture control means which is electrically connected to the aperture value setting means and to the aperture value operation circuit to control said aperture means;

j. exposure information selecting means which supplies the aperture control means selectively with either the signal of the aperture value operation circuit or that of the aperture value setting means, said selecting means being arranged also to supply the shutter control means selectively with either the output signal of the shutter time value operation circuit or that of the shutter time setting means; and

k. photographing mode changeover means operatively connected to said exposure information selecting means to selectively control the supply of a signal to said aperture control means or to said shutter control means in accordance with a photographic mode selected.

18. A camera according to claim 17, wherein said aperture value setting means includes a dial.

19. A camera system comprising:

(A) manual aperture value setting means attachable to and detachable from a camera body, including;

i. first aperture value setting means provided with a transducing means which produces an electrical signal corresponding to a first aperture setting value; and

ii. second aperture value setting means provided with a transducing means which produces an electrical signal corresponding to a second aperture setting value; and

(B) said camera body which permits attachment thereto and detachment therefrom of said manual aperture value setting means, said camera body having;

a. shutter means;

b. shutter time setting means which is manually settable and generates an electrical signal corresponding to the set shutter time;

c. shutter control means which is electrically connected to the shutter time setting means and generates a signal to control the operation of the shutter means;

d. aperture means having an aperture and an aperture presetting means for determining the opening of the aperture;

e. means for measuring the light transmitted through a photographing lens of fully open aperture, wherein said means generates an electrical signal corresponding to the light transmitted through the photographing lens;

f. memory means which receives information of the brightness of an object to be photographed obtained through the photographing lens when the aperture of said lens is fully open, said memory means being arranged to store exposure information corresponding to said brightness information;

g. an aperture value operation circuit which receives output signals of said memory means and said shutter time setting means to compute and produce aperture value information based upon said brightness information;

h. aperture control means which cooperates with the shutter means to control an exposure amount and has a logic circuit, said logic circuit receiving outputs of said manually aperture value setting means and the output of said aperture value operation circuit to produce a control signal for said aperture means;

i. shutter time correction value operation means which computes a shutter time correction value based upon an output signal of the aperture value operation circuit and that of said manual aperture value setting means and which produces information based on the correction value thus computed; and

j. shutter time value operation means which is connected to said shutter time control means and receives a signal of said shutter time setting means and that of said shutter time correction value operation means to perform correction of and control over a shutter time value on the basis of the shutter time correction value information.

21. A photographic camera according to claim 19, wherein said aperture value setting means is arranged to be attachable to and detachable from a camera body.

20. A photographic camera, comprising:

a. shutter means;

b. shutter time setting means which is manually settable and generates an electrical signal corresponding to the set shutter time;

c. shutter control means which is electrically connected to the shutter time setting means and generates signals of operation control of the shutter means;

d. aperture means having an aperture and an aperture presetting means for determining the opening of the aperture;

e. means for measuring the light transmitted through a photographing lens of fully open diaphragm, wherein said means generates an electrical signal corresponding to the light transmitted through the photographing lens;

f. aperture value operation circuit means which receives information of the brightness of an object to be photographed and the output signal of said shutter time setting means to compute an aperture value based upon the brightness information and which produces information based upon the aperture value thus computed;

g. aperture value setting means which can be set independently of said shutter time setting means, said aperture value setting means being provided with at least one transducing means for generating a mechanical signal corresponding to a setting value and with an output terminal;

h. aperture control means having;

i. engaging means arranged to be capable of engaging with said aperture means and to move in response to a start-up action of the camera;

ii. transducing means which produces an electrical signal corresponding to the extent to which said engaging means moves; and

iii. control means for controlling the movement and the stopping action of said engaging means, said control means being arranged to receive an output signal of each of said aperture value setting means, said transducing means of said aperture control means and said aperture value operation circuit means to perform a logical control, by which said aperture presetting means is controlled either to have a value corresponding to the output signal of the aperture value operation circuit means or to have a value corresponding to the setting value set by the aperture value setting means;

i. shutter time correction value operating means which receives an output signal of said transducing means of said aperture control means and that of said aperture value operation circuit means to compute a shutter time information correction value based on the difference between said two output signals and to produce information on said correction value; and

j. shutter time value operation means connected to said shutter control means, said shutter time value operation means being arranged to receive an output signal of said shutter time setting means and that of said shutter time correction value operation means to compute a shutter time value based upon said correction value information and to produce information based upon the shutter time value thus computed.