Camera having an auto-focusing device

• US 4,723,139 A
• Filed: 04/22/1987
• Issued: 02/02/1988
• Est. Priority Date: 06/26/1985
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nippon Kotsu Kabushiki Kaisha (Nikon Corporation)
• Inventors: Ogasawara, Akira
• Primary Examiner(s): PERKEY, WILLIAM B
• Application Number:
  US07/041,628
• Time in Patent Office: 286 Days
• Field of Search: 354/266, 354/267.1
• US Class Current: 396/133
• CPC Class Codes: G02B 7/36 using image sharpness techniques , e.g. image processing techniques for generating autofocus signals image data processing per se G06T; in cameras having a solid state image sensor H04N23/67

Abstract

A camera having a continuous photographing mode in which an exposure operation and a one frame-wind-up operation of a film are repeatedly carried out, comprising RAM, CCD, A/C convertor, a motor, encoder and AF lens control device. CCD and A/D convertor detect a defocus distance of a photographing lens and forming a data representing. The detected defocus distance and stores said data into the RAM. Motor drives the photographing lens. Encoder detects a driven distance of the photographing lens driven by the motor to generate a detection signal and the motor drives the photographing lens such that the drive distance represented by the detection signal coincides with the defocus distance represented by the data of the RAM. AF lens control device discontinues the drive of the photographing lens by the motor prior to the start of the exposure operation in the continuous photographing mode and resuming the drive in the period of a subsequent one-frame wind-up operation and the device controls the motor such that the motor drives the photographing lens in response to the resumption by a distance corresponding to a difference between the drive distance represented by the detection signal at the time of discontinuance and the defocus distance represented by the data of the RAM.

Claims

1. A camera having a continuous photographing mode in which an exposure operation and a one-frame wind-up operation of a film are repeatedly carried out, comprising:

(a) memory means;

(b) data forming means for detecting a defocus distance of a photographing lens and forming a data representing the detected defocus distance;

said data forming means storing said data into said memory means;

(c) drive means for driving said photographing lens;

(d) signal generating means for detecting a drive distance of said photographing lens driven by said drive means to generate a detection signal;

said drive means driving said photographing lens such that the drive distance represented by the detection signal coincides with the defocus distance represented by the data of said memory means; and

(e) control means for discontinuing the drive of said photographing lens by said drive means prior to start of the exposure operation in the continuous photographing mode and resuming the drive during a subsequent one-frame wind-up operation;

said control means controlling said drive means such that said drive means drives the photographing lens in response to the resumption by a distance corresponding to a difference between the drive distance represented by the detection signal at discontinuance and the defocus distance represented by the data of said memory means.

2. A camera having a continuous photographing mode in which exposure operation and one-frame wind-up operation of a film are repreatedly carried out, comprising:

(a) memory means;

(b) focus detection means for detecting a defocus distance of a photographing lens to form a data representing the detected defocus distance;

said focus detection means storing said data into said memory means;

(c) drive means for driving said photographing lens;

(d) signal generating means for detecting a drive distance of the photographing lens to generate a detection signal; and

(e) drive control means for controlling said drive means in accordance with the detection signal and the data of said memory means;

said drive control means discontinuing the drive of the photographing lens by said drive means prior to start of the exposure operation in the continuous photographing mode and resuming the drive in response to the completion of the exposure operation;

said drive control means controlling said drive means such that said drive means drives said photographing lens in response to the resumption by a distance corresponding to a difference between the drive distance represented by the detection signal at the time of discontinuance of the drive and the defocus distance represented by the data of said memory means.

3. A camera according to claim 2 wherein said drive control means drives said drive means such that the drive distance represented by the detection signal coincides with the defocus distance represented by the data of said memory means.

4. A camera according to claim 2 wherein said drive control means includes timer means and inhibits the start of the exposure operation a predetermined time period after the one-frame wind-up operation.

5. A camera according to claim 4 wherein said timer means is activated for said predetermined time period in response to the end of the one-frame wind-up operation, and said drive control means inhibits the start of the exposure operation during the activation of said timer means.

6. A camera according to claim 5 further comprising interval control means for controlling an exposure interval in the continuous photographing mode.

7. A camera according to claim 6 further comprising inhibit signal means for generating an inhibit signal to inhibit the drive of the photographing lens by said drive means;

said interval control means inhibiting the activation of said timer means in response to said inhibit signal.

8. A camera body having a continuous photographing mode in which an exposure operation and a one-frame wind-up operation of a film are repeatedly carried out, and including focus detection means, and drive means for driving a first photographing lens in accordance with a defocus distance detected by said focus detection means, and a second photographing lens not driven by said drive means and said first photographing lens being exchangeably mounted on said camera body;

comprising;

(a) signal generating means for detecting the mounting of said second photographing lens on said camera body for generating a lens detection signal; and

(b) control means for controlling an exposure interval in the continuous photographing mode;

said control means setting the exposure interval to a predetermined time period when said first photographing lens is mounted on said camera body and setting the exposure interval to a shorter period in response to said lens detection signal.

9. A camera according to claim 8 further comprising inhibit signal means for generating an inhibit signal to inhibit said drive means from driving said first photographing lens

said controlling means setting a shorter exposure interval than said predetermined period in response to said inhibit signal when said first photographing lens is mounted on said camera body.

10. A camera for carrying out a one-frame wind-up operation of a film in response to completion of an exposure operation for exposing one frame of said film, comprising:

(a) memory means;

(b) data producing means for detecting a defocus distance of a photographing lens and producing data representing a distance which relates to the detected defocus distance, said data producing means storing said data in said memory means;

(c) drive means for driving said photographing lens;

(d) signal generating means for detecting a drive distance of said photographing lens driven by said drive means to generate a detection signal representing a distance which relates to the detected drive distance; and

(e) control means for discontinuing the drive of said photographing lens by said drive means prior to start of said exposure operation and resuming the drive in response to completion of said exposure operation, said control means controlling said drive means such that said drive means drives the photographing lens, in response to the resumption of the drive, by a distance represented by said detection sigal when the drive is discontinued and the distance represented by the data of said memory means.

11. A camera according to claim 10, wherein said drive means drives said photographing lens such that the distance represented by said detection signal coincides with the distance represented by the data of said memory means.

12. A camera body on which a first photographing lens and a second photographing lens are exchangeably mounted, wherein an optical system of said first photographing lens is driven automatically in accordance with a defocus distance when said first photographing lens is mounted on said camera body and an optical system of said second photographing lens is not driven automatically when said second photographing lens is mounted on said camera body, comprising:

signal generating means for detecting mounting of said second photographing lens on said camera body to generate a lens detection signal; and

control means for controlling an exposure interval between an exposure operation and a subsequent exposure operation, said control means setting the exposure interval to a predetermined time period when said first phtographing lens is mounted on said camera body and setting the exposure interval to a period shorter than said predetermined time period in response to said detection signal.

13. A camera body according to claim 12, which further comprises means for generating an inhibit signal to inhibit said first photographing lens from being driven, and wherein said control means sets the exposure interval to a period shorter than said predetermined period in response to said inhibit signal when said first photographing lens is mounted on said camera.

14. A camera comprising:

means for detecting a defocus distance of a photographing lens;

drive means for driving said photographing lens on the basis of the detected defocus distance;

means for generating an inhibit signal to inhibit said drive means from driving said photographing lens;

control means for controlling an exposure interval between an exposure operation and a subsequent exposure operation to set the exposure interval to a predetermined time period, said control means setting the exposure interval to a period shorter than said predetermined time period in response to said inhibit signal.

15. A camera according to claim 14, wherein said control means includes timer means for counting a predetermined value, and wherein said inhibit signal inhibits said timer means from counting.

16. A camera according to claim 15, which further comprises stopping means for stopping said drive means in response to completion of counting by said timer means.

17. A camera according to claim 16, which further comprises wind-up means for winding up one frame of a film in response to completion of the exposure operation, and wherein said timer means starts counting in response to completion of said winding up by said wind-up means.

18. A camera having a continuous photographing mode in which exposure operation and one-frame wind-up operation of a film are repeatedly carried out, comprising:

(a) memory means;

(b) focus detection means for detecting a defocus distance of a photographing lens to form data representing a distance which relates to the detected defocus distance;

said focus detection means storing said data in said memory means;

(c) drive means for driving said photographing lens;

(d) signal generating means for detecting a drive distance of the photographing lens to generate a detection signal representing a distance which relates to the detected defocus distance; and

(e) drive control means for controlling said drive means in accordance with the detection signal and the data of said memory means;

said drive control means discontinuing the drive of the photographing lens by said drive means prior to start of the exposure operation in the continuous photographing mode and resuming the drive in response to completion of the exposure operation;

said drive control means controlling said drive means such that said drive means drives said photographing lens, in response to resumption of the drive, by a distance corresponding to a difference between the distance represented by the detection signal at the time of discontinuance of the drive and the distance represented by the data of said memory means.

19. A camera according to claim 18, wherein said drive control means drives said drive means such that the distance represented by the detection signal coincides with the distance represented by the data of said memory means.

20. A camera according to claim 18, wherein said drive control means includes timer means and inhibits the start of the exposure operation a predetermined time period after the one-frame wind-up operation.