Illuminating device for a camera

• US 5,432,578 A
• Filed: 07/28/1993
• Issued: 07/11/1995
• Est. Priority Date: 08/19/1992
• Status: Expired due to Fees

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Suzuki, Shinichi
• Primary Examiner(s): Hayes, Monroe H.
• Application Number:
  US08/097,897
• Time in Patent Office: 713 Days
• Field of Search: 354/289.12, 354/127.1, 354/136, 354/137, 354/138, 354/147
• US Class Current: 396/281
• CPC Class Codes: G03B 17/18 Signals indicating condition of a camera member or suitability of light indicating depth of field G03B13/30
• CPC Class Codes: G03B 2217/00 Details of cameras or camera bodies; Accessories therefor

Abstract

A camera protects against wasting battery power by turning off an illuminating device when a photographer is engaged in an photographic operation. The illuminating device includes a back light which illuminates a displace device for display of information related to photography and a release actuation member which generates a half press signal and a full press signal, respectively, upon a first and a second stroke. The back light is turned on according to a "turn on" signal, while the back light is turned off according to the half press signal. The back light is also turned on when the photometric value of a photometric circuit is above a predetermined value.

Claims

1. An illuminating device for a camera having an illuminating element which illuminates a display device which displays information related to photography and a release actuation device which is operated for commanding both preparation for photography and a photographic operation respectively and which outputs first and second command signals respectively, comprising:

a signal output device which outputs a turn on signal,

a control circuit which turns on said illuminating element according to said turn on signal and turns off said illuminating element according to either said first command signal or said second command signal.

2. An illuminating device according to claim 1, wherein:

said release actuation device upon a first stroke outputs said first command signal to begin preparation for photography and upon a second stroke exceeding said first stroke outputs said second command signal to begin photographic operation,

said control circuit turns off said illuminating element, based upon said first command signal from said release actuation device.

3. An illuminating device according to claim 2, further comprising:

a timing circuit which outputs a third command signal after a predetermined time period has elapsed from the turning on of said illuminating element,

wherein said control circuit turns off said illuminating element according to the earlier one of said third command signal and the first command signal input to said control circuit from said timing circuit and from said release actuation device.

4. An illuminating device according to claim 1, wherein:

said release actuation device upon a first stroke outputs said first command signal to begin preparation for photography and upon a second stroke exceeding said first stroke outputs said second command signal to begin photographic operation,

said control circuit turns off said illuminating element, based upon said second command signal from said release actuation device.

5. An illuminating device according to claim 1, further comprising:

a photometric device which measures luminance of a photographic subject,

said signal output device outputting said turn on signal when the luminance measured by said photometric device is less than a predetermined value.

6. An illuminating device according to claim 5, further comprising a mode actuation device which is operated for setting a mode related to photography and outputs a mode command signal according to the mode setting,

said photometric device being started when said mode command signal is output from said mode actuation device.

7. An illuminating device according to claim 6, further comprising a turn on actuation member which is operated to output said turn on signal.

8. An illuminating device according to claim 1, wherein said illuminating element comprises an electroluminescent element.

9. An illuminating device according to claim 1, further comprising a timing circuit which outputs a third command signal after a predetermined time period has elapsed from the turning on of said illuminating element,

wherein said control circuit turns off said illuminating element according to the earlier one of said first, second and third command signals input to said control circuit from said timing circuit and from said release actuation device.

12. An illuminating device according to claim 1 wherein said illuminating element comprises an electroluminescent element.

10. An illuminating device for a camera having an illuminating element which illuminates a display device which displays information related to photography, a release actuation device which upon a first stroke outputs a half press signal to begin preparation for photography and upon a second stroke exceeding said first stroke outputs a full press signal to begin a photographic operation, and a mode actuation device which is operated for setting a mode related to photography and outputs a mode command signal according to the mode setting, comprising:

a photometric device the operation of which is started when said mode command signal is output from said mode actuation device and which measures the luminance of a photographic subject;

a signal output circuit which outputs a turn on signal when the luminance measured by said photometric device is less than a predetermined value;

a timing circuit which outputs a turn-off command signal after a predetermined time period has elapsed from the turning on of said illuminating element; and

a control circuit which turns on said illuminating element according to said turn on signal, and turns off said illuminating element according to the earlier one of said turn-off command signal and the half press signal input to said control circuit from said timing circuit and from said release actuation device.

11. An illuminating device for a camera having an illuminating element which illuminates a display device which displays information related to photography, a release actuation device which upon a first stroke outputs a half press signal to begin preparation for photography and upon a second stroke exceeding said first stroke outputs a full press signal to begin a photographic operation, and a mode actuation device which is operated for setting a mode related to photography and outputs a mode command signal according to the mode setting, comprising:

a photometric device the operation of which is started when said mode command signal is output from said mode actuation device and which measures the luminance of a photographic subject;

a signal output circuit which outputs a turn on signal when the luminance measured by said photometric device is less than a predetermined value;

a timing circuit which outputs a turn-off command signal after a predetermined time period has elapsed from the turning on of said illuminating element; and

a control circuit which turns on said illuminating element according to said turn on signal, and turns off said illuminating element to conserve power according to the earlier one of said turn-off command signal and the half press signal input to said control circuit from said timing circuit and from said release actuation device; and

a turn on actuation member which is operated to output said turn on signal.