Electronic photographing apparatus

• US 4,584,610 A
• Filed: 02/16/1984
• Issued: 04/22/1986
• Est. Priority Date: 02/16/1984
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Nakamura, Kazuo, Kimura, Tadashi, Tamagawa, Akira, Yunoki, Yutaka, Mizokami, Kazunori, Kikuchi, Juro
• Primary Examiner(s): Rubinson, Gene Z.
• Assistant Examiner(s): Lev, Robert G.
• Application Number:
  US06/580,860
• Time in Patent Office: 796 Days
• Field of Search: 358/228, 358/224, 358/225, 358/55, 358/169, 358/226, 358/221, 358/227, 358/209, 358/212, 358/213, 358/168, 358/170, 358/906, 358/335, 250/578, 352/141
• US Class Current: 348/229.1
• CPC Class Codes: H04N 23/75 by influencing optical camera components

Abstract

An electronic photographing apparatus including a photosensor for converting an optical image, which enters through an objective lens, to an electric signal, and two comparators to which a video signal obtained by signal-processing the electric signal is supplied. Supplied to the comparators, respectively, are a reference voltage slightly lower than the saturation level of the video signal and a reference voltage slightly higher than the black level of the video signal. The comparators convert the video signal to a binary signal according to the reference voltages. The binary signals are supplied to a video signal processing circuit and are converted to a binary video signal. When the binary video signal is supplied to the display of an electric finder, an image which is over- or/and underexposed is displayed on the display. When the binary signal is supplied to an automatic exposure unit, the exposure of the scene is automatically controlled according to the over- or/and underexposure.

Claims

1. An electronic photographing apparatus, comprising:

electronic photographing means for converting an image to be photographed into a video signal including retracing signal components;

binary coding means for converting the video signal to a binary signal in accordance with the level of the video signal with respect to one of first and second reference levels which are close to

saturated white and black levels of the video signal, said binary signal including an image component representing at least one poor quality portion of an image reproduced from said video signal and corresponding to one of overexposure and underexposure;

signal processing means for converting the binary signal of said binary coding means to a binary video signal; and

display means for displaying the binary image component representing said poor quality portion of the image which is obtained from the binary video signal of said signal processing means as a two-dimensional optical image.

2. An electronic photographing apparatus according to claim 1, wherein said electronic photographing means comprises a photosensor for converting the image to an electric signal, optical means for imaging the image to said photosensor, and signal processing means for signal-processing and converting the electric signal of said photosensor to the video signal.

3. An electronic photographing apparatus according to claim 1, wherein said binary coding means comprises a first comparator for comparing the video signal with the first reference level having been set slightly lower than the saturation level of the video signal to obtain a first binary signal relative to the first reference level, a second comparator for comparing the video signal with the second reference level having been set slightly higher than the black level of the video signal to obtain a second binary signal relative to the second reference level, and means for removing the retracing signal components of the video signal from the first and second binary signals of said first and second comparators.

4. An electronic photographing apparatus according to claim 3, wherein said binary coding means includes means for composing the first and second binary signals from which the retracing signal components have been removed.

5. An electronic photographing apparatus according to claim 1, further including means for selectively supplying said binary video signal issued from said signal processing means, said video signal issued from said electronic photographing means or a composition signal to said display means, said composition signal being obtained by composing said binary video signal with said video signal.

6. An electronic photographing apparatus according to claim 1, further including memory means for storing said binary video signal representing a poor quality portion of an image reproduced from said video signal and wherein said display means is electronic display means for displaying a video signal from the memory means.

7. An electronic photographing apparatus according to claim 1, further including a plurality of memory means for storing binary video signals representing a poor quality portion of an image reproduced from said video signal and corresponding to said white and said black level and means for simultaneously reading the binary video signals from said memory means and for combining the readout binary video signals into a composite video signal and wherein said display means is means for displaying the composite video signal of said combining means as a composite image.

8. An electronic photographing apparatus according to claim 1, further including means for adjusting brightness and means for stopping the function of said brightness adjusting means.

9. An electronic photographing apparatus according to claim 1, wherein said display means is a liquid cyrstal display.

10. An electronic photographing apparatus according to claim 1, wherein said display means is a light emitting diode display.

11. An electronic photographing apparatus according to claim 1, wherein said display means has an optical filter which forms a properly viewable color contrast.

12. An electronic photographing apparatus, comprising:

electronic photographing means for converting an image to be photographed to a video signal including retracing signal components;

binary coding means for converting the video signal to a binary signal in accordance with the level of said video signal with respect to one of first and second reference levels which are close to saturated white and black levels of the video signal, respectively, said binary signal including an image component representing at least one poor quality portion of an image reproduced from said video signal and corresponding to one of overexposure and underexposure; and

means for automatically adjusting the exposure responsive to the binary signal of said binary coding means.

13. An electronic photographing apparatus according to claim 12, wherein said electronic photographing means comprises a photosensor for converting the image to an electric signal, optical means for imaging the object to said photosensor, and signal processing means for signal-processing and converting the electric signal of said photosensor to the video signal, and wherein said automatic exposure adjusting means comprises means arranged at said optical means and intended to control the amount of light of said image on said photosensor.

14. An electronic photographing apparatus according to claim 12, wherein said binary coding means comprises a first comparator for comparing the video signal with the first reference level having been set slightly lower than the saturation level of the video signal to obtain a first binary signal relative to the first reference level, a second comparator for comparing the video signal with the second reference level having been set slightly higher than the black level of the video signal to obtain a second binary signal relative to the second reference level, and means for removing retracing signal components of the video signal from the first and second binary signals of said first and second comparators.