Electronic endoscope apparatus

• US 6,489,987 B1
• Filed: 01/04/1999
• Issued: 12/03/2002
• Est. Priority Date: 01/09/1998
• Status: Expired due to Fees

• Current Assignee: Fuji Photo Optical Co. Ltd (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Optical Co. Ltd (Fujifilm Holdings Corporation)
• Inventors: Yamanaka, Kazuhiro, Higuchi, Mitsuru
• Primary Examiner(s): LEE, RICHARD J
• Application Number:
  US09/225,204
• Time in Patent Office: 1,429 Days
• Field of Search: H04/N.718, 348/65, 348/68-71, 600/101, 600/109, 600/160, 600/178, 600/180
• US Class Current: 348/65
• CPC Class Codes: A61B 1/05 characterised by the image sensor, e.g. camera, being in the distal end portion
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes

Abstract

This electronic endoscope apparatus is capable of forming a still image with high image quality by reading out all pixels obtained through an image-pickup device by one exposure and faithfully reproducing the movement concerning moving images. A switch between a pixel mix reading system, which mixes pixels accumulated on the image pickup device having a plurality of color filters arranged in units of pixels between upper and lower horizontal lines to read out from the image-pickup device, and an all-pixel reading system, which reads out signals of all pixels accumulated on the image-pickup device by one exposure uses a light shielding period set by a light shielded. This all-pixel reading system forms a still image, and the other pixel mix reading system forms a moving image. Also, moving image data are delayed using a delay memory, and still image data are prevented from being written in a memory as moving image data, whereby display of any incomplete image is prevented on switching the moving image to the still image. Further, black level voltage in a moving image signal will always be used even when the still image is selected.

Claims

1. An image-pickup device having a plurality of color filters arranged in units of pixels;

light shielding means for intercepting illumination light so that pixel signals for a predetermined period of time are not accumulated on said image-pickup device;

switching means for switching driving control for both a pixel mix reading system, which mixes pixels accumulated on said image-pickup device between upper and lower horizontal lines to output from said image-pickup device, and an all-pixel reading system, which reads out signals of all pixels accumulated on said image-pickup device by one exposure through the use of a light shielding period set by said light shielding means;

an image-pickup device driving circuit for controlling so as to read out, concerning all pixel signals accumulated on said image-pickup device by one exposure, image signals on either odd or even horizontal line first, and next to read out image signals on the remaining horizontal line;

a memory for storing, at the execution of said all-pixel reading system, image signals on said odd horizontal line obtained from said image-pickup device and image signals on said even horizontal line;

a phase adjustment memory for adjusting a phase, at the execution of said all-pixel reading system, between image signals on a predetermined horizontal line previously stored in said memory and image signals on another horizontal line;

a mixing circuit for forming a still image signal by mixing pixel signals of said odd horizontal line and said even horizontal line during the same exposure which have been read out from said memory for storing image signals and said phase adjustment memory; and

an image switching circuit for directly inputting a moving image signal of the pixel mix reading system outputted from said image-pickup device to switch either said moving image signal or a still image signal outputted from said mixing circuit on the basis of the operation of a freeze switch.

2. An electronic endoscope apparatus according to claim 1, further comprising:

delay means for delaying moving image data obtained using said pixel mix reading system by a predetermined period of time; and

a signal processing circuit for forming a moving image signal on the basis of moving image data obtained through said delay means.

3. An electronic endoscope apparatus according to claim 2, further comprising:

a delay memory for delaying a moving image signal of said pixel mix reading system outputted from said image-pickup device by a processing period corresponding to one frame; and

an image switching circuit for switching between a moving image signal outputted from said delay memory and said still image signal on the basis of the operation of a freeze switch.

4. An electronic endoscope apparatus according to claim 1, further comprising:

a memory for storing at least moving image data, wherein said circuit for controlling inhibits still image data, which have been read out from said image-pickup device when said all-pixel reading system is selected, from being written in said memory as moving image data.

5. An electronic endoscope apparatus according to claim 1, further comprising:

a memory for storing at least moving image data, wherein said circuit for controlling sets a write-inhibit period so as to prevent still image data, which have been read out from said image-pickup device when said all-pixel reading system is selected, from being written in said memory as moving image data, and continuously reads out the data of either odd field or even field which have been already written in said memory, as frame data for said write-inhibit period.

6. An electronic endoscope apparatus, comprising:

an image-pickup device having a plurality of color filters arranged in units of pixels;

light shielding means for intercepting illumination light so that pixel signals for a predetermined period of time are not accumulated on said image-pickup device;

switching means for switching driving control for both a pixel mix reading system, which mixes pixels accumulated on said image-pickup device between upper and lower horizontal lines to output from said image-pickup device, and an all-pixel reading system, which reads out signals of all pixels accumulated on said image-pickup device by one exposure through the use of a light shielding period set by said light shielding means;

a clamping circuit for clamping an image signal outputted from said image-pickup device through a clamp signal;

switching control means for controlling so as to extract a black information signal in a moving image signal directly outputted from said image-pickup device using said pixel mix reading system even when said all-pixel reading system is selected; and

a signal processing circuit for forming a clamp signal from the black information signal obtained by the control of said switching control means to feed back said clamp signal to said clamping circuit.

7. An electronic endoscope apparatus according to claim 6, further comprising delay means for delaying moving image data obtained using said pixel mix reading system by a predetermined period of time, wherein

said switching control means directly inputs a moving image signal obtained using said pixel mix reading system without through said delay means to extract the black information signal in said moving image signal.