Electronic endoscope apparatus having different image processing characteristics for a moving image and a still image

• US 5,034,888 A
• Filed: 10/11/1990
• Issued: 07/23/1991
• Est. Priority Date: 02/26/1988
• Status: Expired due to Term

• Current Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Original Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Inventors: Uchikubo, Akinobu, Saito, Katsuyuki, Sasaki, Masahiko, Uehara, Masao, Kanno, Masahide
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/595,730
• Time in Patent Office: 285 Days
• Field of Search: 128/6, 358/98, 358/36, 358/37, 358/164, 358/166, 358/167, 364/413.13
• US Class Current: 600/101
• 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
• CPC Class Codes: H04N 5/142 Edging; Contouring
• CPC Class Codes: H04N 5/202 Gamma control circuits for controlling camera response irrespective of the scene brightness H04N23/82

Abstract

An endoscope apparatus is arranged to convert the image signal output from an imaging device into a standard video signal, effect image processing, such as outline emphasis, of the image signal, and display a reproduced image on a display. The endoscope apparatus has the function of stopping input to a memory circuit in accordance with the on action of a freezing switch, switching from a moving image to a still image, and providing a display of the still image. Accordingly, it is possible to select appropriate image processing characteristics in accordance with whether a moving image or a still image is to be displayed.

Claims

1. An electronic endoscope apparatus comprising:

(a) an electronic endoscope including

an elongated inserting section,

an objective optical system disposed at a front end of said inserting section for projecting and focusing illuminating light, and

an imaging device for photoelectrically converting an optical image obtained by said objective optical system;

(b) drive signal generating means for outputting a drive signal for causing an image signal to be read from said imaging device;

(c) signal processing means for producing a standard video signal from the image signal read from said imaging device by applying said drive signal;

(d) display means for providing a display of said standard video signal;

(e) memory means for temporarily storing said video signal, said memory means constituting a part of said signal processing means;

(f) a freezing switch for stopping input of said video signal into said memory means and for causing said memory means to repetitively output an identical still image signal;

(g) outline emphasis means for emphasizing an outline of at least one signal read from said memory means; and

(h) outline emphasis characteristic switching means for outputting a switching signal to change outline emphasis characteristics of said outline emphasis means in synchronization with the operation of said freezing switch.

2. An apparatus according to claim 1, wherein said outline emphasis means is constituted by a horizontal outline emphasis circuit for emphasizing a horizontal outline.

3. An apparatus according to claim 1, wherein said outline emphasis means is constituted by a vertical outline emphasis circuit for emphasizing a vertical outline.

4. An apparatus according to claim 1, wherein said outline emphasis means is a horizontal and vertical outline emphasis circuit for emphasizing horizontal and vertical outlines.

5. An apparatus according to claim 4, wherein said outline emphasis means is a multiple outline emphasis circuit for emphasizing an oblique outline in addition to horizontal and vertical outlines.

6. An apparatus according to claim 3 or 4, wherein said outline emphasis means has means for changing a band of emphasis frequencies, said mean being arranged to broaden the band of emphasis frequencies in a vertical direction when said freezing switch is switched on as compared with when said freezing switch is off.

7. An apparatus according to claim 6, wherein said means for changing the band of emphasis frequencies is constituted by two low-pass filters each having a different cutoff frequency and means for effecting switching thereof.

8. An apparatus according to claim 2 or 4, wherein said outline emphasis means is arranged to set a horizontal emphasis frequency to a high frequency when said freezing switch is switched on as compared with when said freezing switch is off.

9. An apparatus according to claim 1, wherein said outline emphasis means is arranged to increase the amount of emphasis when said freezing switch is switched on.

10. An apparatus according to claim 1, wherein said electronic endoscope is an electronic scope in which said imaging device is disposed in a focal plane of said objective optical system.

11. An apparatus according to claim 10, wherein said freezing switch is provided on said electronic scope.

12. An apparatus according to claim 1, wherein said electronic endoscope is a scope of a type to which a television camera can be externally attached, said scope including a fiber scope having an image guide an entrance end surface of which is disposed in a focal plane of said objective optical system and a television camera which is detachably attached to an eyepiece portion of said fiber scope and which includes a focusing optical system for effecting focusing of an optical image transferred through said image guide and said imaging device for photoelectrically converting said optical image focused by said focusing optical system.

13. An apparatus according to claim 10 or 12, wherein said imaging device is of a type in which a color filter for effecting color separation is disposed at a front of the imaging surface of said imaging device.

14. An apparatus according to claim 10 or 12, wherein said imaging device is of a type in which no color filter for effecting color separation is disposed at a front of the imaging surface of said imaging device.

15. An apparatus according to claim 10 or 12, wherein said light emitting means has a light guide which is arranged to transfer illuminating light supplied to an entrance end surface from an external light source device and then to emit said illuminating light through an exit end surface.

16. An apparatus according to claim 12, wherein said freezing switch is provided on said television camera.

17. An apparatus according to claim 1, wherein said outline emphasis characteristics change an emphasis quantity.

18. An apparatus according to claim 1, wherein said outline emphasis characteristics change an emphasis frequency.

19. An electronic endoscope apparatus comprising:

(a) an electronic endoscope including

an elongated inserting section,

an objective optical system disposed at a front end of said inserting section for projecting and focusing illuminating light, and

an imaging device for photoelectrically converting an optical image obtained by said objective optical system;

(b) drive signal generating means for outputting a drive signal for causing an image signal to be read from said imaging device;

(c) signal processing means for producing a standard video signal from the image signal read from said imaging device by applying said drive signal;

(d) display means for providing a display of said standard video signal;

(e) memory means for temporarily storing said video signal, said memory means constituting a part of said signal processing means;

(f) a freezing switch for stopping input of said video signal into said memory means and for causing said memory means to repetitively output an identical still image signal;

(g) low-level part suppressing means for suppressing a low-level part of an outline emphasis signal for at least one signal to be read from said memory means; and

(h) switching means for switching a suppressing quantity of said low level part suppressing means in synchronization with operation of said freezing switch.

20. An apparatus according to claim 19, wherein said low-level signal suppressing means is arranged to suppress a low-level input signal over a wide range when said freezing switch is on as compared with when said freezing switch is off.