Endoscope apparatus

• US 20050010081A1
• Filed: 06/18/2004
• Published: 01/13/2005
• Est. Priority Date: 06/18/2003
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Doguchi, Nobuyuki, Takahashi, Yoshinori, Ozawa, Takeshi, Takehana, Sakae, Hirao, Isami, Imaizumi, Katsuichi
• Granted Patent: US 7,393,321 B2
• Time in Patent Office: Days
• US Class Current: 600/109
• CPC Class Codes: A61B 1/000095 for image enhancement
• CPC Class Codes: A61B 1/043 for fluorescence imaging
• CPC Class Codes: A61B 1/045 Control thereof
• CPC Class Codes: A61B 1/0638 providing two or more wavelengths
• CPC Class Codes: A61B 1/0646 with illumination filters
• CPC Class Codes: A61B 1/0655 Control therefor
• CPC Class Codes: A61B 1/0669 at proximal end of an endoscope
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: H04N 23/12 with one sensor only
• 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 23/663 for controlling interchangeable camera parts based on electronic image sensor signals
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

An endoscope apparatus includes an endoscope that has a solid-state image-pickup device in which charges are accumulated in order to pick up an object image. The endoscope apparatus further comprises a memory in which a plurality of pieces of information on the accumulation period during which charges are accumulated in the solid-state image-pickup device is stored, and a drive unit that controls the accumulation period, during which charges are accumulated in the solid-state image-pickup device, on the basis of the pieces of information on the accumulation period stored in the memory.

Claims

1. An endoscope apparatus having a solid-state image-pickup device that pick up images of an object, comprising:

an endoscope including the solid-state image-pickup device in which charges are accumulated in order to pick up an image of the object;

a memory in which a plurality of pieces of information on the accumulation period during which charges are accumulated in the solid-state image-pickup device is stored; and

a drive unit that controls the accumulation period, during which charges are accumulated in the solid-state image-pickup device, according to the pieces of information on the accumulation period stored in the memory.

2. The endoscope apparatus according to claim 1, wherein the pieces of information on the accumulation period are determined for respective wavelength bands of images formed by lights to be picked up by the solid-state image-pickup device.

3. An endoscope apparatus according to claim 1, wherein:

a first image pickup mode in which normal light whose wavelengths fall within the visible region is employed, and a second image pickup mode in which special light whose wavelengths fall within a band different from the wavelength band of normal light is employed are supported; and

the pieces of information on the accumulation period are determined relative to each of the first image pickup mode and second image pickup mode.

4. The endoscope apparatus according to claim 1, wherein the solid-state image-pickup device includes a facility for multiplying produced charges with application of a pulse-type signal so as to vary the sensitivity of the solid-state image-pickup device.

5. The endoscope apparatus according to claim 4, wherein the solid-state image-pickup device includes a charge multiplying detector that multiplies produced charges through impact ionization derived from application of the pulse-type signal by controlling the amplitude of the pulse-type signal or the number of pulses of the pulse-type signal, and that thus varies the sensitivity of the solid-state image-pickup device.

6. The endoscope apparatus according to claim 5, wherein the charge multiplying detector is interposed between a horizontal transfer register and a floating diffusion amplifier that are incorporated in the solid-state image-pickup device, or disposed at each of pixel locations in the solid-state image-pickup device.

7. The endoscope apparatus according to claim 1, further comprising a light source unit that illuminates the object.

8. The endoscope apparatus according to claim 7, wherein the light source unit illuminates the object by switching normal light employed in normal light observation and a plurality of special lights employed in special light observation.

9. The endoscope apparatus according to claim 8, wherein the special light observation refers to fluorescence observation employing fluorescence.

10. The endoscope apparatus according to claim 8, wherein the plurality of special lights include blue excitation light to be used for fluorescence and narrow-band lights whose wavelengths fall within the green or red region to be used for reflected light.

11. The endoscope apparatus according to claim 8, wherein the special light observation refers to narrow-band light observation employing narrow-band light.

12. The endoscope apparatus according to claim 8, wherein the plurality of special lights include lights whose wavelengths fall within the blue, green, or red region, and at least one of the lights whose wavelengths fall within the blue, green, or red region is narrow-band light.

13. The endoscope apparatus according to claim 8, wherein the special light observation refers to infrared light observation employing infrared light.

14. The endoscope apparatus according to claim 8, wherein the plurality of special lights include light whose wavelengths fall within the near infrared region.

15. The endoscope apparatus according to claim 1, wherein the plurality of accumulation periods refers to the accumulation periods during which charges are accumulated responsively to a plurality of lights respectively during special light observation.

16. The endoscope apparatus according to claim 15, wherein the special light observation refers to fluorescence observation employing fluorescence.

17. The endoscope apparatus according to claim 16, wherein during the fluorescence observation, the accumulation period during which charges are accumulated responsively to fluorescence is different from the accumulation period during which charges are accumulated responsively to reflected light.

18. The endoscope apparatus according to claim 17, wherein the accumulation period during which charges are accumulated responsively to fluorescence is longer than the accumulation period during which charges are accumulated responsively to reflected light.

19. The endoscope apparatus according to claim 15, wherein the special light observation refers to narrow-band light observation employing narrow-band light.

20. The endoscope apparatus according to claim 19, wherein the accumulation period during which charges are accumulated responsively to narrow-band light, of which wavelengths fall within the blue region, during narrow-band light observation is longer than the accumulation period during which charges are accumulated responsively to narrow-band light of green or red.

21. The endoscope apparatus according to claim 1, wherein the special light observation refers to infrared light observation employing infrared light.

22. The endoscope apparatus according to claim 1, wherein the plurality of accumulation periods refer to the accumulation periods during which charges are accumulated responsively to respective lights of red, green, and blue in the normal light mode.

23. The endoscope apparatus according to claim 1, wherein the plurality of accumulation periods refer to the accumulation periods during which charges are accumulated responsively to respective lights of red, green, and blue in the normal light mode or responsively to plural kinds of wavelength during special light mode.

24. The endoscope apparatus according to claim 1, further comprising a sensitivity control unit that controls the amplification factor, at which charges in the solid-state image-pickup device are amplified, by varying the pulse-type signal.

25. The endoscope apparatus according to claim 24, wherein the sensitivity control unit includes an automatic gain control circuit that increases or decreases the amplification factor, at which charges in the solid-state image-pickup device are amplified, by controlling the amplitude of an applied pulse such that an output signal of the solid-state image-pickup device will assume a predetermined level during special light observation.

26. The endoscope apparatus according to claim 1, wherein the drive unit applies to the solid-state image-pickup device an electronic shutter signal that releases charges accumulated in the solid-state image-pickup device during an exposure period longer than the accumulation period that should be designated, and thus the drive unit controls and sets the accumulation period that should be designated.

27. The endoscope apparatus according to claim 1, wherein the memory is incorporated in the endoscope.

28. The endoscope apparatus according to claim 1, further comprising:

an optical member which is included in an optical system that forms an optical image on the solid-state image-pickup device and whose surface is shaped rotationally asymmetric;

a correction information memory in which correction information associated with the optical property of the optical member is stored; and

a correction unit that corrects an output signal of the solid-state image-pickup device according to the contents of the correction information memory.

29. An endoscope for picking up an object image, comprising:

a solid-state image-pickup device in which charges are accumulated in order to pick up an image of the object; and

a memory in which a plurality of pieces of information on the accumulation period during which charges are accumulated in the solid-state image-pickup device are stored in order to transmit the pieces of information on the accumulation period to driving means that controls the accumulation period during which charges are accumulated in the solid-state image-pickup device.

30. An endoscope apparatus including a solid-state image-pickup device for picking up an object image, comprising:

an endoscope having the solid-state image-pickup device in which charges are accumulated in order to pick up an image of an object;

memory means in which a plurality of pieces of information on the accumulation period during which charges are accumulated in the solid-state image-pickup device is stored; and

driving means for controlling the accumulation period, during which charges are accumulated in the solid-state image-pickup device, on the basis of the pieces of information on the accumulation period stored in the memory means.

31. An endoscope apparatus including an image pickup device for picking up an object image, comprising:

an endoscope having the image pickup device that picks up an image of the object and an optical system that includes an optical member whose surface is shaped rotationally asymmetric;

a memory in which restoration data for use in restoring a change in optical performance caused by the optical member is stored; and

a signal processing unit that restores an output signal of the image pickup device to its original state on the basis of the restoration data stored in the memory and that performs signal processing.

32. An endoscope apparatus including an image pickup device for picking up an object, comprising:

an endoscope having an image pickup device that picks up an image of the object and an optical system that includes an optical member whose surface is shaped rotationally asymmetric;

a memory in which a plurality of pieces of information on the accumulation period during which charges are accumulated in the image pickup device and restoration information for use in restoring a change in optical performance caused by the optical member are stored;

a drive unit that controls the accumulation period, during which charges are accumulated in the image pickup device, on the basis of the pieces of information on the accumulation period stored in the memory; and

a signal processing unit that performs signal processing to restore an output signal of the image pickup device to its original state on the basis of the restoration information stored in the memory.