Frame sequential type imaging apparatus for obtaining high resolution object image by irradiating frame sequential light on the object, photoelectrically converting the object image and processing signals by a solid state imaging device

• US 5,995,136 A
• Filed: 12/13/1994
• Issued: 11/30/1999
• Est. Priority Date: 05/13/1992
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Hattori, Shinichiro, Kanno, Masahide, Hasegawa, Akira
• Primary Examiner(s): Tung, Bryan
• Application Number:
  US08/357,269
• Time in Patent Office: 1,813 Days
• Field of Search: 348/65, 348/68, 348/69, 348/70, 348/268, 348/269, 348/270, 348/271, 348/272, 348/273, 348/274, 348/275, 348/276, 348/277, 348/278, 348/279, 348/280, 348/335, 348/337, 348/340 , 348/342
• US Class Current: 348/70
• CPC Class Codes: A61B 1/045 Control thereof
• CPC Class Codes: A61B 1/05 characterised by the image sensor, e.g. camera, being in the distal end portion
• CPC Class Codes: G02B 23/2484 Arrangements in relation to a camera or imaging device processing or control of video signals generated by an endoscope H04N23/60, H04N23/70
• CPC Class Codes: H04N 2209/046 Colour interpolation to calculate the missing colour values
• CPC Class Codes: H04N 23/125 Colour sequential image capture, e.g. using a colour wheel
• 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 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/11 Arrangement of colour filter arrays [CFA]; Filter mosaics
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

An electronic endoscope apparatus serving as a frame sequential type imaging apparatus comprises an electronic endoscope for picking up an object, a CCU for driving and controlling the electronic endoscope and processing imaging signals originated from the electronic endoscope, and a high resolution monitor displaying video signals processed by the CCU. An imaging optical system is provided at the tip of the electronic endoscope to receive reflected light irradiated on an object. The imaging optical system is provided with specific wavelength optical path changing apparatus for shifting an optical path of reflected light of a predetermined wavelength range between an objective lens system and a CCD. The specific wavelength optical path changing apparatus is a plate glass which transmits frame sequential light reflected from an object through the objective lens system. A surface of the plate glass facing CCD is bisected in two and coated with a first transmission filter and second transmission filter having different transmission characteristics. From among R, G1, G2, and B regions, the first transmission filter transmits the light of R, G1, and B regions and the second transmission filter transmits the light of R and G2 regions. The second transmission filter shifts an optical axis of the transmitted light.

Claims

1. A frame sequential type imaging apparatus comprising:

irradiating means for irradiating light on an object;

image pick-up means for sequentially picking up an observed image of said object in three or more of a plurality of wavelength ranges by the light emitted by said irradiating means; and

image forming position changing means for forming an observed image picked up by said image pick-up means in at least two wavelength ranges in a same position of said plurality of wavelength ranges on an imaging surface of said image picking up means and forming an observed image in at least one of the remaining of said plurality of wavelength ranges in an offset position different from said same position, wherein said offset position produced by said image forming position changing means is a function of the wavelength range of the light emitted by said irradiating means and wherein said image forming position changing means includes a single set of optical elements which are nonmovingly fixed in position such that all of said plurality of wavelength ranges pass through said single set of optical elements.

2. The frame sequential type imaging apparatus according to claim 1, wherein said offset position different from said same position is a position shifted a predetermined amount from said same position.

3. The frame sequential type imaging apparatus according to claim 1, wherein said predetermined amount is 1/2 picture element pitch of said image pick-up means.

4. The frame sequential type imaging apparatus according to any one of claims 1-3, wherein said observed image picked up by said image pick-up means is an observed image irradiated by reflected light from said object, said reflected light being emitted by said irradiating means, further comprising:

wavelength range separating means for separating the light emitted by said irradiating means into light in said plurality of wavelength ranges and irradiating the light on said object.

5. The frame sequential type imaging apparatus according to claim 4, wherein

said wavelength range separating means separates light in a specific wavelength range into multiple light, and

said image forming position changing means forms an observed image irradiated by light in at least a part of said specific wavelength range separated by said wavelength range separating means in said offset position different from said same position.

6. The frame sequential type imaging apparatus according to claim 5, wherein light of said plurality of wavelength ranges is an R light, G light, and B light and light of said specific wavelength range is a G light.

7. The frame sequential type imaging apparatus according to claim 5, further comprising:

memorizing means for memorizing said observed image picked up by said image pick-up means as image information in each of said plurality of wavelength ranges; and

signal processing means for processing signals of image information of said observed image memorized by said memorizing means.

8. The frame sequential type imaging apparatus according to claim 5, wherein

said image forming position changing means includes three or more of a plurality of filters transmitting said reflected light and having different wavelength transmission characteristics, and

said image forming position changing means forms said observed image having passed through at least two of said plurality of filters in said same position and forms said observed image having passed through at least one of remainder of said plurality of filters in said offset position different from said same position.

9. The frame sequential type imaging apparatus according to claim 5, wherein said image forming position changing means is a prism reflecting said reflected light and including a plurality of reflecting surfaces having different reflecting characteristics depending on wavelength ranges.

10. The frame sequential type imaging apparatus according to claim 6, further comprising, for an observed image formed in said image pick-up means in one direction on rectangular coordinates on a surface lying at right angles to an optical axis of said reflected light, image transforming means for extending and compressing said observed image in a direction lying at right angles to said one direction to transform said observed image.

11. The frame sequential type imaging apparatus according to claim 10, further comprising:

memorizing means for memorizing said observed image picked up by said image pick-up means and transformed by said image transforming means as image information in each of said plurality of wavelength ranges; and

signal processing means for processing signals of the image information of said observed image which is transformed and memorized by said memorizing means.

12. The frame sequential type imaging apparatus according to claim 5, wherein said frame sequential type imaging apparatus is an electronic endoscope.

13. The frame sequential type imaging apparatus according to any one of claims 1-3, wherein

said observed image picked up by said image pick-up means is an observed image irradiated by reflected light from said object, the reflected light being emitted by said irradiating means, further comprising:

wavelength range separating means for separating said reflected light into light of said plurality of wavelength ranges and transmitting the light to said image forming position changing means.

14. The frame sequential type imaging apparatus according to claim 13, wherein

said wavelength range separating means separates light in a specific wavelength range into multiple light, and

said image forming position changing means forms an observed image irradiated by light in at least a part of said specific wavelength range separated by said wavelength range separating means in said offset position different from said same position.

15. The frame sequential type imaging apparatus according to any one of claims 1-3, wherein said irradiating means sequentially emits light of said plurality of wavelength ranges.

16. The frame sequential type imaging apparatus according to claim 15, wherein

said observed image picked up by said image pick-up means is an observed image irradiated by reflected light originated from said object, said reflected light being emitted by said irradiating means,

wavelength range separating means for separating light of a specific wavelength range in said plurality of wavelength ranges into multiple light is provided, and

said image forming position changing means forms an observed image in at least a part of said specific wavelength range separated by said wavelength range separating means in said offset position different from said same position.

17. The frame sequential type imaging apparatus according to claim 16, where light of said plurality of wavelength ranges is a R light, G light, and B light and light of said specific wavelength range is a G light.

18. The frame sequential type imaging apparatus according to claim 16, further comprising:

memorizing means for memorizing said observed image picked up by said image picking up means as image information in each of said plurality of wavelength ranges; and

signal processing means for processing signals of image information of said observed image memorized by said memorizing means.

19. The frame sequential type imaging apparatus according to claim 16, wherein

said image forming position changing means includes three or more of a plurality of filters transmitting said reflected light and having different wavelength transmission characteristics, and

said image forming position changing means forms said observed image having passed through at least two of said plurality of filters in said same position and forms said observed image having passed through at least one of remainder of said plurality of filters in said offset position different from said same position.

20. The frame sequential type imaging apparatus according to claim 16, wherein said image forming position changing means is a prism reflecting said reflected light and including a plurality of reflecting surfaces having different reflecting characteristics depending on wavelength ranges.

21. The frame sequential type imaging apparatus according to claim 16, further comprising, for an observed image formed in said image picking up means in one direction on rectangular coordinates on a surface lying at right angles to an optical axis of said reflected light, image transforming means for extending and compressing said observed image in a direction lying at right angles to said one direction to transform said observed image.

22. The frame sequential type imaging apparatus according to claim 16, wherein said frame sequential type imaging apparatus is an electronic endoscope.

23. The frame sequential type imaging apparatus according to any one of claims 1-3, wherein

said observed image pickup up by said image pick-up means is an observed image irradiated by transmitted light having passed through said object, the transmitted light being emitted by said irradiating means, further comprising:

wavelength range separating means for separating light emitted by said irradiating means into the light of said plurality of wavelength ranges and irradiating the light on said object.

24. The frame sequential type imaging apparatus according to claim 23, wherein said wavelength range separating means separates light of a specific wavelength range into multiple light, and

said image forming position changing means forms an observed image irradiated by light in at least a part of said specific wavelength range separated by said wavelength range separating means in said offset position different from said same position.

25. The frame sequential type imaging apparatus according to claim 24, wherein light of said plurality of wavelength ranges is a R light, G light, and B light and light of said specific wavelength range is a G light.

26. The frame sequential type imaging apparatus according to claim 24, further comprising:

memorizing means for memorizing said observed image picked up by said image picking up means as image information in each of said plurality of wavelength ranges, and

signal processing means for processing signals of image information of said observed image memorized by said memorizing means.

27. The frame sequential type imaging apparatus according to claim 24, wherein

said image forming position changing means includes three or more of a plurality of filters transmitting said transmitted light and having different wavelength transmission characteristics, and

said image forming position changing means forms said observed image having passed through at least two of said plurality of filters in said same position and forms said observed image having passed through at least one of remainder of said plurality of filters in said offset position different from said same position.

28. The frame sequential type imaging apparatus according to claim 24, wherein said image forming position changing means comprises a prism reflecting said reflected light and including a plurality of reflecting surfaces having different reflecting characteristics depending on wavelength ranges.

29. The frame sequential type imaging apparatus according to claim 24, further comprising, for an observed image formed in said image pick-up means in one direction of rectangular coordinates on a surface lying at right angles to an optical axis of said reflected light, image transforming means for extending and compressing said observed image in a direction lying at right angles to said one direction to transform said observed image.

30. The frame sequential type imaging apparatus according to claim 29, further comprising:

memorizing means for memorizing said observed image picked up by said image pick-up means and transformed by said image transforming means as image information in each of said plurality of wavelength ranges, and

signal processing means for processing signals of the image information of said observed image which is transformed and memorized by said memorizing means.

31. The frame sequential type imaging apparatus according to claim 30 wherein said signal processing means for restoring and processing the image information of said observed image which is transformed and memorized by said memorizing means.

32. The frame sequential type imaging apparatus according to claim 24, wherein said frame sequential type imaging apparatus comprises a microscope apparatus.

33. The frame sequential type imaging apparatus according to any one of claims 1-3, wherein said observed image picked up by said image pick-up means is an observed image irradiated by transmitted light having passed through said object, the transmitted light being emitted by said irradiating means, further comprising:

wavelength range separating means for separating said transmitted light into light of said plurality of wavelength ranges and transmitting the light to said image forming position changing means.

34. The frame sequential type imaging apparatus according to claim 33, wherein said wavelength range separating means separates light of a specific wavelength range into multiple light, and

said image forming position changing means forms an observed image irradiated by light in at least a part of said specific wavelength range separated by said wavelength range separating means in said offset position different from said same position.

35. The frame sequential type imaging apparatus according to any one of claims 1-3, wherein said irradiating means sequentially emits light of said plurality of wavelength ranges.

36. The frame sequential type imaging apparatus according to claim 35, wherein

said observed image picked up by said image pick-up means is an observed image irradiated by transmitted light having passed through said object, said transmitted light being emitted by said irradiating means,

wavelength range separating means for separating light of a specific wavelength range in said plurality of wavelength ranges into multiple light is provided, and

said image forming position changing means forms an observed image of at least a part of said specific wavelength range separated by said wavelength range separating means in said offset position different from said same position.

37. The frame sequential type imaging apparatus according to claim 36, wherein light of said plurality of wavelength ranges in a R light, G light, and B light and light of said specific wavelength range is a G light.

38. The frame sequential type imaging apparatus according to claim 36, further comprising:

memorizing means for memorizing said observed image picked up by said image picking up means as image information in each of said plurality of wavelength ranges, and

signal processing means for processing signals of image information of said observed image memorized by said memorizing means.

39. The frame sequential type imaging apparatus according to claim 36, wherein

said image forming position changing means includes three or more of a plurality of filters transmitting said transmitted light and having different wavelength transmission characteristics, and

said image forming position changing means forms said observed image having passed through at least two of said plurality of filters in said same position and forms said observed image having passed through at least one of remainder of said plurality of filters in said offset position different from said same position.

40. The frame sequential type imaging apparatus according to claim 36, wherein said image forming position changing means is a prism reflecting said reflected light and including a plurality of reflecting surfaces having different reflecting characteristics depending on wavelength ranges.

41. The frame sequential type imaging apparatus according to claim 36, further comprising, for an observed image formed in said image picking up means in one direction of rectangular coordinates on a surface lying at right angles to an optical axis of said reflected light, image transforming means for extending and compressing said observed image in a direction lying at right angles to said one direction to transform said observed image.

42. The frame sequential type imaging apparatus according to claim 36, wherein said frame sequential type imaging apparatus is a microscope apparatus.

43. An image pick-up system including said frame sequential type imaging apparatus according to claim 1, comprising:

A/D converting means for A/D-converting signals of said observed image, picked up by said image pick-up means, in said plurality of wavelength ranges and producing image information;

memorizing means for memorizing said image information in said plurality of wavelength ranges by said A/D converting means;

controlling means for reading out said image information from said memorizing means by predetermined control;

D/A converting means for D/A-converting image information read out by said controlling means and producing video signals; and

displaying means for inputting said video signals and displaying said observed image with higher resolution than the resolution of said imaging means.