Image-signal generating apparatus

• US 20050073589A1
• Filed: 09/28/2004
• Published: 04/07/2005
• Est. Priority Date: 10/02/2003
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Wakito, Sumio
• Granted Patent: US 8,035,684 B2
• Time in Patent Office: Days
• US Class Current: 348/207.990
• 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 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/70 SSIS architectures; Circuits associated therewith

Abstract

An image-signal generating apparatus comprises a solid-state image pickup device-equivalent load circuit unit including a load approximately equivalent to a solid-state image pickup device such as a charge coupled device, etc. The image-signal generating apparatus further comprises an image-signal generating circuit for generating an image signal corresponding to an output signal output from the solid-state image pickup device through the solid-state image pickup device-equivalent load circuit unit, which is a load to which a driving signal for driving the solid-state image pickup device is applied.

Claims

1. An image-signal generating apparatus for generating an image signal, comprising:

a solid-state image pickup device-equivalent load circuit unit having a load which is approximately equivalent to a solid-state image pickup device; and

an image-signal generating circuit for generating an image signal corresponding to an output signal output from the solid-state image pickup device.

2. The image-signal generating apparatus according to claim 1, wherein the solid-state image pickup device-equivalent load circuit unit has a plurality of solid-state image pickup device-equivalent load circuits having loads which are approximately equivalent to different types of solid-state image pickup devices.

3. The image-signal generating apparatus according to claim 2, further comprising selection means for selecting one solid-state image pickup device-equivalent load circuit out of the plurality of solid-state image pickup device-equivalent load circuits.

4. The image-signal generating apparatus according to claim 2, wherein the plurality of solid-state image pickup device-equivalent load circuits are automatically selected by a control device.

5. The image-signal generating apparatus according to claim 1, wherein the solid-state image pickup device-equivalent load circuit unit includes solid-state image pickup device-equivalent load circuits which use elements having a variable impedance value, and operates the plurality of solid-state image pickup device-equivalent load circuits which are approximately equivalent to different types of solid-state image pickup devices by varying the impedance value of the elements.

6. The image-signal generating apparatus according to claim 1, wherein the solid-state image pickup device is a charge coupled device, and the image signal is a charge coupled device output signal corresponding to an output signal of the charge coupled device.

7. The image-signal generating apparatus according to claim 6, wherein the image-signal generating circuit has a reset-pulse generating circuit for generating a pulse corresponding to a reset portion of the output signal of the charge coupled device.

8. The image-signal generating apparatus according to claim 6, wherein the image-signal generating circuit has a memory circuit for storing data of various charts.

9. The image-signal generating apparatus according to claim 7, wherein the image-signal generating circuit has a memory circuit for storing data of various charts.

10. The image-signal generating apparatus according to claim 9, further comprising a digital-to-analog converter circuit for performing digital-to-analog conversion on a pulse obtained from the memory circuit to generate a pulse corresponding to a data portion of the output signal of the charge coupled device.

11. The image-signal generating apparatus according to claim 10, further comprising a charge coupled device output signal generating circuit for synthesizing a pulse output from the reset-pulse generating circuit and a data pulse output from the digital-to-analog converter circuit and for outputting the synthesized pulse as the charge coupled device output signal.

12. The image-signal generating apparatus according to claim 6, further comprising a delay circuit for delaying the charge coupled device output signal by a predetermined delay amount.

13. The image-signal generating apparatus according to claim 11, further comprising a delay circuit for delaying the charge coupled device output signal output from the charge coupled device output signal generating circuit by a predetermined delay amount.

14. The image-signal generating apparatus according to claim 7, wherein the reset-pulse generating circuit obtains a solid-state image pickup device driving pulse generated from the internal substrate of an endoscope video processor and generates a pulse corresponding to the reset portion of the charge coupled device output signal synchronized with the solid-state image pickup device driving pulse on the basis of the solid-state image pickup device driving pulse.

15. The image-signal generating apparatus according to claim 7, wherein the reset-pulse generating circuit freely varies the width and amplitude of a pulse corresponding to the reset portion of the output signal of the charge coupled device by varying an element for determining the width and the amplitude of the pulse.

16. The image-signal generating apparatus according to claim 10, wherein the digital-to-analog converter circuit freely varies the width and amplitude of a pulse corresponding to the data portion of the output signal of the charge coupled device by varying an element for determining the width and the amplitude of the pulse.

17. The image-signal generating apparatus according to claim 11, wherein the charge coupled device output signal generating circuit generates a charge coupled device output signal by synthesizing the pulse corresponding to the reset portion of the charge coupled device output signal obtained from the reset-pulse generating circuit and the pulse corresponding to the data portion of the charge coupled device output signal obtained from the digital-to-analog converter circuit, and freely varies the amplitude of the charge coupled device output signal by varying an element for determining the amplitude.

18. The image-signal generating apparatus according to claim 12, wherein the delay circuit generates a delay amount corresponding to a delay time due to the length of an endoscope cable.

19. The image-signal generating apparatus according to claim 12, wherein the delay circuit has a plurality of delay units for generating a delay amount corresponding to a delay time due to the length of an endoscope cable, and the plurality of delay units is switchable.

20. The image-signal generating apparatus according to claim 12, wherein the delay circuit varies the delay amount corresponding to a delay time by controlling a variable element which is capable of varying the delay amount.

21. The image-signal generating apparatus according to claim 1, wherein the image-signal generating circuit generates an image signal which is approximately equivalent to an output signal of the solid-state image pickup device.

22. The image-signal generating apparatus according to claim 1, wherein the image-signal generating circuit generates an image signal which is approximately equivalent to an output signal of the solid-state image pickup device and has a waveform having a smaller distortion than that of the output signal of the solid-state image pickup device.

23. The image-signal generating apparatus according to claim 1, wherein the image-signal generating circuit generates an image signal which is approximately equivalent to an output signal of a charge coupled device serving as the solid-state image pickup device and has a waveform having a smaller distortion than that of the output signal of the charge coupled device.

24. The image-signal generating apparatus according to claim 23, wherein the image-signal generating circuit generates an image signal having a waveform in which boundaries between a reset portion, a feed-through portion, and a data portion of the output signal of the charge coupled device are identifiable.

25. The image-signal generating apparatus according to Claim.1, further comprising a connector which is detachably connected to an image-signal processing apparatus, which comprises a driving-signal generating unit for generating a driving signal for driving the solid-state image pickup device and a signal processing unit for performing signal processing in order to generate a standard image signal from the image signal corresponding to an output signal output from the solid-state image pickup device by applying the driving signal.

26. The image-signal generating apparatus according to claim 25, wherein the image-signal processing apparatus is an endoscopic signal processing circuit which is inserted into a body cavity, etc., is connected to an electronic endoscope having the solid-state image pickup device, and is used for endoscopy.

27. A method of inspecting an endoscope video processor to which an electronic endoscope having a solid-state image pickup device mounted thereto is connected,

wherein the method is performed using an image-signal generating apparatus comprising:

a solid-state image pickup device-equivalent load circuit having a load which is approximately equivalent to the solid-state image pickup device; and

an image-signal generating circuit for generating an image signal corresponding to an output signal output from the solid-state image pickup device.

28. The method of inspecting an endoscope video processor according to claim 27, wherein the solid-state image pickup device is a charge coupled device, and the image signal is a charge coupled device output signal corresponding to an output signal of the charge coupled device.

29. The method of inspecting an endoscope video processor according to claim 27, wherein the image-signal generating apparatus includes plural kinds of solid-state image pickup device-equivalent loads corresponding to plural kinds of solid-state image pickup devices, and

wherein when the endoscope video processor is compatible with the different types of solid-state image pickup devices, the image-signal generating apparatus and a meter for performing measurement are connected to a control device, the different types of solid-state image pickup device-equivalent loads are selected by the control device, and the image-signal generating apparatus is automatically adjusted by using data measured by the meter.