Image-signal generating apparatus

• US 8,035,684 B2
• Filed: 09/28/2004
• Issued: 10/11/2011
• Est. Priority Date: 10/02/2003
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Wakito, Sumio
• Primary Examiner(s): Patel; Jay
• Assistant Examiner(s): Pe; Geepy
• Application Number:
  US10/952,417
• Publication Number:
  US 20050073589A1
• Time in Patent Office: 2,569 Days
• Field of Search: 348 65- 76
• US Class Current: 348/65
• 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. A simulated image-signal generating apparatus for generating a simulated image signal, comprising:

a load circuit unit constructed of a passive element which does not have a photoelectric conversion function without an actual solid-state image pickup device, and having an impedance value approximately equivalent to an impedance value of an actual solid-state image pickup device, the load circuit unit outputting a load output signal by application of a driving signal for driving the actual solid-state image pickup device to be synchronized with the driving signal; and

a simulated image-signal generating circuit generating and outputting a simulated image signal that imitates an actual image signal of the actual solid-state image pickup device based on the load output signal.

2. The simulated image-signal generating apparatus according to claim 1, wherein the simulated image signal is a first output and the load circuit unit has a plurality of load circuits having impedance values, which are approximately equivalent to different types of actual solid-state image pickup devices, the simulated image signal being varied in accordance with the impedance values.

3. The simulated image-signal generating apparatus according to claim 2, further comprising selection means for selecting one load circuit out of the plurality of load circuits and outputting a second output differing from the first output in accordance with an impedance value of a load.

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

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

6. The simulated image-signal generating apparatus according to claim 1, wherein the actual 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 simulated image-signal generating apparatus according to claim 6, wherein the simulated 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 simulated image-signal generating apparatus according to claim 6, wherein the simulated image-signal generating circuit has a memory circuit for storing data of various charts.

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

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

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

23. The simulated image-signal generating apparatus according to claim 1, wherein the simulated image-signal generating circuit generates an image signal which is approximately equivalent to an output signal of a charge coupled device serving as the actual 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 simulated image-signal generating apparatus according to claim 23, wherein the simulated 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 simulated 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 actual 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 actual solid-state image pickup device by applying the driving signal.

26. The simulated 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 actual solid-state image pickup device, and is used for endoscopy.

29. The image-signal generating apparatus according to claim 1, wherein the solid-state image pickup device-equivalent load circuit unit is constructed of a resistance device and a capacitance device as the passive device.

30. The image-signal generating apparatus according to claim 1, wherein two terminals of the load circuit unit are applied with the driving signal for driving the actual solid-state image pickup device.

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

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

a load circuit unit constructed of a passive element which does not have a photoelectric conversion function without the actual solid-state image pickup device and having an impedance value approximately equivalent to an impedance value of the actual solid-state image pickup device, the load circuit unit outputting a load output signal by application of a driving signal for driving the actual solid-state image pickup device to be synchronized with the driving signal; and

a simulated image-signal generating circuit generating a simulated image signal corresponding to an actual output signal output from the actual solid-state image pickup device based on the load output signal.

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

31. The method of inspecting an endoscope video processor according to claim 27, wherein two terminals of the load circuit unit are applied with the driving signal for driving the actual solid-state image pickup device.