ENDOSCOPE APPARATUS

Abstract

An endoscope apparatus, includes: an explosion-proof unit that has an image pickup device that outputs photographed video images as video image signals; and an A/D converter that converts the video image signals into digitalized image signals; a control unit that controls the explosion-proof unit; and an energy limiting circuit that is provided at the control unit and that limits electrical energy of digital signals to satisfy intrinsic safety when sending and receiving of the digital signals, wherein the explosion-proof unit is connected to the control unit via the energy limiting circuit with a signal line.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an exterior structure of an endoscope device of the first (and second and third) embodiment of the present invention.

FIGS. 2A and 2B are perspective views showing an exterior structure of a control unit of an endoscope device of the first (and second and third) embodiment of the present invention.

FIG. 3 is a conceptual view illustrating a drive device for an explosion-proof apparatus according to the first (and second and third) embodiments of the present invention.

FIG. 4 is a block diagram showing a structural example of a camera head module and display circuit in FIG. 1 according to the first embodiment.

FIG. 5 is a block diagram showing an example of an energy limiting circuit according to the second embodiment of the present invention.

FIG. 6 is a block diagram showing an example of an energy limiting circuit according to the third embodiment of the present invention.

FIG. 7 is a block diagram showing a structural example of a camera head module and display circuit in FIG. 1 according to the fourth embodiment of the present invention.

Claims

1. An endoscope apparatus, comprising: an explosion-proof unit that has an image pickup device that outputs photographed video images as video image signals; and an A/D converter that converts the video image signals into digitalized image signals;a control unit that controls the explosion-proof unit; andan energy limiting circuit that is provided at the control unit and that limits electrical energy of digital signals to satisfy intrinsic safety when sending and receiving of the digital signals, whereinthe explosion-proof unit is connected to the control unit via the energy limiting circuit with a signal line.

2. The endoscope apparatus according to claim 1, wherein the control unit has: a display unit that displays the image signals that are input via the energy limiting circuit; and a control signal output unit that outputs control signals to the explosion-proof unit via the energy limiting circuit.

3. The endoscope apparatus according to claim 1, wherein the energy limiting circuit has a resistor that is inserted in series on the signal line, and whereinthe resistor has a resistance value corresponding to a cutoff frequency that satisfies transmission speed between the control unit and the explosion-proof unit, and a resistance value that satisfies intrinsic safety.

4. The endoscope apparatus according to claim 1, wherein the energy limiting circuit has: a plurality of capacitative elements that are inserted in series on the signal line; and a resistor that is inserted between a signal output side of the capacitative elements and an earth.

5. The endoscope apparatus according to claim 1, wherein the control unit has a power supply unit that supplies driving power via a power supply line to the explosion-proof unit, and whereina second energy limiting circuit is provided on the power supply line via which the driving power is supplied from the power supply unit so that the second limiting circuit corresponds to the explosion-proof unit that satisfies intrinsic safety.

6. The endoscope apparatus according to claim 5, wherein the second energy limiting circuit has: a resistor that is inserted in series on the power supply line; and Zener diodes whose cathode or anode is connected to the resistor and whose anodes or cathodes are earthed.

7. The endoscope apparatus according to claim 5, wherein the second energy limiting circuit has: a current-limit circuit that has FET or transistors that are inserted in series on the power supply line; and a plurality of Zener diodes that are connected to the current-limit circuit.

8. The endoscope apparatus according to claim 1, wherein the image pickup device is a CMOS image sensor.

9. The endoscope apparatus according to claim 1, wherein the signal line, which connects the explosion-proof unit and the control unit, serves both as a high speed serial interface and as a high speed transmission wire to multiplex signals that are transmitted between circuits.

10. The endoscope apparatus according to claim 1, wherein the explosion-proof unit further has: an insertion portion at a distal end portion of which the image pickup device is provided; and an image processing unit that is provided at a distal side of the insertion portion and that image-processes the digital signals being from the A/D converter.

11. The endoscope apparatus according to claim 1, wherein the explosion-proof unit further has: an insertion portion at a distal end portion of which the image pickup device is provided; and an image processing unit that is provided at a proximal side of the insertion portion and that image-processes the digital signals being from the A/D converter.