JP2007068755A - Light source device for endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device for an endoscope, which is advantageous for miniaturizing the device and reducing the cost, which allows a user to continue the endoscopic observation with an auxiliary lamp even if a main lamp fails during the endoscopic observation. <P>SOLUTION: The light source device for the endoscope comprises the current-controlled main lamp and the voltage-controlled auxiliary lamp for feeding irradiation light to the endoscope, a lamp-lighting power supply, and a system control circuit for lighting the auxiliary lamp when the main lamp is not normally lighted. The lamp-lighting power supply is a common power supply for the main lamp and the auxiliary lamp, and is separately disposed from the power supply system for the system control circuit. The lamp-lighting power supply comprises a first constant-voltage power supply for generating a prescribed power supply voltage, a second constant-voltage power supply for feeding the lighting power supply for the auxiliary lamp by voltage-controlling the prescribed power supply voltage, a constant-current power supply for feeding the lighting power supply for the main lamp by current-controlling the prescribed power supply voltage, and a switch circuit for connecting either the second constant-voltage power supply or the constant-current power supply to the first constant-voltage power supply. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an endoscope light source device that supplies illumination light to an endoscope.

  A conventional endoscope light source device includes a main lamp that is used as a light source lamp that supplies illumination light to an endoscope, and an auxiliary lamp that is used in an emergency in which the main lamp does not turn on due to some trouble. Yes. As main lamps, 100-300W class xenon lamps (discharge tubes) are the mainstream, and this type of main lamp requires a large amount of driving power, so it is provided separately from the power supply system for various circuits of the light source device. Power is supplied by a dedicated power source for the main lamp. The power supply unit dedicated to the main lamp rectifies and smoothes the AC power input from the outside with a rectifying and smoothing circuit, and then converts it into a DC voltage of about 400 V by a power factor correction circuit. The main lamp is turned on by generating an input current to the main lamp and applying a pulse voltage to the negative side of the main lamp by the igniter causing a dielectric breakdown between the discharge electrodes of the main lamp.

JP-A-1-284822

  On the other hand, a tungsten lamp of several W class is mainly used as the auxiliary lamp, and it is lit by receiving power supply from the power supply system for various circuits of the light source device. The light intensity of the illumination light from this auxiliary lamp is very weak compared to the illumination light from the main lamp. For this reason, if the main lamp disappears during endoscopic observation, the auxiliary lamp is turned on instead, but the illumination is too dark to continue the endoscopic observation. I could only get it out of my body. In order to solve this problem, it is conceivable to use a lamp with a large wattage as an auxiliary lamp, but there is a limit because the power supply of the auxiliary lamp is supplied from the circuit power supply of the light source device. When a power supply device dedicated to the auxiliary lamp is provided, the increase in size and cost of the device becomes a problem.

  The present invention has been made in view of the above problems, and is advantageous for downsizing and cost reduction of the apparatus. Even if the main lamp fails during endoscopic observation, the auxiliary lamp can continue endoscopic observation. It aims at obtaining the light source device for endoscopes.

  In the present invention, a voltage-controlled lamp capable of securing a sufficient amount of light for endoscopic observation is used as the auxiliary lamp, and a power supply device for the auxiliary lamp is provided separately from the power supply system for the circuit. In order to share the lamp and share the power supply device, a constant voltage source that supplies power to the auxiliary lamp, a constant current source that supplies power to the main lamp, and the constant voltage source as the auxiliary lamp and constant current It focuses on the fact that it is optimal to configure with a switch circuit connected to one of the sources.

  That is, the present invention relates to a current-controlled main lamp and a voltage-controlled auxiliary lamp that supply illumination light to an endoscope, a lamp lighting power source, and a system that lights the auxiliary lamp when the main lamp does not light normally. In an endoscope light source device including a control circuit, a lamp lighting power source is a common power source for a main lamp and an auxiliary lamp, and is provided separately from a power supply system to a system control circuit, and generates a predetermined power source voltage. A first constant-voltage power supply; a second constant-voltage power supply for controlling the predetermined power supply voltage to supply the lighting power for the auxiliary lamp; and a current control for the predetermined power supply voltage to supply the lighting power for the main lamp A constant current power supply; and a switch circuit for connecting one of the second constant voltage power supply and the constant current power supply to the first constant voltage power supply.

  The switch circuit includes a normally closed first relay circuit interposed between the first constant voltage power source and the constant current power source, and a constant relay interposed between the first constant voltage power source and the second constant voltage power source. When the main lamp does not light normally, it is preferable that the open / close states of the first relay circuit and the second relay circuit are switched via the system control circuit. Specifically, semiconductor switches can be used for the first relay circuit and the second relay circuit. Further, the first relay circuit and the second relay circuit may be configured to open and close in conjunction so that when one of them opens, the other closes.

  It is practical that the main lamp is a xenon lamp and the auxiliary lamp is a halogen lamp.

  According to the present invention, it is advantageous to reduce the size and cost of the apparatus, and it is possible to obtain an endoscope light source device that can continue endoscopic observation with an auxiliary lamp even if the main lamp fails during endoscopic observation. it can.

  FIG. 1 is a schematic configuration diagram of an endoscope system using an endoscope light source device 10 according to the present invention. The endoscope system includes an electronic endoscope 1 in which an individual imaging device 3 is disposed at the distal end of an in-vivo insertion portion 2, and a video processor that generates an observation image signal by performing image processing on an electrical signal output from the individual imaging device 3. 6, a monitor 7 that displays an observation image based on the observation image signal output from the video processor 6, and a light source device that supplies illumination light to the incident end 5 a of the illumination light guide fiber bundle 5 of the electronic endoscope 1 10. The observation range of the electronic endoscope 1 is illuminated with illumination light transmitted to the distal end of the in-body insertion portion 2 via the illumination light guide fiber bundle 5. An incident end 5 a of the illumination light guide fiber bundle 5 is detachably connected to the light source device 10 via a connector 8.

  FIG. 2 is a block diagram showing the main configuration of the control system of the light source device 10. The light source device 10 includes a current-controlled main lamp 11M that is commonly used as a light source lamp that emits illumination light, a voltage-controlled auxiliary lamp 11S that is used in an emergency such as a failure of the main lamp 11M, and the main lamp 11M and the auxiliary lamp 11S. A common lamp lighting power source 12, a system control circuit 13 for comprehensively controlling the entire light source device 10, and a system power source 14 for the system control circuit 13.

  The main lamp 11M is a high-pressure discharge lamp in which a pair of discharge electrodes are inserted from both ends of a light-emitting tube in which a light-emitting substance (mercury, argon gas, metal halide, etc.) is sealed, such as a xenon lamp or a metal halide lamp. Can be used. In this embodiment, a 100 to 300 W xenon lamp is used. The main lamp 11M is fixed in the light source device 10 by a fixing member (not shown). The auxiliary lamp 11S is an incandescent arc tube that can supply illumination light with a brightness that does not cause inconvenience in endoscopic observation, and a halogen lamp of about 150 W is used in this embodiment. The auxiliary lamp 11S is movably held by a drive mechanism (not shown), and is usually located outside the optical path of the main lamp 11M. The auxiliary lamp 11S is on the optical path of the main lamp 11M only when it is turned on instead of the main lamp 11M. Position.

  The system control circuit 13 is activated upon receiving power supply from the system power supply 14, and always determines whether the main lamp 11M is normally lit depending on the high / low state of the lighting state signal output from the lamp lighting power supply 12. Detect. In the present embodiment, for example, a lamp current detection resistor through which a current flows when the main lamp 11M is lit is provided in the lamp lighting power source 12, and a voltage generated at both ends of the lamp current detection resistor is used as a lighting state signal. When the main lamp 11M is lit, the lighting state signal is high because a current flows through the lamp current detection resistor. When the main lamp 11M is not lit, that is, when some abnormality occurs, the lamp current detection resistor is turned on. No current flows and goes low. If the high state of the lighting state signal is detected, the system control circuit 13 continues lighting the main lamp 11M. When the low state of the lighting state signal is detected, a lamp switching signal is output to the lamp lighting power source 12, and the auxiliary lamp 11S is turned on instead of the main lamp 11M. The system power supply 14 is provided separately from the lamp lighting power supply 12, and the AC power supply voltage V input from the outside is applied to the system power supply 14 and the lamp lighting power supply 12, respectively.

  FIG. 3 is a block diagram showing the configuration of the control system of the lamp lighting power supply 12. The lamp lighting power supply 12 includes a rectifying / smoothing circuit 21, a PFC circuit (power factor correction circuit) 22, a constant voltage control circuit 23, a constant current control circuit 24, and an igniter (high voltage generation circuit) 25. The lamp lighting power source 12 first rectifies and smoothes an AC power source voltage V inputted from the outside by a rectifying / smoothing circuit 21 to obtain a DC voltage, and then a power factor is improved by a PFC circuit 22 so that an output voltage of the PFC circuit 22 is constant. The voltage control circuit 23 sets the DC voltage to a specified magnitude. In the present embodiment, the output voltage of the PFC circuit 22 (the input voltage of the constant voltage control circuit 23) is about DC 400V. The PFC circuit 22 can be omitted. The output voltage of the constant voltage control circuit 23 is given to the constant current control circuit 24 when the main lamp 11M is turned on, and is given to the auxiliary lamp 11S when the auxiliary lamp 11S is turned on. This switching is executed based on a lamp switching signal from the system control circuit 13. The constant current control circuit 24 controls the magnitude of the current input to the main lamp 11M so that a constant lamp lighting power can be supplied to the main lamp 11M. An igniter (high voltage generation circuit) 25 is connected between the output side of the constant current control circuit 24 and the negative side of the main lamp 11M, and the igniter 25 causes a pulse voltage that causes dielectric breakdown between the discharge electrodes of the main lamp 11M. When (high frequency high voltage) is applied, the discharge electrodes of the main lamp 11M become conductive and current starts to flow, thereby turning on the main lamp 11M. On the other hand, when the output voltage of the constant voltage control circuit 23 is given to the auxiliary lamp 11S, the auxiliary lamp 11S is turned on immediately. In this case, the magnitude of the output voltage of the constant voltage control circuit 23 is defined by the magnitude of the rated voltage of the auxiliary lamp 11S.

  FIG. 4 is a block diagram showing a configuration of the constant voltage control circuit 23. The constant voltage control circuit 23 includes a first DC / DC converter 31 (first constant voltage power source) that generates a DC voltage having a specified magnitude from the output voltage of the PFC circuit 22, and a DC generated by the first DC / DC converter 31. A second DC / DC converter 32 (second constant voltage power supply) that reduces the voltage to generate the rated voltage of the auxiliary lamp 11S, and a first relay provided between the first DC / DC converter 31 and the constant current control circuit 24. A circuit 41 and a second relay circuit 42 provided between the first DC / DC converter 31 and the second DC / DC converter 32 are provided. Here, the first relay circuit 41 is a normally closed switch, and the second relay circuit 42 is a normally open switch, and the respective open / close states are switched by a lamp switching signal from the system control circuit 13. Normally, as shown by the solid line in FIG. 4, the first DC / DC converter 31 and the constant current control circuit 24 are connected via the first relay circuit 41, but the first switching circuit 31 receives the lamp switching signal from the system control circuit 13. As soon as the first relay circuit 41 is opened, the second relay circuit 42 is closed, and the first DC / DC converter 31 and the second DC / DC converter 32 are connected via the second relay circuit 42 as shown by the broken line in FIG. Is done. A semiconductor switch such as a diode or a transistor can be used for the first relay circuit 41 and the second relay circuit 42. When there is no lamp switching signal from the system control circuit 13, the first DC / DC converter 31 and the constant current control circuit 24 are connected, and when there is a lamp switching signal, the first DC / DC converter 31 and the second DC / DC converter. One relay that switches to connect 32 may be used.

The light source device 10 having the above configuration operates as follows.
When the AC power supply voltage V is turned on, the lamp lighting power source 12 lights the main lamp 11 and the system power source 14 activates the system control circuit 13. At this time, the lamp lighting power source 12 is in a state where the first relay circuit 41 of the constant voltage control circuit 23 is closed and the second relay circuit 42 is opened, that is, the first DC / DC converter 31 and the constant current control circuit 24 are in the first state. The first DC / DC converter 31 and the second DC / DC converter 32 are disconnected by the second relay circuit 41. At the same time, the auxiliary lamp 11S is located outside the optical path of the main lamp 11M and is turned off. When activated, the system control circuit 13 always detects whether the main lamp 11M is normally lit from the high / low state of the lamp lighting state signal, and if the high state of the lighting state signal is detected, the system control circuit 13 continues. The lighting of the main lamp 11M is continued. On the other hand, when the low state of the lighting state signal is detected, a lamp switching signal is output to the lamp lighting power source 12 to switch the open / close state of the first relay circuit 41 and the second relay circuit 42 of the constant voltage control circuit 23, and to assist The lamp 11S is turned on. With the lamp switching signal, the first relay circuit 41 is opened and the second relay circuit 42 is closed, that is, the first DC / DC converter 31 and the second DC / DC converter 32 are connected via the second relay circuit 42. The first relay circuit 41 disconnects the first DC / DC converter 31 and the constant current control circuit 24. When the lamp switching signal is output, the auxiliary lamp 11S is moved on the optical path of the main lamp 11M between the main lamp 11M and the incident end 5a of the illumination light guide fiber bundle 5 by a driving mechanism (not shown). The Since a halogen lamp of about 150 W is used as the auxiliary lamp 11S, good endoscopic observation can be realized by the illumination light from the auxiliary lamp 11S even if the main lamp 11M breaks down. At this time, since the first relay circuit 41 is opened and the main lamp 11M is disconnected from the auxiliary lamp 11S, the main lamp 11M is not overloaded. When the AC power supply voltage V is interrupted, the lamp lighting power source 12 and the system power source 14 are stopped, and the lamps that are lit are extinguished.

  According to the embodiment described above, the lamp lighting power source 12 is configured by combining the constant voltage control circuit 23 and the constant current control circuit 24, and the lamp lighting power source 12 is used as a common power source for the main lamp 11M and the auxiliary lamp 11S. The rated voltage of the auxiliary lamp 11M can be increased to such an extent that the amount of light necessary for endoscopic observation can be secured. Even if the main lamp 11M breaks down during endoscopic observation, a good endoscope with the auxiliary lamp 11S can be obtained. Observation is feasible. Further, since it is not necessary to provide separate power sources for the main lamp 11M and the auxiliary lamp 11S, it is advantageous for downsizing and cost reduction of the apparatus.

1 is a schematic configuration diagram of an endoscope system using an endoscope light source device according to the present invention. FIG. It is a block diagram which shows the main structures of the control system of the endoscope light source device of FIG. It is a block diagram which shows the structure of the lamp lighting power supply of FIG. FIG. 4 is a block diagram showing a configuration of a constant voltage control circuit in FIG. 3.

Explanation of symbols

1 Electronic Endoscope 10 Light Source Device (Endoscope Light Source Device)
11M main lamp 11S auxiliary lamp 12 lamp lighting power supply 13 system control circuit 14 system power supply 21 rectification smoothing circuit 22 PFC circuit (power factor correction circuit)
23 constant voltage control circuit 24 constant current control circuit 25 igniter (high voltage generation circuit)
31 1st DC / DC converter (1st constant voltage power supply)
32 Second DC / DC converter (second constant voltage power supply)
41 First relay circuit 42 Second relay circuit

Claims (4)

A current-controlled main lamp for supplying illumination light to the endoscope, a voltage-controlled auxiliary lamp, a lamp lighting power source, and a system control circuit for lighting the auxiliary lamp when the main lamp does not light normally. In the endoscope light source device provided,
The lamp lighting power source is a common power source for the main lamp and the auxiliary lamp, and is provided separately from the power supply system to the system control circuit,
A first constant voltage power supply for generating a predetermined power supply voltage; a second constant voltage power supply for controlling the predetermined power supply voltage to supply a lighting power for the auxiliary lamp; and a current control for the predetermined power supply voltage A constant current power supply for supplying the lighting power for the main lamp; and a switch circuit for connecting one of the second constant voltage power supply and the constant current power supply to the first constant voltage power supply;
An endoscope light source device characterized by comprising: The endoscope light source device according to claim 1, wherein the switch circuit includes a normally closed first relay circuit interposed between the first constant voltage power source and the constant current power source, and the first A normally open second relay circuit interposed between the constant voltage power source and the second constant voltage power source, and when the main lamp does not light normally, the system control circuit An endoscope light source device in which an open / close state of the first relay circuit and the second relay circuit is switched. The endoscope light source device according to claim 2, wherein the first relay circuit and the second relay circuit are semiconductor switches. The endoscope light source device according to any one of claims 1 to 3, wherein the main lamp is a xenon lamp and the auxiliary lamp is a halogen lamp.

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