JP2018166986A - Endoscope and endoscope apparatus - Google Patents

Abstract

To provide an endoscope and an endoscope apparatus which can continue power supply to a light source when a voltage applied to the light source is reduced.SOLUTION: An endoscope includes: a light source provided on one tip end in an axial direction of a tubular inserting part that is to be inserted into a body cavity for irradiating light into the body cavity; and a first electric conductive path for applying voltage to the light source. The endoscope includes: a detection circuit for detecting the applied voltage via the first electric conductive path; and a switching circuit which switches the voltage to be applied to the light source via a second electric conductive path, which is different from the first electric conductive path, when the voltage detected by the detection circuit is lower than a predefined voltage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an endoscope and an endoscope apparatus that include a light source and a current path for applying a voltage to the light source.

  In recent years, LEDs (Light Emitting Diodes) have been used as light sources for endoscope devices, and LEDs have been inserted into scopes (inserted into the human body) together with solid-state imaging devices such as CMOS (Complementary Metal Oxide Semiconductor) and CCD (Charge Coupled Devices). The optical fiber for guiding the light from the light source to the tip portion is unnecessary.

  Electric power is supplied to the LED from a dedicated power source built in a processor unit (main body unit) in which the insertion unit is detachably mounted. When the endoscope apparatus is portable, a battery is used as a power source for LEDs.

  For example, Patent Document 1 describes an endoscope apparatus in which a plurality of light emitting diodes (LEDs) for illumination are divided into a plurality of sets, and a battery is connected to each set of light emitting diodes. In this endoscope apparatus, when the capacity of one battery supplying power to one LED set decreases, power can be supplied from another battery to another LED set manually or automatically. ing.

JP 2007-252686 A

  However, the technique described in Patent Document 1 has a problem in that power supply to the light source cannot be continued, for example, when a connection failure such as disconnection occurs in a current path from a battery to a light source such as an LED.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an endoscope and an endoscope capable of continuing power supply to a light source when a voltage applied to the light source is reduced. An object of the present invention is to provide an endoscope apparatus.

  An endoscope according to an aspect of the present invention includes a light source that is disposed at a distal end portion on one axial side of a tubular insertion portion that is inserted into a body cavity and that emits light into the body cavity, and a voltage applied to the light source. In an endoscope comprising a first current path for applying a voltage, a detection circuit that detects a voltage applied via the first current path, and a voltage detected by the detection circuit is lower than a predetermined voltage, A switching circuit for switching so that a voltage is applied to the light source via a second energization path different from the first energization path.

  According to the above, when the voltage applied to the light source is reduced, it is possible to continue power supply to the light source.

1 is an external view of an endoscope according to Embodiment 1. FIG. 1 is a block diagram illustrating a configuration example of an endoscope apparatus according to Embodiment 1. FIG. 3 is a timing chart showing switching of a voltage applied to a light source in the endoscope according to the first embodiment. It is a block diagram which shows the structural example of the endoscope apparatus which concerns on Embodiment 2. FIG. 6 is a timing chart showing switching of a voltage applied to an image sensor in the endoscope according to the second embodiment.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described. Moreover, you may combine arbitrarily at least one part of embodiment described below.

(1) An endoscope according to an aspect of the present invention includes a light source that is disposed at a distal end portion in one axial direction of a tubular insertion portion that is inserted into a body cavity and that irradiates light into the body cavity, In an endoscope comprising a first current path for applying a voltage to a light source, a detection circuit for detecting a voltage applied via the first current path, and a voltage detected by the detection circuit from a predetermined voltage When the voltage is low, the switching circuit includes a switching circuit that switches so that a voltage is applied to the light source via a second current path different from the first current path.

  In this aspect, a voltage is applied to the light source disposed at the one end portion of the tubular insertion portion via the first energization path. When the voltage applied via the first current path is lower than the predetermined voltage, switching is performed so that another voltage is applied to the light source via the second current path. Thereby, the power supply to the light source is continued.

(2) The insertion portion has a bending portion that can be bent on the other side of the distal end portion, and the detection circuit detects a voltage at a position closer to the light source than the bending portion, The switching circuit is preferably switched at a position closer to the light source than the position.

  In this aspect, the voltage applied via the first energization path is detected at a position closer to the light source than the bending portion in the insertion portion, and at a position closer to the light source than the detection position of the voltage, Switches the voltage applied to the light source. Thereby, for example, when disconnection or the like occurs due to repeated bending operations in the bending portion, a decrease in the voltage applied to the light source is reliably detected. In addition, even when the voltage applied to the light source is switched, it is continuously detected that the voltage applied via the first current path is lower than the predetermined voltage.

(3) It is preferable to further include an image sensor that is arranged at the distal end portion and images the inside of the body cavity when a voltage is applied via the second energization path.

  In this aspect, since the imaging element images the inside of the body cavity irradiated with light from the light source, it is not necessary to provide an optical fiber at the insertion portion. Further, when the voltage is switched, the voltage applied to the image sensor is directed to the light source, so that it is not necessary to prepare the third voltage.

(4) It is preferable that the detection circuit and the switching circuit are mounted, and further includes a circuit board that relays connection between the light source and the first energization path, and between the imaging element and the second energization path. .

  In this aspect, since the detection circuit and the switching circuit are mounted on the circuit board that relays the connection between the light source and the first current path and the connection between the image sensor and the second current path, the detection circuit and the switching There is no need to prepare a new circuit board for the circuit.

(5) a drive control circuit that controls a frame rate of image data generated by imaging by the image sensor; and the drive control circuit, when the brightness of an image based on the image data is lower than a predetermined brightness, It is preferable to reduce the frame rate.

  In this aspect, when the luminance of the image based on the image data generated by imaging by the image sensor is lower than the predetermined luminance, the frame rate of the image data is reduced. As a result, when the luminance of the light source decreases due to switching of the voltage applied to the light source, the exposure time of the image sensor increases, and the decrease in the luminance of the image is alleviated.

(6) a second detection circuit for detecting a voltage applied via the second current path, and when the voltage detected by the second detection circuit is lower than the second voltage, from the first current path It is preferable to further include a second switching circuit that switches so that the voltage of 1 is applied to the image sensor.

  In this aspect, when the voltage applied via the second energization path is lower than the second voltage, switching is performed so that the voltage applied via the first energization path is applied to the image sensor. Thereby, the electric power feeding to an image sensor is continued.

(7) An endoscope apparatus according to an aspect of the present invention includes the above-described endoscope and the endoscope that is detachably mounted, and a first voltage that applies a first voltage to the first current path. And a main body having a second power source for applying a second voltage to the second current path.

  In this aspect, the first voltage is applied from the first power source of the main body to the first energization path, and the second voltage is applied from the second power source to the second energization path. Thus, an endoscope capable of continuing power supply to the light source when the voltage applied to the light source decreases is applied to the endoscope apparatus.

[Details of the embodiment of the present invention]
Specific examples of an endoscope and an endoscope apparatus according to an embodiment of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to a claim are included. In addition, the technical features described in each embodiment can be combined with each other.

(Embodiment 1)
FIG. 1 is an external view of an endoscope according to the first embodiment, and FIG. 2 is a block diagram illustrating a configuration example of the endoscope apparatus according to the first embodiment. The endoscope 100 according to the first embodiment is a flexible endoscope for an upper digestive tract, for example. The endoscope 100 includes a tubular insertion portion 40 to be inserted into a body cavity, an operation portion 50 for performing an operation on the insertion portion 40, and a connector portion 70 that is detachably attached to a processor portion 80 (see FIG. 2). , And a flexible universal cord 60 that connects the connector portion 70 and the operation portion 50. The endoscope apparatus according to the first embodiment includes an endoscope 100 and a processor unit 80, and a plug of the connector unit 70 is detachably attached to a receptacle (not shown) of the processor unit 80. The

  The insertion portion 40 is long and includes a distal end portion 41, a bending portion 42, and a flexible tube portion 43 in order from one side that is opposite to the operation portion 50 side in the axial direction. The distal end portion 41 is hard and continues to the bending portion 42. The bending portion 42 is actively bent according to the operation of the bending knob 51 included in the operation portion 50. The flexible tube portion 43 has flexibility and bends passively. The other side of the flexible tube 43 in the axial direction is connected to the operation unit 50.

  Moving to FIG. 2, the distal end portion 41 includes a circuit board 10 on which the light source 11 that is an LED that irradiates the inside of the body cavity is mounted, and a circuit board 20 on which the imaging element 21 that is a CMOS that images the inside of the body cavity is mounted. It is configured to include. The light source 11 may be a combination of two or more LEDs in series or series-parallel, or may be a light emitter other than LEDs. The image sensor 21 may be a CCD, for example.

  The circuit board 20 is disposed between the light source 11 and the first current path 1 for applying a voltage to the light source 11 from the other side in the axial direction, and to the imaging element 21 and the imaging element 21 in the axial direction. The connection with the 2nd electricity supply path 2 for applying a voltage from the other side is relayed. That is, the plus side of the light source 11 is connected to the first current path 1 via the terminal T1 of the circuit board 10 and the terminals T2 and T3 of the circuit board 20. The plus terminal of the image sensor 21 is connected to the second energization path 2 via the terminal T4 of the circuit board 20. An electric circuit is provided between the terminals T2 and T4.

  On the other hand, the negative side of the light source 11 is connected to a ground wire (GND) 3 via a terminal T5 of the circuit board 10 and terminals T6 and T7 of the circuit board 20. The ground terminal of the image sensor 21 is connected to the terminals T6 and T7 on the circuit board 20. The terminals T1 and T2 and the terminals T5 and T6 are individually connected by wiring.

  On the circuit board 20, a serializer 22 that converts image data generated by imaging by the imaging device 21 into a serial signal, a semiconductor switch 23 that opens and closes an electric circuit between the terminals T2 and T3, and an electric circuit between the terminals T2 and T4 A semiconductor switch 24 that opens and closes, a comparator 25 that compares the voltage applied via the terminal T3 and the voltage of the reference voltage source 27, and an inverter 26 that inverts the logic of the output of the comparator 25. .

  In the first embodiment, the comparator 25 and the voltage source 27 correspond to a detection circuit, and the semiconductor switches 23 and 24 and the inverter 26 correspond to a switching circuit. The switching circuit is not limited to this, and may be, for example, another switch having one circuit and two contacts. Note that the power supply voltage of the semiconductor switches 23 and 24, the comparator 25, and the inverter 26 may be a voltage of 3V applied via the second current path 2 and the terminal T4. This power supply voltage is, for example, a voltage obtained by appropriately reducing a voltage of 15V applied via the first current path 1 and the terminal T3, and a voltage of 3V applied via the second current path 2 and the terminal T4. Each of them may be generated by inputting it to the anode of a Schottky barrier diode with the cathode abutted.

  The connector unit 70 decodes the current control circuit 71 that controls the magnitude of the current flowing into the light source 11 through the first current path 1 and the serial signal of the image data input through the signal line 4 into a parallel signal. And a driver circuit 73 (corresponding to a drive control circuit) that preprocesses the image data decoded by the deserializer 72 and supplies the processed image data to the processor unit 80. The connector unit 70 relays the second energization path 2 and the ground wire 3 between the universal cord 60 and the processor unit 80.

  The processor unit 80 includes a first power source 81 that applies a first voltage of 15 V to the first current path 1 via the current control circuit 71 and a second power source 82 that applies a second voltage of 3 V to the second current path 2. And have. The first voltage and the second voltage are not limited to 15V and 3V, respectively. The processor unit 80 further includes an image signal processing circuit 83 that performs signal processing on the image data from the driver circuit 73 and outputs a display signal to an external monitor, a front panel 84 for accepting a user operation, and a driver. And a system controller 85 that controls operations of the circuit 73, the image signal processing circuit 83, and the front panel 84.

  The serializer 22 can exchange control signals bidirectionally with a deserializer 72 described later. The image data converted into a serial signal by the serializer 22 is sent to the signal line 4 via the terminal T8 of the circuit board 20.

  When the voltage applied via the terminal T3 is higher than the voltage of the voltage source 27, the comparator 25 turns on the semiconductor switch 23 and turns off the semiconductor switch 24 via the inverter 26. The comparator 25 also turns off the semiconductor switch 23 and turns on the semiconductor switch 24 via the inverter 26 when the voltage applied via the terminal T3 is lower than the voltage of the voltage source 27. Thus, when the voltage applied via the first current path 1 becomes lower than the voltage of the voltage source 27, the voltage is switched so that the voltage is applied to the light source 11 via the second current path 2. Even when the voltage applied to the light source 11 is switched, the voltage applied to the comparator 25 via the terminal T3 does not change, so that the voltage applied via the first current path 1 is the voltage source 27. It continues to be detected that the voltage has dropped below the voltage.

  The current control circuit 71 increases the current flowing into the light source 11 by increasing the voltage applied to the first current path 1 in accordance with the current control signal from the driver circuit 73, and is applied to the current path 1. By reducing the voltage, the current flowing into the light source 11 is reduced.

  The driver circuit 73 performs gamma correction on the image data from the deserializer 72. The driver circuit 73 also supplies a current flowing into the light source 11 according to temperature data from a temperature sensor (not shown) arranged around the image sensor 21 and image brightness based on the image data from the deserializer 72. In order to control, a current control signal is given to the current control circuit 71. As a result, when the ambient temperature of the image sensor 21 increases or when the luminance of the image increases, the current flowing into the light source 11 decreases. Furthermore, when the ambient temperature of the image sensor 21 decreases or when the brightness of the image decreases, the current flowing into the light source 11 increases. For example, the average brightness of the screen or the brightness at the center of the screen is used as the brightness of the image.

  The driver circuit 73 further generates an image generated by the image sensor 21 when the luminance of the image is significantly decreased and the luminance of the image cannot be increased only by the control of the current control circuit 71 by the current control signal. The data frame rate is reduced via the deserializer 72, the signal line 4, and the serializer 22. Thereby, since the shutter interval of the image sensor 21 becomes longer, the exposure time of the image sensor 21 increases. The frame rate of the image data may be changed by a command from the system controller 85.

  In the endoscope 100 described above, the circuit board 10 is arranged so that the direction along the surface is orthogonal to the axial direction of the insertion portion 40 and the irradiation direction of light from the light source 11 coincides with the axial direction. The tip 41 is disposed at the most advanced position. A hole for allowing a lens unit (not shown) to guide light to the image sensor 21 on the circuit board 20 is opened in the center of the circuit board 10. The light irradiation direction from the light source 11 may be a direction intersecting the axial direction.

  The circuit board 20 is divided into three sub-boards as a whole. An imaging element 21 is mounted on the surface of the rectangular first substrate. A serializer 22 is mounted on the surface of the rectangular second substrate. Terminals T2, T3, T4, T6, T7, and T8 are provided on the surface of the trapezoidal third substrate. Wirings to the terminals T1, T2,... T8 are connected by soldering, for example. The first substrate and the second substrate, and the second substrate and the third substrate are individually connected by a flexible and flat connection cable.

  The first substrate and the second substrate are bent at the connection cable so that the surfaces are orthogonal to each other and are mountain-folded when viewed from the surface. The third substrate and the second substrate are bent 180 degrees at the connection cable so that the surfaces are opposite to each other. In this case, the fold line in the connection cable of the third board and the second board is orthogonal to the fold line in the connection cable of the first board and the second board. The circuit board 20 bent in this way is arranged on the other side of the above-described lens unit so that the surface of the first substrate and the surface of the circuit board 10 are in parallel. The method of bending the circuit board 20 is not limited to the method described above.

  Below, the case where the voltage applied to the light source 11 with the endoscope 100 mentioned above falls is demonstrated. FIG. 3 is a timing chart showing switching of the voltage applied to the light source 11 in the endoscope 100 according to the first embodiment. The upper part of the figure shows the time change of the voltage applied to the light source 11, and the lower part of the figure shows the time change of the frame rate of the image data. In these figures, the horizontal axis represents time (t) and the vertical axis represents voltage (V) and frequency (Hz), respectively.

  Before time t1, it is assumed that a voltage of 15V or slightly lower than 15V is applied to the light source 11 from the first power supply 81 via the current control circuit 71 and the first energization path 1. The frame rate of image data is 60 Hz as a standard. After time t1, some abnormality occurs in the first power supply 81, the current control circuit 71, or the first energization path 1, and the voltage applied to the light source 11 starts to decrease. Along with this, the amount of light from the light source 11 decreases.

  If the current control circuit 71 is operating normally from time t1 to time t2, the current flowing into the light source 11 is controlled to increase, but the voltage applied to the light source 11 reaches a peak at 15V. Therefore, the amount of light from the light source 11 continues to decrease.

  When the luminance of the image based on the image data decreases below a predetermined luminance at time t2, the driver circuit 73 decreases the frame rate of the image data from, for example, 60 Hz to 30 Hz. Thereafter, the voltage applied to the light source 11 continues to decrease, and the amount of light from the light source 11 continues to decrease.

  For example, when the voltage of the voltage source 27 is 2.5 V, the semiconductor switch 23 is turned off at time t3 when the voltage applied to the comparator 25 via the terminal T3 falls below 2.5 V, and the semiconductor switch 24 Is switched on so that a voltage is applied to the light source 11 via the second energization path 2. As a result, a second voltage of 3 V is applied to the light source 11 from the second power supply 82.

  When the voltage of the voltage source 27 is higher than 3V, the voltage applied to the light source 11 by switching the voltage is 3V even though the voltage applied through the first current path 1 is higher than 3V. Therefore, the voltage of the voltage source 27 is preferably set to a voltage as close as possible to 3V.

  When the state in which the luminance of the image based on the image data is lower than the predetermined luminance continues after switching of the voltage applied to the light source 11, the driver circuit 73 changes the frame rate of the image data from 30 Hz to 15 Hz, for example, at time t4. Reduce. After that, when the state where the brightness of the image based on the image data is lower than the predetermined brightness continues, the driver circuit 73 reduces the frame rate of the image data from 15 Hz to 8 Hz or 7 Hz, for example, at time t5.

  The rate at which the driver circuit 73 reduces the frame rate of the image data is not limited to ½. The time interval at which the frame rate is controlled is, for example, 1 second, but may be controlled at a shorter time interval.

  As described above, according to the first embodiment, the first voltage of 15 V is applied from the other side to the light source 11 disposed at the distal end portion 41 on the one side of the tubular insertion portion 40 via the first current path 1. Is done. When the voltage applied via the first current path 1 is lower than 2.5 V, for example, the second voltage of 3 V is applied to the light source 11 via the second current path 2 from the other side of the insertion portion 40. Switch. Therefore, when the voltage applied to the light source 11 decreases, it is possible to continue power supply to the light source 11.

  Further, according to the first embodiment, the voltage applied via the first current path 1 is detected at a position closer to the light source 11 than the bending portion 42 in the insertion portion 40, and the light source is further than the voltage detection position. The voltage applied to the light source 11 is switched at a position on the 11 side. Thereby, for example, when disconnection or the like occurs due to repeated bending operations in the bending portion 42, it is possible to reliably detect a decrease in the voltage applied to the light source 11. Further, even when the voltage applied to the light source 11 is switched, it is continuously detected that the voltage applied via the first current path 1 has dropped below the predetermined voltage, so that the voltage is switched and switched back. Can be prevented from occurring.

  Furthermore, according to the first embodiment, since the imaging element 21 images the inside of the body cavity irradiated with the light from the light source 11, it is not necessary to provide an optical fiber in the insertion portion 40. Further, when the voltage is switched, the second voltage applied to the image sensor 21 is directed to the light source 11, so that it is not necessary to prepare the third voltage.

  Furthermore, according to the first embodiment, the detection circuit (the comparator 25 and the voltage source) is provided on the circuit board 20 that relays the connection between the light source 11 and the first conduction path 1 and the connection between the imaging element 21 and the second conduction path 2. 27) and the switching circuit (semiconductor switches 23 and 24 and the inverter 26) are mounted, it is not necessary to prepare a new circuit board for the detection circuit and the switching circuit.

  Furthermore, according to the first embodiment, when the luminance of the image based on the image data generated by imaging by the imaging element 21 is lower than the predetermined luminance, the frame rate of the image data is reduced. Therefore, when the luminance of the light source 11 decreases due to switching of the voltage applied to the light source 11, the exposure time of the image sensor 21 increases, and the decrease in the luminance of the image can be mitigated.

  Furthermore, according to the first embodiment, the first voltage is applied from the first power supply 81 of the processor unit 80 to the first conduction path 1, and the second voltage is applied from the second power supply 82 to the second conduction path 2. Therefore, it is possible to apply the endoscope 100 capable of continuing power supply to the light source 11 when the voltage applied to the light source 11 is reduced to the endoscope apparatus.

  In the first embodiment, the case where the voltage applied to the light source 11 is switched from approximately 15 V to 3 V has been described as an example. However, when the light source 11 does not emit light even when a voltage of 3 V is applied, 3 V is applied. This voltage may be boosted and applied to the light source 11. In the description using FIG. 3, it is preferable that the voltage of the voltage source 27 is as close as possible to 3 V, but the present invention is not limited to this. For example, the voltage of the voltage source 27 may be matched with or close to the threshold value of the voltage to be applied to the light source 11 in order for the light source 11 to emit light. Further, when the light source 11 includes a plurality of light emitting elements connected in series, when the voltage applied to the light source 11 is switched, the voltage applied via the second current path 2 is You may make it make it light-emit by applying to some light emitting elements.

  In the first embodiment, the switching is performed so that the second voltage is applied to the light source 11 via the second energization path 2. However, the present invention is not limited to this. For example, a third voltage is applied to a third current path (not shown) via a terminal T9 (not shown), and the comparator 25 compares the voltage applied via the terminal T9 with the voltage of the voltage source 27. At the same time, the semiconductor switch 24 may open and close the electric circuit between the terminals T2 and T9. In this case, the voltage applied to the light source 11 is smoothly switched by keeping the voltage of the voltage source 27 close to the third voltage. The third voltage is preferably a voltage close to the first voltage.

(Embodiment 2)
The first embodiment is a mode in which the voltage applied to the light source 11 is switched, while the second embodiment is a mode in which the voltage applied to the image sensor 21 is further switched. FIG. 4 is a block diagram illustrating a configuration example of the endoscope apparatus according to the second embodiment. In the endoscope 100b according to the second embodiment, in addition to the configuration of the endoscope 100 according to the first embodiment, a second detection circuit and a second switching circuit described later are added to the surface of the circuit board 20. . An electric circuit is added between the plus terminal of the image sensor 21 and the terminal T3. The endoscope apparatus according to the second embodiment includes an endoscope 100b and a processor unit 80.

  On the circuit board 20, a semiconductor switch 33 that opens and closes an electric circuit between the plus terminal of the image sensor 21 and the terminal T4, a semiconductor switch 34 that opens and closes an electric circuit between the plus terminal of the image sensor 21 and the terminal T3, and a terminal T4 are provided. A comparator 35 that compares the voltage applied via the reference voltage source 37 and an inverter 36 that inverts the logic of the output of the comparator 35 are further mounted. Between the terminal T3 and the semiconductor switch 34, a 12V Zener diode 38 having a cathode connected to the terminal T3 side is connected in series.

  In the second embodiment, the comparator 35 and the voltage source 37 correspond to the second detection circuit, and the semiconductor switches 33 and 34, the inverter 36, and the Zener diode 38 correspond to the second switching circuit. The comparator 35 may share the voltage source 27 with the comparator 25 instead of the voltage source 37. Instead of the Zener diode 38, a step-down converter IC may be used. The power supply voltages of the semiconductor switches 33 and 34, the comparator 35, and the inverter 36 are, for example, a voltage obtained by appropriately lowering a voltage of 15 V applied via the first current path 1 and the terminal T3, and the second current path 2 and What is necessary is just to generate | occur | produce each 3V applied via terminal T4 with the voltage to the anode of the Schottky barrier diode which faced | matched the cathode.

  When the voltage applied via the terminal T4 is higher (or lower) than the voltage of the voltage source 37, the comparator 35 turns on (or off) the semiconductor switch 33 and turns off the semiconductor switch 34 via the inverter 36 ( Or on). As a result, when the voltage applied via the second current path 2 becomes lower than the voltage of the voltage source 37, the voltage is applied to the image sensor 21 via the first current path 1 and the Zener diode 38. Switch to. Even when the voltage applied to the image sensor 21 is switched, the voltage applied to the comparator 35 via the terminal T4 does not change, and therefore the voltage applied via the second current path 2 is reduced. Continue to be detected.

  In addition, about the structure similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  Below, the case where the voltage applied to the image pick-up element 21 with the endoscope 100b mentioned above falls is demonstrated. FIG. 5 is a timing chart showing switching of the voltage applied to the image sensor 21 in the endoscope 100b according to the second embodiment. In the figure, the horizontal axis represents time (t), and the vertical axis represents voltage (V). The thick solid line in the figure indicates the voltage applied to the image sensor 21, and the thin solid line indicates the voltage applied to the light source 11.

  Prior to time t6, the second voltage of 3V is applied to the image sensor 21 from the second power source 82 via the second current path 2. After time t6, some abnormality occurs in the second power supply 82 or the second energization path 2, and the voltage applied to the image sensor 21 starts to decrease.

  For example, when the voltage of the voltage source 37 is 2.5V, the semiconductor switch 33 is turned off and the semiconductor switch 34 is turned off at time t7 when the voltage applied to the image sensor 21 via the terminal T4 falls below 2.5V. Is switched on so that a voltage is applied to the image sensor 21 via the first current path 1 and the Zener diode 38. As a result, a voltage of 3 V obtained by stepping down the first voltage of the first power supply 81 is applied to the image sensor 21.

  As described above, according to the second embodiment, when the second voltage applied via the second current path 2 is lower than the voltage of the voltage source 37, the first voltage applied via the first current path 1. Is applied to the image sensor 21. Therefore, it is possible to continue power supply to the image sensor 21.

DESCRIPTION OF SYMBOLS 100, 100b Endoscope 1 1st electricity supply path 2 2nd electricity supply path 3 Ground wire 4 Signal line 10 Circuit board 11 Light source 20 Circuit board 21 Imaging element 22 Serializer 23, 24 Semiconductor switch 25 Comparator 26 Inverter 27 Voltage source 40 Insertion part 41 distal end portion 42 bending portion 43 flexible tube portion 50 operation portion 51 bending knob 60 universal cord 70 connector portion 71 current control circuit 72 deserializer 73 driver circuit 80 processor portion 81 first power source 82 second power source 83 image signal processing circuit 84 front Panel 85 System controller T1, T2, T3, T4, T5, T6, T7, T8 terminals

Claims (7)

A light source for irradiating light into the body cavity disposed at one end in the axial direction of the tubular insertion portion inserted into the body cavity, and a first current path for applying a voltage to the light source. In an endoscope,
A detection circuit for detecting a voltage applied via the first current path;
An endoscope comprising: a switching circuit that switches so that a voltage is applied to the light source through a second energization path different from the first energization path when the voltage detected by the detection circuit is lower than a predetermined voltage. The insertion portion has a bending portion that can be bent on the other side of the distal end portion,
The detection circuit detects a voltage at a position closer to the light source than the curved portion,
The endoscope according to claim 1, wherein the switching circuit performs switching at a position closer to the light source than the position.   The endoscope according to claim 1, further comprising an image sensor that is disposed at the distal end portion and that images the inside of the body cavity when a voltage is applied via the second energization path.   4. The circuit board according to claim 3, further comprising a circuit board that is mounted with the detection circuit and the switching circuit, and relays connections between the light source and the first energization path, and between the imaging element and the second energization path. Endoscope. A drive control circuit for controlling a frame rate of image data generated by the image pickup device;
The endoscope according to claim 3 or 4, wherein the drive control circuit reduces the frame rate when the luminance of an image based on the image data is lower than a predetermined luminance. A second detection circuit for detecting a voltage applied via the second current path;
2. A second switching circuit that switches so that a voltage from the first energization path is applied to the image sensor when the voltage detected by the second detection circuit is lower than the second voltage. The endoscope according to any one of 5 to 5. The endoscope according to any one of claims 1 to 6,
A main body having a first power source for applying a first voltage to the first current path and a second power source for applying a second voltage to the second current path; Including endoscopic device.

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