JP5028284B2 - Endoscope light source device and endoscope system - Google Patents

Description

  The present invention relates to an endoscope light source device and an endoscope system including a rotary shutter that passes and blocks illumination light that illuminates the inside of a subject.

  The light source device for an endoscope includes a light source and a light guide that guides light from the light source to an illumination window at the distal end of an insertion portion of the endoscope that is inserted into a subject, and emits light from the illumination window. Illuminates the subject. An image in the subject is obtained by imaging the image light of the portion irradiated with the illumination light with a solid-state imaging device arranged at the distal end of the insertion portion, and the obtained image is displayed on the monitor to show the state in the subject. Can be observed.

  The illumination light is required to have a sufficient amount of light to image the inside of the subject with a solid-state imaging device. However, if the amount of light is increased, heat generation causes problems such as deterioration of the material at the tip of the endoscope. There is. Conversely, if the amount of light is reduced, heat generation is reduced, but the image becomes dark due to insufficient light amount, and the image quality of the image obtained from the solid-state imaging device is significantly deteriorated. In order to solve such a problem, a light source device for an electronic endoscope using a rotary shutter in which a part of a disk is cut is proposed (see Patent Documents 1 and 2).

  In the inventions described in Patent Documents 1 and 2, a rotary shutter is rotatably mounted on the optical path of the illumination light, the illumination light is allowed to pass when the notch enters the optical path, and the other part enters the optical path. The illumination light is blocked. Then, the rotational position of the rotary shutter is detected by a sensor, and based on the detected position, the illumination light is allowed to pass during the charge accumulation period of the solid-state imaging device and the illumination light is shielded during other periods. The rotation is controlled. Since the illumination light is shielded during the period other than the charge accumulation period, the integrated light amount can be reduced and the heat generation amount can be reduced as compared with the case where the illumination light is continuously applied. In addition, it is possible to secure a sufficient amount of light for imaging the inside of the subject with the solid-state imaging device, and it is possible to prevent image quality deterioration due to a decrease in the amount of light.

Also, an example in which a rotary shutter is used for switching between visible light and fluorescence in an electronic endoscope system that uses visible light and fluorescence as illumination light to obtain an image by visible light and a fluorescence image by fluorescence is disclosed ( (See Patent Document 3). In Patent Document 3, a fluorescent excitation light source is driven while visible light is blocked by a rotary shutter.
Japanese Patent No. 3403596 Japanese Patent No. 3370871 JP 2006-187426 A

  In an endoscope light source device using a rotary shutter, as described above, the rotation position of the rotary shutter is detected by a sensor, and the rotation cycle of the rotary shutter is synchronized with the cycle of the readout pulse based on this detection signal. Synchronized with the pulse. For this reason, the detection signal is not output due to a sensor failure, the wiring connected to the sensor is disconnected, etc., or the synchronization pulse driver that transmits the synchronization pulse fails or the wiring is disconnected to obtain the synchronization pulse. When it disappears, the above-mentioned control becomes impossible, and the illumination light may be blocked during the entire charge accumulation period. When this happens, the image is not shown at all, so that the inside of the subject cannot be observed.

  When the situation described above occurs, the test must be stopped and the insertion part must be removed from the subject. However, the situation at the distal end of the insertion part cannot be grasped, which hinders the removal work. . Conventionally, as a method for dealing with such a case, a wire for bending the distal end of the insertion portion is cut to straighten the distal end of the insertion portion. However, if the wire is cut, the endoscope cannot be used thereafter, so a new one must be purchased.

  As a method for solving the above problem, it is conceivable to stop the rotary shutter at a position where illumination light passes when a sensor breaks down. However, unless a detection signal or a synchronization pulse is obtained, it is impossible to stop the rotary shutter at a position where the illumination light passes, and this method is out of the question. Further, even if the rotary shutter stops at a position where the illumination light is accidentally passed, the illumination light continues to hit, so the amount of heat generation cannot be reduced.

  The inventions described in Patent Documents 1 to 3 do not discuss the above-mentioned problem and naturally take no countermeasures.

  The present invention has been made in view of the above problems, and transmits a synchronization pulse synchronized with a position detection means for detecting the rotational position of a rotary shutter or a readout pulse that defines a readout timing of accumulated charges of a solid-state imaging device. An object of the present invention is to provide an endoscope light source device and an endoscope system that can easily remove an endoscope from within a subject when a transmission means that malfunctions or breaks during examination. .

  The present invention is an endoscope light source device having a solid-state imaging device that images the inside of a subject, and is rotatably mounted on an optical path of illumination light that illuminates the inside of the subject, and allows the illumination light to pass therethrough. A rotary shutter for alternately providing an illumination period and a light-shielding period for shielding the illumination light at regular intervals, a rotational position detecting means for detecting the rotational position of the rotary shutter, and a detection signal from the rotational position detecting means Based on this, the rotation period of the rotary shutter is synchronized with a synchronization pulse that is synchronized with the period of a readout pulse that defines the readout timing of the accumulated charge of the solid-state image sensor, and the illumination period is the charge accumulation period of the solid-state image sensor. Control means for controlling the rotation of the rotary shutter to coincide with the rotation, and rotation for measuring the amount of rotation of the rotary shutter At least one of a measurement unit, a storage unit that stores correspondence information indicating a correspondence relationship between the rotation amount and the rotation position, a failure of the position detection unit, or a failure of the synchronization pulse transmission unit that transmits the synchronization pulse Failure detection means for detecting one failure, and when the failure detection means detects a failure, the control means is preset based on the correspondence information and the measured value of the rotation amount measurement means The rotary shutter is stopped at a stop position. The failure of the position detection means includes not only the failure of the position detection means itself but also the disconnection of the wiring connected to the position detection means. The failure of the synchronization pulse transmission means refers to the failure of the synchronization pulse transmission means itself. Of course, a failure of the wiring connected to the synchronous pulse transmission means is included.

  The control means has a comparator for comparing the measured value with the rotation amount of the correspondence information corresponding to the stop position, or the range of the rotation amount, and when the failure is detected by the failure detection means Based on the comparison result of the comparator, the rotary shutter is stopped at the rotation position where the rotation amount of the correspondence information corresponding to the stop position, or the range of the rotation amount and the measured value coincide with each other. It is preferable. Alternatively, the stop position is preferably the illumination period, the light-shielding period, or a position corresponding to the middle of these periods.

  It is preferable that the apparatus further includes setting change means for changing the setting of the stop position according to at least one of the specifications of the endoscope, the specifications of the light source that emits the illumination light, and the operation input. Furthermore, it is preferable that the rotation amount measuring unit measures the rotation amount by counting a numerical value assigned according to the rotation position.

  The rotation amount measuring means preferably resets the measured value to an initial value at a fixed timing. Moreover, it is preferable that the said fixed timing is whenever the said rotary shutter rotates once. Furthermore, when a failure of the position detection unit is detected by the failure detection unit and a failure of the synchronization pulse transmission unit is not detected, the control unit sets the rotation cycle of the rotary shutter as the cycle of the synchronization pulse. It is preferable to make them different. The failure detection means detects whether or not the detection signal is normally output by monitoring whether or not the detection signal is normally output, or whether or not the synchronization pulse signal is normally output. It is preferable to detect a failure of the synchronous pulse transmission means by monitoring.

  An endoscope system according to the present invention includes the endoscope light source device according to any one of claims 1 to 10 and an endoscope connected to the light source device.

  According to the endoscope light source device and the endoscope system of the present invention, the position detecting means for detecting the rotational position of the rotary shutter is synchronized with the readout pulse that defines the failure of the position detection unit or the readout timing of the accumulated charge of the solid-state imaging device. Based on the measured value of the rotary shutter rotation amount and the correspondence between the rotation amount of the rotary shutter and the rotation position when at least one of the failure of the synchronization pulse transmission means for transmitting the synchronized pulse is detected. Since the rotation of the rotary shutter is controlled so that the rotary shutter is stopped at a preset stop position, when the stop position corresponds to the illumination period of the rotary shutter, a sufficient field of view for securing the insertion portion is ensured. be able to. In addition, when the stop position corresponds to the light shielding period of the rotary shutter, heat generation can be prevented by continuing the illumination light. Furthermore, when the stop position is in the middle of the illumination period and the light shielding period, it is possible to secure a field of view that does not hinder the removal operation of the insertion portion and to prevent heat generation. Therefore, when the position detection means for detecting the rotational position of the rotary shutter or the synchronization pulse transmission means for transmitting the synchronization pulse fails during the examination, the endoscope can be easily removed from the subject.

  In FIG. 1, an electronic endoscope system 2 includes an electronic endoscope 10, a processor device 11, a light source device 12, and the like. The electronic endoscope 10 is connected to a flexible insertion portion 14 that is inserted into a body cavity, an operation portion 15 that is connected to a proximal end portion of the insertion portion 14, a processor device 11, a light source device 12, and the like. Connector 16, and a universal cord 17 that connects the operation unit 15 and the connector 16.

  At the distal end of the insertion portion 14, a distal end portion 14a in which a CCD 33 (see FIG. 2) for in-vivo imaging is incorporated is continuously provided. A bending portion 14b connecting a plurality of bending pieces is provided behind the tip portion 14a. The bending portion 14b is bent in the vertical and horizontal directions when the angle knob 19 provided in the operation portion 15 is operated and the wire inserted in the insertion portion 14 is pushed and pulled. Thereby, the front-end | tip part 14a is orient | assigned to the desired direction in a body cavity.

  In FIG. 2, an observation window 30 and an illumination window 31 are provided at the distal end portion 14a. An optical system 32 for capturing image light in the subject is attached to the back of the observation window 30, and a CCD 33 is attached to the back of the optical system 32. The CCD 33 is, for example, an interline transfer type CCD. Signal lines 34 and 35 for mediating exchange of various signals with the processor device 11 are connected to the CCD 33 via the universal cord 17. The signal lines 34 and 35 are connected to the processor device 11 via the universal cord 17 and the connector 16.

  On the other hand, an irradiation lens 36 is provided behind the illumination window 31. The irradiation lens 36 faces the emission end of an optical fiber (for example, made of quartz) 37 as a light guide. The light guided from the light source device 12 to the irradiation lens 36 by the optical fiber 37 is irradiated into the subject through the illumination window 31.

  The processor device 11 is electrically connected to the electronic endoscope 10, the light source device 12, the monitor 21, a keyboard (not shown), a printer (not shown), and the like, and the operation of the entire electronic endoscope system 2 is performed. Overall control. The processor device 11 is provided with a CCD driver 41, a timing generator (hereinafter abbreviated as TG) 42, a signal processor 43, a synchronization pulse driver 44, and a CPU 50 for controlling them. The CCD 33 is connected to a CCD driver 41 via a signal line 34, and a TG 42 controlled by the CPU 50 is connected to the CCD driver 41. Based on the timing signal input from the TG 42, the CCD driver 41 generates a readout pulse that defines the readout timing of the stored charge of the CCD 33 and an electronic shutter pulse that determines the shutter speed of the electronic shutter of the CCD 33. The CCD 33 is controlled. The synchronization pulse driver 44 is connected to the TG 42 and sends a synchronization pulse synchronized with the period of the readout pulse to the controller 57 (to be described later) of the light source device 12 based on a timing signal including the same timing as the readout pulse input from the TG 42. . The signal processing unit 43 is connected to the CCD 33 via the signal line 35. The image pickup signal output from the CCD 33 is subjected to amplification, A / D conversion, and various types of image processing by the signal processing unit 43 to be converted into a video signal. Displayed as an endoscopic image.

  The light source device 12 includes a light source 51, a lens 52, a rotary shutter 53, a motor 54, a motor driver 55, a position detector 56, a controller 57 for controlling them, and a stop position selection switch 58 (see FIG. 1, hereinafter referred to as a selection switch). Abbreviated). As the light source 51, for example, a xenon lamp, a halogen lamp, an LED (light emitting diode), a fluorescent light emitting element lamp, or an LD (laser diode) is used. The light emitted from the light source 51 is collected by the lens 52 and guided to the incident end of the optical fiber 37.

  As shown in FIG. 3, the rotary shutter 53 has a disk shape and is partially cut out in a fan shape. In reference numerals 53a and 53b, the notched portion is a light passage portion 53b, and the remaining portion is a light shielding portion 53a. The rotary shutter 53 is connected to a rotating shaft 54a of a motor 54 that is arranged in parallel with the optical axis of the light source 51, and the light shielding portion 53a and the light passing portion 53b are alternately turned by the rotation of the motor 54. Enter inside. When the light passage part 53b enters the optical path P, it becomes an irradiation period in which light is irradiated into the subject through the optical fiber 37, the irradiation lens 36, and the illumination window 31 (state shown in FIG. 3A). When entering the optical path P, a light shielding period in which the light into the subject is shielded is entered (state shown in FIG. 3B). Therefore, the ratio between the central angle of the light shielding part 53a and the central angle of the light passing part 53b is equal to the ratio between the light shielding period and the irradiation period. The central angles of the light shielding portion 53a and the light passage portion 53b are angles so that the irradiation period becomes equal to the charge accumulation period when the rotation period of the rotary shutter 53 is controlled to be equal to the period of the synchronization pulse. Is set.

  The motor 54 is a pulse motor and rotates by a predetermined angle when a drive pulse is supplied from the motor driver 55. In the present embodiment, one rotation is performed with 48 drive pulses, that is, 7.5 ° is rotated by one step (rotation angle in one drive pulse).

  The position detector 56 is configured by a photo sensor or the like, and is disposed in the vicinity of the outer periphery of the rotary shutter 53. The position detector 56 outputs an ON signal to the synchronization processing circuit 61 described later when the light shielding unit 53a passes and an OFF signal when the light passing unit 53b passes. Further, the position detector 56 may be arranged outside the vicinity of the outer periphery of the rotary shutter 53, for example, may be arranged inside the rotary shutter 53.

  The selection switch 58 can select the stop position of the rotary shutter 53 from any one of the open position, the light shielding position, and the semi-light shielding position. The stop position selected by the selection switch 58 is stored in a comparison value storage unit 64 described later. Is done. Note that the selection switch 58 may be provided in the processor device 11 or the operation unit 15. Moreover, you may provide in the keyboard (not shown) etc. which were externally connected to the processor apparatus 11 or the light source device 12.

  The controller 57 includes a synchronization processing circuit 61, a failure detection circuit 62, a counter 63, a comparison value storage unit 64, a comparison circuit 65, a stop switch 66, and a rotation control circuit 67.

  The synchronization processing circuit 61 performs synchronization processing for controlling the motor 54 based on the position detection signal and the synchronization pulse from the synchronization pulse driver 44 in the processor device 11. The synchronization processing circuit 61 detects a position detection signal based on an on / off signal sent from the position detector 56. In this embodiment, an edge that switches from an off signal to an on signal is detected as a position detection signal, that is, in the state shown in FIG. 3A, the position of a boundary line 53c that switches from the light passage portion 53b to the light shielding portion 53a. Is the position where the off signal switches to the on signal. Therefore, the synchronization processing circuit 61 detects the light shielding start timing as a position detection signal. The position of the boundary line 53d (see FIG. 3B) at which the light shielding unit 53a switches to the light passage unit 53b, that is, the irradiation start timing at which the output of the position detector 56 switches from the on signal to the off signal is not limited thereto. May be detected as a position detection signal.

  FIG. 4 is a timing chart showing a case where the synchronization processing by the synchronization processing circuit 61 is normally performed based on the position detection signal and the synchronization pulse. The CCD 33 performs charge accumulation and readout in accordance with the electronic shutter pulse and read pulse generated by the CCD driver 41, and outputs an image pickup signal. FIG. 4 illustrates the charge accumulation period and the image pickup signal output period. ing. Then, based on the position detection signal and the synchronization pulse, the synchronization processing circuit 61 controls the rotation of the motor 54 so that the timing of switching from the irradiation period to the light shielding period is matched with the output timing of the synchronization pulse. Thereby, the charge accumulation period of the CCD 33 and the irradiation period of the light source device 12 are synchronized. In the present embodiment, as described above, the light shielding start timing is detected as the position detection signal. From this detection timing of the position detection signal, rotation is performed so that a synchronization pulse is output at a constant interval td. This interval td is a time lag from the timing of the light shielding start to the timing at which the light source 51 is completely shielded, and the position of the position detector 56 and the timing of the rotary shutter 53 at the timing of the light shielding period start. The length of the interval td is set according to the rotational position.

  The failure detection circuit 62 monitors whether or not the output from the position detector 56 and the synchronization pulse output from the synchronization pulse driver 44 are normally output, and at least one of the output from the position detector 56 and the synchronization pulse. Is not detected for a predetermined period, a failure detection signal is output to the stop switch 66. In the present embodiment, when the output from the position detector 56 is not detected, it is assumed that the position detector 56 has malfunctioned. When the synchronization pulse is not detected, the synchronization pulse driver 44 has a failure. Assuming that The failure of the position detector 56 refers to the failure of the position detector 56 itself and the disconnection of the wiring connected to the position detector 56. The failure of the synchronization pulse driver 44 refers to the failure of the synchronization pulse driver 44 itself. It is assumed that there is a break in one of the wirings that transmit the synchronization pulse from the failure and synchronization pulse driver 44.

  The counter 63 counts drive pulses supplied from the motor driver 55 to the motor 54 and outputs the counter output value. Further, the counter 63 resets the counter output value to 0 when the drive pulse for one rotation of the rotary shutter 53 is counted. In the present embodiment, as described above, the rotary shutter 53 makes one rotation with 48 driving pulses. Therefore, when the counter 63 counts from 1 to 48, the counter 63 is reset to 0, and starts counting from 1.

  The comparison value storage unit 64 stores in advance a counter output value corresponding to each stop position when the rotary shutter 53 is stopped, that is, any value from 1 to 48 as a comparison value. As shown in Table 1, as the stop position stored in the comparison value storage unit 64, the light passage unit 53b opens the front of the light source 51 and passes the light, and the light shielding unit 53a is from the light source 51. Are set as a total light blocking position for blocking all of the light, and a light blocking position at which the light blocking portion 53a blocks about half of the light from the light source 51. As an example of a comparison value corresponding to these stop positions, “48” is set. , “10”, “20” are stored. Further, the comparison value storage unit 64 records selection information indicating which one of the light passing position, the total light blocking position, and the semi-light blocking position is selected. Then, any one of the light passing position, the total light blocking position, and the semi-light blocking position is selected by the selection switch 58, and selection information indicating the selected stop position is recorded. Table 1 shows a state where the light passage position is selected as the stop position.

  The comparison circuit 65 reads the comparison value set from the comparison value storage unit 64 when the stop switch 66 is turned on, and stops the rotation control circuit 67 when the output value of the counter 63 matches the comparison value. Output a signal.

  When normal, the rotation control circuit 67 outputs a motor timing pulse to the motor driver 55 according to the synchronization processing performed by the synchronization processing circuit 61, and when a failure detection signal is sent from the failure detection circuit 62, the rotation control circuit 67 According to the rotation stop signal from 65, the generation or output of the motor timing pulse is stopped.

  The stop switch 66 switches the connection / disconnection state between the comparison circuit 65 and the rotation control circuit 67. The stop switch 66 is turned on (connected) only when a failure detection signal is sent from the failure detection circuit 62, and otherwise. Is off (not connected).

  The operation of the above configuration will be described with reference to the flowchart of FIG. When performing an examination with the electronic endoscope system 2, the electronic endoscope 10 and the devices 11 and 12 are turned on, the insertion portion 14 is inserted into the body cavity, and illumination light from the light source device 12 is obtained. While illuminating the inside of the body cavity, the image inside the body cavity by the solid-state imaging device 33 is observed on the monitor 21. Further, the stop position of the rotary shutter 53 is selected by the selection switch 58 to one of light passing, light blocking, and semi-light blocking positions.

  When the light source device 12 is turned on (st1), the light source 51 emits light, the rotary shutter 53 rotates, and the position detector 56 and the failure detection circuit 62 start operating (st2).

  The rotation control circuit 67 determines the presence / absence of a rotation stop signal (st3). When the rotation stop signal is not detected, the rotation control circuit 67 generates a motor timing pulse corresponding to the synchronization processing circuit 61 and outputs it to the motor driver 55 (st4). When the motor timing pulse is input, the motor driver 55 generates a driving pulse and outputs the driving pulse to the motor 54 and the counter 63.

  Each time a driving pulse is output from the motor driver 55, the motor 54 rotates by one step, and the counter 63 adds one count (st5).

  The failure detection circuit 62 monitors the output from the position detector 56 and the synchronization pulse from the synchronization pulse driver 44. When there is an output from the position detector 56 and a synchronization pulse, no failure detection signal is output ( st6). When the position detection signal is detected (st7), it is determined that the rotation is one rotation, and the counter 63 is reset (st8). Thus, by resetting the counter 63 by detecting the position detection signal, the actual rotational position of the rotary shutter 53 and the value of the counter 63 can be matched.

  Since the charge accumulation period of the CCD 33 and the irradiation period of the light source device 12 are synchronized by the synchronization processing described above, the CCD 33 can obtain a sufficient amount of light and can observe an image with good image quality. When the observation is completed without any failure in the position detector 56 and the synchronous pulse driver 44, the user observes the image on the monitor 21 and moves the insertion portion 14 of the electronic endoscope 10 from the inside of the subject. Can be easily removed. Then, the power is turned off (st9) and the inspection is finished.

  On the other hand, when either one of the output from the position detector 56 and the synchronization pulse is not detected for a predetermined period, the failure detection circuit 62 outputs a failure detection signal (st6), and the stop switch 66 is turned on (st10). ). When the stop switch 66 is turned on, the comparison circuit 65 reads a comparison value corresponding to a preselected stop position from the comparison value storage unit 64 and compares this comparison value with the counter output value (st11). If it is different from the comparison value, the process returns to the process (st3) for determining the presence / absence of the rotation stop signal via the power on / off selection (st9). At this time, since the rotation stop signal is not detected, the rotation control circuit 67 generates a motor timing pulse corresponding to the signal of the synchronization processing circuit 61 and outputs it to the motor driver 55 (st4). The motor driver 55 generates a drive pulse in response to the motor timing pulse, outputs a drive pulse to the motor 54 and the counter 63, rotates the motor 54, and adds one to the count of the counter 63 (st5). In this way, while the comparison value and the counter output value are different, the order of st3, st4, st5, st6, st10, st11, st9, st3 is repeated, and the motor 54 performs one step rotation and the counter 63 counts. The addition is repeated. When the rotation of the motor 54 and the count of the counter 63 are added and the comparison value matches the counter output value (st11), the comparison circuit 65 outputs a rotation stop signal (st12). The rotation control circuit 67 detects this rotation stop signal (st3), and the generation or output of the motor timing pulse by the rotation control circuit 67 stops, so that the output of the drive pulse by the motor driver 55 stops and the motor 54 stops. . As a result, the rotary shutter 53 stops at a predetermined position (st13).

  In this way, when the rotary shutter 53 is rotated, the driving pulse is counted and the counter output value is compared with the comparison value corresponding to the stop position, and when the rotary shutter 53 reaches the pre-selected stop position. Therefore, when the inspection is stopped and the insertion portion 14 of the electronic endoscope 10 is to be removed from the subject, the light passage position or the semi-light-shielding position is obtained in order to grasp the state of the distal end portion 14a. The position can be selected and stopped, and the image can be confirmed. When the irradiation period by the light source device 12 becomes long, the rotary shutter 53 is stopped at an appropriate position, such as selecting all the light blocking positions. Therefore, the endoscope can be easily removed from the subject through the insertion portion 14. When the endoscope is removed, the power is turned off (st9), and the examination is completed or the examination is performed by another electronic endoscope system.

  In the first embodiment, the stop position is determined by the input setting by the selection switch 58, and the comparison value corresponding to the stop position is read to perform stop control of the rotary shutter 53. For example, the stop position may be set in advance according to the specifications of the electronic endoscope 10 or the light source 51 and stored in the comparison value storage unit 64. In this case, for example, the electronic endoscope 10 and the light source 51 are provided with memories for storing the respective specifications, and when the processor device 11 is connected and turned on, the specifications are read by reading information from these memories. To get. Further, in the first embodiment, the configuration is selected from the three stop positions of light passage, total light shielding, and semi-light-shielding. However, the present invention is not limited to this. Other than the semi-light-shielding position where light from the light source 51 is shielded by about half. In addition, a stop position that shields at least a part of the light source 51, for example, 1/3, 1/4, may be set, and the stop position to be selected is not limited to three, but may be selected from four or more. It may be. In the first embodiment, the comparison values corresponding to the stop positions are set to one (“48”, “10”, “20”), respectively. Since the counter output values at the time of the state are not one by one, the comparison value according to each stop position is not limited to one by one. For example, the comparison range according to each stop position is “31 to 48”. , “1-19”, “20-30”, and when the counter output value matches somewhere within the comparison range, control may be performed so as to stop.

  In the above embodiment, when either the output from the position detector or the synchronization pulse is not detected, the stop switch is turned on and the stop operation is started, but the present invention is not limited to this. Alternatively, only the output from the position detector may be monitored and the stop operation may be started. In this case, the failure detection circuit is omitted from the configuration of the first embodiment, and the stop switch 66 monitors the output from the position detector 56, turns off when there is an output, and turns on when there is no output. What is necessary is just to set it as the structure which has the function used as a state.

  If the synchronization pulse is output normally and only the output from the position detector is lost, the rotation control of the motor is performed so that the rotation cycle of the rotary shutter is different from the cycle at which the synchronization pulse is output. After that, the stop operation may be started. In this case, as in the light source device 80 shown in FIG. 6, the configuration of the controller 81 includes a synchronization processing circuit 61, a failure detection circuit 62, a counter 63, a comparison value storage unit 64, a comparison circuit 65, a rotation control circuit 67, And a cycle switching circuit 83 and a stop switch 84. In addition, about the thing using the same components as the said 1st Embodiment, a same sign is attached | subjected and description is abbreviate | omitted. Further, in the present embodiment, the failure detection circuit 62 monitors only the output from the position detector 56, and when the output from the position detector 56 is not detected for a predetermined period, the failure detection signal is sent to the cycle switching circuit 83. Output to.

  The cycle switching circuit 83 normally does not operate when a failure detection signal is not output from the failure detection circuit 62, a failure detection signal is output from the failure detection circuit 62, and a synchronization pulse is input from the synchronization pulse driver 44. In this case, the rotation of the motor 54 is controlled so that the period of the synchronization pulse and the rotation period of the rotary shutter 53 are different. When the rotation period of the motor driver 55 is changed to be shorter than the period in which the synchronization pulse is output by the control of the period switching circuit 83, the state shown in FIG. 7 is obtained, and the synchronization process is performed while the irradiation period and the light shielding period remain at the same ratio. The irradiation period and the light shielding period are each shorter than in the case of. As a result, the rotary shutter 53 enters an irradiation state at some timing within the charge accumulation period, and the subject is irradiated with light, so that an image can be observed. At this time, the amount of light within the charge accumulation period varies, and although the image displayed on the monitor 21 is in a flicker state, it does not hinder the observation of the image. When the cycle switching circuit 83 is activated, the rotation of the motor 54 is within the range of 85% to 99% and 101% to 115% with respect to the rotation cycle of the motor 54 when synchronized with the cycle of the synchronization pulse. It is preferable to change the cycle, and it is preferable to change the rotation cycle of the motor 54 within a range of about 95% or about 105%. This can reduce the flicker state of the image.

  As described above, even when the output from the position detector 56 is lost and the synchronization process becomes impossible, the rotation control of the motor 54 is controlled so that the cycle of outputting the synchronization pulse and the rotation cycle of the rotary shutter 53 are different. By performing the above, it is possible to return to the image observable state shown in FIG.

  The stop switch 84 detects the output of the sync pulse from the sync pulse driver 44. When the sync pulse is output, the stop switch 84 is in the off state (not connected), and when the output is lost, the stop switch 84 is in the on state (connected). It has a function.

  The operation of the above configuration will be described with reference to the flowchart shown in FIG. When the power sources of the devices 80 and 12 are turned on (st1), the light source 51 emits light, the rotary shutter 53 rotates, and the position detector 56 and the failure detection circuit 62 start operating (st2).

  The rotation control circuit 67 determines whether or not there is a rotation stop signal (st3), the rotation stop signal is not detected, and the failure detection signal from the failure detection circuit 62 that monitors the output of the position detector 56 is not detected. In the case (st4), a motor timing pulse corresponding to the synchronization processing circuit 61 is generated and output to the motor driver 55 (st5). When the motor timing pulse is input, the motor driver 55 generates a driving pulse and outputs the driving pulse to the motor 54 and the counter 63.

  When there is no output from the position detector 56, when the failure detection circuit 62 outputs a failure detection signal (st4), the cycle switching circuit 83 is activated, and the cycle of the synchronization pulse output from the synchronization pulse driver 44, A control signal for performing rotation control so as to make the rotation cycle of the rotary shutter 53 different is sent to the rotation control circuit 67 (st6).

  On the other hand, every time a drive pulse is output, the counter 53 increments the count by one (st7), and when the position detection signal is detected (st8), it is determined as one rotation and the counter 63 is reset ( st9). By resetting the counter 63 with the position detection signal, the actual rotation of the rotary shutter 53 and the value of the counter 63 can be matched.

  When there is a synchronization pulse input to the synchronization processing circuit 61 and the stop switch 84 (st10), it is possible to observe the image on the monitor 21 in a state where the synchronization processing or cycle change is performed. The endoscope can be easily removed. Then, the power is turned off (st11), and the inspection ends. On the other hand, when the sync pulse driver 44 fails and no sync pulse is input to the sync processing circuit 61 and the stop switch 84 (st10), the sync processing circuit 61 maintains the state immediately before the sync pulse input is lost. The stop switch 84 is turned on (st12). When the stop switch 84 is turned on, the comparison circuit 65 reads the comparison value corresponding to the stop position selected in advance from the comparison value storage unit 64, and compares this comparison value with the counter output value (st13). If it is different from the comparison value, the process returns to the process (st3) for determining the presence / absence of the rotation stop signal via the power on / off selection (st11). At this time, since the rotation stop signal is not detected and the failure detection signal is detected (st4), the rotation control circuit 67 generates a motor timing pulse in accordance with the control signal from the cycle switching circuit 83 (st6), Output to the motor driver 55. The motor driver 55 generates a drive pulse according to the motor timing pulse, outputs a drive pulse to the motor 54 and the counter 63, rotates the motor 54, and adds one to the count of the counter 63 (st7). As described above, while the comparison value and the counter output value are different, the order of st3, st4, st6, st7, st8, (st9), st10, st12, st13, st11, st3 is repeated, and the motor 54 rotates. The addition of the count of the counter 63 is repeated. When the rotation of the motor 54 and the count of the counter 63 are added and the comparison value matches the counter output value (st13), the comparison circuit 65 outputs a rotation stop signal (st14). The rotation control circuit 67 detects this rotation stop signal (st3), and the generation or output of the motor timing pulse by the rotation control circuit 67 stops, so that the drive pulse by the motor driver 55 stops and the motor 54 stops. As a result, the rotary shutter 53 stops at a predetermined position (st15), and the power is turned off (st11).

  In the above embodiment, when the output from the position detector or the synchronization pulse is lost, the stop operation is automatically started. However, the present invention is not limited to this, and the output from the position detector or the synchronization pulse is used. Alternatively, the timing at which the rotary shutter 53 is stopped may be input from the outside by operating the selection switch 58. In this case, when the selection switch 58 is operated at an arbitrary timing of the user, the stop switches 66 and 84 are turned on, and the rotary shutter 53 reaches the selected stop position and stops.

  In the above embodiment, the counter output value corresponding to the stop position of the rotary shutter 53 is counted using the drive pulse for driving the pulse motor, but the present invention is not limited to this. Any configuration may be used as long as the rotation shaft of the rotary shutter 53 or the motor 54 rotates every predetermined angle. For example, a rotary encoder that detects the rotation of the rotary shutter 53 or the motor 54 is provided separately. The position detection unit used in the above embodiment may be provided at every predetermined angular interval, and the position detection signals output from these may be counted.

  In the above embodiment, the electronic endoscope provided with the CCD 33 for in-vivo imaging is illustrated. However, the present invention is not limited to this, and the present invention is applied to an electronic endoscope provided with a CMOS as a solid-state imaging device for imaging. In addition, the present invention can be applied not only to an electronic endoscope but also to an ultrasonic endoscope. Alternatively, the present invention can be applied not only to living body observation but also to an industrial endoscope. In this case, when the insertion portion of the endoscope is removed, the endoscope itself can be prevented from being damaged.

It is a figure which shows the structure of an electronic endoscope system. It is a block diagram which shows the electrical structure of an electronic endoscope and a light source device. It is explanatory drawing which shows the positional relationship of a rotary shutter, a light source, and a position detector. It is a timing chart which shows the operation state at the time of normal mode. It is a flowchart which shows operation | movement of a light source device. It is a block diagram which shows the electric constitution of the light source device to which 2nd Embodiment of this invention is applied. It is a timing chart which shows the operation state at the time of period change mode. It is a flowchart which shows operation | movement of the light source device to which 2nd Embodiment is applied.

Explanation of symbols

2 Electronic Endoscope System 10 Electronic Endoscope 11 Processor Device 12 Light Source Device 21 Monitor 33 Solid-State Image Sensor 39 Optical Fiber 41 CCD Driver 42 Timing Generator 50 CPU
51 Light Source 53 Rotary Shutter 54 Motor 57 Controller 61 Synchronization Processing Circuit 62 Failure Detection Circuit 63 Counter 64 Comparison Value Storage Unit 65 Comparison Circuit 66, 84 Stop Switch 67 Rotation Control Circuit

Claims (11)

An endoscope light source device having a solid-state imaging device for imaging the inside of a subject,
A rotary shutter that is rotatably mounted on an optical path of illumination light that illuminates the inside of the subject, and that alternately provides an illumination period during which the illumination light passes and a light shielding period during which the illumination light is shielded; and
Rotational position detecting means for detecting the rotational position of the rotary shutter;
Based on a detection signal from the rotational position detecting means, the rotation period of the rotary shutter is synchronized with a synchronization pulse synchronized with a period of a readout pulse that defines a readout timing of accumulated charges of the solid-state imaging device, and the illumination Control means for controlling the rotation of the rotary shutter so that the period coincides with the charge accumulation period of the solid-state imaging device;
A rotation amount measuring means for measuring a rotation amount of the rotary shutter;
Storage means for storing correspondence information representing a correspondence relationship between the rotation amount and the rotation position;
A failure detection means for detecting at least one of the failure of the position detection means or the failure of the synchronization pulse transmission means for transmitting the synchronization pulse;
When a failure is detected by the failure detection means, the control means stops the rotary shutter at a preset stop position based on the correspondence information and the measurement value of the rotation amount measurement means. Endoscope light source device. The control means includes a comparator that compares the measured value with the rotation amount of the correspondence information corresponding to the stop position, or the range of the rotation amount.
When a failure is detected by the failure detection means, based on the comparison result of the comparator, the rotation amount of the correspondence information corresponding to the stop position, or the range of the rotation amount and the measured value match. The light source device for an endoscope according to claim 1, wherein the rotary shutter is stopped at a rotation position.   The light source device for an endoscope according to claim 1, wherein the stop position is the illumination period, the light shielding period, or a position that is intermediate between these periods.   The apparatus further comprises setting changing means for changing the setting of the stop position according to at least one of the specifications of the endoscope, the specifications of the light source that emits the illumination light, and the operation input. Item 4. The endoscope light source device according to Item 3.   5. The endoscope light source according to claim 1, wherein the rotation amount measuring unit measures the rotation amount by counting a numerical value assigned according to the rotation position. apparatus.   6. The endoscope light source device according to claim 1, wherein the rotation amount measuring unit resets the measurement value to an initial value at a constant timing.   The light source device for an endoscope according to claim 6, wherein the certain timing is every time the rotary shutter rotates once.   When a failure of the position detection unit is detected by the failure detection unit and a failure of the synchronization pulse transmission unit is not detected, the control unit makes the rotation cycle of the rotary shutter different from the cycle of the synchronization pulse. The light source device for an endoscope according to any one of claims 1 to 7.   9. The fault detection unit according to claim 1, wherein the fault detection unit detects a fault of the position detection unit by monitoring whether or not the detection signal is normally output. Endoscopic light source device.   9. The failure detection unit detects a failure of the synchronization pulse transmission unit by monitoring whether or not the synchronization pulse signal is normally output. Endoscope light source device.   An endoscope system comprising: the endoscope light source device according to any one of claims 1 to 10; and an endoscope connected to the light source device.

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