JP5279181B2 - Endoscope device with automatic light control processing function, automatic light control device for endoscope, program for endoscope device, and method for operating endoscope device - Google Patents

Description

  The present invention relates to an endoscope apparatus having an automatic light control function for adjusting the brightness of a subject image. In particular, the present invention relates to an endoscope apparatus having a heat-preventing light amount adjustment function.

  Endoscope devices equipped with an automatic light control function can increase or decrease the amount of light emitted from a light source such as a lamp or the like in order to maintain the brightness of the subject image displayed on the monitor at an appropriate level. To adjust the intensity and amount of light applied to the subject. In the case of automatic light control using an aperture, the luminance value of the subject image is detected based on an image signal read from an image sensor provided at the distal end of the video scope. Then, the diaphragm is opened and closed based on the difference between the detected luminance value and the reference luminance value indicating the standard brightness, and the light quantity is adjusted.

When the aperture is fully open or close to full open, the amount of light emitted from the distal end of the scope is large, and the scope distal end has heat, causing problems in circuits and the like. In order to prevent this, when the period in which the aperture is fully open continues for a predetermined time, a dimming process is performed to reduce the aperture to the fully closed position or an opening close thereto. When resuming the endoscopic work, an operation switch provided on the front panel is operated, and thereby the dimming process is canceled (see Patent Document 1).
JP 2002-282207 A

  In the standby state before the scope is used, the diaphragm is fully opened because the distance between the subject and the scope tip is large, and as a result, the light reduction process is executed. When shifting from the standby state to the endoscopic operation, the operation must be started after the operation switch is pressed, and it is not possible to shift to the endoscopic operation as occasion demands. Further, even when the endoscopic work is temporarily interrupted, the operation switch must be pressed to resume the work, and the endoscopic work cannot proceed efficiently.

  An endoscope apparatus according to the present invention is an endoscope apparatus capable of automatic light control processing, and generates a video signal based on a video scope having an image sensor and an image signal corresponding to a subject image read from the image sensor. Signal processing means for adjusting the amount of light to the subject by opening and closing the iris so that the brightness of the subject image displayed based on the video signal is maintained at an appropriate brightness, and the iris Is provided with dimming means for closing the diaphragm to a predetermined opening when the state of being fully open continues for a predetermined period. Here, “substantially in a fully open state” means that the valve is in a fully open state or a state close to a fully open state, and includes a case where a state where the aperture is not less than a predetermined opening degree close to a fully open state is continued. For example, the automatic light control means may open and close the aperture based on the difference between the luminance value obtained from the image signal and the reference luminance value indicating appropriate brightness.

  In the endoscope apparatus of the present invention, when the brightness of the subject image has reached a predetermined brightness corresponding to the endoscope working state, the automatic light control means, from the state where the dimming means is operating, The diaphragm is driven again to adjust the amount of light. Here, the predetermined brightness corresponding to the endoscopic work state means a brightness that falls within a general brightness range of an observation image that is normally obtained during the endoscopic work. For example, when the videoscope is leaned against a holder or the like in a standby state before endoscopic work, the state in which the diaphragm is closed by the dimming means is maintained. When shifting from this state to endoscopic work, the distance between the distal end of the scope and the subject, that is, the inside of the body cavity approaches, and the brightness of the subject image obtained during normal observation is restored. When such brightness is reached, the automatic dimming process automatically resumes.

  The predetermined brightness corresponding to the endoscopic work state may be set as appropriate according to the use environment, and automatic light control can be resumed before the light quantity becomes excessive, and the state has not shifted to the observation state. Nevertheless, the brightness may be set so that there is no fear of resuming the automatic light control processing. For example, what is necessary is just to set to the same brightness as the reference | standard at the time of an automatic light control process. When the automatic light control process is executed based on the luminance value, the diaphragm may be driven when the luminance value reaches a predetermined luminance value corresponding to the predetermined brightness. For example, the predetermined luminance value is set as the reference luminance value. You only have to set it.

  In order to quickly restart the automatic light control process, it is necessary to detect a change in the brightness of the actual subject image by irradiating the subject with light to some extent. Therefore, the aperture of the diaphragm in the dimming process may be determined not in the vicinity of full closing but in a range that is frequently opened and closed during the automatic dimming process. For example, the opening degree may be set to a ratio of about 1/4 to 3/4 with respect to the full opening of the diaphragm.

  The automatic dimming device for an endoscope of the present invention is applicable to an electronic endoscope device or a light source device for a fiberscope, so that the brightness of a subject image is maintained at an appropriate brightness. Automatic light control means for adjusting the amount of light is provided. The automatic light control means adjusts the amount of light to the subject by, for example, opening / closing operation of a diaphragm or light emission amount adjustment by a light source such as a lamp. The endoscope apparatus according to the present invention includes a light reduction unit that reduces the light amount to the subject to a predetermined light amount when the state in which the light amount to the subject exceeds the predetermined light amount continues for a predetermined period. The predetermined amount of light is determined as the amount of light that does not cause a thermal problem at the scope tip. Then, the automatic light control means performs the light amount adjustment again when the light amount to the subject reaches a light amount that provides the brightness of the subject image corresponding to the endoscope working state.

  The program according to the present invention includes an automatic light control unit that adjusts the amount of light to the subject so that the brightness of the subject image is maintained at an appropriate brightness, and a state in which the amount of light to the subject exceeds the predetermined amount of light continues for a predetermined period. If the light amount to the subject reaches the light amount that provides the brightness of the subject image corresponding to the endoscope work state The automatic light control means is made to function so as to execute the light amount adjustment.

  The automatic dimming method for an endoscope of the present invention adjusts the amount of light to the subject so that the brightness of the subject image is maintained at an appropriate brightness, and the state in which the amount of light to the subject exceeds the predetermined amount of light is determined for a predetermined period. If it continues, the light intensity to the subject will be reduced to the specified light intensity, and if the light intensity to the subject reaches the light intensity that provides the brightness of the subject image corresponding to the endoscope working state, the light intensity adjustment will be performed again It is characterized by performing.

  According to the present invention, it is possible to effectively perform an endoscope operation without a complicated operation without causing a thermal problem at the distal end of the scope.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of an electronic endoscope apparatus according to the first embodiment.

  The electronic endoscope apparatus includes a video scope 10 and a processor 20, and a monitor 30 is connected to the processor 20. The video scope 10 is detachably connected to the processor 20.

  When the lamp 24 in the processor 20 is turned on, the light emitted from the lamp 24 enters the incident end 12A of the light guide 12 through the diaphragm 26 and a condenser lens (not shown). The light guide 12 transmits the light from the lamp 24 to the distal end of the scope, and the light that has passed through the light guide 12 is emitted from the distal end of the scope through a light distribution lens (not shown). Thereby, the observation site is illuminated.

  The light reflected at the observation site passes through the objective lens (not shown) and reaches the light receiving surface of the CCD 14. As a result, a subject image is formed on the CCD 14 and an image signal corresponding to the subject image is generated. Image signals are read from the CCD 14 at regular time intervals and sent to the signal processing circuit 22 of the processor 20. Reading of the image signal from the CCD 14 is controlled by a CCD driver provided in the signal processing circuit 22, and here, the image signal for one field is read at 1/60 second intervals according to the NTSC system as a video standard.

  The signal processing circuit 22 performs various processes on the image signal such as white balance adjustment and gamma correction to generate a video signal in accordance with a predetermined video standard. The generated video signal is output to the monitor 30, whereby the observation image is displayed on the monitor 30. In the signal processing circuit 22, a luminance signal is generated based on the image signal.

  A system control circuit 21 including a CPU, a ROM, and a RAM controls the operation of the processor 20 and outputs a control signal to each circuit such as a signal processing circuit. The ROM stores a program related to operation control. A cancel button 25 provided in the processor 20 is a button for canceling a dimming process, which will be described later, and allows the automatic dimming process to be restarted by an operator's operation.

  The diaphragm 26 opens and closes in order to adjust the amount of illumination light from the lamp 24, and is driven by a drive unit (not shown) such as a motor. The light control circuit 23 is a DSP (Digital Signal Processor) that performs automatic light control processing, and is configured as a programmable circuit. The dimming circuit 23 controls the opening / closing operation of the diaphragm 26 based on the luminance data sent from the signal processing circuit 22 so that the subject image displayed on the monitor 30 is maintained at an appropriate brightness. That is, based on the difference between the detected luminance of the subject image and the reference luminance, a control signal is output to the drive unit, and the opening of the diaphragm 26 is adjusted.

  The diaphragm 26 is configured as a plate-shaped axially rotatable diaphragm, and the amount of light to the subject changes according to the rotation angle of the diaphragm 26. The opening degree of the diaphragm 26 is divided into 240 steps and is set to any value in the range of 0 to 240. In the fully automatic state, the opening degree of the diaphragm 26 is displaced between 60 and 200 in the normal automatic light control process.

  FIG. 2 is a flowchart showing an automatic dimming process executed by the dimming circuit 23. FIG. 3 is a graph showing the luminance value and the throttle opening in time series.

  In step S101, automatic light control processing is executed. Specifically, the difference (brightness difference) between the luminance value Y of the subject image based on the luminance data and the preset reference luminance value Y0 is calculated, and if the luminance difference exceeds the allowable range, the luminance value is referred to. The diaphragm 26 opens and closes so as to match the luminance value Y0. Here, the luminance value of the subject image is represented by a luminance level divided into 256 levels, and is set to any value in the range of 0 to 255. As the representative luminance value of the subject image, for example, the average luminance of the image signal for one frame or one field is calculated. The reference luminance value represents a luminance value indicating the appropriate brightness of the subject image. For example, the luminance value Y0 is set to 128.

  In step S102, it is determined whether or not the diaphragm 26 is substantially fully open. As shown in FIG. 3, in the state where the automatic dimming process is executed (section S1), when the endoscope operation is interrupted, the distance between the distal end of the scope and the subject increases, and the luminance value Y and the reference luminance value A large difference is generated from Y0, and as a result, the diaphragm 26 is fully opened. Alternatively, the video scope 10 is held by a holder or the like before the endoscope operation is started with the processor 20 turned on, and the diaphragm 26 is inevitably opened to the full open. If it is determined that the aperture 26 is not substantially fully open, a timer is initialized in step S108, and the process returns to step S101. On the other hand, if it is determined that the diaphragm 26 is substantially fully open, the process proceeds to step S103.

  In step S103, the period during which the aperture 26 is fully opened is counted. Specifically, 1 is incremented to the counter variable, the counter variable is integrated each time step S103 is repeatedly executed, and the fully open duration time of the diaphragm 26 is measured. In step S104, it is determined whether or not the duration time of the fully opened state exceeds a predetermined time T0 seconds based on the accumulated counter variable. Here, the predetermined time T0 is set to 30 seconds.

  If it is determined in step S104 that the duration of the fully open state does not exceed the predetermined time T0, the process returns to step S101. On the other hand, if it is determined that the duration of the fully open state exceeds the predetermined time T0 (section S2 in FIG. 3), the process proceeds to step S105 to prevent the scope tip from being prevented from heat and quickly resume light quantity adjustment. Therefore, the diaphragm 26 is closed to a predetermined opening K0 that can sufficiently detect the brightness of the subject image and prevents heat. As described above, the opening K of the diaphragm 26 is represented by any level of 0 to 240, and the predetermined opening K0 here represents an opening of 3/4 when fully opened (see FIG. 3). ). In step S106, it is determined whether or not the luminance value Y exceeds the reference luminance value Y0.

  When the distance between the subject and the scope tip returns to the distance assumed in the normal observation state due to various reasons such as resuming the endoscope operation, the intensity of the reflected light from the subject increases and is detected accordingly. The luminance value Y increases (section S3). In step S106, when the luminance value Y exceeds the reference luminance value Y0, it is determined that endoscopic work is being performed, and automatic light control processing is executed (section S4).

  If it is determined in step S106 that the luminance value Y has exceeded the reference luminance value Y0, the process proceeds to step S108, the counter variable is reset to 0, and the process returns to step S101. Thereby, the automatic light control process is started again. On the other hand, if it is determined in step S106 that the luminance value Y does not exceed the reference luminance value Y0, the process proceeds to step S107, and it is determined whether or not the release button 25 has been operated. If it is determined that the cancel button 25 has been operated, the timer is reset in step S108, and the process returns to step S101. On the other hand, if it is determined that the release button 25 has not been operated, the process returns to step S106.

  As described above, according to the present embodiment, the automatic dimming process is executed by opening and closing the diaphragm 26 based on the luminance value Y of the subject image (S101), and the fully opened state of the diaphragm 26 is maintained for a predetermined period T0 (30 seconds). If this continues, the throttle is closed to a predetermined opening K0 to prevent heat and maintained in that state (S105). Thereafter, when the luminance value Y reaches the reference luminance value Y0, the automatic dimming process is resumed (S106, S107). As a result, even if the diaphragm 26 is closed to prevent heat, the automatic light control processing is quickly executed in accordance with the resumption of the endoscope operation.

  Further, since the diaphragm 26 does not close to the fully closed state or close to it at the time of dimming processing, the actual brightness of the subject image, that is, the amount of light to the subject is appropriately detected even during the dimming processing, and automatic dimming processing is performed. When the operation is resumed, the amount of movement of the diaphragm 26 can be reduced, and the brightness can be adjusted quickly.

  For canceling the dimming process, a target luminance value other than the reference luminance value Y0 may be set. For example, the luminance value may be set when halation occurs due to the approach between the tip and the subject. In order to quickly adjust the brightness, when automatic dimming is resumed, the first diaphragm 26 may be configured to narrow down more than the luminance difference. Alternatively, the automatic dimming process may be resumed after a certain period of time has passed after exceeding the reference luminance value Y0. The opening K0 of the diaphragm 26 during the dimming process is arbitrary, and may be set to any opening between 50% and 80% when fully opened, for example. Alternatively, based on the operating environment of the diaphragm, the opening may be set to any one of 1/5 to 4/5 when fully opened. It may be determined based on the correspondence between the aperture of the aperture and the amount of light to the subject, the aperture opening / closing operation range, etc., and if it is determined so that the opening / closing operation converges without divergence when automatic light control processing is resumed Good. Also, regarding the determination of the timing for resuming automatic dimming, pay attention to the amount of change in luminance instead of the luminance value, and when the increase in the amount of change in luminance continues, the brightness of the subject image obtained during endoscopic work is reached. It may be determined that

It is a block diagram of the electronic endoscope apparatus which is 1st Embodiment. It is a flowchart which shows the automatic light control process performed by the light control circuit. It is the graph which showed the luminance value and the aperture opening in time series.

Explanation of symbols

10 Videoscope 14 CCD (Image sensor)
20 processor 22 signal processing circuit 23 dimming circuit 26 aperture 30 monitor

Claims (6)

A video scope having an image sensor;
Signal processing means for generating a video signal based on an image signal corresponding to a subject image read from the image sensor;
In order to maintain the brightness of the subject image displayed based on the video signal at an appropriate brightness, the difference between the brightness value obtained from the image signal and the reference brightness value indicating the appropriate brightness of the subject image Automatic dimming means for adjusting the amount of light to the subject by opening and closing the aperture based on,
When the state in which the diaphragm is substantially fully open continues for a predetermined period, the light reduction means for closing the diaphragm to a predetermined opening,
Endoscopic said automatic dimming means, said aperture, characterized in that adjusting the case where the luminance value in a state of being maintained at a predetermined opening degree reaches the reference brightness value, again amount by driving the diaphragm Mirror device. The automatic light control means is, when resuming the light quantity adjustment, the endoscope apparatus according to claim 1, characterized in that refine the diaphragm than the difference between the reference luminance value and the luminance value.   The endoscope apparatus according to claim 1, wherein the predetermined opening degree is an opening degree in a ratio of approximately 1/5 to 4/5 with respect to the full opening of the diaphragm. So as to maintain the brightness of the subject image at a proper brightness, the subject by opening and closing the aperture based on a difference between the reference luminance value indicating the proper brightness of the luminance value and the object image obtained from the images signals Automatic dimming means to adjust the amount of light to
A dimming unit that closes the aperture to a predetermined opening and reduces the light amount to the subject to a predetermined light amount when the state in which the light amount to the subject exceeds the predetermined light amount continues for a predetermined period;
The automatic light control means is, when the luminance value in a state in which the diaphragm is maintained at the predetermined opening degree has reached the reference brightness value, the endoscope auto-dimming and executes again the light quantity adjustment apparatus. Endoscope device
So as to maintain the brightness of the subject image at a proper brightness, the subject by opening and closing the aperture based on a difference between the reference luminance value indicating the proper brightness of the luminance value and the object image obtained from the images signals Automatic dimming means to adjust the amount of light to
When the state in which the amount of light to the subject exceeds the predetermined amount of light continues for a predetermined period, the diaphragm is closed to a predetermined opening and functions as a dimming means for reducing the amount of light to the subject to a predetermined amount of light,
If the luminance value in a state in which the diaphragm is maintained at the predetermined opening degree has reached the reference brightness value, to perform again the light quantity adjustment, the program for causing to function as the automatic light control means. The automatic light control means, so as to maintain the brightness of the subject image at a proper brightness, the diaphragm based on a difference between the reference luminance value indicating the proper brightness of the luminance value and the object image obtained from the images signals Adjust the amount of light to the subject by opening and closing
The operation method of the endoscope apparatus in which the dimming unit closes the diaphragm to a predetermined opening and reduces the light amount to the subject to a predetermined light amount when the light amount to the subject exceeds the predetermined light amount for a predetermined period. Because
The automatic light control means is, when the diaphragm has reached the reference luminance value is the luminance value in a state of being maintained at the predetermined opening degree, operation method of the endoscope apparatus and executes again the light quantity adjustment .

Images