JP3548238B2 - Light source device for endoscope - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an endoscope light source device that automatically adjusts the brightness of an image captured by a television camera detachably attached to an eyepiece of an endoscope to a certain level.
[0002]
[Prior art]
In this type of endoscope light source device, an illumination light flux supplied to an illumination light guide of an endoscope is controlled so that an average value or a peak value of a video signal output from a television camera maintains a predetermined reference value. Automatically controlling.
[0003]
[Problems to be solved by the invention]
In the conventional light source device for an endoscope as described above, when the television camera is detached from the eyepiece in order to replace the television camera with the eyepiece of the endoscope, the television camera is substantially If not directed to a bright object as described above, the illumination light flux supplied to the light guide of the endoscope will be automatically increased.
[0004]
However, even if the illumination light flux supplied to the light guide increases, the brightness of the video imaged by the television camera does not change, so that the maximum level of the illumination light flux continues to be supplied to the light guide after all.
[0005]
At this time, if the insertion portion of the endoscope is in the patient's body cavity and the exit end of the light guide is relatively close to the mucosal surface, the mucosal surface is burned by the heat of the illumination light. There is a risk.
[0006]
Accordingly, an object of the present invention is to provide a safe endoscope light source device that does not cause a burn accident due to illumination light when the television camera is detached from the eyepiece of the endoscope. .
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a light source device for an endoscope of the present invention is provided with a video signal output from a television camera detachably attached to an eyepiece of an endoscope, and the brightness of the video is input. In the endoscope light source device configured to automatically control the illuminating light beam supplied to the illumination light guide of the endoscope so as to maintain a constant level, the television camera is connected to the eyepiece of the endoscope. A television camera attachment / detachment detection means for detecting whether or not the television camera is attached to the eyepiece; when the television camera is not attached to the eyepiece according to the detection result, the television camera is supplied to the light guide; The illumination light flux is reduced or illumination light is not supplied to the light guide.
[0008]
Note that the television camera attachment / detachment detecting means does not change the average value or the peak value of the video signal for a certain fixed time or more, and during this time, the illumination light flux of the maximum level or a level close to the maximum level is supplied to the light guide. In this case, it may be determined that the television camera is detached from the eyepiece.
[0009]
【Example】
Embodiments will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes an endoscope, and an observation image of a subject 100 formed by an objective lens 3 built in a distal end of an insertion unit 2 is transmitted to an eyepiece unit 5 by an image guide fiber bundle 4. . Reference numeral 6 denotes a light guide fiber bundle for transmitting illumination light for illuminating the subject 100.
[0010]
A small color television camera 10 having a built-in solid-state imaging device is detachably attached to the eyepiece unit 5. The television camera 10 has a built-in camera control unit. After the image is captured by the solid-state imaging device, the video signal of the endoscope observation image processed by the camera control unit is output from the television camera 10 and is output to the television monitor 11. It is sent and the endoscope observation image is displayed there.
[0011]
The light source device 20 for supplying illumination light to the light guide fiber bundle 6 is provided with a movable stop 22 for adjusting the area of the illumination light beam incident on the light guide fiber bundle 6 from the light source lamp 21. The operation is controlled by the microcomputer 25 via the aperture driving circuit 23. Reference numeral 24 denotes a power supply circuit for the light source lamp 21.
[0012]
Further, the video signal output from the television camera 10 is transmitted to the television monitor 11 and is also branched and transmitted to the light source device 20 and input to the averaging circuit 27. The averaging circuit 27 integrates the luminance signal for one screen, outputs the average value, converts the average value into a digital signal by the A / D converter 28, and inputs the digital signal to the microcomputer 25.
[0013]
In the endoscope light source device configured as described above, normally, the endoscope observation image displayed on the television monitor 11 is set so that the average value of one screen of the luminance signal becomes the reference value set by the operator. Of the movable diaphragm 22 is controlled so that the brightness of the movable aperture 22 becomes constant. The state of the movable diaphragm 22 is adjusted, for example, to 100 levels.
[0014]
FIG. 2 is a flowchart showing the contents of software for performing the control by the microcomputer 25, and S indicates a processing step.
Here, first, the average value of the luminance signal values is read (S1), and the average value AV is compared with a set reference value (S2).
[0015]
If the AV matches the reference value, the reading of S1 and the comparison with the reference value of S2 are repeated. If the AV is larger than the reference value, the movable diaphragm 22 is driven in the closing direction by a predetermined amount, and then the reading of S1 is performed. (S3, S4), and if the AV is smaller than the reference value, the movable aperture 22 is driven in the opening direction by a predetermined amount, and then the process is repeated from the reading of S1 (S3, S5).
[0016]
When such processing is being performed, the average value of the luminance signal does not change for a certain period of time (for example, 10 seconds), and the illumination light flux of the maximum level or a level close to the maximum level with respect to the light guide fiber bundle 6 during that time. Is supplied, the microcomputer 25 determines that the television camera 10 has been removed from the eyepiece 5.
[0017]
Then, the movable stop 22 is forcibly stopped down, and a dimming mode is set to reduce the illumination light beam supplied to the light guide fiber bundle 6. If the average value of the luminance signal changes during the dimming mode, the dimming mode is canceled.
[0018]
FIG. 3 is a flowchart showing the contents of software for performing such dimming mode control when the television camera 10 is detached, and is executed, for example, by interrupt processing once per second.
[0019]
Here, first, the previous average value is stored in the variable Pre_AV, and the current average value is stored in the variable AV (S11), and it is determined whether or not the average value of the luminance signal has changed (S12).
[0020]
Therefore, if there is no change in the average value of the luminance signal, it is next determined whether or not the mode is the dimming mode (S13). If the mode is already the dimming mode, the interrupt processing is terminated as it is.
[0021]
If the current mode is not the dimming mode in S13, the state of the movable stop 22 is subsequently checked, and the movable stop 22 is not fully opened and the maximum light flux enters the light guide fiber bundle 6. If not, the interrupt processing is terminated (S14).
[0022]
If the movable diaphragm 22 is fully opened in the determination in S14, the timer counter Time is incremented by "1" (S15), and it is determined whether or not the Time reaches a predetermined duration Set_Time (for example, 10 seconds). (S16).
[0023]
Therefore, if the Time has not reached the predetermined duration, the interrupt processing is terminated. If the Time has reached the predetermined duration, the movable stop 22 is stopped down to a predetermined state and the light beam incident on the light guide fiber bundle 6 is, for example, fully opened. The mode is set to the dimming mode to reduce to half (S17).
[0024]
Subsequently, after waiting for one second until the state of the movable aperture 22 is calmed down (S18), it is determined that the average value of the luminance signal has changed in the next interrupt processing, so that the dimming mode is not immediately released. Then, the average value of the luminance signal after the dimming is written in the variable AV (S19), and the interrupt processing is terminated.
[0025]
If it is determined in S12 that the average value of the luminance signal has changed, it is next determined whether or not the mode is the dimming mode (S20).
[0026]
If it is determined that the mode is already in the dimming mode, the dimming mode is released (S21), the counter Time of the timer is returned to 0 (S22), and the interrupt processing is terminated.
[0027]
It should be noted that the present invention is not limited to the above embodiment. In the case of the dimming mode, the light emission brightness of the light source lamp 21 may be reduced by controlling the power supply circuit of the light source lamp 21. At this time, the illumination light may not be supplied to the light guide fiber bundle 6 at all. Further, the brightness of the video signal output from the television camera 10 may be determined based on the peak value instead of the average value of the luminance signal values.
[0028]
【The invention's effect】
According to the present invention, when the television camera is not attached to the eyepiece of the endoscope, the illumination light flux supplied to the light guide of the endoscope is reduced, or the illumination light is supplied to the light guide. Therefore, when the television camera is detached from the eyepiece, there is no possibility that excessive illumination light is supplied to the light guide to cause a burn accident, and safety is greatly improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a configuration of an embodiment.
FIG. 2 is a control processing flowchart of the embodiment.
FIG. 3 is a control processing flowchart of the embodiment.
[Explanation of symbols]
5 Eyepiece 6 Light Guide Fiber Bundle 10 TV Camera 21 Light Source Lamp 22 Movable Aperture 25 Microcomputer

Claims (2)

A video signal output from a television camera detachably attached to the eyepiece of the endoscope is input and supplied to the endoscope illumination light guide so that the brightness of the video is maintained at a constant level. In an endoscope light source device that automatically controls the illumination light flux to be emitted,
A television camera attachment / detachment detecting means for detecting whether the television camera is attached to the eyepiece of the endoscope is provided, and the television camera is not attached to the eyepiece according to the detection result. A light source device for an endoscope, wherein when in a state, an illumination light flux supplied to the light guide is reduced or illumination light is not supplied to the light guide. The television camera attachment / detachment detecting means is provided when the average value or the peak value of the video signal does not change for a certain period of time or more, and when the illumination light flux of the maximum level or a level close to the maximum level is supplied to the light guide during that time. 2. The light source device for an endoscope according to claim 1, wherein it is determined that the television camera is detached from the eyepiece.

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