JPH0876029A - Light source device for endoscope - Google Patents

Abstract

PURPOSE: To provide a safe light source device for an endoscope in which a burn trouble caused by illuminating light is prevented from occurring in the case of a condition where a television camera is detached from the eyepiece section of the endoscope. CONSTITUTION: A television camera attachment/detachment detecting means 25 for detecting whether the television camera 10 is attached to the eyepiece section 5 of the endoscope or not is provided, so that an illuminating luminous flux supplied to a light guide 6 is decreased or the illuminating light is not supplied to the light guide 6 in the case of the condition where the television camera 10 is not attached to the eyepiece part 5 based on the detection result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope for automatically adjusting the brightness of an image picked up by a television camera detachably attached to an eyepiece of an endoscope to a constant level. The present invention relates to a light source device.

[0002]

2. Description of the Related Art In this type of endoscope light source device,
The illumination luminous flux supplied to the illumination light guide of the endoscope is automatically controlled so that the average value or the peak value of the video signal output from the television camera maintains a predetermined reference value.

[0003]

In the conventional endoscope light source device as described above, the television camera is removed from the eyepiece portion in order to replace the television camera with the eyepiece portion of the endoscope. In the state, unless the television camera is aimed at a considerably brighter object, the illumination luminous flux supplied to the light guide of the endoscope is automatically increased.

However, even if the illumination luminous flux supplied to the light guide increases, the brightness of the image picked up by the television camera does not change, so that the illumination luminous flux of the maximum level continues to be supplied to the light guide. Become.

At that time, if the insertion portion of the endoscope is inside the body cavity of the patient and the exit end of the light guide is relatively close to the mucous membrane surface, the mucous membrane surface is heated by the illumination light. May cause burns.

[0006] Therefore, the present invention provides a safe light source device for an endoscope in which the television camera is detached from the eyepiece portion of the endoscope without the risk of a burn accident due to illumination light. To aim.

[0007]

In order to achieve the above object, the light source device for an endoscope according to the present invention outputs a video signal output from a television camera detachably attached to an eyepiece of the endoscope. In the endoscope light source device, which is configured to automatically control the illumination light flux that is input and supplied to the illumination light guide of the endoscope so as to maintain the brightness of the image at a constant level, the television set A television camera attachment / detachment detecting means for detecting whether or not the 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. In this case, the illumination light flux supplied to the light guide is reduced or the illumination light is not supplied to the light guide.

The television camera attachment / detachment detecting means is
When the average value or the peak value of the video signal does not change for a certain period of time or more, and the illumination light flux of the maximum level or a level close thereto is supplied to the light guide during that time, the television camera causes the eyepiece. You may judge that it has been removed from the section.

[0009]

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 the tip of the insertion section 2 is transmitted to an eyepiece section 5 by an image guide fiber bundle 4. . Reference numeral 6 is a light guide fiber bundle for transmitting illumination light that illuminates the subject 100.

A small color television camera 10 incorporating a solid-state image pickup device is detachably attached to the eyepiece unit 5. The television camera 10 has a built-in camera control unit, and a video signal of an endoscopic observation image processed by the camera control unit after being imaged by the solid-state imaging device is output from the television camera 10 and is displayed on the television monitor 11. It is sent and the endoscopic observation image is displayed there.

The light source device 20 for supplying illumination light to the light guide fiber bundle 6 is provided with a movable diaphragm 22 for adjusting the area of the illumination light beam bundle which is incident on the light guide fiber bundle 6 from the light source lamp 21. However, its operation is controlled by the microcomputer 25 via the diaphragm drive circuit 23. Reference numeral 24 is a power supply circuit for the light source lamp 21.

The video signal output from the television camera 10 is sent to the television monitor 11 and at the same time branched to the light source device 20 and input to the averaging circuit 27. The averaging circuit 27 integrates the luminance signal for one screen and outputs the average value, which is converted into a digital signal by the A / D converter 28 and input to the microcomputer 25.

In the light source device for an endoscope constructed as described above, usually, the one screen average value of the luminance signal becomes the reference value set by the operator, that is, the endoscope displayed on the television monitor 11. The light blocking state of the illumination light beam bundle of the movable diaphragm 22 is controlled so that the brightness of the mirror observation image becomes constant. The state of the movable diaphragm 22 is adjusted in 100 steps, for example.

FIG. 2 is a flow chart 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 A
V is compared with the set reference value (S2).

If AV matches the reference value, S
Repeated reading of 1 and comparison with the reference value of S2
Is larger than the reference value, the movable diaphragm 22 is driven in the closing direction by a predetermined amount, and the reading from S1 is repeated (S3.
S4), if AV is smaller than the reference value, the movable diaphragm 22 is driven in the opening direction by a predetermined amount, and the reading of S1 is repeated (S3, S5).

When such a process is performed, the average value of the luminance signal does not change for a certain period of time (for example, 10 seconds), and during that period, the light guide fiber bundle 6 has a maximum level or a level close to the maximum level. When the illumination luminous flux of 1 is supplied, the microcomputer 25 determines that the television camera 10 is removed from the eyepiece unit 5.

Then, the movable diaphragm 22 is forcibly narrowed down,
The light guide fiber bundle 6 is set to the dimming mode that reduces the illumination light flux supplied to the fiber bundle 6. When the average value of the luminance signal changes in the dimming mode, the dimming mode is released.

FIG. 3 is a flow chart showing the contents of software for controlling the dimming mode at the time of detaching the television camera 10 as described above. For example, the interrupt processing is performed once per second.

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 there is a change in the average value of the luminance signal ( S12).

Therefore, if there is no change in the average value of the luminance signal, it is next judged whether or not it is in the dimming mode (S1).
3) If it is already in the dimming mode, the interrupt processing is ended as it is.

If it is determined in step S13 that the dimming mode is not currently set, then the state of the movable diaphragm 22 is checked, and the movable diaphragm 22 is not fully opened and the maximum light flux is not directed to the light guide fiber bundle 6. If it is not incident, the interrupt processing is terminated as it is (S14).

If the movable diaphragm 22 is fully opened in the determination of S14, the timer counter Time is incremented by "1" (S15) to determine whether Time has reached a predetermined duration Set_Time (for example, 10 seconds). It is determined (S16).

Therefore, if the time has not reached the predetermined duration, the interrupt processing is terminated, and when the time reaches the predetermined duration, the movable diaphragm 22 is narrowed to a predetermined state so that the light flux incident on the light guide fiber bundle 6 is reduced. For example, it is set to a dimming mode in which it is reduced to half of that at full opening (S17).

Then, after waiting for one second until the state of the movable diaphragm 22 has settled down (S18), it is determined in the next interrupt process that the average value of the luminance signal has changed, and the dimming mode is immediately released. The average value of the brightness signal after dimming is written in the variable AV so that it does not exist (S19), and the interrupt process ends.

If the average value of the luminance signal changes in the determination in S12, it is next determined whether or not it is in the dimming mode (S20). If it is not in the dimming mode, the interrupt process is terminated as it is.

If it is already determined that the mode is the dimming mode, the dimming mode is canceled (S21), the counter Time of the timer is reset to 0 (S22), and the interrupt processing is ended.

The present invention is not limited to the above embodiment, and 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 in the dimming mode. In the light mode, no illumination light may be supplied to the light guide fiber bundle 6. 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 brightness signal values.

[0028]

According to the present invention, when the television camera is not attached to the eyepiece of the endoscope, the luminous flux supplied to the light guide of the endoscope is reduced or the light guide is reduced. Since the illumination light is not supplied to the light guide, when the television camera is removed from the eyepiece, there is no possibility that excessive light is supplied to the light guide to cause a burn accident, and safety is significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of an example.

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 diaphragm 25 Microcomputer

Claims (2)

[Claims] 1. An endoscope illumination device for inputting a video signal output from a television camera detachably attached to an eyepiece of an endoscope to maintain the brightness of the image at a constant level. In a light source device for an endoscope adapted to automatically control an illumination light beam supplied to a light guide for television, a television for detecting whether or not the television camera is attached to an eyepiece portion of the endoscope. When the camera attachment / detachment detection means is provided and the detection result indicates that the television camera is not attached to the eyepiece, the illumination light flux supplied to the light guide is reduced or the illumination light is not supplied to the light guide. A light source device for an endoscope characterized by the above. 2. The television camera attachment / detachment detection means is such that the average value or peak value of the video signal does not change for a certain period of time or more, and the illumination light flux of a maximum level or a level close to it is relative to the light guide. The light source device for an endoscope according to claim 1, wherein when supplied, the television camera determines that the television camera is removed from the eyepiece.