JPS639286Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light amount control means for illumination light guided by an optical fiber bundle for illuminating a test area in an endoscope, and relates to a device configuration for obtaining a wide light amount control range.

In this type of endoscope, when observing deep inside a body cavity or taking a photograph, an area to be examined is illuminated with light guided from the outside through an optical fiber bundle. by the way,
While photographing requires strong illumination light to enhance the finished effect, it is necessary to illuminate the subject area with such strong illumination light during visual observation, which is performed over a relatively long period of time. This is undesirable as it gives thermal stimulation to the area to be examined.

Therefore, an illumination light amount control means has been adopted that reduces the amount of illumination light by inserting an optical filter into the illumination light path during visual observation, and moves the filter out of the optical path area when taking photographs. In this case, in order to minimize stimulation of the subject by strong illumination light, the filter is moved out in synchronization with the shutter operation for photographing.

In addition, even during visual observation, if the observation surface is too bright, it will not only be dazzling but also reduce the contrast of the examined area and make it difficult to see minute lesions, so depending on the area and condition of the examined area, It is preferable that the brightness of the illumination light (the amount of illumination light) be adjustable. Therefore, if the light source is an incandescent lamp,
Although it is possible to vary the illumination light over a relatively wide range by using dimming means such as controlling the supply voltage, in this case as well, when considering the change in color rendering that is involved in reducing the amount of light, it is necessary to The range is also limited. In particular, when a discharge lamp is used as a light source, the power supply control range while the discharge lamp continues to emit light is limited, and the range in which the amount of illumination light can be controlled is extremely narrow.

Therefore, if it were possible to control the changes in the amount of illumination light and the changes in the amount of light in the discharge lamp light source over a wide range while maintaining good color rendering properties in the incandescent lamp light source, the practical benefits would be enormous.

In response to such practical requirements, the present invention provides a device that can control the amount of illumination light over a wide range.

The illustrated embodiment will be described in detail below.

FIG. 1 is a block diagram showing the circuit configuration of the device of the present invention, in which a light source 2 ( For example, a xenon discharge tube or an incandescent light bulb) is configured so that its power supply can be controlled by the lamp light amount adjustment circuit section 3.

On the other hand, a light intensity adjustment dial (light intensity adjustment member) 4 consisting of an externally operable variable register or the like is configured to be able to vary the control amount of the lamp light intensity adjustment circuit section 3; The adjustment member) 4 is configured to output an operation signal that changes in response to changes in the adjustment state to the comparison circuit section 5. The comparison circuit unit 5 compares and determines the signal value of the operation signal with a preset setting value, and outputs the resulting determination signal to the lamp light amount adjustment circuit unit 3 and a drive circuit unit 7, which will be described later. It's becoming like that.

Then, in the optical path between the light incident end surface of the optical fiber bundle 1 and the light source 2, a passing light amount control section 6a consisting of a group of small holes, a mesh window, an optical filter, etc. is installed in a part of the light shielding blade 6, and a driving circuit section 7 is provided. It is configured so that it can be freely accessed and exited. In addition, this light shielding blade 6
In addition to the above-mentioned passing light amount control section 6a, it is also possible to use another part of its rotating portion as a shutter blade for controlling the optical path to a fully closed or fully open state, and in this case, the above-mentioned The drive circuit section 7 is configured to function as a drive control circuit section for an electromagnetic relay, a pulse motor, a servo motor, or the like having three stable states. Furthermore, in addition to controlling the light amount, it is also possible to use a color filter for changing the color tone of the passing light as the passing light amount control section 6a.

This drive circuit section 7 is placed under the control of a sequence circuit section 8 which can be controlled by a push button operation or the like, and is also configured to be operated by a signal from the comparison circuit section 5. Furthermore, the control signal from the sequence circuit section 8 is also given to the lamp light amount adjustment circuit section 3, so that it operates in synchronization with the drive circuit section 7. In addition, in order to achieve synchronization between the lamp light amount adjustment circuit section 3 and the drive circuit section 7, a signal from the comparison circuit section 5 to the lamp light amount adjustment circuit section 3 is given to the drive circuit section 7. It has been done.

With such a configuration, in the device of the present invention, the amount of light reaching the light incident end face of the optical fiber bundle 1 is determined by the second illustrated characteristic line l ₁
First, the light amount is changed from the maximum light amount region p ₁ to the intermediate region in the light amount variable region p ₁ to p ₃ .
In p ₂ , even if the light amount adjustment dial 4 is operated to control the power supplied to the light source 2 from the lamp light amount adjustment circuit section 3, the amount of light emitted from the light source 2 is adjusted to the characteristic line in FIG.
l Control as shown in ₂ . At this time, the passing light amount control unit 6a does not enter the optical path area between the light source 2 and the light incident end face of the optical fiber bundle 1.

Therefore, the amount of light emitted from the light source 2 directly appears as the amount of light incident on the light incident end face.

Then, the light source light intensity is reduced up to the intermediate region _p2 , which is limited by the specificity of the light source 2 (for example, the discharge light sustaining power in the case of a xenon discharge tube or the decrease in the light source color temperature in the case of an incandescent lamp). When the amount of light emitted is reduced by operating the dial 4, the signal value of the operation signal output from the dial (light amount adjusting member) 4 is compared with the set value in the comparison circuit section 5,
When the operation signal value becomes, for example, less than the set value, a determination signal is output from the comparison circuit section 5 to the drive circuit 7,
In the control operation of the circuit 7, a passing light amount controller 6 is inserted into the optical path between the light source 2 and the incident end surface of the optical fiber bundle 1.
a is caused to enter by the rotating operation of the light shielding blade 6.

At the same time, the previous judgment signal also acts on the lamp light amount adjustment circuit section 3, and the lamp light amount adjustment circuit section 3
However, the control state is suddenly changed from the state in which the control has been performed in the direction of reducing the amount of light emitted to near the initial control state, that is, in the direction of increasing the amount of light emitted.

By this control operation, the amount of passing light controller 6a
With the controlled attenuation of the amount of transmitted light and the increased amount of light emitted from the light source 2, the amount of light incident on the light incident end face is reduced as shown at point p ₂ of the characteristic line l ₁ in Fig. 2. It is possible to control the state continuously or to a state close to this continuously.

Even if the amount of light emitted from the light source 2 is reduced by continuing to operate the light amount adjustment dial 4 (characteristic line l ₃ in FIG. 2), the amount of incident light is changed to
It can be controlled as shown in _l1 .

On the other hand, in addition to operating this light intensity adjustment dial 4,
Under the control of the sequence circuit section 8 by a separate push button operation, etc., from the area p ₁ before and after the entrance/exit of the optical path area of the passing light amount control section 6a in the incident light amount change areas p ₁ to p _3.
It is also possible to selectively determine p ₂ and p ₃ from p ₂ . Furthermore, the action of the sequence circuit section 8 is to control the light source 2 to instantaneously bring it into a high-intensity light emitting state, especially when controlling the shutter operation when the light shielding blade 6 is used as both the passing light amount control section 6a and the shutter blade function. It can also be used for flash operation control.

In this way, the device of the present invention controls the amount of emitted light from the light source in synchronization with moving the passing light amount control member in and out of the optical path of light input to the optical fiber bundle for an endoscope. Even if the light amount control operation is within the light emitting amount control range limited by the specificity of the illumination light amount, it is possible to control the illumination light amount within a wider range than the range. The control range of the amount of illumination light can be determined by using several members that change the transmittance of the passing light amount control member, and by repeating the control of the amount of light emitted several times within that range. It is possible to obtain an illumination light amount change range that is several times larger than the individual amount control range. Further, the passage light amount control member may be moved in and out of the optical path area by manual replacement, or the structure may be such that the amount of light emitted by the light source is changed by sensing the entry of the replaced control member into the optical path area. The amount of illumination light does not necessarily need to change continuously as the control member moves in and out of the optical path area, but may change stepwise.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the device of the present invention, and FIG. 2 is a diagram showing the characteristics of the main parts of the device of the present invention. DESCRIPTION OF SYMBOLS 1... Optical fiber bundle, 2... Light source, 3... Lamp light intensity adjustment circuit section, 4... Light intensity adjustment dial, 5...
... Comparison circuit, 6 ... Light shielding blade, 6a ... Passing light amount control section, 7 ... Drive circuit section, 8 ... Sequence circuit section.

Claims (1)

[Scope of utility model registration request] In an illumination light amount control device for an endoscope in which light from a light source enters the light input end of an illumination fiber optical system for an endoscope, the light amount of the light source is adjusted via a light amount adjustment circuit unit, and the adjustment state is adjusted. a light amount adjusting member that outputs an operation signal for controlling the illumination fiber optics system; a comparison circuit unit that compares and determines the operation signal value output from the light amount adjustment member with a preset setting value and outputs a judgment signal of the result to the light amount adjustment circuit and the drive circuit; When the light intensity of the light source is gradually reduced by operating the adjustment member, the light intensity adjustment circuit increases the light intensity of the light source all at once based on the determination signal from the comparison circuit section, and at the same time, the driving circuit increases the light intensity of the light source. An illumination light amount control device for an endoscope, characterized in that a control member is caused to enter the optical path area.