JPH07171098A - Light quantity controller of endoscope - Google Patents

Abstract

PURPOSE:To form an optimum image with which an ultrasonic probe is well checkable without more than needed darkening of a screen at the time of using the probe. CONSTITUTION:This light quantity controller of an endoscope capable of introducing the ultrasonic probe 15 into an object to be observed from the front end of the endoscope is provided with a sample-hold circuit 28 which extracts the luminance signal of an endoscope image, a comparator 27, a reference voltage source 29 which sets the reference voltage at the time of not using the ultrasonic probe, a reference voltage source 30 which sets the reference voltage when the probe is used, etc. The reference voltage sources 29, 30 are changed over by the operation signal of the operating knob of the ultrasonic probe. The detected value of the luminance signal is evaluated small when the ultrasonic probe is used according thereto. Since the light quantity control is executed by the detection signal, more than the necessary darkening of the screen is prevented. The signal on the input side of the comparator 27 may be changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light quantity control device for an endoscope,
In particular, the present invention relates to the content of light quantity control when ultrasonic wave transmission / reception is possible in an electronic endoscope.

[0002]

2. Description of the Related Art For example, in an electronic endoscope apparatus, illumination light output from a light source lamp is supplied from the tip to the inside of the body to be observed, and an image inside the body to be observed is displayed on the tip of the electronic endoscope as a scope. Arranged solid-state image sensor, namely CCD (Char
ge Coupled Device). And this CC
The video signal obtained in D is subjected to image processing and supplied to the monitor at the subsequent stage. In the light quantity control device for this endoscope, the light quantity is controlled based on, for example, the luminance signal of the video signal. That is, the output light amount is controlled so that the detected luminance signal is constant, and thus the brightness of the image is kept in a good state.

[0003]

However, in the conventional light quantity control device for an endoscope, when the ultrasonic probe is used, there is a problem that the endoscope image becomes dark. That is, when the ultrasonic probe is introduced into the body to be observed from the tip of the endoscope, the tip of the white ultrasonic probe enters the imaging area of the endoscope, but this white probe reflects the illumination light. Therefore, the image becomes darker than necessary.
Therefore, it becomes difficult to confirm the exact position of the ultrasonic probe.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optimum image which enables the confirmation of the probe to be satisfactorily performed without the screen becoming darker than necessary when using the ultrasonic probe. An object is to provide a light amount control device for an endoscope that can be formed.

[0005]

In order to achieve the above object, the present invention provides a light quantity of an endoscope capable of obtaining an ultrasonic image by introducing an ultrasonic probe from the tip of an endoscope into the body to be observed. The control device is provided with a circuit that detects the brightness of the image captured by the endoscope and evaluates the detection signal of this brightness at different levels when the ultrasonic probe is used and when it is not used. It is characterized in that the evaluation level is switched and the light amount is controlled by a control signal when the ultrasonic probe is projected from the tip.
The conversion of the above evaluation level (photometric evaluation level) is achieved by changing the reference voltage of the comparator or by changing the time constant of the integrating circuit when sampling the detection signal (as the input signal of the comparator). To be done.

[0006]

According to the above construction, when the operation knob of the ultrasonic probe is pushed, for example, the normal evaluation level can be switched to the evaluation level when the ultrasonic probe is used. That is, when the reference value of the comparator is converted, when the ultrasonic probe is used, the reference value is converted in the upward direction, and when the input signal of the comparator is converted, the input signal value is decreased in the integrating circuit. The constants will be changed. Thereby, when controlling the light amount, the brightness of the image when the reflected light from the ultrasonic probe is detected is discounted and detected, and the image is prevented from becoming too dark.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of a light quantity control device for an endoscope according to a first embodiment. In the drawing, an electronic endoscope 10 as a scope is connected to a processor and a light source device via a connector. It is connected to 12. A CCD (solid-state image sensor) 13 is provided at the tip of the electronic endoscope 10, and an endoscope image signal processing circuit 14 for performing image processing such as white balance and gamma correction is connected to the CCD 13. The video signal output from the endoscopic image signal processing circuit 14 is supplied to the monitor.

In the electronic endoscope 10, the ultrasonic probe 15 can be inserted into the treatment instrument insertion channel, and the ultrasonic probe 15 is provided with an operation knob 16. Then, by operating the operation knob 16, the vibrator 17 is driven to project, and ultrasonic waves are transmitted and received by the vibrator 17. A control circuit 18 and an ultrasonic image signal processing circuit 19 are connected to the ultrasonic probe 15,
An operation signal of the operation knob 16 is supplied to the control circuit 18, and the transducer 17 is used in the ultrasonic image signal processing circuit 19.
An ultrasonic image signal is formed on the basis of the reflected echo signal obtained in (3), and this ultrasonic image signal is supplied to the monitor.

Further, a light guide 20 for supplying illumination light is arranged from the electronic endoscope 10 to the processor and the light source device 12, and the processor and the light source device 12 are optically connected to the light guide 20. And the condenser lens 2
2, a diaphragm 23, and a lamp 24 are connected, and a light source control circuit 25 is connected to the diaphragm 23. Therefore, the light amount control circuit 25 drives and controls the diaphragm 23, thereby controlling the amount of light supplied to the light guide 20.

A sample hold circuit 28 for extracting the brightness (Y) signal obtained by the comparator 27 and the endoscope image signal processing circuit 14 is provided in the preceding stage of the light quantity control circuit 25, and the reference of the comparator 27 is provided. Two reference voltage sources 29, 30 and a switch 31 are provided for setting the voltage. The reference voltage source 29 generates a reference voltage Vref1 when the ultrasonic probe 15 is not used, and the reference voltage source 30 generates a reference voltage Vref2 when the ultrasonic probe 15 is used. Vref2 is set higher than the reference voltage Vref1 (Vref2
ref2> Vref1).

The first embodiment has the above-mentioned structure. When the electronic endoscope 10 is used, the lamp 24 is first turned on,
The output light of the lamp 24 is supplied to the light guide 20 via the condenser lens 22. By this light guide 20, the illumination light guided to the tip of the electronic endoscope 10 is irradiated from the tip to the inside of the object to be observed, whereby the image inside the object to be observed is captured by the CCD 13. And this CC
The video signal obtained in D13 is sent to the monitor after the predetermined image processing is completed in the endoscope image signal processing circuit 14.
An image of the inside of the object to be observed is displayed on the monitor.

The sampling and holding circuit 28 samples and holds the luminance (Y) signal obtained by the endoscopic image signal processing circuit 14, and the sample and hold signal (voltage) is input to the comparator 27. It The switching circuit 31 in this case is connected to one reference voltage source 29 side, and the comparator 27
The input voltage from the sample hold circuit 28 is compared with the reference voltage Vref1, and when the output voltage is higher than the reference voltage Vref1, the light quantity control circuit 25 narrows the diaphragm 23, and in the opposite case, the diaphragm 23 is opened. Controlled as.

On the other hand, when the ultrasonic probe 15 is used, the ultrasonic probe 15 is placed at the tip of the electronic endoscope 10 and then the operation knob 16 is pushed to form an ultrasonic image. At the same time, the operation signal of the operation knob 16 is supplied to the control circuit 18, and the control circuit 18 switches the switching circuit 31 to the other reference voltage source 30 side. Therefore, in this case, the reference voltage Vref2 higher than the reference voltage Vref1 is used, and even if the reflected light of the ultrasonic probe 15 increases the brightness of the endoscopic image, the increase amount is small and detected. To be evaluated. As a result, the diaphragm amount of the diaphragm 23 when the ultrasonic probe 15 is used is smaller than that when the ultrasonic probe 15 is not used, and it is possible to prevent the image from becoming dark.

The vibrator 1 of the ultrasonic probe 15
The reflected echo signal obtained in 7 is supplied to the ultrasonic image signal processing circuit 19, where after image processing is performed,
Supplied to the monitor. Therefore, an image of the tomographic plane of the applied portion is displayed on the monitor.

FIG. 2 shows the configuration of the second embodiment of the light quantity control signal detection / evaluation circuit.
In the embodiment, the evaluation level is converted on the input signal side of the comparator 27. That is, as shown in the figure, two sample hold circuits 3 using an integrating circuit are used.
3, 34, a switching circuit 35, and a reference voltage source 36 are provided, and different time constants are set in the integrating circuits of the sample hold circuits 33, 34. The switching circuit 35 connects one sample-hold circuit 33 when the ultrasonic probe 15 is not used and connects the other sample-hold circuit 34 when the ultrasonic probe 15 is used. The constant is set smaller than the time constant of one sample hold circuit 33. Therefore, when the ultrasonic probe 15 is used, the integration amount becomes small even if the luminance signal has the same amount.

According to the second embodiment, in the sample hold circuits 33 and 34, the luminance signal is integrated with different time constants, and when the operation knob 16 of the ultrasonic probe 15 is pushed, switching is performed. Since the circuit 35 selects the sample hold circuit 34, the luminance signal is discounted and detected. Then, in the comparator 27, the output voltage of the sample hold circuit 34 is compared with the reference voltage Vref, and the light amount control described above is executed by the output of the comparator 27. Also in this case, when the ultrasonic probe 15 is used, the luminance signal is evaluated and detected small, and it is possible to prevent the image from being unnecessarily darkened.

The sample hold circuit 3 of the second embodiment.
In 3 and 34, the time constant of the integrating circuit is changed, but not limited to this, it is possible to use another circuit that converts the level of the input signal to the comparator 27.

Further, in the above embodiment, as the control signal indicating that the ultrasonic probe is projected from the tip of the endoscope,
Although the operation signal of the operation knob is used, a state in which the ultrasonic probe actually protrudes from the tip of the endoscope is detected by some sensor, and this detection signal may be used as the control signal.

[0019]

As described above, according to the present invention,
Evaluate the brightness signal of the endoscope, etc. detected for light quantity control at different levels when the ultrasonic probe is used and when not used, and switch to the evaluation level when the ultrasonic probe is used. Since the light amount is controlled, it is possible to prevent the image from being unnecessarily dark due to the reflected light of the ultrasonic probe. Therefore, this probe can be confirmed well on the screen.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a light amount control device for an endoscope according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a detection / evaluation circuit for controlling a light amount according to a second embodiment.

[Explanation of reference numerals] 10 ... Electronic endoscope, 13 ... CCD, 15 ... Ultrasonic probe, 16 ... Operating knob, 17 ... Transducer, 20 ... Light guide, 23 ... Aperture, 25 ... Light quantity control circuit, 27 ... Comparator 28, 33, 34 ... Sample and hold circuit, 29, 30, 36 ... Reference voltage source, 31, 35 ... Switching circuit.

Claims (1)

[Claims] 1. A light amount control device for an endoscope, which is capable of obtaining an ultrasonic image by introducing an ultrasonic probe from the tip of the endoscope into the body to be observed, and controls the brightness of the image captured by the endoscope. Detected, provided with a circuit to evaluate the detection signal of this brightness at different levels when the ultrasonic probe is used and when not used, by the control signal when the ultrasonic probe is projected from the endoscope tip, A light amount control device for an endoscope, wherein the evaluation level is switched to perform light amount control.