JP2000039569A - Light source device for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely prevent the tarnish of a light guide. SOLUTION: An MPU is provided with a CPU 31 performing interruption processing controlling the quantity of light made incident on the light guide by integral and processing in accordance with the output of the various kinds of switches from a panel switch 17, etc., a ROM 32 in which a program for the CPU 31 to perform processing is stored, an RAM 33 for which the CPU 31 reads and writes needed data in the middle of processing performance, an RTC 34 instructing the CPU 31 to perform the interruption processing at a specified time interval, and an analog-digital converter 35 converting a signal (object brightness signal) from the DC circuit 7 of a CCU into a digital signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a light source device for an endoscope,
More specifically, the present invention relates to a light source device for an endoscope, which is characterized in a portion for controlling the amount of illumination light from a lamp.

[0002]

2. Description of the Related Art An endoscope for observing an image of a subject by inserting an elongated insertion portion into a test site such as a lumen is widely used in the medical field, the industrial field, and the like.

In an endoscope, an illuminating light from a light source device is radiated to a test site, an image of the irradiated test site is formed by an observation optical system, and the image is observed with the naked eye from an eyepiece. Or an observation image is obtained by an imaging means.

[0004] In an endoscope device provided with such a light source device, the brightness of an obtained image may vary depending on the distance, width and size of the subject, the state of the subject, and the like. Could not be obtained or obstruct observation. In order to solve this problem, a configuration in which the light intensity of the endoscope image can be controlled by adjusting the amount of emitted light in the light source device according to the brightness of the observation image obtained conventionally and adjusting the amount of illumination light. Has been adopted.

When controlling the brightness of an endoscope image by adjusting the amount of illumination light, the user manually sets the desired brightness and automatically performs the dimming operation by the aperture of the light source device. ing. In other words, when the brightness of the observation screen is brighter than the desired brightness set by the user, the aperture of the light source device is reduced to the desired brightness, and when the brightness of the observation screen is darker, the aperture of the light source device is reduced. It opens to the brightness you want. By using the endoscope device having such a configuration, it is possible to keep the brightness of the observation image almost constant and obtain an image which is always easy to observe.

When the amount of illumination light is adjusted by the above-described method, whether the aperture is to be narrowed or opened is determined by the brightness of the subject image detected by the CCD. During a period in which the brightness is lower than the desired brightness set by the user, the state in which the aperture is fully opened or close to full open is continued. For example, typical cases include a case where the endoscope is suspended at the time of non-inspection, a case where the endoscope is observed at a far point, and a case where the CCD becomes dirty.

[0007] If the stop is kept fully open or close to full open, a large amount of light is incident on the light guide that supplies illumination light to the subject due to the recent increase in the amount of light emitted from the light source lamp. There was a risk of burning.

Therefore, conventionally, Japanese Unexamined Patent Publication No. 9-215659
JP, JP-A-8-24219, JP-A-1-30
In order to solve the above-described problem, if the brightness of the subject to be detected does not change for a predetermined time, as described in Japanese Patent Application Laid-Open No. 31222/1996 and Japanese Patent Application Laid-Open No. 8-76029, the amount of light incident on the light guide is reduced, or No light is incident on the guide. Alternatively, the aperture limits the amount of light incident on the light guide or the amount of light emitted from the light source lamp so that the amount of light does not enter the light guide beyond a predetermined amount of light.

[0009]

However, in the method of controlling the amount of light incident on the light guide if the brightness of the object to be detected does not change for a predetermined time as in the prior art, the method of controlling the light source lamp is difficult. Due to the difference in the maximum light emission amount depending on the type, the light guide may be burned before the predetermined time is reached, and the setting of the predetermined time must be changed according to the maximum light emission amount of the light source lamp. There is a problem that it becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an endoscope light source device that can easily and surely prevent light guide burning.

[0011]

According to the present invention, there is provided an endoscope light source device comprising: an illumination light supply unit for supplying an endoscope having a light guide for transmitting illumination light to a subject; Detecting means for repeatedly detecting at predetermined intervals; and brightness (EE) of the object detected by the detecting means.
_When the brightness of the object (EE _n ) is darker than the target brightness, the aperture for controlling the amount of illumination light is reduced to the target brightness when _n ) is brighter than the target brightness set. In an endoscope light source device having automatic light control means for opening the aperture to a target brightness, and aperture drive means for driving the aperture of the automatic light control means, wherein the object repeatedly detected by the detection means Brightness (EE _n ) and the brightness of the subject (EE _n )
The brightness of the subject detected i times earlier (E
E _ni ) satisfies a predetermined integration start condition, the brightness (EE _n ) of the subject detected at that time is determined by the determination condition “Q
× t = ∫ (k / EE _n ) dt = Q _max (Q = the amount of incident light of the illumination light on the light guide, t = the time of incidence of the illumination light on the light guide, Q _max = the light guide A maximum light amount of the illumination light that does not burn, k = constant), and a light amount limiting unit that limits the light amount of the illumination light incident on the light guide when the determination condition is satisfied. Be composed.

In the light source device for an endoscope according to the present invention, the integration means includes a brightness (EE _n ) of the subject repeatedly detected by the detection means and a brightness (E _n ) of the subject.
E _n ) the brightness (E) of the subject detected i times before
If E _ni ) satisfies the predetermined integration start condition, the brightness (EE _n ) of the object detected at that time is determined by the determination condition “Q × t = ∫ (k / EE _n ) dt = Q _max (Q = Light incident on the light guide, t = incident time of the illumination light on the light guide, Q _max = maximum light quantity of the illumination light that does not burn the light guide, k = constant). By integrating and limiting the light amount of the illumination light to be incident on the light guide when the light amount limiting means satisfies the determination condition, it is possible to easily and surely prevent the light guide from burning.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 7 relate to an embodiment of the present invention. FIG. 1 is a configuration diagram showing a configuration of an electronic endoscope device having a light source device as a light source device for an endoscope, and FIG. FIG. 3 is a block diagram showing the configuration of the MPU of FIG. 1, FIG. 4 is a first flowchart for explaining the operation of the light source device of FIG. 1, and FIG. FIG. 6 is a first explanatory diagram illustrating the operation of the light source device of FIG. 1, and FIG. 7 is a second explanatory diagram illustrating the operation of the light source device of FIG. It is.

As shown in FIG. 1, the electronic endoscope apparatus 1 comprises:
An electronic endoscope 2 inserted into a body cavity, and the electronic endoscope 1
A camera control unit (hereinafter, referred to as CCU) 3 for inputting an output signal of the above and outputting a video signal, and a light source device for an endoscope of the present embodiment for supplying illumination light to the electronic endoscope 1. And a light source device 4.

The CCU 3 is a solid-state image sensor 5 for converting a subject image provided in the electronic endoscope 2 into an electric signal.
And a DC conversion circuit 7 for smoothing the output signal of the preamplifier 6 with an arbitrary time constant.
A signal processing of the output signal of the preamplifier 6 and a monitor 8
And a video processing circuit 9 for outputting a video signal to the video processing circuit.

The light source device 4 supplies illumination light to an incident end face of a light guide 10 provided in the electronic endoscope 1 for transmitting the illumination light to the tip of the electronic endoscope 1. A lamp 11 comprising a main lamp and an emergency light,
A condenser lens 12 between the incident end face of the light guide 10 and the lamp 11 for converging illumination light emitted from the lamp 11 to the incident end face of the light guide 10.
A diaphragm 14 driven by a stepping motor 13 between the lamp 11 and the condenser lens 12 that can arbitrarily change the illumination light flux between the lamp 11 and the condenser lens 12; and a diaphragm driving the diaphragm 14 by controlling the stepping motor 13 It comprises a drive circuit 15 and an MPU (microcomputer) 16 that receives a signal from the DC conversion circuit 7 of the CCU 3 and controls the lamp 11 and the aperture drive circuit 15 and the like.

Further, the light source device 4 includes a panel such as a brightness changeover switch which allows an operator to arbitrarily set the brightness of the observation screen, and a self / hand changeover switch for switching between so-called automatic light control and manual light control. A switch 17 is provided so that a signal from the panel switch 17 is input to the MPU 16.

As shown in FIG. 2, the aperture driving circuit 15
Is configured to include a motor drive circuit section 21 and a pulse control circuit section 22, and the pulse control circuit section 22 responds to an automatic dimming output from the panel switch 17 by using the MPU 16.
From a CPU (central processing circuit) 31 to be described later.
The driving speed of the stepping motor 13 can be changed by receiving a speed signal instructing the driving speed of the stepping motor, converting the signal into a pulse signal having a frequency corresponding to the speed signal, and inputting the pulse signal to the motor driving circuit unit 21. It has become.

However, the pulse control circuit section 22 may be included in the MPU 16 and in this case,
U16 inputs and outputs a signal for instructing opening and closing of the aperture 14 to the motor drive circuit section 21, thereby enabling opening and closing of the aperture 14.

As shown in FIG. 3, the MPU 12 executes an interrupt process for controlling the amount of light incident on the light guide by integration, which will be described later, a process corresponding to various switch outputs from the panel switch 17, and the like. ,
A ROM (read only memory) 32 storing a program for the CPU 31 to execute a process, a RAM (random access memory) 33 for reading and writing data required by the CPU 31 during the process,
An RTC (real-time clock) 34 for instructing the CPU 31 to perform interrupt processing at predetermined time intervals;
And an analog-to-digital converter 35 for converting a signal (brightness signal of a subject) from the DC conversion circuit 7 into a digital signal.

The CPU 31 takes in a digital signal from the analog-to-digital converter 35. At this time, the output signal of the DC conversion circuit 7 is output to the analog-to-digital converter 35 in a range of, for example, 0 to 255. The signal is converted into a digital signal and input to the CPU 31 of the MPU 16.

Table 1 shows target brightnesses corresponding to, for example, five brightness levels (L1, L2, L3, L4, L5) of the brightness of the observation screen adjusted by operating the panel switch 17. The value indicates the target brightness stored in the ROM 32.

[0024]

[Table 1] As shown in Table 1, in the CPU 31 of the MPU 16, the target brightness value (255, 255) corresponding to the target brightness level (L1, L2, L3, L4, L5) specified by the operation of the panel switch 17 by the operator. 128, 64, 32, 1
6) is read from the ROM 32 and, for example, when the operator selects L3 as the target brightness level, the target brightness value “64” is read from the ROM 32 and stored in the RAM 33.

Next, the operation of the embodiment constructed as described above will be described.

In this embodiment, the five digital variables Q, t, Q _MAX , EE _n , and EE _ni are defined as follows. That is, Q: the amount of incident light to the light guide t: the incident time Q _MAX : the maximum value of the amount of light Q × t that does not cause burning of the light guide EE _n : the 8-bit brightness value of the subject input to the MPU 12 at the nth time EE _ni : 8 input to MPU 12 i times before EE _n
This is the brightness value of the subject in bits.

As shown in FIG. 4, in the light source device 4 of the present embodiment, when the power is turned on in step S1, the state when the power was last turned off in step S2, information setting (load), and each unit The endoscope is normal, the electronic endoscope 2
Performs an initial setting operation such as confirmation of whether or not is connected.

Next, in step S3, a lamp lighting signal is output to turn on the lamp 11, and lamp-related processing such as confirmation of whether to turn on the main lamp or the emergency light is executed.

Subsequently, at step S4, the panel switch 1
7 and performs panel-related processing such as setting of automatic light control / manual light control, setting of the brightness level of the subject, driving of the pump and setting of the high / low level thereof, and setting of whether or not to perform transillumination. After the execution, for example, when the automatic light control is selected, the automatic light control processing is executed by another processing in step S5, and the processing of steps S4 and S5 is repeated until the power is turned off. When interrupt processing is instructed at intervals, the following interrupt processing is executed.

In the automatic light control process in step S5, the target brightness value (255, 255) corresponding to the target brightness level (L1, L2, L3, L4, L5) specified by the operation of the panel switch 17 is set. 128, 64, 32, 1
6) is read from the ROM 32 and stored in the RAM 33. The output signal of the DC conversion circuit 7 is converted into a digital signal by the analog-to-digital converter 35, and the brightness value EE _n of the input subject is detected. The aperture driving circuit 15 is controlled so that the value EE _n becomes the target brightness value.

When an interrupt process is instructed at a predetermined time interval from the RTC 34, as shown in FIG. 5, at step S11, when this interrupt occurs, the output signal of the DC conversion circuit 7 is converted by the analog-to-digital converter 35. It is converted into a digital signal for detecting the brightness value EE _n of the object entered.

The brightness value EE _n of the subject at this time is
Are stored in the RAM 33, and the RAM 33 stores up to the brightness value EE _{ni of the} subject written i times ago.
That is, as soon as the written brightness value (digital value) of the subject becomes the data captured i + 1 times earlier,
It is overwritten with the brightness value (digital value) of the subject that has been cleared or captured i times ago.

Next, in step S12, the brightness value EE of the subject captured i times ago stored in the RAM 33
_ni, a brightness value EE _n and the stored and are integrated start condition ROM32 the current captured object (EE _n ≒ E
E _ni , and EE _n ≧ EE _ni , and there is no change in the input signal by operating various switches of the electronic endoscope 2 or the panel switch 17). Light guide 1 in step S13
The integral calculation of the quantity of light Q incident on 0 is performed (Q ′ = (k / E
After calculating E _n ) + Q, Q = Q ′. k: an experimentally determined constant: the arithmetic program is stored in the ROM 32. ), The integration result in step S14 satisfies the light amount limitation condition (Q = Q _MAX , or exceeds Q _MAX :
It is determined whether or not the comparison program is stored in the ROM 32).
Aperture drive circuit 15 based on the control data stored in
To limit the amount of light incident on the light guide 10.

If the integration start condition is not satisfied in step S12 while the flow of FIG. 5 is being performed, the integration is not started in step S16, or the integration is reset if integration is in progress (Q = 0). If the light quantity is being limited in step S15, this is canceled and the next interrupt processing instruction is awaited. If it is determined in step S14 that the integration result does not satisfy the light quantity limiting condition, the next interrupt processing instruction is awaited.

Each time the interrupt processing is instructed at a predetermined time interval from the RTC 34 in this way, the flow shown in FIG. 6 is executed to limit the time until the light quantity incident on the light guide 10 is limited. However, when the amount of light incident on the light guide 10 is large as shown in FIG. 6, the length becomes short, and when the amount of light incident on the light guide is small as shown in FIG. 7, the length becomes long. 6 and 7, i is set to 1 for simplicity.

As described above, in this embodiment, the RTC
At a predetermined time interval from 34, the integral calculation of the light amount Q incident on the light guide 10 is performed, and the integration result satisfies the light amount limitation condition (Q = Q _MAX or exceeds Q _MAX ).
Then, the aperture driving circuit 15 is controlled by the control data stored in the ROM 32 in advance to limit the amount of light incident on the light guide 10, so that the amount of illumination light incident on the light guide 10 is automatically controlled, and it is simple and reliable. Burn of the light guide can be prevented.

[Appendix] (Appendix 1) Illumination light supply means for supplying an endoscope provided with a light guide for transmitting illumination light to the subject, and the brightness of the subject is repeatedly detected at predetermined intervals. Detecting means for controlling the light amount of the illumination light to the target brightness when the brightness (EE _n ) of the object detected by the detecting means is brighter than the set target brightness; When (EE _n ) is darker than the set target brightness, an automatic dimming control means for opening the aperture to the target brightness and an aperture driving means for driving the aperture of the automatic dimming control means are included. in view mirror light source device, the brightness of the subject is repeatedly detected and (EE _n) by the detecting means, the brightness of the brightness (EE _n) from detected before i times the said object of the subject (EE _ni) is, after satisfying a predetermined integration start conditions the brightness of the object to be detected at that time the (EE _n), the determination condition "Q × t = ∫ (k / EE n) dt = Q max (Q = the Light incident on the light guide, t = incident time of the illumination light on the light guide, Q _max = maximum light quantity of the illumination light that does not burn the light guide, k = constant). An endoscope light source device, comprising: an integrating means for performing an integration, and a light amount limiting means for limiting an amount of the illumination light to be incident on the light guide when the determination condition is satisfied.

(Additional Item 2) The predetermined integration start condition is that EE _n ≒ EE _ni , EE _n ≧ EE _ni , and that there is no change in an input signal input to the automatic light control means. The light source device for an endoscope according to Additional Item 1, characterized in that:

(Additional Item 3) The endoscope according to Additional Item 1, wherein if the predetermined integration start condition is not satisfied during the integration by the integration means, the integration is reset. Light source device for mirror.

(Additional Item 4) As a result of the integration by the integration means satisfying the Q _max , the integration start condition is not satisfied while the light quantity incident on the light guide is limited by the light quantity limitation means. 2. The light source device for an endoscope according to claim 1, wherein the light amount limitation by the light amount limitation means is released when the state is reached.

[0041]

As described above, according to the light source device for an endoscope of the present invention, the integrating means uses the brightness of the subject (EE _n ) repeatedly detected by the detecting means and the brightness of the subject (EE _n ). _n ), if the brightness (EE _ni ) of the subject detected i times before the predetermined integration start condition is satisfied, the brightness (EE _n ) of the subject detected at that time is determined by the determination condition “Q
× t = ∫ (k / EE _n ) dt = Q _max (Q = light amount of illumination light incident on the light guide, t = incident time of illumination light on the light guide, Q _max = illumination light that does not burn the light guide) (Maximum light quantity, k = constant) ", and if the light quantity limiting means satisfies the above-mentioned determination condition, the quantity of the illuminating light to be incident on the light guide is limited. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of an electronic endoscope device including a light source device which is a light source device for an endoscope according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a configuration of an aperture driving circuit in FIG. 1;

FIG. 3 is a configuration diagram showing a configuration of an MPU in FIG. 1;

FIG. 4 is a first flowchart illustrating the operation of the light source device of FIG. 1;

FIG. 5 is a second flowchart illustrating the operation of the light source device of FIG. 1;

FIG. 6 is a first explanatory view illustrating the operation of the light source device of FIG. 1;

FIG. 7 is a second explanatory view illustrating the operation of the light source device of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope apparatus 2 ... Electronic endoscope 3 ... CCU 4 ... Light source apparatus 5 ... Solid-state image sensor 6 ... Preamplifier 7 ... DC conversion circuit 8 ... Monitor 9 ... Video processing circuit 10 ... Light guide 11 ... Lamp 12 ... Condenser lens 13 Stepping motor 14 Aperture 15 Aperture drive circuit 16 MPU 17 Panel switch 21 Motor drive circuit 22 Pulse control circuit 31 CPU 32 ROM 33 RAM 34 RTC 35 Analog digital converter

Claims (1)

[Claims] An illumination light supply unit configured to supply an endoscope having a light guide for transmitting illumination light to a subject; a detection unit configured to repeatedly detect brightness of the subject at predetermined intervals; Brightness of the subject detected by the means (EE _n )
When the brightness is higher than the set target brightness, the aperture for controlling the amount of the illumination light is reduced to the target brightness, and when the brightness of the subject (EE _n ) is darker than the set target brightness, the aperture is set to the target. An endoscope light source device having an automatic dimming control unit that opens up to a maximum brightness, and an aperture driving unit that drives the aperture of the automatic dimming control unit, wherein the brightness of the subject is repeatedly detected by the detecting unit. (EE _n ) and the brightness (EE _n ) of the object, i
The brightness (EE _ni ) of the subject detected the last time is
When the predetermined integration start condition is satisfied, the brightness (EE _n ) of the subject detected at that time is determined by the determination condition “Q × t = ∫ (k
/ EE _n ) dt = Q _max (Q = light quantity of the illumination light incident on the light guide, t = incident time of the illumination light on the light guide, Q _max = quantity of the illumination light that does not burn the light guide (Maximum light quantity, k = constant) ", and light quantity limiting means for limiting the light quantity of the illuminating light incident on the light guide when the determination condition is satisfied. Light source device for endoscope.