JP2003180631A - Automatic light control device for endoscope and electronic endoscopic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep the brightness of the image of a subject proper regardless of a video scope to be connected. <P>SOLUTION: A lamp 12, an iris 16, a motor 18, a motor driver 20, a system control circuit 22 including a CPU 24 and a light control circuit 23 are provided in a processor 10. The system control circuit 22 reads the data of the arrangement relation between the object lens 53 and light distribution scope 52 provided to the leading end 60 of the video scope 50 stored in an EEPROM 57. Then, the weighting functions respectively corresponding to a plurality of the areas prescribed by splitting the image of the subject formed on the CCD 54 in the video scope 50 are decided on the basis of the data of the read arrangement relation. The light control circuit 23 calculates the whole brightness value showing the brightness of the whole of the image of the subject on the basis of the weighting functions to drive the iris 16 according to the difference between the whole brightness value and a reference brightness value showing proper brightness. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus equipped with a videoscope having an image pickup device such as a CCD and a processor to which the videoscope is connected, and particularly to a device for illuminating an observation site. The present invention relates to automatic light control for adjusting the amount of light and maintaining the brightness of a subject image observed.

[0002]

2. Description of the Related Art In conventional automatic light control, a typical representative of the brightness of a subject image based on an image signal corresponding to the subject image read from an image pickup device for picking up a subject (observation site) illuminated with illumination light. Brightness (for example, a brightness average value) is calculated, and the illumination light amount is adjusted based on the difference between this brightness value and a reference brightness value representing the proper brightness of the subject image. As the photometric method for calculating the brightness value, there are average photometry for obtaining the average brightness of the entire screen, peak photometry in which a relatively high brightness value in the entire screen is the brightness of the subject image, etc. Select the metering method as required.

[0003]

A video provided with an objective lens for forming an image of a subject on an image pickup device and an illumination lens (a light distribution lens such as a diffusion lens) for irradiating the subject with light emitted from a light guide. The tip specifications such as the diameter of the scope tip vary depending on the site to be observed (stomach, bronchus, large intestine, etc.), and the location of the objective lens and light distribution lens varies depending on the scope tip specifications. . As a result, the amount of light received by the image pickup element also changes due to the difference in the arrangement relationship of the lenses, that is, the difference in the specifications of the tip portion of the connected videoscope. However, conventionally, since the light amount is adjusted by the same photometric method regardless of the connected videoscope, it is not possible to properly detect the brightness of the subject image depending on the lens arrangement at the tip portion, and as a result, the subject There were cases where the brightness of the image could not be maintained properly.

Therefore, according to the present invention, an automatic light control device and an automatic light control device capable of maintaining the brightness of a subject image at an appropriate brightness regardless of the difference in the specifications of the tip of the connected videoscope. An object of the present invention is to obtain an electronic endoscope apparatus including the device.

[0005]

An electronic endoscope apparatus according to the present invention is an electronic endoscope apparatus including a videoscope and a processor, and at least the objective lens and the illumination lens are provided at the tip of the videoscope. An image pickup device is provided, and the videoscope is detachably connected to the processor. Further, a monitor that displays an observation image can be connected to the processor. The electronic endoscope apparatus is provided with a light source for illumination and an image signal processing means, and light emitted from the light source is emitted toward a subject through a light guide usually provided in a videoscope. Is irradiated. However, a light emitting diode (LED) may be provided as a light source at the tip of the scope. The light emitted from the tip of the scope irradiates the entire observation site with the illumination lens provided at the tip of the scope. When the subject is irradiated with light, the reflected light reaches the image pickup device via the objective lens provided at the tip portion, whereby a subject image is formed on the image pickup device. The image signal processing means reads the image signal generated in the image sensor at predetermined time intervals and generates a luminance signal for one frame (or one field).

The electronic endoscope apparatus of the present invention has a scope tip data memory, a photometric system setting means, a photometric means, and a light quantity adjusting means in order to execute automatic light control processing.
The scope tip data memory stores, as data, specifications of the tip of the videoscope, including tip specifications including at least the positional relationship between the objective lens and the illumination lens. However, the arrangement relationship of the lenses indicates a relationship such as the position of the illumination lens with respect to the objective lens (the position of the objective lens with respect to the illumination lens) or the distance from the objective lens to the illumination lens. At the tip, there are two illumination lenses arranged. In this case,
The tip specification is expressed as a relative difference in position and distance of the objective lens with respect to each of the two illumination lenses. The brightness of a subject image formed on an image sensor such as a CCD is affected by the positional relationship of the lenses. For example, depending on the position of the illumination lens, the amount of light received by the image sensor is relatively large in a specific area. There is. As a result, a specific part of the subject image is displayed relatively brighter than other parts. In the present invention, the tip specification data including the illumination characteristic or the light receiving characteristic of the tip is stored in advance and is detected by the tip specification detecting means.
The subject image formed on the image sensor is divided into a plurality of areas, and the photometric method setting means determines a weighting coefficient for each of the plurality of areas according to the detected tip specifications. Regarding the area division (division number or division area), for example, various division formats such as 5 divisions divided into a central area and 4 peripheral areas, 6 divisions, and multiple divisions in a honeycomb shape are available. Applicable.

Since the subject image is divided into a plurality of areas, the brightness of the subject image can be detected by various photometric methods. For example, average photometry, center-weighted average photometry, center-weighted photometry, Spot metering is possible. In this case, the photometric method is changed by changing the weighting coefficient for each of the plurality of areas. In the present invention, the weighting coefficient, that is, the photometric method is determined so that a representative luminance value of the entire subject image is calculated based on an area that is important in detecting the brightness of the subject image among the plurality of areas. The important area depends on the characteristics of the tip of the videoscope, and it is possible that half of the divided area is important, only the peripheral area is important, or all areas are important as luminance information. There are some cases. The difference between this important area and other areas is that when the overall brightness value of the subject image is calculated in consideration of the partial brightness values of the unimportant area, it is calculated as a lower brightness value or a higher brightness value than necessary, There is a point that wrong light amount adjustment is executed. And
The photometric means detects a plurality of partial luminance values representing the brightness of the image in each of the plurality of areas from the luminance signal, and multiplies the plurality of partial luminance values by a corresponding weighting coefficient to obtain a plurality of partial luminance values. An overall brightness value representing the overall brightness of the subject image for one frame (one field) is calculated. Regarding the calculation of the total luminance value, for example, the photometric means calculates the total luminance value by dividing the total sum of the partial luminance values multiplied by the weighting coefficient by the number of a plurality of areas.

By determining the weighting coefficient in accordance with the characteristics of the tip portion, it is possible to calculate the overall luminance value by emphasizing the partial luminance value of a specific area among a plurality of areas, and to make the weighting uniform. It is also possible to calculate the overall brightness value. That is, the overall brightness value can be calculated based on the partial brightness value that is important as the brightness information from the positional relationship between the objective lens and the illumination lens. Then, the light amount adjusting means adjusts the light amount of the light applied to the subject based on the overall brightness value. For example, the difference between the reference value that represents a proper brightness value as the brightness and the overall brightness value may be calculated, and the diaphragm or the like may be driven based on the difference to adjust the light amount.

For example, when a specific portion of a subject image becomes relatively brighter than other portions due to the influence of the tip portion specification, the luminance information of the area of that portion is important luminance information. If the overall brightness value is calculated based on the brightness information of the dark area, the aperture is opened more than necessary, the amount of light received by the image sensor is increased, and the observed subject image becomes excessively bright. Therefore, it is preferable that the photometric method setting unit sets the weighting coefficient of the high brightness area in which the partial brightness value becomes a high brightness value due to the tip end characteristic to a larger value than the weighting coefficients of other areas. The weighting coefficient of each area is determined so that the weighted average photometry can be executed by setting the weighted area in the high brightness area. The photometric means calculates the overall brightness value according to the determined weighting coefficient.

On the other hand, depending on the specifications of the tip, there may be no difference in the brightness value in the entire subject image. (For example, when two illumination lenses are arranged at the tip and an objective lens is arranged between them). Since the average photometry is desirable as the photometry method at this time, the photometry method setting means sets the weighting coefficients of the plurality of areas equal to each other, and the photometry means calculates the overall luminance value by the average photometry.

In many videoscopes, a forceps channel into which a treatment instrument for treating an observation site is inserted is formed, and a forceps port is formed at the distal end of the scope. Therefore, when the treatment instrument is protruding from the forceps port, the image of the treatment instrument is displayed on the monitor together with the image of the observation site. When the treatment instrument, which is a metal member, comes out of the forceps port, the light reflected by the treatment instrument causes the portion corresponding to the image of the treatment instrument to have a very high brightness, which causes so-called halation. When automatic light control is performed on the basis of this high-brightness information, other parts become darker than necessary. Therefore, the arrangement relationship of the forceps port formed at the tip with respect to the objective lens and the illuminating lens is stored in the scope tip data memory in advance as data, and the photometric method setting means sets the forceps in a plurality of areas according to the tip specifications. It is desirable to select a forceps mouth area where the image of the treatment instrument protruding from the mouth appears, and the photometric means determines whether or not the partial luminance value of the forceps mouth area is larger than the boundary luminance value according to the occurrence of halation. When the partial brightness value of the forceps opening area is larger than the boundary brightness value, it is considered that the treatment instrument is used, and the photometric means calculates the overall brightness value from the partial brightness value detected in the area other than the forceps opening area. .

The image of the tip of the treatment instrument often appears near the corner of the screen of the monitor. Therefore, it is desirable that the subject image formed on the image sensor is radially divided with the center of the subject image as a reference. That is, the entire subject image is divided into a plurality of divided areas with the radiation from the center as the boundary line.

Regarding the weighting coefficient, the weighting coefficient suitable for the tip specifications of each video scope that can be connected to the memory in the processor is stored in the memory in advance, and the photometric system setting means causes the tip of the connected video scope. It is preferable to read the data of the weighting coefficient according to the partial characteristic.

An automatic light control device for an endoscope according to another aspect of the present invention has an image pickup device, includes a videoscope to be inserted into the body, and a processor to which the videoscope is connected. It is incorporated into an electronic endoscope apparatus having an illuminating light source that emits light and a signal processing unit that processes an image signal according to a subject image read from an image sensor to generate a luminance signal. Then, the light control device detects a tip end specification of the videoscope, and a scope tip data memory in which a tip end specification including at least the positional relationship between the objective lens and the illumination lens is stored as data in the tip end of the videoscope. And a weighting coefficient for each of a plurality of areas defined by dividing the subject image formed on the image sensor according to the tip specification detected by the tip specification detecting means. From the plurality of partial luminance values, the setting means and the plurality of partial luminance values representing the brightness of the image in each of the plurality of areas are detected from the luminance signal, and the plurality of partial luminance values are multiplied by the corresponding weighting factors. A photometric means for calculating an overall brightness value representing the brightness of the entire subject image,
And a light quantity adjusting means for adjusting the quantity of light to be sent to the inside of the body based on the overall brightness value. Alternatively, an electronic endoscope apparatus according to another aspect of the present invention includes a videoscope having at least an objective lens, an illuminating lens, and an image pickup device at a tip thereof, and a processor to which the videoscope is detachably connected. An electronic endoscope apparatus, in which an area forming a subject image is divided into a plurality of areas, a priority area is determined from the plurality of areas according to the tip specifications, and the priority area is emphasized compared to other areas. Brightness calculation means for calculating the overall brightness value of the subject image,
And a light amount adjusting means for adjusting the light amount of the light radiated toward the subject based on the overall brightness value.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An electronic endoscope apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an electronic endoscope apparatus according to this embodiment. An electronic endoscopic device including a videoscope and a processor is used when performing an internal examination such as a stomach or performing an operation, and when the examination is started, the videoscope is inserted into the internal body. .

The electronic endoscope apparatus is provided with a videoscope 50 having a CCD (Charge-Coupled Device) 54 which is one of image pickup devices, and a processor 10 for processing an image signal read from the CCD 54. A monitor 32 that displays is connected to the processor 10. The video scope 50 is detachably connected to the processor 10, and a keyboard 34 is connected to the processor 10 in addition to the monitor 32.

When a lamp power switch (not shown) is turned on, the lamp power supply section 11 including the lamp control circuit 11A.
Power is supplied to the lamp (light source for illumination) 12 from the lamp 12, whereby light is emitted from the lamp 12. The light emitted from the lamp 12 is incident on the incident end 51 a of the optical fiber bundle 51 provided in the videoscope 50 via the condenser lens 14.
Incident on. The optical fiber bundle 51 is a bundle of ultra-fine optical fibers that transmits the light emitted from the lamp 12 to the tip portion 60 of the videoscope 50 having the observation site,
The light that has passed through the optical fiber bundle 51 is emitted from the emission end 51b. As a result, the light distribution lens 52, which is a lens for illumination,
The observation site S is irradiated with light via. A forceps channel 58 is formed in the videoscope 50, and a treatment instrument (not shown here) is inserted into the forceps channel 58 when treating an observation site. Further, in addition to the forceps channel 58, a pipe (not shown) for supplying air and water is also formed in the videoscope 50.

The light reflected at the observation region S reaches the light receiving region of the CCD 54 through the objective lens 53, whereby a subject image of the observation region S is formed in the light receiving region of the CCD 54. In the present embodiment, the simultaneous single plate type is applied as the color image pickup method, and yellow (Ye), cyan (Cy), magenta (Mg), and green (G) color elements are in a checkered pattern on the light receiving surface of the CCD. Complementary color filters (not shown) arranged in line are arranged so as to correspond to the respective pixel positions in the light receiving region. Then, in the CCD 54, an image signal of a subject image corresponding to a color passing through the complementary color filter is generated by photoelectric conversion, and an image signal for one frame or one field is sequentially read out at a predetermined time interval according to the color difference line sequential method. . In this embodiment, the NTSC system is applied as the color television system,
Image signals for one frame (one field) are sequentially read out at intervals of 1/30 (1/60) seconds and sent to the initial signal processing circuit 55.

In the initial signal processing circuit 55, various processes including white balance and gamma correction are performed on the color image signal to generate a luminance signal and a color difference signal as a video signal. In addition, the initial signal processing circuit 55,
A CCD driver (not shown) for driving the CCD 54 is included, and a drive signal is output from the CCD driver to the CCD 54. The generated video signal is sent to the processor signal processing circuit 28, and the luminance signal included in the video signal is also sent to the dimming circuit 23. A synchronization signal or the like is sent to the dimming circuit 23 at a predetermined timing in accordance with a luminance signal for one frame (one field) that is sequentially sent to the dimming circuit 23.

In the processor signal processing circuit 28, the video signal sent from the initial signal processing circuit 55 is subjected to predetermined processing. The processed video signal is a monitor 3 as a video signal such as an NTSC composite signal, a Y / C separated signal (so-called S video signal), an RGB separated signal, or the like.
2 and the subject image is displayed on the monitor 32.

The system control circuit 22 includes a CP
U24, ROM25, RAM26 are included, CP
U24 controls the entire processor 10 and controls the dimming circuit 2
3, lamp control circuit 11A, processor signal processing circuit 2
The control signal is output to each circuit such as 8. In the timing control circuit 30, a clock pulse for adjusting the processing timing of the signal is output to each circuit in the processor 10, and a synchronizing signal accompanying the video signal is sent to the processor signal processing circuit 28. The ROM 25 in the system control circuit 22 stores in advance a program for controlling the entire electronic endoscope apparatus and data of a dimming table described later.

A diaphragm 16 is provided between the incident end 51a of the light guide 51 and the condenser lens 16 for adjusting the amount of light applied to the subject S, and is opened and closed by driving a motor 18. In this embodiment, the DSP (Digital
By the dimming circuit 23 composed of the Signal Processor),
The light amount of the light passing through the diaphragm 16, that is, the light irradiated to the subject S is adjusted. The brightness signal output from the initial signal processing circuit 55 is converted into a digital brightness signal by an A / D converter (not shown), and then input to the dimming circuit 23. As will be described later, the subject image formed on the CCD 54 is divided into a plurality of areas, and the light control circuit 23 calculates a brightness value for each area based on the brightness signal sent thereto, and further, the brightness value is calculated. Based on the calculated brightness value, a representative brightness value corresponding to the brightness of the entire subject image is calculated. According to the overall brightness value, the dimming circuit 2
A control signal is sent from 3 to the motor driver 20, and the motor 18 is driven by the motor driver 20. As a result, the diaphragm 16 opens to a predetermined opening.

Inside the video scope 50, there are provided a scope control unit 56 for controlling the entire video scope 50, and an EEPROM 57 in which data relating to the video scope 50 including characteristics of the distal end portion of the scope is previously stored. The data on the specifications of the scope tip includes
The number and size of pixels of the CCD 54, the positional relationship between the light distribution lens 52 and the objective lens 53, and the forceps channel 58.
The data regarding the arrangement of the forceps port 59A formed at the tip of the is included. The scope control unit 56 controls the initial signal processing circuit 55 and reads scope-related data from the EEPROM 57. When the video scope 50 is connected to the processor 10, data is transmitted and received between the scope control unit 56 and the system control circuit 22, and the scope-related data is transferred to the system control circuit 2.
Sent to 2. As will be described later, the light control circuit 23 performs automatic light control based on the specification data of the sent scope tip.

The front panel 46 is provided with a setting switch 46A for setting a reference luminance value which is a standard in automatic light control. When an operator operates the switch, a signal corresponding to the operation is sent to the system control circuit. Sent to 22. The reference brightness value data is temporarily stored in the RAM 26 and is sent from the system control circuit 22 to the dimming circuit 23 as needed. When a key operation is performed on the keyboard 34 to display character information on the monitor 32, a signal corresponding to the operation of the keyboard 34 is input to the system control circuit 22, and based on the signal, a character signal is displayed in the processor signal processing circuit 28. Superimposed on the signal.

FIG. 2 shows the tip 60 of the videoscope,
FIG. 9 is a diagram showing a subject image displayed on the monitor 32 when a treatment instrument is used through the forceps channel 58. The characteristics of the tip portion 60 will be described with reference to FIG.

Usually, in the videoscope, the arrangement of the objective lens and the light distribution lens at the tip of the scope differs depending on the difference in observation symmetry. For example, in a videoscope for observing the lower gastrointestinal tract such as the large intestine, since the scope has a large diameter, in addition to the forceps channel, it is necessary to stain and clean the air supply and water supply nozzles for cleaning the outer surface of the lens and the observation site. Water jet nozzles are formed in the scope, and the positions of the objective lens and the light distribution lens at the tip end are affected by these nozzles. On the other hand, in the case of a videoscope for the upper digestive tract for observing the bronchus or esophagus, the scope has a small diameter and the positions of the objective lens and the light distribution lens are limited. In this way, the specifications of the tip of the scope differ depending on the type of video scope. In this embodiment, two videoscopes 50 for the upper digestive tract and the lower digestive tract are prepared, the videoscope 50 for the upper digestive tract is represented as a type A videoscope, and the videoscope 50 for the lower digestive tract is a type B videoscope. Expressed as a scope.

In the case of the type A videoscope 50, the light guide 51 is branched in two directions near the tip portion 60 of the videoscope 50, and as shown in FIG.
The light distribution lens 52 includes two light distribution lenses 52A and 52B. In addition to the forceps port 59A, the tip 60 is provided with an air supply / water supply port 61. The objective lens 53 is
The light distribution lenses 52A and 52B are arranged between the light distribution lenses 52A and 52B, and the light distribution lenses 52A and 52B are arranged at symmetrical positions with the objective lens 53 interposed therebetween. Therefore, the objective lens 53
It can be said that the amount of light received by the CCD 54 arranged in the rear is substantially uniform over the entire light receiving region. On the other hand, in the case of the type B video scope 50, the type A video scope 5
As with 0, the two light distribution lenses 52A and 52B are attached to the tip portion 6
Although the light distribution lenses 52A and 52B are provided at positions asymmetrical with respect to the objective lens 53, the distance from the light distribution lens 52A to the objective lens 53 is from the light distribution lens 52B to the objective lens 53. Short compared to the distance.
On the other hand, the amount of illumination light from the light distribution lens 52B is larger than the amount of illumination light from the light distribution lens 52A due to the difference in the size of the aperture diameter. Therefore, in the light receiving area of the CCD 54, the light receiving amount of a certain specific area becomes relatively large. Also,
Two air supply and water supply ports 61 are formed in the tip portion 60, one is used for water supply and the other is used for air supply.

As described above, the amount of light received by the CCD 54 changes depending on the positional relationship between the objective lens 53 that forms the subject image and the light distribution lenses 52A and 52B through which the light that illuminates the observed portion of the subject passes. To do. Therefore, the brightness (luminance value) of the subject image detected by the light control circuit 23 also changes depending on the characteristics of the tip portion. Therefore, in the present embodiment, as will be described later, the brightness of the subject image is detected according to the characteristics of the scope tip portion 60.

Further, the position of the forceps port 59A in the distal end portion 60 also differs for each scope, and therefore the position of the image of the treatment instrument distal end portion 59 that appears when the treatment instrument is used also differs for each scope. As shown in FIG. 2, type A
In the case of, the distal end portion 59 of the treatment instrument is projected on the left corner of the monitor 32, and in the case of type B, it is projected on the upper portion of the monitor 32. The display position of the treatment instrument distal end portion 59 depends on the positional relationship between the objective lens 53 and the forceps port 59A. In the present embodiment, as will be described later, when a treatment instrument is used, the brightness of the subject image is detected in consideration of the image portion of the treatment instrument tip portion 59.

FIG. 3 is a main routine showing a process for controlling the overall operation of the processor executed by the CPU 24 of the processor 10. Further, FIG. 4 is a diagram showing divided areas of a subject image. Main power switch (not shown)
When is turned on, the process is started.

In step 101, the diaphragm position and the like are initialized. In step 102, the videoscope 50
Is connected to the processor 10. If it is determined that the video scope 50 is connected, the process proceeds to step 103. On the other hand, videoscope 50
If it is determined that the is not connected, the repeating step 102 is executed.

In step 103, the videoscope 50
Scope-related data including characteristic data of the tip of the scope is read out from the EEPROM 57 inside. And
In step 104, the value of the weighting coefficient is determined based on the read characteristic data of the tip portion.

As shown in FIG. 4, the light receiving area 54A of the CCD 54 on which the subject image is formed is divided into 12 areas, which are respectively represented by area 1, area 2, ... Area 12. . In the present embodiment, the light receiving area 54A is set to 1 by drawing a boundary line radially from the center point CP.
When the video scope 50 is connected, the value of the weighting coefficient W (x) (x = 1, 2, ... 12) of each area according to the scope type is determined. . The value of the weighting coefficient W (x) differs depending on the type of the videoscope 50, and in the present embodiment, the weighting coefficient W (x) is stored in the ROM 25 in advance as dimming table data.

When the type A videoscope 50 is connected, the objective lens 53 is sandwiched between the light distribution lenses 52A and 5A.
2B is in a symmetrical position, and the amount of light received by the CCD 54 is substantially uniform over the entire light receiving area. Therefore, the brightness value of the entire subject image is calculated in consideration of the brightness values of the areas 1 to 12 (hereinafter, referred to as partial brightness values).
The weighting factors W (x) of each area are all set to the same value. This indicates that in the case of the type A videoscope 50, the overall brightness value is calculated by so-called average photometry. Here, the values of the weighting factors W (x) are all set to 1.

On the other hand, when the type B videoscope 50 is connected, the light distribution lenses 52A and 52B are asymmetric with respect to the objective lens 53, and as a result, the light receiving amount of a specific portion of the light receiving area 54A is different. The amount is larger than that in the region, and on the contrary, the amount of received light in the other regions is small. Here, the amount of light received in area 5, area 6, and area 7 (see FIGS. 2 and 4) is smaller than in other areas. Therefore, the value of the weighting coefficient W (x) of the area 1, the area 11, and the area 12 is set to be smaller than the value of the weighting coefficient W (x) of the other area, as shown below. W (x) = 1.2 (x = 1 to 4, 8 to 12) (1) W (x) = 0.8 (x = 5, 6, 7) (2) This is a type B videoscope. In the case of 50, areas other than area 5, area 6, and area 7 are set as important areas,
It indicates that the overall luminance value is calculated by so-called weighted average photometry. Tip 6 of the connected videoscope 50
The data of the weighting coefficient W (x) corresponding to 0 is stored in the ROM 25.
When it is read from, it is sent to the light control circuit 23. Also,
In step 104, the area data corresponding to the position of the forceps opening 59A is sent to the light control circuit 23 based on the data regarding the arrangement of the forceps opening 59A included in the scope-related data, as described later. When step 104 is executed, the process proceeds to step 105.

In step 105, it is determined whether the video scope 50 has been removed for replacement with another type of video scope. If it is determined that the video scope 50 has been removed, the process returns to step 102. On the other hand, when it is determined that the video scope 50 has not been removed, the process proceeds to step 106, and other processes such as a process related to keyboard operation and a time display process are executed. When step 106 is executed, step 1
Return to 05. Steps 102 to 106 of the main routine
Is repeatedly executed until the power is turned off.

FIG. 5 is an interrupt routine showing the automatic light control processing executed in the light control circuit 23. The interrupt routine shown in FIG. 3 corresponds to the time interval (1/30 seconds) for reading the image signal for one frame. It is processed by interrupting the routine.
The brightness value represented in the present embodiment represents a brightness level represented in the range of 0 to 255.

At step 201, it is judged if the halation occurrence state variable KM is 0 or not. The halation occurrence state variable KM is a state in which the distal end portion 59 of the treatment instrument projects from the forceps port 59A of the scope distal end portion 60, so that the luminance value of the area where the image of the image treatment instrument tip portion 59 is projected becomes high. That is, it is a variable indicating a state in which halation is substantially occurring or can be regarded as being occurring, and when halation is occurring due to the use of the treatment instrument, KM = 1 is set, while the treatment instrument is Is not used and halation has not occurred, KM = 0 is set. When it is determined in step 201 that the halation occurrence state variable KM is 0, the process proceeds to step 202.

FIG. 6 is a subroutine of step 202.

In step 301, the location of the area defined by division and the division number D in the light receiving area 54A are set. In the present embodiment, the light receiving area 54A is divided into areas 1 to 12 as shown in FIG. 4, and the division number D is 12. In step 302, the reference brightness value Vref set by the operator or default is read. Here, the reference brightness value Vref is set to 128. In step 303,
Weighting coefficient W (x) of each area (x = 1, 2, ...
The value of 12) is set according to the weighting coefficient data sent from the system control circuit 22. In the case of the type A videoscope 50, the weighting coefficient W
(X) are all set to 1, and in the case of the type B videoscope 50, the weighting factor W is calculated by the equations (1) and (2).
The value of (x) is determined. When step 303 is executed, the process proceeds to step 304.

In step 304, partial brightness values A (x) (x = 1, 2, ... 1) representing the brightness average value of each area.
2) is calculated. The partial brightness value A (x) is calculated by dividing the sum of the brightness values of the pixels in the corresponding area A (x) by the number of pixels in the area (x). In step 305, the sum of luminances SUM (= ΣW) obtained by summing the products W (x) · A (x) of the weighting coefficient W (x) in each area and the partial luminance value A (x) for all areas 1 to 12
(X) × A (x)) is calculated.

Then, in step 306, the total luminance S
UM is divided by the number of areas D (= 12), and the overall brightness value Vr is calculated as a representative brightness value indicating the brightness of the entire subject image. When step 306 is executed, the process proceeds to step 307.

At step 307, the difference ΔV between the overall luminance value Vr and the reference luminance value Vref is obtained. Then, in step 308, a control signal is sent to the motor driver 20 based on the obtained brightness difference ΔV. This allows
The diaphragm 16 is driven by a predetermined amount so that the brightness difference ΔV is eliminated. When step 308 is executed, this subroutine ends, and the process returns to step 202 in FIG.

On the other hand, when it is judged in step 201 of FIG. 5 that the halation occurrence state variable KM is 1,
Move to step 203.

FIG. 7 shows a subroutine of step 203.

Execution of steps 401 to 403 corresponds to execution of steps 301 to 303 in FIG. That is,
Areas, the number of areas, the reference brightness value Vref, and the weighting coefficient W (x) of each area are defined. In step 404, the weighting coefficient W (e) of the forceps opening area AK in which the treatment instrument tip portion 59 is displayed on the screen in the areas 1 to 12 is set to 0. When step 405 is executed, the process proceeds to step 406.

The execution of steps 406 to 410 is the same as the execution of steps 304 to 308 of FIG. 6, respectively. That is, the overall brightness value Vr is calculated, and the diaphragm 16 is driven based on the brightness difference ΔV between the brightness average value Vr and the reference brightness value Vref. However, in the calculation of the overall brightness value Vr, the product of the partial brightness value A (x) of the forceps opening area AK and the corresponding weighting coefficient W (e) becomes zero. Therefore, the overall brightness value Vr is not affected by the partial brightness value in the forceps opening area AK. When step 410 is executed, this subroutine ends and step 20 in FIG.
Return to 3.

When step 202 or step 203 is executed, the process proceeds to step 204. In step 204, it is determined whether the partial brightness value A (x) of the forceps opening area AK is larger than the boundary brightness value Vb. As described above, the forceps opening area AK represents an area in which the image of the treatment instrument distal end portion 59 appears in the areas 1 to 12, and, for example, in the case of the type A videoscope 50, the area 4 is displayed.
The treatment instrument tip 59 is displayed on the screen, and in the case of the type B videoscope 50, the treatment instrument tip 59 is displayed in the area 2.
Is displayed (see FIGS. 2 and 4). The position of the forceps port 59A where these treatment instrument tip portions 59 appear is previously stored as data in the EEPROM 57,
When the videoscope 50 is connected to the processor 10, it is read in step 103 of FIG.
In step 104, the data of the forceps port area AK corresponding to the position of the forceps port 59A is sent to the light control circuit 23 together with the data of the weighting coefficient W (x). The boundary brightness value Vb is a threshold value in which the halation occurs, and the partial brightness value A (x) of the forceps opening area AK when the light is reflected by the metallic treatment instrument tip 59 is equal to or more than the boundary brightness value Vb. If the treatment device is used, it is considered that halation is occurring. Here, the boundary brightness value Vb is 220.

In step 204, the partial brightness value A (x) of the forceps opening area is larger than the boundary brightness value Vb, that is, the distal end portion 59 of the treatment instrument projects from the distal end portion 60, so that the forceps opening area AK is compared with other areas. When it is determined that the state is the high brightness state, the process proceeds to step 205 and the halation occurrence state variable KM is set to 1. As a result, step 203 is executed in the next light amount adjustment process. On the other hand, when it is determined in step 204 that the partial brightness value A (x) of the forceps opening area is not larger than the boundary brightness value Vb, that is, the treatment instrument is not used, the process proceeds to step 206, and the halation occurrence state variable KM is set. Set to 0. As a result, step 202 is executed in the next light amount adjustment. When step 205 or step 206 is executed, this interrupt routine ends.

As described above, according to this embodiment, the specification data regarding the tip portion 60 of the video scope 50 is read in step 103, and the weighting coefficient W (x) is determined in step 104. Then, the partial luminance value A (x), and further the entire luminance value Vr are calculated based on each weighting coefficient W (x). Then, based on the brightness difference ΔV between the overall brightness value Vr and the reference brightness value Vref, the diaphragm 1
6 is driven.

In the present embodiment, two types A and B of video scopes 50 are connected, but other types, that is, video scopes having specifications other than the specifications of the tip portion shown in FIG. 2 are connected. You may allow it. In this case, a weighting coefficient W suitable for the tip end characteristic
(X), that is, the photometric method (spot photometry, etc.) is set. Further, when the number of pixels of the image pickup element is different from the number of pixels forming the subject image displayed on the screen, the division area and the number of divisions may be set for the displayed subject image.

The data of the weighting coefficient W (x) may be stored in advance in the EEPROM 57 instead of the ROM 25 in the processor 10. In this case, the data of the weighting coefficient W (x) is directly read and the overall brightness value is calculated based on the data.

The number of the light distributing lenses 52 is not limited to two, and may be a single unit. Further, the typical overall brightness value Vr representing the brightness of the entire subject image may be calculated by a method other than the above-described calculation method (steps 306 and 406). The same applies to the partial luminance value A (x).

In the present embodiment, the lamp 12 as a light source and the signal processing circuit are integrated in the processor 10, but the light source device and the signal processing device are separately prepared. You may.

[0056]

As described above, according to the present invention, the brightness of a subject image can be maintained at an appropriate brightness regardless of the connected videoscope.

[Brief description of drawings]

FIG. 1 is a block diagram of an electronic endoscope apparatus according to the present embodiment.

FIG. 2 is a diagram showing an image of an observation site displayed together with a scope tip and a treatment instrument.

FIG. 3 is a diagram showing a main routine of an operation of the entire electronic endoscope apparatus.

FIG. 4 is a diagram showing a plurality of divided areas.

FIG. 5 is a diagram showing an interrupt routine of automatic light control processing.

FIG. 6 is a subroutine of the light amount adjustment processing of FIG.

FIG. 7 is a subroutine of a light amount control process in consideration of the forceps port of FIG.

[Explanation of symbols]

10 processors 12 lamps (light source for lighting) 16 aperture 18 motor 20 motor driver 22 System control circuit 23 Light control circuit 24 CPU 25 ROM 26 RAM 50 video scope 52 Light distribution lens (lighting lens) 53 Objective lens 54 CCD (imaging device) 55 Initial signal processing circuit 57 EEPROM (Scope tip data memory) 58 forceps channel 59 Treatment instrument tip 59A forceps mouth 60 Tip of scope A (x) partial brightness value W (x) Weighting coefficient Vr overall brightness value Vref reference brightness value

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/238 H04N 5/238 Z (72) Inventor Kenichi Iriyama 2-36 Maenocho, Itabashi-ku, Tokyo No. 9 F-Term in Asahi Gaku Gakuin Co., Ltd. (reference) 2H040 BA11 CA10 GA02 4C061 CC06 DD03 FF40 JJ17 JJ18 LL02 MM05 NN01 NN05 QQ09 RR02 RR15 RR18 RR22 WW10 WW18 5C022 AA09 AB06 AB15 AC69 AC74

Claims (9)

[Claims] 1. A videoscope having at least an objective lens, an illuminating lens, and an image pickup device at its tip,
An electronic endoscope apparatus including a processor to which the video scope is detachably connected, wherein an illumination light source that emits light for illuminating a subject, and an image signal corresponding to a subject image from the image sensor And a tip end specification data memory that stores, as data, image signal processing means for generating a luminance signal, and tip end specifications including at least the positional relationship between the objective lens and the illumination lens in the tip end portion of the videoscope. A tip part specification detecting means for detecting the tip part specification of the videoscope; and a weighting coefficient for each of a plurality of areas defined by dividing an object image formed on the image sensor, the tip part A photometric system setting means defined according to the specification, and a plurality of portions representing the image brightness in each of the plurality of areas A degree value is detected from the luminance signal, and a plurality of the partial luminance values are multiplied by the corresponding weighting coefficient to calculate an overall luminance value representing the brightness of the entire subject image from the plurality of partial luminance values. An electronic endoscope apparatus comprising: a photometric unit; and a light amount adjusting unit that adjusts a light amount of light emitted toward the subject based on the overall brightness value. 2. The photometric method setting means sets a weighting coefficient of a high brightness area in which the partial brightness value becomes a relatively high brightness value to another area according to the tip end specification detected by the tip end specification detecting means. Is determined to be a larger value than the weighting coefficient, and the photometric means calculates the overall luminance value by performing the weighted average photometry in the high luminance area as the weighted area among the plurality of areas. The electronic endoscope apparatus according to claim 1. 3. The photometric system setting means sets equal weighting coefficients for each of the plurality of areas, and the photometric means calculates the overall luminance value by average photometry. Electronic endoscope device. 4. The two illumination lenses are arranged at the tip portion, and the positional relationship between the objective lens and the illumination lens is a relative position and distance of the objective lens with respect to each of the two illumination lenses. The electronic endoscope apparatus according to claim 1, wherein the electronic endoscope apparatus is different. 5. The tip end specification includes a positional relationship of a forceps port formed at the tip end part with respect to the objective lens and an illumination lens, and the photometric system setting means sets the plurality of the plurality of parts according to the tip end specification. In the area, the forceps opening area in which the image of the tip of the treatment instrument protruding from the forceps opening appears is selected, and the photometric means determines that the partial brightness value of the forceps opening area is larger than the boundary brightness value according to the occurrence of halation. If the partial brightness value of the forceps opening area is larger than the boundary brightness value, the overall brightness value is calculated from the partial brightness values detected in areas other than the forceps opening area. The electronic endoscope apparatus according to claim 1. 6. The plurality of areas are defined by being radially divided with respect to a central portion of a subject image formed on the image pickup device as a reference.
The electronic endoscope apparatus according to item 1. 7. A weighting coefficient memory in which weighting coefficients suitable for specifications of respective tip portions of connectable videoscopes are stored in advance as data, and the photometric system setting means weights according to the tip characteristic. 2. The coefficient data is read out.
The electronic endoscope apparatus according to item 1. 8. A light source for illumination, comprising a videoscope having an image pickup device, inserted into the body, and a processor to which the videoscope is connected, and illuminating light to be sent to the body.
An automatic light control device for an endoscope incorporated in an electronic endoscope device having signal processing means for processing an image signal according to a subject image read from the image pickup device to generate a luminance signal, A scope tip data memory in which tip specifications including at least the positional relationship between the objective lens and the illuminating lens are stored as data at the tip of the scope, and tip specification detection means for detecting the tip specifications of the videoscope. And a photometric method setting unit that determines a weighting coefficient for each of a plurality of areas defined by dividing the subject image formed on the image sensor according to the tip specifications, and an image brightness in each of the plurality of areas. A plurality of partial luminance values representing the brightness are detected from the luminance signal, and the plurality of partial luminance values corresponding to the plurality of partial luminance values are detected. A photometric unit that calculates the overall brightness value that represents the brightness of the entire subject image from the plurality of partial brightness values by multiplying by a weighting coefficient, and adjusts the amount of light sent to the inside of the body based on the overall brightness value. An automatic light control device for an endoscope, comprising: a light amount adjusting means. 9. A videoscope having at least an objective lens, an illumination lens, and an image pickup device at its tip,
An electronic endoscope apparatus including a processor to which the video scope is detachably connected, wherein an area forming a subject image is divided into a plurality of areas, and the plurality of areas are selected in accordance with the tip specifications. Luminance calculation means for calculating an overall luminance value of a subject image by defining an important area and placing more emphasis on the important area than other areas; and light radiated toward the subject based on the overall luminance value. And a light amount adjusting means for adjusting the light amount of the electronic endoscope device.