JP2003250760A - Automatic light regulator for endoscope and electronic endoscope unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To regulate the quantity of light for maintaining images of objects at proper brightness while controlling halation. <P>SOLUTION: A processor 10 of an electronic endoscope unit is provided with a histogram circuit 23 to generate histogram data pertaining to the brightness of images of objects from image signals read out of a CCD 54 of a video scope 50 connected to the processor 10. A panel switch 30 is provided with an incremental switch 30A and a decremental switch 30B for varying the control luminance level to let operators set halation brightness values and halation reference ratios as control luminance levels. At a CPU 24, halation ratios are calculated from histogram data and the halation brightness values to set to open or close a stop 34 based on the comparison of the halation ratios thus calculated path the halation reference ratios. <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 endoscope apparatus capable of observing an image of a predetermined portion by inserting an endoscope (scope) into an organ such as a stomach, and more particularly to the brightness of a subject image. The present invention relates to a light amount adjustment for adjusting the light amount of the illumination light with which the observation site is irradiated so that the light intensity is constant.

[0002]

2. Description of the Related Art In a conventional endoscope apparatus, the brightness of a subject (luminance of the subject) is determined based on an image signal corresponding to a subject image.
Is detected, and the light amount of the illumination light is adjusted by comparing with a reference value indicating appropriate brightness of the subject. If the brightness is higher than the reference value, the diaphragm is closed to reduce the light amount, while if the brightness is lower than the reference value, the diaphragm is opened to increase the light amount.

As the value representing the brightness of the subject image to be compared with the reference value, an average brightness value representing the average brightness of the entire subject or a peak brightness value representing the maximum brightness is applied. The level of the reference value can be changed by operating the switch provided in the.

[0004]

When the light amount is adjusted by comparing the average luminance value with the reference value, halation is likely to occur, which hinders inspections and treatments. On the other hand, when the light intensity is adjusted by comparing the peak luminance value with the reference value, halation can be suppressed, but the observed subject image becomes dark as a whole. Although the brightness problem can be solved to some extent by changing the setting of the reference value level, it is difficult for the operator to change the setting of the reference value level while operating the endoscope. For this reason, it becomes difficult to always maintain the brightness of the subject at an appropriate brightness while performing a treatment or the like.

Therefore, it is an object of the present invention to obtain an electronic endoscope apparatus and an automatic light control apparatus for an endoscope, which can adjust the light amount for maintaining an appropriate brightness of a subject image while suppressing halation. To do.

[0006]

An electronic endoscope apparatus according to the present invention is an electronic endoscope apparatus including a videoscope having an image pickup device and a processor to which the videoscope is connected. The image signal read from is processed and a video signal is output to a monitor or the like. The electronic endoscope apparatus of the present invention, in order to obtain the histogram data regarding the brightness of the subject image, a histogram processing unit that performs a predetermined histogram process based on the image signal read from the image sensor, and the subject based on the histogram data. A halation ratio calculating means for calculating a halation ratio indicating a ratio of the number of high-luminance pixels to the number of all pixels forming the image is provided. For example, the brightness value indicating the brightness of the subject image is set to any value in the range of 0 to 255 as the brightness level. The high-brightness pixel is a pixel having a brightness value equal to or higher than the halation brightness value, and the halation ratio represents the ratio of halation to the entire subject image. The halation brightness value is a threshold value at which halation is considered to occur, and is set to a level lower than the boundary value at which halation actually occurs. For example, when the brightness value is in the range of 0 to 255,
It is set to any value of approximately 200 to 230. The electronic endoscope device adjusts the light amount of the light for illuminating the subject every predetermined period so that the subject image displayed on the monitor or the like holds the brightness reference of the subject image corresponding to the determined brightness level. The light quantity adjusting means adjusts the light quantity of the light illuminating the subject for every predetermined period based on the comparison between the halation reference rate indicating the brightness reference of the subject image and the halation rate. The value of the halation reference ratio functions as a reference value when adjusting the light amount, and the light amount adjustment described below is performed depending on whether the calculated halation ratio is equal to or higher than the set halation reference ratio. The adjustment of the light amount may be performed, for example, in each reading period of the image signal for one frame.

In order to maintain the brightness of the subject image as a reference for the brightness of the subject image, the light amount adjusting means reduces the light amount if the calculated halation ratio value is larger than the calculated halation reference ratio value, and decreases it if the calculated halation ratio value is smaller. Increase the amount of light.
For example, in the case where the light source section has a diaphragm provided between the light source such as a halogen lamp and the incident end of the optical fiber bundle provided in the videoscope, the light amount is adjusted by opening and closing the diaphragm. Alternatively, in the case where the light emitting diode is provided at the tip of the videoscope, the light amount is adjusted by adjusting the amount of current sent to the light emitting diode.
The electronic endoscope apparatus of the present invention is configured so that the operator can set the value of the halation reference ratio, and according to the input operation of the operator, the reference value setting that sets the value of the halation reference ratio as the reference value. Means are provided. For example, when a switch for setting the value of the halation reference ratio is provided on the front panel of the processor, the reference value setting means sets the value of the halation reference ratio according to the operation of the switch. The light amount adjusting means adjusts the light amount based on the set halation reference ratio.

In the present invention, instead of the average brightness value and the peak brightness value of the brightness of the subject image, the light amount is adjusted with reference to the ratio of the halation portion to the entire subject image.
Therefore, the occurrence of halation can be detected quickly, and the light amount adjustment for preventing halation from continuing for a long time is executed. Furthermore, since the operator can change the value of the halation reference ratio, the brightness of the subject image can be maintained at an appropriate brightness according to the operator's preference.

In order to allow the operator to change the value of the halation reference ratio stepwise, it is desirable to further have a memory for storing a plurality of halation reference ratio values having different values stepwise. For example, the front panel may be provided with a switch capable of setting a stepwise brightness level corresponding to the halation reference ratio. A plurality of halation luminance ratio values are determined according to the level of the brightness level. The value of the halation reference ratio referred to when adjusting the light amount is selected by the operator from a plurality of values. The operator can set the brightness of the subject image to a desired brightness by the same operation as the conventional setting of the average value or the peak value.

The optical characteristics of the videoscope, that is, the characteristics of the light distribution lens, the objective lens and the optical fiber bundle, and the characteristics of the image pickup device differ depending on the organ to be observed.
Therefore, it is preferable to classify the videoscopes according to the observation site object and set the value of the halation reference ratio for each videoscope of the same type. Therefore, it is desirable that the electronic endoscope apparatus further includes scope type detecting means for detecting the type of the videoscope, and the reference value setting means sets the value of the halation reference ratio according to the type of the videoscope. The value of the halation reference ratio corresponding to the type of video scope may be stored in advance in a memory or the like.

In the electronic endoscope apparatus according to another aspect of the present invention, the halation luminance value can be set by the operator. That is, the electronic endoscope apparatus uses a histogram processing unit that performs a predetermined histogram process based on an image signal read from an image sensor to obtain histogram data relating to the brightness of a subject image, and all pixels based on the histogram data. A halation ratio calculation means for calculating a halation ratio indicating the ratio of the number of high-luminance pixels having a brightness value equal to or higher than the halation brightness value, which is a threshold value for the occurrence of halation, and a halation reference ratio indicating a brightness standard of a subject image. Based on the comparison with the halation ratio, the light amount adjusting means for adjusting the light amount of the light for illuminating the subject for each predetermined period so that the brightness of the subject image maintains the reference of the brightness of the subject image, and operator's input Halation brightness value setting means for setting the halation brightness value according to the operation is provided. When the halation brightness value is changed, the value of the halation ratio calculated when adjusting the light amount changes. Therefore, the brightness of the subject can be maintained at an appropriate brightness according to the operator's preference.

In order to allow the operator to change the value of the halation brightness value in a stepwise manner, it is desirable to further have a memory for storing a plurality of halation brightness values having different values in a stepwise manner. Further, it is desirable to further include scope type detecting means for detecting the type of the videoscope, and the halation luminance value setting means sets the halation luminance value according to the type of the videoscope.

In the electronic endoscope apparatus according to another aspect of the present invention, the halation reference ratio value and the halation brightness value can be simultaneously set by the operator. That is, the electronic endoscope apparatus, in order to obtain the histogram data regarding the brightness of the subject image, a histogram processing unit that performs a predetermined histogram processing based on the image signal read from the image sensor, and based on the histogram data,
Halation ratio calculation means for calculating a halation ratio indicating the ratio of the number of high-luminance pixels having a luminance value equal to or higher than the halation luminance value that is a threshold value for halation generation with respect to the total number of pixels, and a halation criterion indicating a criterion for the brightness of a subject image Based on the comparison between the ratio and the halation ratio, a light amount adjusting means for adjusting the light amount of the light illuminating the subject for each predetermined period so that the brightness of the subject image holds the reference of the brightness of the subject image. According to the operator's input operation,
Reference value setting means for simultaneously setting the halation reference ratio as a reference value and the halation luminance value.

In order to allow the operator to simultaneously change the value of the halation reference ratio and the halation brightness value in stages, a plurality of halation brightness values having different values in a stepwise manner and a plurality of halation brightness values determined corresponding to the respective halation brightness values are provided. It is desirable to further have a memory for storing the value of the halation reference percentage of The halation brightness value and the halation reference ratio value are simultaneously selected by the operator. Further, it is desirable to further include scope type detecting means for detecting the type of video scope, and the reference value setting means sets the halation reference ratio and the halation brightness value at the same time according to the type of video scope.

An automatic light control device for an endoscope of the present invention is an automatic light control device for an endoscope that adjusts the amount of light that illuminates a subject, and obtains histogram data relating to the brightness of a subject image. Histogram processing means for performing a predetermined histogram process based on an image signal corresponding to the subject image, and a high-luminance pixel having a luminance value equal to or higher than a halation luminance value serving as a threshold value for halation with respect to the total number of pixels based on the histogram data. Based on the comparison between the halation ratio calculating means for calculating the halation ratio indicating the number of the images and the halation reference ratio indicating the reference for the brightness of the subject image and the halation ratio, the brightness of the subject image is calculated based on the brightness of the subject image. Light amount adjusting means for adjusting the light amount of the light for illuminating the subject for each predetermined period so as to hold the reference, and the input operation by the operator Accordingly, characterized by comprising a reference value setting means for setting a value of halation reference rate as a reference value.

An automatic light control device for an endoscope of the present invention is an automatic light control device for an endoscope that adjusts the amount of light that illuminates a subject, and obtains histogram data relating to the brightness of a subject image. Histogram processing means for performing a predetermined histogram process based on the image signal read from the image sensor, and a high-luminance pixel having a luminance value equal to or higher than a halation luminance value that is a threshold value for halation with respect to the total number of pixels based on the histogram data. Based on the comparison between the halation ratio calculating means for calculating the halation ratio indicating the number of the images and the halation reference ratio indicating the reference for the brightness of the subject image and the halation ratio, the brightness of the subject image is calculated based on the brightness of the subject image. A light amount adjusting means for adjusting the light amount of the light for illuminating the subject for each predetermined period so as to hold the reference, and an operator According force operation, characterized in that a halation brightness value setting means for setting a halation brightness value.

The automatic light control device for an endoscope of the present invention is an automatic light control device for an endoscope that adjusts the amount of light that illuminates a subject, and obtains histogram data relating to the brightness of a subject image. Histogram processing means for performing a predetermined histogram process based on the image signal read from the image sensor, and a high-luminance pixel having a luminance value equal to or higher than a halation luminance value that is a threshold value for halation with respect to the total number of pixels based on the histogram data. Based on the comparison between the halation ratio calculating means for calculating the halation ratio indicating the number of the images and the halation reference ratio indicating the reference for the brightness of the subject image and the halation ratio, the brightness of the subject image is calculated based on the brightness of the subject image. A light amount adjusting means for adjusting the light amount of the light for illuminating the subject for each predetermined period so as to hold the reference, and an operator According force operation, characterized by comprising a reference value setting means for simultaneously setting the halation reference rate and halation brightness value as a reference value.

[0018]

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. The electronic endoscope device is a device for performing inspections, operations, and the like on internal organs such as the stomach,
When the examination or the like is started, the videoscope is inserted into the body for photographing the observation site.

In the electronic endoscope apparatus, CC is used as an image pickup device.
Videoscope 50 having D54, and processor 1 for processing image signals sent from the videoscope 50
0 and a monitor 32 for displaying a subject image 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.

The light emitted from the light source lamp 12 is incident on an incident end 51A of an optical fiber bundle 51 provided in the videoscope 50 through a condenser lens (not shown). The optical fiber bundle 51 is an optical fiber that transmits the light emitted from the lamp 12 to the tip side of the videoscope 50 having the observation site, and the light that has passed through the optical fiber bundle 51 is emitted from the emission end 51B. As a result, the observation site S is irradiated with light.

The light reflected at the observation site S reaches the light receiving surface of the CCD 54 through an objective lens (not shown), and an image of the observation site S is formed on the light receiving surface of the CCD 54. In the present embodiment, the single-plate simultaneous type is applied as a color imaging 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 a line are arranged so as to correspond to the respective pixels on the light receiving surface. 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. . As a color television system, for example, the NTSC system is applied, and it is 1/30 (1 /
The image signal for one frame (one field) is sequentially read out every 60) second intervals and sent to the processor 10.

The signal processing circuit 20 of the processor 10 includes:
A CCD gain control circuit for controlling the gain of the image signal output from the CCD 54, a timing circuit for adjusting the timing (delay time) of reading the image signal, an R for controlling the R, G, B gains for white balance adjustment, A G and B gain control circuit, a gamma correction circuit for performing gamma correction, a color matrix circuit for generating a luminance signal, a color difference signal, and the like are included (all not shown). Various processes are performed on the image signal input to the signal processing circuit 20 in each circuit, and as a result, a video signal is generated. The generated video signal is output to the monitor 32 as a video signal such as an NTSC composite signal, a Y / C separated signal (S video signal), an RGB separated signal, etc., whereby a subject image is displayed on the monitor 32.

CPU (Central Processing Unit) 24
Controls the processor 10 as a whole, outputs a control signal to each circuit such as a signal processing circuit 20 including an IC chip, and stores a ROM (not shown) storing a program for executing light amount adjustment. Have. A data rewritable EEPROM 57 is provided in the video scope 50, and data relating to the characteristics of the scope is EE.
It is stored in the PROM 57 in advance. When the videoscope 50 is connected to the processor 10, EEPRO
The data stored in M57 is sent to the processor 10 and stored in the memory 26.

The front panel of the processor 10 includes a series of panel switches 3 including switches for setting a reference brightness level which is a standard in automatic light control.
0 is provided. The up switch 30A is operated to raise the reference brightness level, and the down switch 30B is operated.
Is operated to reduce the reference brightness level. When a key operation is performed on the keyboard 34 to display character information such as patient information on the monitor 32, a signal corresponding to the operation of the keyboard 34 is input to the CPU 24, and the signal is controlled by the CRTC (CRT controller) 22 based on the signal. A signal is sent. Then, a character signal corresponding to the key operation is output from the CRTC 22 and superimposed on the video signal. Also, RTC (Real Time Clock) 2
The date and time data from 8 is read by the CPU 24,
The character signal according to the current date and time is output from the CRTC 22.

A diaphragm 34 for adjusting the amount of light applied to the subject S is provided between the incident end 51A of the light guide 51 and the light source lamp 12, and the opening / closing amount is adjusted by the diaphragm control circuit 32. To be done. The signal processing circuit 20 generates a luminance signal for one frame based on the image signal sent, and sends it to the histogram circuit 23.
The histogram circuit 23 generates histogram data regarding the brightness of the subject image based on the transmitted luminance signal, and outputs the histogram data to the CPU 24. Then, a control signal is sent to the aperture control circuit 32 based on the histogram data and the reference brightness level. As a result, the diaphragm 34 opens and closes so that the brightness of the subject image becomes constant.

FIG. 2 is a diagram showing a main routine executed by the CPU 24 in the processor 10.

In step S101, the CPU 24 and variables are initialized. In step S102, as will be described later, a process regarding the panel switch 30 is performed, and when a predetermined switch is operated, a process for the switch is performed. In step S103, the process relating to the keyboard 34 is performed, and when a predetermined key is operated, the process corresponding to the key operation is performed.

In step S104, clock processing is performed, data corresponding to the date and time is read from the RTC 28, and the date and time are displayed on the monitor 32. In step S105, a process regarding the video scope 50 is performed as described later. Then, in step S106, other processing is performed. Steps S102 to S106 are repeatedly executed until the main power supply of the processor 10 is turned off.

FIG. 3 is a diagram showing a subroutine of the panel switch process in S102 of FIG. Further, FIG. 4 shows a table in which halation brightness values and halation reference ratio values corresponding to the respective reference brightness levels are shown, and FIG. 5 shows a histogram.

In step S201, it is determined whether any one of the panel switches 30 has been operated by the operator. If it is determined that none of the switches has been operated, then the subroutine ends. On the other hand, if it is determined that one of the switches has been operated by the operator, step S20
Go to 2. In step S202, the reference brightness level vb
It is determined whether or not the up switch 30A for raising is operated by the operator.

When it is determined in step S202 that the up switch 30A is operated by the operator, the process proceeds to step S203. In step S203, it is determined whether or not the variable vb representing the reference brightness level of brightness is set to the maximum level. In the present embodiment, the reference brightness level at the time of adjusting the light amount has nine levels (-
4, -3, -2, -1, 0, +1, +2, +3, +4)
The reference brightness level vb is maximum (= +
It is determined whether or not it is set to 4). When it is determined that the reference brightness level vb is set to the maximum level, the reference brightness level vb cannot be further increased, and thus this subroutine is terminated without setting the level. On the other hand, when it is determined that the reference brightness level vb is not set to the maximum level, the process proceeds to step S204.

In step S204, the reference brightness level v
b is increased by one step. Then, based on the table T1 of FIG. 4, the value of the variable vrg representing the halation brightness value and the value of the variable vrp representing the halation reference ratio according to the reference brightness level vb which is increased by one step are set. In this embodiment,
The brightness value of each pixel forming the subject image is set to any value in the range of 0 to 255. The halation brightness value vrg is a brightness value as a threshold value at which halation is considered to occur, and is 200 to 230 here.
Is set to any value within the range (see FIG. 5). Further, the halation reference ratio vrp represents a reference ratio of pixels having a luminance equal to or higher than the halation luminance value vrg with respect to all pixels forming the subject image, based on the reference of the brightness of the subject image. The values of the halation luminance value vrg and the halation reference ratio vrp for each reference luminance level vb are stored in the memory 26. When step S204 is executed, this subroutine ends.

On the other hand, when it is determined in step S202 that the up switch 30A is not operated by the operator, the process proceeds to step S205. In step S205, it is determined whether or not the down switch 30B for lowering the reference brightness level vb has been operated by the operator. If it is determined that the down switch 30B is not operated, the process proceeds to step S208, the process for the operation of the other switches is performed, and this subroutine ends. On the other hand, if it is determined in step S205 that the down switch 30B has been operated, the process proceeds to step S206.

In step S206, it is determined whether or not the reference brightness level vb of brightness is set to the minimum level (= -4). When it is determined that the reference brightness level vb is set to the minimum level, the reference brightness level vb
Cannot be lowered further than this, so this subroutine ends without setting the level. On the other hand, when it is determined that the reference brightness level vb is not set to the minimum level, the process proceeds to step S207.

In step S207, the reference brightness level v
b is lowered by one step and the reference luminance level v is lowered by one step
The values of the halation luminance value vrg and the halation reference ratio vrp corresponding to b are set. When step S207 is executed, this subroutine ends.

FIG. 6 is a diagram showing a subroutine of scope processing executed in step S105 shown in FIG.

In step S301, it is determined whether the videoscope 50 is connected to the processor 10. When it is determined that the video scope 50 is connected, the process proceeds to step S308, and it is determined whether the video scope 50 has been removed. When it is determined that the video scope 50 has not been removed, the subroutine ends as it is. On the other hand, when it is determined in step S308 that the video scope 50 has been removed, the process proceeds to step S309 and the monitor 32
The display of the scope name is deleted from. Step S309
Is executed, the subroutine ends.

On the other hand, when it is determined in step S301 that the videoscope 50 is not connected to the processor 10, the process proceeds to step S302. In step S302, it is determined whether the videoscope 50 is connected. When it is determined that the video scope 50 is not connected, the subroutine ends as it is. On the other hand, in step S302, the videoscope 5
When it is determined that 0 is connected, the process proceeds to step S303, and the data regarding the video scope 50 is read from the EEPROM 57 of the video scope 50. When step S303 is executed, the process proceeds to step S304.

In step S304, it is determined based on the read data whether the connected videoscope 50 is a digestive scope. In the present embodiment, the video scope 50 is classified into two types, a digestive model and a model other than that, and as shown in FIG. 4, the halation luminance value vr for each reference luminance level vb.
g, the value of halation reference ratio vrp differs depending on the scope for digestive organs and the scope for other organs (such as lungs). When it is determined in step S304 that the connected videoscope 50 is a digestive scope, the process proceeds to step S305 and the scope connection type variable v
s is set to 0. The connection type variable vs is a variable indicating the type of the video scope connected, and the scope connection type variable vs is set to 0 in the case of the digestive video scope, and the scope connection in the case of other video scopes. The type variable vs is set to 1. Further, in step S305, the digestive videoscope (vs vs.
= 0), the halation reference ratio vrp and the halation brightness value vrg are set based on the table T1.

On the other hand, if it is determined in step S304 that the connected videoscope 50 is not a digestive organ videoscope, the flow advances to step S306 to set the scope connection type variable vs to 1. Then, the halation reference ratio vrp and the halation luminance value vrg corresponding to the video scope (vs = 1) not for digestive organs are set based on the table T1. When step S305 or step S306 is executed, step S307
Then, the monitor 32 displays the scope name. When step S307 is executed, the subroutine ends.

FIG. 7 is a diagram showing an interrupt routine for executing the automatic light adjustment processing operation. In the present embodiment, the dimming process is executed by interrupting the main routine every frame (1/30 second).

In step S401, the histogram circuit 23 generates histogram data (see FIG. 5) relating to the brightness of the subject image for one screen, and the CPU 24
Read by. This histogram is for monitor 3
A value (0 to 255) that can be taken as the brightness value of each pixel forming the subject image displayed in 2 is taken as the horizontal axis and sent from the signal processing circuit 20 (FIG. 1) to the histogram circuit 23 (FIG. 1). It is a graph in which the number of pixels (frequency) corresponding to each luminance value on the horizontal axis is plotted on the vertical axis based on the luminance signal for one frame, and the luminance distribution of the subject image is shown. When step S401 is executed, the process proceeds to step S402.

In step S402, a variable v representing the halation ratio is generated based on the generated histogram data.
The value of p is calculated. The halation ratio is the halation luminance value vrg with respect to the total number of pixels forming the subject image.
It represents the ratio of the number of pixels having the above luminance values, and is calculated based on the halation luminance value vrg corresponding to the reference luminance level vb set by the operator. When step S402 is executed, the process proceeds to step S403.

In step S403, the halation ratio vp and the halation reference ratio vrp are compared to determine whether the halation ratio vp is larger than the halation reference ratio vrp. Halation standard ratio vrp
Represents a halation ratio that serves as a reference for considering the brightness of the subject image as an appropriate range, and is set in advance according to the reference brightness level vb set by the operator. When it is determined in step S403 that the halation ratio vp is larger than the halation reference ratio vrp, the process proceeds to step S405, and the diaphragm 34 is closed to a predetermined opening so that the light amount of the light irradiated to the subject decreases. When step S405 is executed, this interrupt routine ends.

On the other hand, if it is determined in step S403 that the halation ratio vp is not larger than the halation reference ratio vrp, the process proceeds to step S404. In step S404, it is determined whether or not the halation ratio vp is smaller than the difference between the halation reference ratio vrp and the allowable range variable va. The permissible range variable va is a variable indicating the permissible range of the brightness of the subject in order to increase the light amount so that halation does not occur. In the present embodiment, the value of the permissible range variable va is vrg × 2/3.
Is set to. If it is determined in step S404 that the halation ratio vp is not smaller than the difference between the halation reference ratio vrp and the permissible range variable va, the light amount is determined to be appropriate, and the interrupt routine ends without driving the diaphragm 34. To do. On the other hand, if it is determined in step S404 that the halation ratio vp is smaller than the difference between the halation reference ratio vrp and the permissible range variable va, the process proceeds to step S406, and the diaphragm 34 is arranged to increase the light amount of the light emitted to the subject. Opens up to a predetermined opening. When step S406 is executed,
This interrupt routine ends.

As described above, according to the present embodiment, when the video scope 50 is connected to the processor 10, the halation luminance value vrg according to the type of the video scope 50,
The halation reference ratio vrp is set (step S
305, S306). The values of the halation brightness value vrg and the halation reference ratio vrp can be changed by the operator as the reference brightness level vb, and the halation brightness value vrg and the halation reference ratio vrp are set according to the operator's operation on the up switch 30A and the down switch 30B. (Steps S204, S
207). Then, in the light amount adjustment process, histogram data is generated in the histogram circuit 23 (step S401), and the halation ratio vp is calculated based on the set halation luminance value vrg (S40).
2). The halation ratio vp is compared with the set halation reference ratio vrp, and the diaphragm 34 is opened / closed so that the light amount becomes appropriate (steps S405 and S406).

In this embodiment, by changing the setting of the reference luminance level vb, the halation luminance value vrg,
Although the halation reference ratio vrp is changed each time, only the halation brightness value vrg or the halation reference ratio vrp may be changed according to the setting change of the reference brightness level vb.
At this time, the configuration may be performed regardless of the type of the video scope connected.

FIG. 8 is a diagram showing a table T2 of the correspondence relationship between the reference brightness level vb and the halation reference ratio vrp. Here, the value of the halation brightness value vrg is set to a constant value (= 200). Reference brightness level v
The higher b is, the higher the halation reference ratio vrp is, and the operator selects a desired reference brightness level vb.
Can be set. In this case, step S20
In 4, S207 and step S305 (S306), only the halation reference ratio vrp is set.

FIG. 9 is a diagram showing a table T3 of the correspondence relationship between the reference brightness level vb and the halation brightness value vrg. Here, the value of the halation reference ratio vrp is set to a constant value (= 10%). Reference brightness level vb
Becomes higher, the halation luminance value vrg also becomes higher. In this case, in steps S204, S207 and step S305 (S306), the halation luminance value v
Only rg is set.

Regarding the structure for adjusting the light quantity, instead of adjusting the light quantity of the light incident on the optical fiber bundle by opening and closing the diaphragm, a light emitting diode is provided at the tip of the videoscope and the current supplied to the light emitting diode is controlled. By doing so, the light amount of the light applied to the subject may be adjusted. Further, instead of the electronic endoscope device, the configuration for performing the above-described light amount adjustment may be applied to the endoscope light source device.

[0052]

As described above, according to the present invention, it is possible to perform the light amount adjustment for keeping the subject image at an appropriate brightness while suppressing the halation.

[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 a main routine executed by a CPU in a processor.

FIG. 3 is a diagram showing a subroutine of panel switch processing in S102 of FIG.

FIG. 4 is a diagram showing a table of halation luminance values and halation reference ratio values corresponding to respective reference luminance levels.

FIG. 5 is a diagram showing a histogram.

6 is a diagram showing a subroutine of scope processing executed in step S105 shown in FIG.

FIG. 7 is a diagram showing an interrupt routine for executing an automatic light adjustment processing operation.

FIG. 8 is a diagram showing a table of a correspondence relationship between a reference brightness level and a halation reference ratio.

FIG. 9 is a diagram showing a table of a correspondence relationship between reference brightness levels and halation brightness values.

[Explanation of symbols]

10 processors 12 Light source lamp 23 Histogram circuit 24 CPU 26 memory 34 Aperture 50 video scope 51 Optical fiber bundle 54 CCD (imaging device) vrg halation brightness value vrp halation standard ratio vp halation ratio

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[Procedure amendment]

[Submission date] January 21, 2003 (2003.1.2
1)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

An electronic endoscope apparatus according to the present invention is an electronic endoscope apparatus including a videoscope having an image pickup device and a processor to which the videoscope is connected. The image signal read from is processed and a video signal is output to a monitor or the like. The electronic endoscope apparatus of the present invention, in order to obtain the histogram data regarding the brightness of the subject image, a histogram processing unit that performs a predetermined histogram process based on the image signal read from the image sensor, and the subject based on the histogram data. A halation ratio calculating means for calculating a halation ratio indicating a ratio of the number of high-luminance pixels to the number of all pixels forming the image is provided. For example, the brightness value indicating the brightness of the subject image is set to any value in the range of 0 to 255 as the brightness level. The high-brightness pixel is a pixel having a brightness value equal to or higher than the halation brightness value, and the halation ratio represents the ratio of halation to the entire subject image. The halation brightness value is an assumed threshold value that is considered to cause halation, and is set to a level lower than the boundary value at which halation actually occurs. For example, when the brightness value is in the range of 0 to 255, it is set to any value of approximately 200 to 230. Therefore, in the following description, when the term “halation ratio” is used, this does not mean the ratio of halation actually occurring, but the ratio of pixels whose brightness value is equal to or higher than this halation brightness value until the user gets tired. The electronic endoscope apparatus holds the brightness reference of the subject image corresponding to the predetermined brightness level of the subject image displayed on the monitor,
The light amount adjusting means is provided for adjusting the light amount of the light for illuminating the subject for each predetermined period, and the light amount adjusting means controls the subject based on the comparison between the halation ratio and the halation reference ratio indicating the brightness standard of the subject image. The amount of light to be illuminated is adjusted every predetermined period. The value of the halation reference ratio functions as a reference value when adjusting the light amount, and the light amount adjustment described below is performed depending on whether the calculated halation ratio is equal to or higher than the set halation reference ratio. The adjustment of the light amount may be performed, for example, in each reading period of the image signal for one frame.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

In order to allow the operator to change the value of the halation reference ratio stepwise, it is desirable to further have a memory for storing a plurality of halation reference ratio values having different values stepwise. For example, a switch that can set the brightness level stepwise corresponding to the halation reference ratio may be provided on the front panel.
A plurality of halation luminance ratio values are determined according to the level of the brightness level. The value of the halation reference ratio referred to when adjusting the light amount is selected by the operator from a plurality of values. The operator can set the brightness of the subject image to a desired brightness by the same operation as the conventional setting of the average value or the peak value.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

In the electronic endoscope apparatus, CC is used as an image pickup device.
Videoscope 50 having D54, and processor 1 for processing image signals sent from the videoscope 50
0 and a monitor 32 ′ for displaying a subject image 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.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

The signal processing circuit 20 of the processor 10 includes:
A CCD gain control circuit for controlling the gain of the image signal output from the CCD 54, a timing circuit for adjusting the timing (delay time) of reading the image signal, an R for controlling the R, G, B gains for white balance adjustment, A G and B gain control circuit, a gamma correction circuit for performing gamma correction, a color matrix circuit for generating a luminance signal, a color difference signal, and the like are included (all not shown). Various processes are performed on the image signal input to the signal processing circuit 20 in each circuit, and as a result, a video signal is generated. The generated video signal is output to the monitor 32 'as a video signal such as an NTSC composite signal, a Y / C separated signal (S video signal), an RGB separated signal, etc., whereby a subject image is displayed on the monitor 32'.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

The front panel of the processor 10 includes a series of panel switches 3 including switches for setting a reference brightness level which is a standard in automatic light control.
0 is provided. The up switch 30A is operated to raise the reference brightness level, and the down switch 30B is operated.
Is operated to reduce the reference brightness level. Monitor the text information such as patient information on the keyboard 34 '
When a key operation is performed for displaying on 2 ', a signal corresponding to the operation of the keyboard 34' is input to the CPU 24, and a control signal is sent to the CRTC (CRT controller) 22 based on the signal. Then, a character signal corresponding to the key operation is output from the CRTC 22 and superimposed on the video signal. In addition, RTC (Real Time
Clock) 28, the date and time data is read by the CPU 24, and the character signal according to the current date and time is displayed on the CRT.
It is output from C22.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

In step S101, the CPU 24 and variables are initialized. In step S102, as will be described later, a process regarding the panel switch 30 is performed, and when a predetermined switch is operated, a process for the switch is performed. In step S103, the process relating to the keyboard 34 'is performed, and when a predetermined key is operated, the process corresponding to the key operation is performed.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

In step S104, clock processing is performed, data corresponding to the date and time is read from the RTC 28, and the date and time are displayed on the monitor 32 '. In step S105, as will be described later, the video scope 50
Processing is performed. Then, in step S106, other processing is performed. Steps S102 to S106 are repeatedly executed until the main power supply of the processor 10 is turned off.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

In step S301, it is determined whether the videoscope 50 is connected to the processor 10. When it is determined that the video scope 50 is connected, the process proceeds to step S308, and it is determined whether the video scope 50 has been removed. When it is determined that the video scope 50 has not been removed, the subroutine ends as it is. On the other hand, when it is determined in step S308 that the video scope 50 has been removed, the process proceeds to step S309 and the monitor 3
The display of the scope name is deleted from 2 '. Step S3
When 09 is executed, the subroutine ends.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction content]

On the other hand, if it is determined in step S304 that the connected videoscope 50 is not a digestive organ videoscope, the flow advances to step S306 to set the scope connection type variable vs to 1. Then, the halation reference ratio vrp and the halation luminance value vrg corresponding to the video scope (vs = 1) not for digestive organs are set based on the table T1. When step S305 or step S306 is executed, step S307
Proceed to and the scope name is displayed on the monitor 32 '. When step S307 is executed, the subroutine ends.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction content]

In step S401, the histogram circuit 23 generates histogram data (see FIG. 5) relating to the brightness of the subject image for one screen, and the CPU 24
Read by. This histogram is for monitor 3
The value (0 to 255) that can be taken as the luminance value of each pixel forming the subject image displayed on 2 ′ is taken as the horizontal axis and sent from the signal processing circuit 20 (FIG. 1) to the histogram circuit 23 (FIG. 1). It is a graph in which the number of pixels (frequency) corresponding to each luminance value on the horizontal axis is plotted on the vertical axis based on the luminance signal for one frame, and the luminance distribution of the subject image is shown. When step S401 is executed, the process proceeds to step S402.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction content]

On the other hand, if it is determined in step S403 that the halation ratio vp is not larger than the halation reference ratio vrp, the process proceeds to step S404. In step S404, it is determined whether or not the halation ratio vp is smaller than the difference between the halation reference ratio vrp and the allowable range variable va. The permissible range variable va is a variable indicating the permissible range of the brightness of the subject in order to increase the light amount so that halation does not occur. In the present embodiment, the value of the allowable range variable va is vrp × 2/3.
Is set to. If it is determined in step S404 that the halation ratio vp is not smaller than the difference between the halation reference ratio vrp and the permissible range variable va, the light amount is determined to be appropriate, and the interrupt routine ends without driving the diaphragm 34. To do. On the other hand, if it is determined in step S404 that the halation ratio vp is smaller than the difference between the halation reference ratio vrp and the permissible range variable va, the process proceeds to step S406, and the diaphragm 34 is arranged to increase the light amount of the light emitted to the subject. Opens up to a predetermined opening. When step S406 is executed,
This interrupt routine ends.

[Procedure Amendment 12]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 13]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

[Procedure Amendment 14]

[Document name to be corrected] Drawing

[Correction target item name] Figure 8

[Correction method] Change

[Correction content]

[Figure 8]

Claims (10)

[Claims] 1. An electronic endoscope apparatus comprising a videoscope having an image pickup device and a processor to which the videoscope is connected, wherein the electronic endoscope device is read from the image pickup device in order to obtain histogram data relating to the brightness of a subject image. Histogram processing means for performing a predetermined histogram processing based on the image signal, and a ratio of the number of high-luminance pixels having a luminance value equal to or higher than a halation luminance value serving as a threshold for halation with respect to the total number of pixels based on the histogram data. Based on a comparison between the halation ratio calculating means for calculating the halation ratio and the halation reference ratio indicating the brightness standard of the subject image and the halation ratio. The amount of light that illuminates the subject is adjusted every predetermined period so that An electronic endoscope apparatus comprising: a light quantity adjusting means; and a reference value setting means for setting a value of the halation reference ratio as a reference value according to an input operation of an operator. 2. An electronic endoscope apparatus comprising a videoscope having an image pickup device and a processor to which the videoscope is connected, which is read from the image pickup device in order to obtain histogram data regarding the brightness of a subject image. Histogram processing means for performing a predetermined histogram processing based on the image signal, and a ratio of the number of high-luminance pixels having a luminance value equal to or higher than a halation luminance value serving as a threshold for halation with respect to the total number of pixels based on the histogram data. Based on a comparison between the halation ratio calculating means for calculating the halation ratio and the halation reference ratio indicating the brightness standard of the subject image and the halation ratio. The amount of light that illuminates the subject is adjusted every predetermined period so that An electronic endoscope apparatus comprising: a light quantity adjusting means; and a halation brightness value setting means for setting the halation brightness value according to an input operation of an operator. 3. An electronic endoscope apparatus comprising a videoscope having an image pickup device and a processor to which the videoscope is connected, wherein the electronic endoscope device is read from the image pickup device in order to obtain histogram data regarding the brightness of a subject image. Histogram processing means for performing a predetermined histogram processing based on the image signal, and a ratio of the number of high-luminance pixels having a luminance value equal to or higher than a halation luminance value serving as a threshold for halation with respect to the total number of pixels based on the histogram data. Based on a comparison between the halation ratio calculating means for calculating the halation ratio and the halation reference ratio indicating the brightness standard of the subject image and the halation ratio. The amount of light that illuminates the subject is adjusted every predetermined period so that An electronic endoscope apparatus comprising: a light amount adjusting means; and a reference value setting means for simultaneously setting the halation reference ratio and the halation luminance value as reference values according to an input operation by an operator. 4. A memory for storing a plurality of values of halation reference ratios having different values stepwise, wherein the value of the halation reference ratio is selected by an operator from the plurality of values. The electronic endoscope apparatus according to claim 1, wherein: 5. The memory further comprises a memory for storing a plurality of halation luminance values having different values in stages, and the halation luminance value is selected by an operator from the plurality of values. The electronic endoscope apparatus according to claim 2. 6. The apparatus further comprises a memory for storing a plurality of halation luminance values having different values in a stepwise manner and a plurality of halation reference ratio values determined corresponding to the respective halation luminance values. The electronic endoscope apparatus according to claim 3, wherein the value of the halation reference ratio is simultaneously selected by an operator. 7. The scope type detecting means for detecting the type of the video scope is further provided, and the reference value setting means sets different values according to the type of the video scope. Item 4. The electronic endoscope device according to any one of Items 3. 8. An automatic light control device for an endoscope, which adjusts the amount of light for illuminating a subject, wherein a predetermined value is obtained based on an image signal corresponding to the subject image in order to obtain histogram data regarding the brightness of the subject image. And a halation ratio indicating the ratio of the number of high-luminance pixels having a luminance value equal to or higher than the halation luminance value that is a threshold value for halation with respect to the total number of pixels, based on the histogram data. Based on a comparison between the halation ratio calculation means and the halation reference ratio indicating the brightness standard of the subject image and the halation ratio, the brightness of the subject image is maintained as the brightness standard of the subject image. Light quantity adjusting means for adjusting the light quantity of the light for illuminating the light source for each predetermined period, and the reference value and Automatic light system for endoscope characterized by comprising a reference value setting means for setting the value of the halation reference percentage of Te. 9. An automatic light control device for an endoscope, which adjusts the amount of light for illuminating a subject, wherein histogram data relating to the brightness of a subject image is obtained based on an image signal read from the image sensor. Histogram processing means for performing a predetermined histogram process, and, based on the histogram data, calculates a halation ratio indicating a ratio of the number of high-luminance pixels having a luminance value equal to or higher than a halation luminance value that is a threshold value for halation with respect to the total number of pixels. Based on a comparison between the halation ratio calculating means and the halation reference ratio indicating the brightness standard of the subject image and the halation ratio, the brightness of the subject image holds the brightness standard of the subject image, A light amount adjusting means for adjusting the light amount of the light for illuminating the subject every predetermined period, and an operator's input operation Endoscopic automatic light control device is characterized in that a halation brightness value setting means for setting the halation brightness value. 10. An automatic light control device for an endoscope, which adjusts a light amount of light for illuminating a subject, wherein histogram data relating to brightness of a subject image is obtained based on an image signal read from the image sensor. Histogram processing means for performing a predetermined histogram process, and, based on the histogram data, calculates a halation ratio indicating a ratio of the number of high-luminance pixels having a luminance value equal to or higher than a halation luminance value that is a threshold value for halation with respect to the total number of pixels. Based on a comparison between the halation ratio calculating means and the halation reference ratio indicating the brightness standard of the subject image and the halation ratio, the brightness of the subject image holds the brightness standard of the subject image, Light quantity adjusting means for adjusting the light quantity of the light that illuminates the subject every predetermined period, and for operator input operation There, the halation reference ratio and automatic light control device for an endoscope characterized by comprising a reference value setting means for simultaneously setting the said halation brightness value as a reference value.