JP4311959B2 - Electronic endoscope device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic endoscope apparatus including a video scope having an image sensor. In particular, the brightness of the subject image displayed on the display device can be appropriately maintained by adjusting the amount of light that irradiates the observation site or by adjusting the charge accumulation amount based on the shutter speed of the image sensor. It relates to dimming processing.
[0002]
[Prior art]
In a conventional electronic endoscope apparatus, when an image signal corresponding to a subject image is read from an image sensor in a video scope, a luminance value indicating the brightness of the subject image is calculated. Based on the difference between the luminance value and the reference luminance value indicating appropriate brightness, for example, the amount of light irradiated to the affected area is adjusted by the diaphragm. There are two types of metering methods for calculating brightness values: average metering, which calculates the average brightness of the entire subject image, and peak metering, where the brightness of the subject image is a relatively high brightness value in the entire subject image. The operator selects a photometric method as necessary.
[0003]
In the conventional electronic endoscope apparatus, when the affected part and the distal end of the videoscope are close to each other, or when the distal end of a treatment tool such as a forceps appears in the observation image, halation is likely to occur in the peripheral area of the observation image. . When halation occurs in the peripheral area in a state where the peak metering method is applied, the light amount adjustment is performed so that the irradiation light amount is reduced although the brightness of the entire screen is appropriate. For this reason, a method is known in which an area near the center where an observation target site that needs to be clearly displayed on a display device is set as a peak photometry area, and a peripheral area is set as an average photometry area (for example, Patent Documents). 1).
[0004]
[Patent Document 1]
JP 2000-333901 A (FIG. 3)
[0005]
[Problems to be solved by the invention]
An operator such as a doctor performs treatment, observation, etc. while operating the angle knob provided in the operation part of the video scope to bend the distal end part of the scope insertion part in a predetermined bending direction of up, down, left and right, The knob is rotated so that the region of interest is projected near the center of the screen. However, average photometry is applied to the area where the operator is gazing until the focus area around the observation screen or other than the observation screen is projected in the center of the screen by curving the distal end of the scope. For this reason, the gaze portion appears dark in the entire observation image, which hinders endoscope operation, observation, treatment, and the like.
[0006]
Therefore, in the present invention, while operating the video scope, an electronic endoscope apparatus capable of always clearly displaying the portion to be watched on the display device by always performing peak photometry on the portion to be watched on the screen. An object is to provide an automatic light control device for an endoscope, an automatic light control method, and an automatic light control program.
[0007]
[Means for Solving the Problems]
An electronic endoscope apparatus provided with a videoscope having an image sensor of the present invention includes a light source for illuminating a subject, a peak photometric area in the center of the entire subject image, and at least a peripheral portion of the subject image A metering area setting means for determining an average metering area so as to include the brightness of the subject image based on an image signal read from the image sensor by performing peak metering in the peak metering area and performing average metering in the average metering area; Brightness calculating means for calculating the representative brightness value indicating the brightness, and subject image brightness adjusting means for appropriately maintaining the brightness of the subject image based on the representative brightness value. The video scope is provided with a bending operation unit for bending the distal end portion.
[0008]
For example, the representative luminance value calculating means may calculate a value obtained by multiplying the peak value of the peak photometric area and the average luminance value of the average photometric area by a predetermined coefficient and adding them as the representative luminance value. The subject image brightness adjusting unit may adjust the light amount to the subject by opening and closing the aperture, or may adjust the brightness using the electronic shutter function of the image sensor. For average metering, the average brightness of the average metering region may be calculated, or the average of the luminance values of each pixel may be calculated, or the average value may be calculated using a histogram distribution. The photometry area setting means sets the peak photometry area and the average photometry area for the subject image whose brightness is adjusted, that is, the subject image to be displayed. For example, if the number of pixels of the image sensor does not match the number of pixels constituting the displayed subject image, the region may be set for the display subject image that has undergone pixel conversion by thinning or interpolation processing.
[0009]
Further, the electronic endoscope apparatus according to the present invention includes a bending detection unit that detects a bending direction and a bending change amount of the distal end portion of the scope, and a peak photometry that moves the peak photometric region in the entire subject image according to the bending direction and the bending change amount. And an area moving means. For example, the operation portion of the video scope is provided with a bending operation portion for bending the distal end portion of the scope in first and second directions (for example, left and right and up and down directions) orthogonal to each other, and performs a predetermined operation. As a result, the scope tip is curved along a predetermined direction. The image sensor provided at the distal end of the scope has a subject image that is observed along the direction toward the distal end surface of the scope, and the peak photometric area is centered in the bending operation section, that is, in the neutral state where the distal end is straight. Should be set. Then, the peak photometry area moves in accordance with the bending operation of the scope tip by the bending operation.
[0010]
When the bending operation is started, the bending detection means detects the bending direction and detects the bending change amount. Since the amount of curve change occurs immediately after the start of the operation, the peak photometric area moves in the direction along the curve direction in the entire subject image. For example, if it curves to the left, it moves to the left in the entire subject image. When the bending operation is stopped, a bending change amount opposite to that at the start of the bending operation is generated, so that the peak photometry area moves along the reverse direction (for example, the right direction) so as to return to the vicinity of the original center. When the bending operation is completely stopped, the amount of bending change does not occur and the peak photometry is located at the center. In this way, while the scope tip is bent from the neutral state to a predetermined angle, the peak photometry area first moves along the direction corresponding to the bending direction, and this time, while moving along the opposite direction, Return to the center position. The same applies when returning from the curved state to the neutral state.
[0011]
When the site of interest is displayed in the center of the observation screen, the operator does not curve the scope tip and the gaze area overlaps the peak photometry area. On the other hand, when the part to be observed is on the periphery or the outside of the screen, the scope tip is bent in a predetermined direction so that the part is projected to the center of the screen, but the peak photometric area is also moved according to the bending operation. While the scope tip is curved, the gaze area always overlaps the peak photometry area. Therefore, the peak photometry area is always executed for the site to be observed, and appropriate light quantity adjustment and further appropriate diagnosis and treatment are performed.
[0012]
It can be considered that the operation position of the bending operation portion and the bending angle of the distal end portion of the scope have a substantially 1: 1 correspondence. Therefore, the bending detection means detects the bending direction and the bending change amount of the scope distal end portion by detecting the operation direction and the operation change amount of the bending operation portion. When a bending operation unit capable of rotating an axis, such as a rotary knob, is applied, the bending direction detection means detects an angular velocity including rotation direction information when the bending operation unit is rotated. The bending direction and the bending change amount are detected based on the detected sign of the angular velocity. For example, when a first rotation operation unit and a second rotation operation unit that are capable of axial rotation for separately bending the distal end portion of the scope along two axial directions (vertical and horizontal directions) orthogonal to each other are provided The direction detection means detects angular velocities at the time of the rotation operation for the first and second rotation operation units. In this case, the peak photometry area moves separately in each of the first direction and the second direction.
[0013]
Although the peak photometry area may be moved at a constant speed, it is considered that there is a part of interest outside the screen as the bending operation is larger, and therefore it is preferable that the amount of movement changes according to the bending operation. Therefore, it is preferable that the curved peak photometric area moving means move the peak photometric area by a movement amount corresponding to the magnitude of the curve change amount. For example, the bending detection means detects the amount of change in the bending of the scope tip by detecting the amount of change in operation of the bending operation section, and the peak photometric area moving means peaks the amount of movement corresponding to the magnitude of the operation change amount. Move the metering area.
[0014]
On the other hand, when the movement amount of the peak metering region is made to correspond to the bending amount of the entire scope tip, the electronic endoscope apparatus includes a bending time detection unit that detects the bending time of the scope tip continuously bending in a predetermined direction. The peak photometry area moving means moves the peak photometry area by a movement amount obtained from the bending time and the bending change amount. For example, operation time detection means for detecting the bending time of the scope distal end by detecting operation time in a predetermined direction with respect to the bending operation part is provided, and the bending detection means detects an operation change amount of the bending operation part. Thus, the amount of change in the bending of the distal end of the scope is detected, and the peak photometric area moving means moves the peak photometric area by the amount of movement corresponding to the operation time and the operation change amount.
[0015]
Even if the operator does not intentionally bend the scope tip, it will bend slightly during the endoscope operation. In such an unconscious bending operation, it is desirable not to move the peak photometric area. Therefore, in the case of determining based on the magnitude of the bending change amount, a bending change amount magnitude judging means for judging whether or not the magnitude of the bending change amount at the distal end portion of the scope exceeds the reference bending change magnitude. It is good to have. The peak photometry area moving means does not move the peak photometry area when the amount of change in the curvature of the distal end of the scope does not exceed the amount of change in the reference bend. The peak photometry area moving means does not move the peak photometry area when the magnitude of the operation change amount does not exceed the reference operation change quantity. For example, in the case of a bending operation unit capable of rotating the shaft, the bending detection means detects an angular velocity at the time of the rotation operation on the bending operation unit, and determines whether the angular velocity exceeds the reference angular velocity. A size discrimination means is provided. The peak photometry area moving means does not move the peak photometry area when the angular velocity does not exceed the reference angular velocity.
[0016]
Or you may judge whether the scope front-end | tip part is bent consciously based on the time bent continuously. In this case, it is provided with a bending time determining means for determining whether or not the bending time of the scope tip portion continuously bending in a predetermined direction exceeds the reference bending time, and the peak photometric area moving means includes the bending time as a reference. If the bending time is not exceeded, the peak photometric area is not moved. An operation time discriminating unit that determines whether or not the operation time exceeds the reference operation time may be provided, and the peak photometry area moving unit does not move the peak photometry area when the operation time does not exceed the reference operation time. .
[0017]
The subject image brightness adjustment device for an electronic endoscope apparatus of the present invention illuminates a subject with light from a light source and has a peak photometric area at the center in the entire subject image formed by an imaging device of a videoscope. And determining the average photometry area so as to include at least the periphery of the subject image, and performing peak photometry in the peak photometry area and executing the average photometry in the average photometry area, thereby performing the imaging. Luminance calculation means for calculating a representative luminance value indicating the brightness of the subject image based on an image signal read from the element, and subject image brightness adjustment means for appropriately maintaining the brightness of the subject image based on the representative luminance value Bending detection means for detecting the bending direction and bending change amount of the scope tip, and the peak photometric area according to the bending direction and bending change amount Characterized in that a peak metering area moving means for moving in the entire object image.
[0018]
The subject image brightness adjustment method for an electronic endoscope apparatus according to the present invention illuminates a subject with light from a light source and has a peak photometric area at the center in the entire subject image formed by an imaging device of a videoscope. And determining an average photometric area so as to include at least a peripheral portion of the subject image, performing peak photometry in the peak photometric area, and performing average photometry in the average photometric area, thereby reading an image read from the image sensor Calculating a representative luminance value indicating the brightness of the subject image based on the signal, appropriately maintaining the brightness of the subject image based on the representative luminance value, detecting a bending direction and a bending change amount of the scope tip, The peak photometric area is moved in the entire subject image according to the bending direction and the amount of bending change.
[0019]
The object image brightness adjustment program for an electronic endoscope apparatus of the present invention illuminates a subject with light from a light source and forms a peak photometric area in the central portion of the entire subject image formed by an imaging device of a videoscope. And determining the average photometry area so as to include at least the periphery of the subject image, and performing peak photometry in the peak photometry area and executing the average photometry in the average photometry area, thereby performing the imaging. Luminance calculation means for calculating a representative luminance value indicating the brightness of the subject image based on an image signal read from the element, and subject image brightness adjustment means for appropriately maintaining the brightness of the subject image based on the representative luminance value And the bending direction and the bending change amount detected by the bending detecting means for detecting the bending direction and the bending change amount of the distal end portion of the scope, And characterized in that the over-click metering area to function and peak metering area moving means for moving in the entire object image.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an electronic endoscope apparatus according to an embodiment of the present invention will be described with reference to the drawings.
[0021]
FIG. 1 is a block diagram of an electronic endoscope apparatus according to the first embodiment.
[0022]
The electronic endoscope apparatus includes a video scope 50 having a CCD (Charge-Coupled Device) 54 and a processor 10 for processing a signal read from the CCD 54, and a monitor 32 and a keyboard 34 for displaying a subject image. Are connected to the processor 10. The videoscope 50 is detachably connected to the processor 10, and when examination, surgery, or the like is started, the videoscope insertion portion 61 is inserted into the body.
[0023]
When a lamp power switch (not shown) is turned on, power is supplied from the lamp power supply unit 11 including the lamp control circuit 11A to the lamp 12, and light is emitted from the lamp 12. The light emitted from the lamp 12 enters the incident end 51 </ b> A of the light guide 51 provided in the video scope 50 through the condenser lens 14. The light guide 51 is an extremely thin optical fiber bundle that transmits light emitted from the lamp 12 to the distal end portion 60 of the video scope 50 having the observation site S, and the light that has passed through the optical fiber bundle 51 is emitted from the emission end 51B. To do. As a result, light is irradiated to the observation region S that is the subject through the light distribution lens 52 that is an illumination lens.
[0024]
The light reflected at the observation site S passes through the objective lens 53 and reaches the light receiving area of the CCD 54, whereby an optical image of the observation site S is formed in the light receiving area of the CCD 54. In the present embodiment, a simultaneous single plate type is applied as a color imaging method, and yellow (Ye), cyan (Cy), magenta (Mg), and green (G) color elements are checkered on the light receiving surface of the CCD. Are arranged so as to correspond to the respective pixel positions of the light receiving area. Then, in the CCD 54, the optical image of the observation region S is converted into an image signal composed of a plurality of pixel signals corresponding to the color passing through each color element of the complementary color filter, and the image signal for one frame or one field at a predetermined time interval. Are sequentially read according to the color difference line sequential method. In the present embodiment, the NTSC system is applied as a color television system, and image signals for one frame (one field) are sequentially read out every 1/30 (1/60) second interval, and an initial signal processing circuit. 55.
[0025]
The initial signal processing circuit 55 includes a preamplifier, a sample hold circuit, an image memory, an image processing circuit (none of which are shown), and the image signal input to the initial signal processing circuit 55 is received by each circuit. Is converted into a digital image signal and temporarily stored in the image memory. The digital image signal read from the image memory is subjected to processing such as white balance adjustment and gamma correction in an image processing circuit. The processed image signal is sent to the processor 10. Further, a luminance signal that is a luminance component of the image signal input to the initial signal processing circuit 55 is generated and sent to the dimming circuit 23 at a predetermined timing. Here, a luminance signal is sent every 1/30 (1/60) second interval according to the NTSC system.
[0026]
In the processor signal processing circuit 28, predetermined processing is performed on the image signal sent from the initial signal processing circuit 55. The processed image signal is output to the monitor 32 as a video signal (video signal) such as an NTSC composite signal, a Y / C separation signal (S video signal), or an RGB separation signal, whereby a subject image is displayed on the monitor 32. .
[0027]
The system control circuit 22 is provided with a CPU 24, a ROM 25, and a RAM 26. The CPU 24 controls the entire processor 10, and sends control signals to each circuit such as the light control circuit 23, the lamp control circuit 11A, and the processor signal processing circuit 28. Output. In the timing control circuit 30, a clock pulse for adjusting a signal processing timing is output to each circuit in the processor 10, and a synchronization 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.
[0028]
A diaphragm 16 that adjusts the amount of light applied to the subject S is provided between the incident end 51 </ b> A of the light guide 51 and the condenser lens 14, and opens and closes by driving the motor 18. In the present embodiment, the amount of light that passes through the diaphragm 16, that is, the light that is applied to the subject S, is adjusted by a light control circuit 23 that is configured by a DSP (Digital Signal Processor). Furthermore, in this embodiment, as will be described later, the subject image displayed through the monitor 32 is divided into a plurality of blocks, and the average luminance value is calculated for each block. Then, average photometry is performed on the entire observation image, and peak photometry is performed near the center of the observation image. A luminance value indicating the brightness of the entire subject image is calculated based on the luminance value obtained by average metering and the luminance value obtained by peak metering, and a control signal is sent from the light control circuit 23 to the motor driver 20 based on this luminance value. As a result, the motor 18 is driven by the motor driver 20, and as a result, the diaphragm 16 is opened (or closed) so as to have a predetermined opening.
[0029]
In the video scope 50, a scope control unit 56 for controlling the entire video scope 50 and an EEPROM 57 in which data related to the video scope 50 are stored in advance are provided. 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. In this embodiment, the number of pixels of the CCD 54 is smaller than the number of pixels of the monitor 32, and the subject image formed on the CCD 54 is an image displayed on the monitor 32 as it is.
[0030]
The operation section 50P of the video scope 50 is provided with an angle knob 58. When an operator such as a doctor rotates the angle knob 58, the distal end portion 60 of the video scope 50 is bent in the up / down / left / right directions orthogonal to each other. . Angular velocity sensors 59A and 59B are connected to the angle knob 58, and signals related to the rotational operation are detected from the angular velocity sensors 59A and 59B in accordance with the rotational operation on the operation knob 58 and sent to the dimming circuit 23.
[0031]
The front panel 46 is provided with a setting switch 46A for setting a reference luminance value Yr used as a standard in automatic light control. When the operator operates the switch, a signal corresponding to the operation is sent to the system control circuit 22. Sent. The reference luminance value data is temporarily stored in the RAM 26 and sent from the system control circuit 22 to the dimming circuit 23 as necessary.
[0032]
FIG. 2 is a diagram schematically showing the angle knob 58.
[0033]
The angle knob 58 includes a left / right knob 58A for bending the distal end portion 60 in the left / right direction and an up / down knob 58B for bending the tip portion 60 along the up / down direction. The shaft 58D and the left and right shafts C are connected. When the left / right knob 58A or the upper / lower knob 58B is rotated, the shafts 58C and 58D rotate in conjunction with the rotation. The upper and lower and left and right shafts 58C and 58D are respectively connected to corresponding pulleys (not shown), and a wire extending to the distal end portion 60 is hung around each pulley. When the up / down knob 58A or the left / right knob 58B is operated, the distal end portion 60 bends in the up / down or left / right direction according to the operation amount. Angular velocity sensors 59A and 59B are connected to the upper and lower shafts 58A and 58B, respectively, and the angular velocities in the rotational direction of the knob when the distal end portion 60 is bent are detected. Then, as described later, a signal corresponding to the detected angular velocity (hereinafter referred to as an angular velocity signal) is sent to the dimming circuit 23 of the processor 10.
[0034]
FIGS. 3 and 4 are diagrams showing an automatic light control processing routine, which executes processing by interrupting a main routine (not shown) every 1/30 (1/60) seconds in accordance with the NTSC system. FIG. 5 is a diagram showing an observation image composed of a plurality of blocks, and FIG. 6 is a diagram showing the movement of the peak photometry area in accordance with the rotation operation with respect to the angle knob 58. FIG. 7 is a view showing an observation image in which high luminance is generated in a minute region.
[0035]
In step S101, as shown in FIG. _xy The peak photometry area A1 and the average photometry area A2 are set.
[0036]
The observation image A shown in FIG. 5 corresponds to the subject image displayed on the monitor 32, and 8 × 8 = 64 blocks B _xy The observation image A is configured such that (x = 0 to 7, y = 0 to 7) are arranged in a matrix. Here, the subscript x represents the horizontal direction of the screen of the monitor 32, and the subscript y represents the vertical direction of the screen of the monitor 32. Furthermore, each block B _xy Is an 8 × 8 pixel P _xyij (I = 0 to 7, j = 0 to 7), and the entire observation image is composed of 64 × 64 (= 4096) pixels. Here, the suffix i represents the horizontal direction of the screen of the monitor 32, and the suffix j represents the vertical direction of the screen of the monitor 32. Each pixel P _xyij Is the brightness value Y _xyij Each pixel P _xyij A luminance signal corresponding to the luminance value is sent from the video scope 50 to the dimming circuit 23. In the present embodiment, the brightness of the subject image is divided into 256 levels, and the luminance value is set to any value from 0 to 255 as the luminance level.
[0037]
For the observation image A, a peak photometry area A1 in which a boundary line is drawn around the center and an average photometry area A2 composed of the entire observation image are defined. In the peak photometry area A1, peak photometry and average photometry area A2 are defined. Average photometry is performed. Here, the area ratio between the peak photometry area A1 and the average photometry area A2 is about 1: 3. Since internal organs such as the large intestine have a tubular shape, when the distal end portion 60 of the video scope 50 faces the center of the organ, the peripheral portion of the distal end portion 60 is close to the organ. In other words, the portion projected in the peripheral region of the observation image A becomes an inner wall that is close to the distal end portion 60 in the organ. And when the front-end | tip part 60 approaches the site | part which should be noted, an operator will bend the front-end | tip part 60 and will point the front end surface of the front-end | tip part 60 to a site | part of interest. The range of the peak photometry area A1 with respect to the entire observation image A is determined in consideration of the fact that the part to be focused is displayed in the center of the observation image A, the peak photometry can be performed on the whole part, and the like. When step S101 is executed, the process proceeds to step S102.
[0038]
In step S102, the angular velocity Rh is detected as numerical data from the angular velocity signal detected and sent by the angular velocity sensor 59A corresponding to the left / right knob 58A. Here, the angular velocity Rh detected when the left / right knob 58A is operated in order to bend the tip 60 in the left direction is indicated by a positive value, and when the left / right knob 58A is rotated in order to bend in the right direction. The detected angular velocity Rh is indicated by a negative value. The angular velocity Rh is detected based on the position of the left / right knob 58A according to the curved state of the tip 60 before the rotation operation. In step S103, it is determined whether or not the detected angular velocity Rh is greater than a threshold value r1 (> 0). That is, it is determined whether or not the operated rotation direction of the left / right knob 58A is a direction in which the distal end portion 60 is bent leftward (counterclockwise in this case), and the magnitude of each speed Rh (| Rh | ) Is larger than the threshold value r1. The threshold value r1 indicates the magnitude of the minimum angular velocity necessary to move the peak photometric area A1 in the left-right direction, and whether the left / right knob 58A has been consciously operated to bend the tip 60 in the direction of the region to be observed. This is a reference value for determining whether or not.
[0039]
If it is determined in step S103 that the angular velocity Rh is greater than the threshold value r1, that is, if it is determined by the operator that the left / right knob 58A has been consciously operated counterclockwise, the process proceeds to step S104. In step S104, the peak photometric area A1 moves leftward by a predetermined amount in the entire observation image A according to the detected angular velocity Rh (see FIG. 6). That is, the peak photometric area A1 moves to the left in the entire observation image A as the tip 60 is curved in the left direction where there is a portion to be noticed. When step S104 is executed, the process proceeds to step S108.
[0040]
On the other hand, if it is determined in step S103 that the angular velocity Rh is not greater than the threshold value r1, the process proceeds to step S105. In step S105, it is determined whether or not the angular velocity Rh satisfies the following expression.
-R1 ≦ Rh ≦ r1 (1)
That is, it is determined whether or not the left and right knob 58A is substantially operated because the operator is not consciously operating the left and right knob 58A.
[0041]
When it is determined in step S105 that the angular velocity Rh satisfies the expression (1), the process proceeds to step S106, and the peak photometric area A1 is maintained near the center without moving. On the other hand, when the angular velocity Rh does not satisfy the expression (1), that is, it is determined that the angular velocity Rh is smaller than −r1, the left / right knob 58A is rotated clockwise in order to consciously curve the tip portion 60 to the right. The process proceeds to step S107. In step S107, the peak photometric area A1 moves to the right in the entire observation image A by a predetermined amount according to the magnitude of the angular velocity Rh. When step S106 or step S107 is executed, the process proceeds to step S108.
[0042]
In step S108, the angular velocity Rv is detected as numerical data from the angular velocity signal detected and sent by the angular velocity sensor 59B corresponding to the up / down knob 58B. Here, the angular velocity Rv detected when the up / down knob 58B is operated to bend the tip 60 upward is indicated by a positive value, and is detected when the up / down knob 58B is operated to bend down. The angular velocity Rv to be performed is indicated by a negative value. In step S109, it is determined whether or not the detected angular velocity Rv is larger than a threshold value r2 (> 0). That is, it is determined whether or not the operated rotation direction of the up / down knob 58B is a direction in which the tip end portion 60 is bent upward (here, counterclockwise), and further, the magnitude of each speed Rv (| Rv | ) Is larger than the threshold value r2. The threshold value r2 indicates the magnitude of the minimum angular velocity required to move the peak photometric area A1 in the vertical direction. Whether the vertical knob 58B has been consciously operated to curve the tip 60 in the direction of the region to be observed. It becomes a standard for judging whether or not.
[0043]
If it is determined in step S109 that the angular velocity Rv is greater than the threshold value r2, that is, if it is determined that the up / down knob 58B is consciously operated by the operator, the process proceeds to step S110. In step S110, the peak photometric area A1 moves upward by a predetermined amount in the entire observation image A according to the detected angular velocity Rv (see FIG. 6). That is, the peak photometric area A1 moves upward in the entire observation image A as the tip 60 is curved upward in a certain region where the region to be noticed is located. When step S110 is executed, the process proceeds to step S114 of FIG.
[0044]
On the other hand, if it is determined in step S109 that the angular velocity Rv is not greater than the threshold value r2, the process proceeds to step S111. In step S111, it is determined whether or not the angular velocity Rv satisfies the following expression.
−r2 ≦ Rv ≦ r2 (2)
That is, it is determined whether the operator has not operated the up / down knob 58B consciously, and substantially does not operate the up / down knob 58B.
[0045]
When it is determined in step S111 that the angular velocity Rv satisfies the expression (2), the process proceeds to step S112, and the peak photometric area A1 is maintained near the center without moving. On the other hand, when it is determined that the angular velocity Rv does not satisfy the expression (2), that is, the angular velocity Rh is smaller than −r2, it is considered that the up / down knob 58B has been operated in order to consciously curve the tip portion 60 downward. The process proceeds to step S113. In step S113, the peak photometric area A1 moves downward in the entire observation image A by a predetermined amount according to the magnitude of the angular velocity Rv. When step S112 or step S113 is executed, the process proceeds to step S114 in FIG.
[0046]
In step S114, 64 blocks B _xy For each, the average luminance value (hereinafter referred to as the block luminance average value) YB _xy Is calculated.
YB _xy = ΣY _xyij / 64 (3)
Each block B _xy Block luminance average value YB _xy Is obtained, the process proceeds to step S115, and the peak luminance value Y is measured for the peak photometric area A1. _p Is calculated, and the average luminance value J is calculated for the average photometric area A2. _ave Is calculated.
[0047]
Average luminance value J _ave Are the blocks B belonging to the average photometric area A2. _xy Block luminance average value YB _xy Is obtained by the following formula.
J _ave = ΣYB _xy / 48 ... (4)
(However, Σ represents the sum of only x and y in the average photometric area A2.)
On the other hand, peak value Y _p In the case of each block B in the peak metering area A1 _xy Luminance average value YB _xy Are compared, and the maximum luminance average value YB among them is compared. _xy Is the peak value Y _p It is determined as When step S115 is executed, the process proceeds to step S116.
[0048]
In step S116, the reference luminance value Y in the automatic light control process. _r The luminance value I of the observation image A to be compared with is calculated based on the following formula. Hereinafter, the luminance value I is referred to as a representative luminance value.
I = α × J _ave + Β × Y _pp ... (5)
Where α and β are weighting coefficients. The values of the weighting coefficients α and β may be set according to the use situation, but here, α is set to a value sufficiently smaller than β. When step S116 is executed, the process proceeds to step S117.
[0049]
In step S117, the representative luminance value I and the reference luminance value Y _r And the tolerance C are compared. Reference luminance value Y _r Is set to 128 here. Representative luminance value I and reference luminance value Y _r Is larger than the tolerance C, that is, outside the tolerance range, the process proceeds to step S118, and a control signal corresponding to the difference is sent from the light control circuit 23 to the motor driver 20. As a result, the diaphragm 16 is opened / closed by a predetermined amount so that the brightness of the subject image is appropriate. When step S118 is executed, the processing routine ends. On the other hand, the representative luminance value I and the reference luminance value Y _r Is equal to or less than the tolerance C, that is, within the tolerance range, it is determined that the brightness of the subject image is substantially appropriate, and the processing routine ends.
[0050]
FIG. 7 shows an observation image in which only some pixels in the peak photometry area A1 have high luminance. As shown in FIG. 7A, in a state in which a notable part is projected in the peak photometric area A1, the block B _xy Specific pixel P in _xyij (In FIG. 7A, i = j = 4, that is, P _xy44 ) Only in a high brightness state. Block B _xy Pixel P in _xy44 Reference luminance value Y for pixels other than _r (= 128) and the pixel P _xy44 Only has a high luminance value (= 255). In this embodiment, block B _xy Block luminance average value YB for _xy Is calculated and the luminance average value YB of other blocks is calculated. _xy Peak value Y while being compared with _p Is determined. Therefore, the pixel P _xyij Luminance value of the peak value Y as it is _p Is not calculated. Calculated block luminance average value YB _xy Is a high-intensity pixel P _xyij It is substantially calculated based on the other pixels.
[0051]
Further, as shown in FIG. 7B, the block B is not limited to a single pixel but a plurality of pixels in a minute region VS in a high luminance state due to the influence of minute irregularities on the mucous membrane or part of the body. _xy Each block luminance average value YB _xy Is calculated and other block luminance average value YB _xy Peak value Y while being compared with _p Therefore, the peak value Y remains as it is due to the influence of the minute region VS having the pixels in the high luminance state. _p Is not determined to be a high luminance value.
[0052]
As described above, according to the present embodiment, the peak photometry area A1 in which the peak photometry is executed and the average photometry area A2 in which the average photometry is executed are set in the observation image A, and the peak photometry area A1 is included in the observation image A. In the center. On the other hand, angular velocity sensors 59A and 59B are connected to the left and right knobs 58A and 58B, respectively, which are rotated to bend the tip 60, and the angular velocities are detected when rotated. The peak photometric area A1 moves in a predetermined direction in the observation image A according to the moving direction and the moving amount determined by the detected angular velocity.
[0053]
For example, when the left / right knob 58A is rotated counterclockwise in order to bend leftward from the neutral state where the tip 60 extends straight, the peak photometry area A1 first moves to the left and the rotation operation ends. This time, it moves in the opposite right direction and returns to the vicinity of the original center. When the left / right knob 58A is rotated clockwise in order to return the tip 60 to the neutral state from the curved state, the peak photometric area A1 first moves to the right and then moves to the opposite left. While returning to the center of the original. Thereby, peak photometry is always realized in the image area in which the site to be watched is projected.
[0054]
The representative luminance value may be calculated by a method other than the equation (5). The block luminance average value YB _xy May be calculated using the histogram distribution of luminance, and the average luminance value J is calculated so as to calculate the average value of the brightness of the subject image. _ave You can ask for. The range and size of the peak photometric region A1 may be set to a range and size other than those of the present embodiment, and may be located in the central portion of the observation image A. Further, the range of the average photometric area may be set to the peripheral area of the observation image A excluding the peak photometric area A1.
[0055]
In the present embodiment, the brightness of the subject image displayed on the monitor 32 is adjusted by opening and closing the diaphragm 16, but the brightness of the subject image is adjusted by adjusting the amount of charge read by the electronic shutter function of the CCD 54. You may adjust.
[0056]
In this embodiment, left and right knobs 58A and 58B for rotation operation are provided to curve the distal end portion 60, but a bending operation member that is bent by an operation other than rotation may be applied. Furthermore, a configuration in which the curvature of the tip portion 60 is directly detected may be employed.
[0057]
Next, a second embodiment will be described with reference to FIG. In the second embodiment, when the knob is continuously operated for a certain time in a predetermined direction, it is determined that an operation for intentionally bending the distal end portion 60 toward the observation site to be noticed is performed. To do. Further, the peak photometric area is moved according to the amount of knob rotation. Other configurations are substantially the same as those in the first embodiment.
[0058]
FIG. 8 is a diagram showing an automatic light control processing routine in the second embodiment.
[0059]
In step S201, time variables T1 and T2 are set to 0, respectively. The time variables T1 and T2 are variables for counting the time during which the left and right knobs 58A and the upper and lower knobs 58B are continuously operated, respectively. In step S202, as in step S102 of FIG. 3, the angular velocity Rh related to the bending in the left-right direction is detected. Then, in step S203, it is determined whether or not the detected angular velocity Rh is larger than the threshold value r1, as in step S103 of FIG.
[0060]
If it is determined in step S203 that the angular velocity Rh is greater than the threshold value r1, the process proceeds to step S204. In step S204, it is determined whether or not the time variable T1 is greater than the time threshold t1. The time threshold t1 corresponds to the minimum continuous operation time required to move the peak photometric area A1 in the left-right direction, and the operation for bending the tip 60 in the left direction is continuously performed according to the threshold t1. It is determined whether or not it has been over for a predetermined time.
[0061]
If it is determined in step S204 that the time variable T1 is larger than the time threshold t1, the operation of the left / right knob 58A for intentionally bending the tip 60 to the left is continuously performed for a time corresponding to the time threshold t1 or more. The process proceeds to step S205. In step S205, according to the rotational movement amount of the left / right knob 58A, the peak photometric area A1 moves leftward in the entire observation image A by the movement amount corresponding to the rotational operation amount. However, the rotational movement amount of the left / right knob 58A is calculated based on the measured angular velocity Rh and the time variable T1. On the other hand, if it is determined in step S204 that the time variable T1 is not greater than the time threshold t1, the process proceeds to step S206, where the time variable T1 is incremented by one. When step S205 or step S206 is executed, the process proceeds to step S213.
[0062]
On the other hand, if it is determined in step S203 that the angular velocity Rh is not greater than the threshold value r1, the process proceeds to step S207, and it is determined whether or not the angular velocity Rh satisfies the above equation (1). If it is determined in step S207 that the angular velocity Rh satisfies the expression (1), the process proceeds to step S208, and the peak photometric area A1 is maintained near the center without moving. In step 209, the time variable T1 is set to zero. When step S209 is executed, the process proceeds to step S213.
[0063]
On the other hand, when it is determined in step S207 that the angular velocity Rh does not satisfy the expression (1), the process proceeds to step S210. Similar to step S204, in step S210, it is determined whether or not the time variable T1 is greater than the time threshold t1. If it is determined that the time variable T1 is greater than the time threshold t1, it is considered that the operation of the left / right knob 58A for intentionally bending the tip 60 to the right is continuously performed for a time corresponding to the time threshold t1 or more. In step S211, the peak photometry area A1 moves rightward by a predetermined amount in the entire observation image A according to the rotational movement amount of the left / right knob 58A. On the other hand, when it is determined in step S210 that the time variable T1 is not greater than the time threshold t1, the process proceeds to step S212, and the time variable T1 is incremented by one. When step S211 or step S212 is executed, the process proceeds to step S213.
[0064]
In step S213, as in step S108 in FIG. 3, the angular velocity Rv related to the bending in the vertical direction is detected. In step S214, it is determined whether or not the detected angular velocity Rv is larger than the threshold value r2, as in step S109 of FIG.
[0065]
If it is determined in step S214 that the angular velocity Rv is greater than the threshold value r2, the process proceeds to step S215. In step S215, it is determined whether or not the time variable T2 is greater than the time threshold t2. The time threshold t2 corresponds to the minimum continuous operation time required to move the peak photometric area A1 in the vertical direction, and the operation for bending the tip 60 in the left direction is continuously performed according to the threshold t2. It is determined whether or not it has been over for a predetermined time.
[0066]
If it is determined in step S215 that the time variable T2 is larger than the time threshold value t2, the operation of the left / right knob 58A for intentionally bending the tip 60 upward is performed continuously for a time corresponding to the time threshold value t2. The process proceeds to step S216. In step S216, the peak photometric area A1 moves upward in the entire observation image A by a predetermined amount according to the rotational movement amount of the up / down knob 58B. The rotational movement amount of the up / down knob 58B is calculated based on the measured angular velocity Rv and the time variable T2. On the other hand, if it is determined in step S215 that the time variable T2 is not greater than the time threshold t2, the process proceeds to step S217, and the time variable T2 is incremented by one. When step S216 or step S217 is executed, the process proceeds to step S224. On the other hand, when it is determined in step S214 that the angular velocity Rv is not greater than the threshold value r2, the process proceeds to step S218, and it is determined whether or not the angular velocity Rv satisfies the above equation (2).
[0067]
If it is determined in step S218 that the angular velocity Rv satisfies the expression (2), the process proceeds to step S219, and the peak photometric area A1 is maintained near the center without moving. In step 220, the time variable T2 is set to zero. When step S220 is executed, the process proceeds to step S224.
[0068]
On the other hand, if it is determined in step S218 that the angular velocity Rv does not satisfy the expression (2), the process proceeds to step S221. Similar to step S210, in step S221, it is determined whether or not the time variable T2 is greater than the time threshold t2. If it is determined that the time variable T2 is greater than the time threshold t2, it is considered that the operation of the left and right knob 58A for intentionally bending the tip 60 downward has been performed continuously for a time corresponding to the time threshold t2. In step S222, the peak photometric area A1 moves downward by a predetermined amount in the entire observation image A according to the rotational movement amount of the up / down knob 58B. On the other hand, if it is determined in step S221 that the time variable T2 is not greater than the time threshold t2, the process proceeds to step S223, and the time variable T2 is incremented by one. When step S222 or step S223 is executed, the process proceeds to step S213.
[0069]
The execution of steps S224 to 228 is the same as the execution of steps 114 to 118 in FIG. That is, the block luminance average value YB for each block _xy Is calculated, and the peak luminance value Y is respectively obtained for the peak photometry area A1 and the average photometry area A2. _p , Average luminance value J _ave Is calculated. Then, the representative luminance value I is calculated based on the equation (5), and the representative luminance value I and the reference luminance value Y are calculated. _r It is determined whether or not the difference between is within an allowable range. When it is outside the allowable range, the diaphragm 16 is driven to open and close. When step S228 is executed, the process returns to step S202.
[0070]
In the first and second embodiments, the observation image A is a plurality of blocks B. _xy However, peak metering and average metering may be executed without dividing.
[0071]
FIG. 9 is a diagram illustrating an observation image of the electronic endoscope apparatus according to the third embodiment. In the third embodiment, the luminance values of all the pixels constituting the peak photometric area A1 are compared as they are, and the peak value Y _p The peak photometry is performed, and the average luminance value J is obtained by uniformly averaging the luminance values of all the pixels in the peak photometric area A2. _ave Average photometry is performed to determine
[0072]
【The invention's effect】
As described above, according to the present invention, in the electronic endoscope apparatus, while the video scope is operated, the portion to be watched is always displayed on the display device by performing peak photometry on the portion to be watched on the screen. It can be clearly projected.
[Brief description of the drawings]
FIG. 1 is a block diagram of an electronic endoscope apparatus according to a first embodiment.
FIG. 2 is a view schematically showing an angle knob.
FIG. 3 is a diagram showing a front part of an automatic light control processing routine in the first embodiment.
FIG. 4 is a diagram showing a latter part of an automatic light control processing routine in the first embodiment.
FIG. 5 is a diagram showing an observation image composed of a plurality of blocks.
FIG. 6 is a diagram showing movement of a peak photometry area in accordance with an operation on a knob.
FIG. 7 is a view showing an observation image in which high luminance is generated in a minute region.
FIG. 8 is a diagram showing an automatic light control processing routine in the second embodiment.
FIG. 9 is a view showing an observation image in the third embodiment.
[Explanation of symbols]
10 processor
16 Aperture
22 System control circuit
23 Dimming circuit
32 monitors
50 video scope
54 CCD (Image sensor)
58 Angle knob (curving operation part)
58A Left and right knob (first rotation operation unit)
58B Up / down knob (second rotary operation unit)
59A, 59B Angular velocity sensor
60 Tip (scope tip)
Rv, Rh Angular velocity (bending direction, bending change amount)
r1, r2 threshold value (reference curve change amount)
t1, t2 time threshold (standard operation time)
A1 Peak metering area
A2 Average metering area
I Representative luminance value

Claims (18)

An electronic endoscope apparatus comprising a videoscope having an imaging element for imaging a subject at a distal end portion of an insertion portion and a bending operation portion for bending the distal end portion at a portion other than the insertion portion. And
A light source for illuminating the subject;
A photometric area setting means for determining an average photometric area so as to include at least a peripheral part of the subject image, while defining a peak photometric area in the center of the entire subject image,
Luminance calculation for calculating a representative luminance value indicating brightness of a subject image based on an image signal read from the image sensor by performing peak metering in the peak metering region and performing average metering in the average metering region Means,
Subject image brightness adjusting means for appropriately maintaining the brightness of the subject image based on the representative luminance value;
A bending detection means for detecting the bending direction and the bending change amount of the tip portion by detecting the operation direction and the operation change amount of the bending operation portion;
An electronic endoscope apparatus comprising: a peak photometry area moving unit that moves the peak photometry area in the entire subject image according to the bending direction and the amount of change in bending. The bending operation unit is a bending operation unit capable of rotating an axis;
The bending detection means detects a bending direction and a bending change amount of the tip portion by detecting an angular velocity including rotation direction information at the time of a rotation operation with respect to the bending operation unit. The electronic endoscope apparatus described. The bending operation unit is configured by a first rotation operation unit and a second rotation operation unit that are capable of axial rotation for separately bending along two axial directions orthogonal to each other,
The electronic endoscope apparatus according to claim 2, wherein the curvature detection unit detects the angular velocities at the time of a rotation operation on the first and second rotation operation units. 2. The electronic endoscope according to claim 1, wherein the peak photometry area moving unit moves the peak photometry area in a direction corresponding to the bending direction by a movement amount corresponding to a magnitude of the bending change amount. Mirror device. 4. The peak photometric area moving means moves the peak photometric area in a direction based on the rotation direction information by an amount of movement corresponding to the magnitude of the angular velocity. The electronic endoscope apparatus described. A bending time detecting means for detecting a bending time of the tip portion by detecting a continuous operation time in a predetermined direction with respect to the bending operation portion;
2. The inside of an electron according to claim 1, wherein the peak photometry area moving means moves the peak photometry area in a direction corresponding to the bending direction by a movement amount corresponding to the operation time and the operation change amount. Endoscopic device. Rotation operation time detecting means for detecting the bending time of the tip portion by detecting continuous rotation operation time in a predetermined direction with respect to the bending operation unit,
3. The electron according to claim 2, wherein the peak photometric area moving unit moves the peak photometric area in a direction corresponding to the bending direction by a movement amount corresponding to the operation time and the magnitude of the angular velocity. Endoscopic device. A first rotation operation time detection means and a second rotation operation detection means for respectively detecting continuous rotation operation times in a predetermined direction with respect to each of the first and second rotation operation sections;
The said peak photometry area movement means moves the said peak photometry area | region by the movement amount according to the magnitude | size of the said rotation operation time and the said angular velocity to the direction corresponding to the said curving direction. Electronic endoscope device. By determining whether or not the magnitude of the operation change amount exceeds the reference operation change amount, whether or not the magnitude of the bending change amount at the tip portion exceeds the reference curvature change amount Further comprising a bending change magnitude determining means for determining whether
5. The peak photometry area moving means does not move the peak photometry area when the magnitude of the operation change amount does not exceed the reference operation change quantity. An electronic endoscope apparatus according to any one of the above. Angular velocity magnitude determining means for determining whether or not the magnitude of the angular velocity exceeds a reference angular velocity;
The bending detection means detects the angular velocity at the time of a rotation operation on the bending operation unit;
6. The peak photometric area moving means does not move the peak photometric area when the angular velocity does not exceed a reference angular velocity. Electronic endoscope device. Angular velocity magnitude determination means for determining whether or not the magnitude of the angular velocity according to the first rotation operation section and the second rotation operation section exceeds the reference angular speed;
The bending detection means detects the angular velocities at the time of a rotation operation with respect to the first and second rotation operation units;
6. The peak photometric area moving means does not move the peak photometric area when the angular velocity does not exceed a reference angular velocity. Electronic endoscope device. By determining whether or not the operation time exceeds the reference operation time, it is determined whether or not the bending time during which the scope tip is continuously bent in a predetermined direction exceeds the reference bending time. 7. The electronic endoscope according to claim 6, further comprising time discriminating means, wherein the peak photometric area moving means does not move the peak photometric area when the bending time does not exceed a reference bending time. Mirror device. A rotation operation time determining means for determining whether or not the rotation operation time exceeds a reference rotation operation time;
The electronic endoscope apparatus according to claim 7, wherein the peak photometry area moving unit does not move the peak photometry area when the rotation operation time does not exceed a reference rotation operation time. Rotation operation time determination means for determining whether or not the rotation operation time detected by the first rotation operation time detection means and the second rotation operation detection means exceeds a reference rotation operation time. ,
9. The electronic endoscope apparatus according to claim 8, wherein the peak photometry area moving means does not move the peak photometry area when the rotation operation time does not exceed a reference rotation operation time. In the entire subject image formed by the videoscope imaging device by illuminating the subject with light from the light source, a peak metering region is defined at the center and an average metering region is provided so as to include at least the periphery of the subject image. Photometric area setting means to be determined;
Luminance calculation for calculating a representative luminance value indicating brightness of a subject image based on an image signal read from the image sensor by performing peak metering in the peak metering region and performing average metering in the average metering region Means,
Subject image brightness adjusting means for appropriately maintaining the brightness of the subject image based on the representative luminance value;
Bend detection means for detecting a bend direction and a bend change amount of the distal end portion of the video scope;
A subject image brightness adjustment device for an electronic endoscope apparatus, comprising: a peak metering region moving unit that moves the peak metering region in the entire subject image in accordance with the bending direction and the amount of bending change. In the entire subject image formed by the videoscope imaging device by illuminating the subject with light from the light source, a peak metering region is defined at the center and an average metering region is provided so as to include at least the periphery of the subject image. Set
By performing peak metering in the peak metering region and performing average metering in the average metering region, a representative luminance value indicating the brightness of the subject image is calculated based on the image signal read from the image sensor,
Maintaining the brightness of the subject image appropriately based on the representative luminance value,
Detecting the bending direction and bending change amount of the distal end portion of the videoscope,
A subject image brightness adjustment method for an electronic endoscope apparatus, wherein the peak photometry area is moved in the entire subject image in accordance with the bending direction and the amount of bending change. In the entire subject image formed by the videoscope imaging device by illuminating the subject with light from the light source, a peak metering region is defined at the center and an average metering region is provided so as to include at least the periphery of the subject image. Photometric area setting means to be determined;
Luminance calculation for calculating a representative luminance value indicating brightness of a subject image based on an image signal read from the image sensor by performing peak metering in the peak metering region and performing average metering in the average metering region Means,
Subject image brightness adjusting means for appropriately maintaining the brightness of the subject image based on the representative luminance value;
Peak photometry area moving means for moving the peak photometry area in the entire subject image in accordance with the curve direction and curve change detected by the curve detection means for detecting the curve direction and curve change of the distal end portion of the video scope; A program for adjusting the brightness of a subject image for an electronic endoscope apparatus. An electronic endoscope apparatus comprising a videoscope having an imaging element for imaging a subject at a distal end portion of an insertion portion and a bending operation portion for bending the distal end portion at a portion other than the insertion portion. And
A light source for illuminating the subject;
A photometric area setting means for determining an average photometric area so as to include at least a peripheral part of the subject image, while defining a peak photometric area in the center of the entire subject image,
Luminance calculation for calculating a representative luminance value indicating brightness of a subject image based on an image signal read from the image sensor by performing peak metering in the peak metering region and performing average metering in the average metering region Means,
Subject image brightness adjusting means for appropriately maintaining the brightness of the subject image based on the representative luminance value;
Bend detecting means for detecting the bend direction and bend change amount of the tip;
An electronic endoscope apparatus comprising: a peak photometry area moving unit that moves the peak photometry area in the entire subject image according to the bending direction and the amount of change in bending.

Images