JP3392911B2 - Electronic endoscope device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus having a color correcting means for detecting a distance to an object and correcting a color signal for the object in accordance with the distance.

[0002]

2. Description of the Related Art In recent years, endoscopes have been widely used for diagnosis in the medical field and, if necessary, for medical treatment using a treatment tool.

FIG. 28 shows a conventional electronic endoscope apparatus. This electronic endoscope apparatus has an electronic endoscope 1, and this electronic endoscope 1 has an elongated and flexible insertion portion 2, for example, and has a large-diameter operation at the rear end of the insertion portion 2. The section 3 is continuously provided. A flexible universal cable 4 extends laterally from the vicinity of the rear end of the operation portion 3, and a connector 5 is provided at the tip of the cable 4.

The electronic endoscope 1 is connected via the connector 5 to a video processor 6 having a built-in light source device and a signal processing circuit. Further, a color monitor 7 is connected to the video processor 6.

A hard tip portion 9 and a bending portion 10 adjacent to the tip portion 9 and capable of bending to the rear side are sequentially provided on the tip end side of the insertion portion 2.

Further, by rotating the bending operation knob 11 provided on the operation section 3, the bending section 10 is rotated.
Can be bent to the left or right or up and down. Further, the operation portion 3 has an insertion opening 1 that communicates with a treatment tool channel (not shown) provided in the insertion portion 2.
Two are provided.

As shown in FIG. 29, a light guide 14 for transmitting illumination light is inserted into the insertion portion 2 of the electronic endoscope 1. The tip end surface of the light guide 14 is arranged at the tip end portion 9 of the insertion portion 2, and the illumination light can be emitted from the tip end portion 9. In addition, the light guide 1
The incident end side of 4 is inserted into the universal cable 4 and connected to the connector 5.

At the tip portion 9, the objective lens system 1
5 is provided, and the solid-state imaging device 16 is provided at the image forming position of the objective lens system 15. This solid-state image sensor 1
No. 6 has sensitivity in a wide wavelength range including the visible range and the ultraviolet range to the infrared range. Signal lines 26 and 27 are connected to the solid-state imaging device 16, and these signal lines 2
6, 27 are the insertion portion 2 and the universal cable 4
It is inserted inside and connected to the connector 5.

On the other hand, the light source device 20 provided in the video processor 6 is provided with a lamp 21 which emits light in a wide band from ultraviolet light to infrared light. As the lamp 21, a general xenon lamp, a strobe lamp, or the like can be used. The xenon lamp and strobe lamp emit a large amount of not only visible light but also ultraviolet light and infrared light.

Electric power is supplied to the lamp 21 by a power supply section 22. A rotary filter 24, which is rotationally driven by a motor 23, is arranged in front of the lamp 21. Filters that transmit light in the respective wavelength regions of red (R), green (G), and blue (B) for normal observation are arranged in the rotary filter 24 along the circumferential direction. Further, the motor 23 is controlled in rotation by a motor driver 25 and driven.

After passing through the rotary filter 24, R, G,
The light that has been time-sequentially separated into the lights of the respective wavelength regions of B is further incident on the incident end of the light guide 14, guided to the tip portion 9 via the light guide 14, and emitted from the tip portion 9. The observation site is illuminated.

The return light from the subject (subject) such as an observation site due to the illumination light is imaged on the solid-state image pickup device 16 by the objective lens system 15 and photoelectrically converted. The solid-state image sensor 16 includes the signal line 26.
A drive pulse is applied from the driver 31 in the video processor 6 via the, and an electric signal (video signal) corresponding to the image of the subject photoelectrically converted by the drive pulse is read out. There is.

The electric signal read from the solid-state image pickup device 16 is input to the preamplifier 32 provided in the video processor 6 or the electronic endoscope 1 through the signal line 27. ing. This preamp 3
The video signal amplified by 2 is input to the AGC circuit 55 and the dimming circuit 56. The AGC circuit 55 is feedback-controlled by the AGC control circuit 57, and the signal level is controlled by the output control signal of the AGC control circuit 57. On the other hand, the dimming circuit 56 generates a dimming signal for the light source based on the output video signal from the preamplifier 32 and outputs it to the light source device 20 to control the amount of illumination light.

The output signal of the AGC circuit 55 is input to the process circuit 33, subjected to signal processing such as γ correction and white balance, and converted into a digital signal by the A / D converter 34.

This digital video signal is selected by the select circuit 35, for example, three memories (1) 36a, memories (2) 36b, and memories corresponding to respective colors of red (R), green (G), and blue (B). (3) It is adapted to be selectively stored in 36c. R stored in the memory (1) 36a, the memory (2) 36b, the memory (3) 36c,
The G and B color signals are simultaneously read out and input to the color correction circuit 60.

In the color correction circuit 60, the R and B color signals are input to the coefficient multipliers 51 and 52, respectively. Coefficient multiplier 51, 52
In, the size of the input signal is converted into a predetermined size. This conversion is performed by a preset value or a value set from the outside.

The R, G, B color signals color-corrected by the color correction circuit 60 are converted into analog signals by the D / A converter 37 and output as R, G, B color signals, and an encoder. It is input to the encoder 38 and is output from the encoder 38 as an NTSC composite signal.

The R, G, B color signals or N
The TSC composite signal is input to the color monitor 7, and the observation site is displayed in color by the color monitor 7.

Further, the video processor 6 is provided with a timing generator 42 for generating the timing of the entire system, and the timing generator 42 synchronizes the circuits such as the motor driver 25, the driver 31, and the selection circuit 35. Has been taken.

[0020]

In the above-described color correction method, the color adjustment is performed by simply changing the magnitude of the R or B signal by the indicating means or the like.

For example, in endoscopic observation of a body cavity, the visceral wall to be inspected has a predetermined color. Therefore, when observing a far point, the screen is affected by the secondary reflected light of the visceral wall. There are problems that the overall color becomes dark and the color balance is lost.

However, in the conventional color correction method described above,
Correction of different colors depending on the distance of the observation point such as the influence of the secondary reflected light of the internal organ wall is not considered,
It was sometimes difficult to adjust to the desired color.

The present invention has been made in view of these circumstances, and an object thereof is to provide an electronic endoscope apparatus capable of easily correcting a color that changes depending on the distance of an observation point.

[0024]

An electronic endoscope apparatus according to the present invention includes an electronic endoscope including an image pickup unit that converts light information from a subject into an electric signal, and an electric signal of the image pickup unit as a video signal. In the electronic endoscope apparatus having a video signal processing means for processing, the video signal processing means determines a distance between the subject and the imaging means based on an electric signal of the imaging means, and Based on the determination result of the distance determining means, the distance between the subject and the image pickup means
As the distance increases, the color density of the subject increases.
And a color correction unit that corrects the color signal so that the color becomes lighter . Further, the electronic endoscope apparatus according to the present invention,
Equipped with imaging means that converts light information from the subject into electrical signals
The electric signal of the electronic endoscope and the image pickup means is a video signal.
To an electronic endoscope apparatus having a video signal processing means for processing
Where the video signal processing means is a video of the imaging means.
Output from AGC control circuit that adjusts signal gain
The subject and the imaging means based on an AGC control signal
Of the distance determining means for determining the distance
Based on the determination result, the distance between the subject and the image pickup means
As the distance increases, the color density of the subject increases.
Color correction means for correcting the color signal so that
It is a thing. Further, the electronic endoscope apparatus according to the present invention,
The electronic endoscope apparatus according to claim 1, wherein:
The correction by the color correction means is linear or non-linear and adaptive.
It is characterized by being. Further according to the invention
The electronic endoscope apparatus is the electronic endoscope according to claim 1.
In the child endoscope apparatus, a predetermined color of the subject
Further, a specific color correction means for increasing the correction amount of the specific color is further provided.
It is characterized by that.

[0025]

According to a first aspect of the present invention, the distance discriminating means discriminates the distance between the object and the image pickup means based on the electric signal from the image pickup means, and the color correcting means discriminates the distance discriminating means. Based on the result, the subject and the front
The color signal is corrected so that the color density of the subject becomes lighter as the distance from the image pickup means increases .
The invention according to claim 2 is characterized in that
AGC control circuit for adjusting the gain of the image signal of the image pickup means
The subject based on the AGC control signal output from the road
And the image pickup means, and the color correction means determines
Therefore, based on the determination result of the distance determining means,
As the distance between the object and the image pickup means increases,
The color signal so that the color density of the subject becomes lighter.
To correct. The invention described in claim 3 is the same as claim 1 or 2.
In the mounted electronic endoscope apparatus, the color correction means
Positive is linear or non-linear and adaptive. In claim 4
The invention described in the above is an electronic endoscope according to any one of claims 1 to 3.
In the mirror device, the subject of
The correction amount of a predetermined specific color of the body is increased.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 9 relate to a first embodiment of the present invention, FIG. 1 is a block diagram showing a configuration of a signal processing system of an electronic endoscope apparatus, FIG. 2 is a block diagram showing a configuration of a first color correction circuit, FIG. 3 is an explanatory view showing the operation of color correction by the first color correction circuit,
FIG. 4 is a block diagram showing the configuration of the second color correction circuit, FIG. 5 is an explanatory diagram showing the operation of color correction by the second color correction circuit, and FIG.
Is an explanatory view showing an operation section of the external adjusting means, FIG. 7 is a block diagram showing a first configuration example of the third color correction circuit, FIG. 8 is a block diagram showing a second configuration example of the third color correction circuit, FIG. 9 is the third
It is a block diagram which shows the 3rd structural example of a color correction circuit.

FIG. 1 shows the configuration of a signal processing system of the electronic endoscope apparatus of this embodiment.

As shown in FIG. 28, the electronic endoscope 1 is adapted to be connected to a video processor 6 having a light source device and a signal processing circuit built therein. As shown in FIG. A light guide 14 that transmits illumination light is inserted into the insertion portion 2 of the endoscope so that the illumination light can be emitted from the emission end face of the tip 9 of the insertion portion. Further, the incident end side of the light guide 14 is arranged to face the light source device 20 provided in the video processor 6.

The tip 9 has an objective lens system 1
5 is provided, and the solid-state imaging device 16 is provided at the image forming position of the objective lens system 15. Signal lines 26 and 27 are connected to the solid-state imaging device 16, and these signal lines 2
Reference numerals 6 and 27 denote a driver 31 in the video processor 6 and the video processor 6 or the electronic endoscope 1, respectively.
It is connected to a preamplifier 32 provided inside.

On the other hand, the light source device 20 provided in the video processor 6 is provided with a lamp 21 composed of a xenon lamp, a strobe lamp or the like, and power is supplied from a power source section 22. In front of the lamp 21, a rotary filter 24 in which filters that transmit light in the respective wavelength regions of red (R), green (G), and blue (B) are arranged along the circumferential direction is provided, and a motor driver is provided. It is adapted to be rotationally driven by a motor 23 whose rotation is controlled by 25.

After passing through the rotary filter 24, R, G,
The light, which is time-sequentially separated into the light of each wavelength region of B, is incident on the incident end of the light guide 14, guided to the tip 9 through the light guide 14, and emitted from the tip 9.
It is designed to illuminate the observation site.

The return light from the observed region or the like due to this illumination light is imaged on the solid-state image pickup device 16 by the objective lens system 15 and photoelectrically converted. A driver 31 is connected to the solid-state image sensor 16 via the signal line 26.
Drive pulse is applied, and an electric signal (video signal) corresponding to the image of the subject photoelectrically converted by this drive pulse is read out and input to the preamplifier 32 via the signal line 27. Has become.

The video signal amplified by the preamplifier 32 is input to the AGC circuit 55 and the dimming circuit 56.
The AGC circuit 55 is feedback-controlled by the AGC control circuit 57, and the signal level is controlled by the output control signal of the AGC control circuit 57. On the other hand, the dimming circuit 56 generates a dimming signal for the light source based on the output video signal from the preamplifier 32 and outputs it to the light source device 20 to control the amount of illumination light.

The output signal of the AGC circuit 55 is input to the process circuit 33, subjected to signal processing such as γ correction and white balance, converted into a digital signal by the A / D converter 34, and then passed through the select circuit 35. For example, it is selectively stored in three memories (1) 36a, memory (2) 36b, and memory (3) 36c corresponding to respective colors of red (R), green (G), and blue (B). ing.
And these memory (1) 36a and memory (2) 3
6b, the R, G, B color signals stored in the memory (3) 36c are simultaneously read out and input to the color correction circuit 60.

The color correction circuit 60 includes the first color correction circuit 10
It has a first color correction circuit 102, a second color correction circuit 103, and a third color correction circuit 103, and each color correction circuit performs color correction as described below.

The color correction by the color correction circuit 60 is performed by a preset value or a value set by the external adjusting means 58.

The R, G, B color signals color-corrected by the color correction circuit 60 are converted into analog signals by the D / A converter 37 and output as R, G, B color signals. It is input to the encoder 38 and output from the encoder 38 as an NTSC composite signal. The R, G, B color signals or the NTSC composite signal is input to a color monitor or the like so that the observed region is displayed in color.

Further, in the video processor 6, a timing generator 42 for generating the timing of the entire system.
The timing generator 42 synchronizes the circuits such as the motor driver 25, the driver 31, and the select circuit 35.

Next, the configuration and operation of each correction circuit in the color correction circuit 60 will be described.

For example, in the case of an electronic endoscope, it may be made yellowish as a whole in order to make the color look like a fiberscope. In this case, in the conventional color correction method described above,
This can be achieved by reducing the B signal.

However, for example, when the subject is dyed blue with methylene blue or the like, the one in which the B signal is reduced as described above has a low saturation of blue itself, and the dyed subject becomes dark, which makes it difficult to perform the inspection. May be.

In order to lighten the red color of the mucous membrane, R
When the signal is reduced, the color saturation of blood in bleeding etc. becomes smaller and the blood can be distinguished (fresh blood and old blood).
Has the drawback that it becomes difficult.

Further, in the case of an electronic endoscope, at the time of inspection,
The color reproducibility of blood is important. Particularly, in the hue direction, fine adjustment is necessary.

In the case of the conventional color correction method, it is possible to adjust the hue direction by adjusting the signals of the two systems of the R and B signals, but the adjustment becomes complicated because the signals of the two systems are adjusted. There is a possibility that colors other than the color to be adjusted (color of blood in this case) may change significantly.

As described above, the user adjusts the color so as to obtain a desired color, particularly considering the colors of blood and redness and the overall color. In the case of blood or reddish color, its color (hue) is important, but it is very difficult to adjust the hue only by increasing / decreasing the R signal and B signal, and it has a great influence on other colors.
Also, when adjusting the overall color (such as a mucous membrane color) to a desired color, simply adjusting only the R and B signals has a large effect on other colors, and the adjustment image is difficult to open. That is,
It has been difficult to adjust only the target color to the desired color so as not to affect other colors by adjusting the signals of the two systems of the R signal and the B signal.

Therefore, in the present embodiment, the first color correction circuit 1
01 and the second color correction circuit 102 perform color correction such that only the correction amount of a predetermined specific color that needs adjustment at the time of inspection becomes large, and color correction that has little influence on other color components can be performed. Further, the third color correction circuit 103 corrects the color that changes depending on the distance of the observation point.

The RGB color signals input to the color correction circuit 60 are first input to the first color correction circuit 101. FIG. 2 shows the configuration of the first color correction circuit 101.

The RGB color signals input to the first color correction circuit 101 are input to the color change signal generator 161. The color change signal generator 161 generates the color change signal C according to the following equation.

[0049]           C = R- (pG + qB)               However, when R- (pG + qB) <0, C = 0 (1) Here, for example, consider the case of p = 1 and q = 1.

When the subject color is the R primary color, G = 0, B = 0
Is. That is, C = R. Next, the subject color is yellow Y
In the case of e, R = G, B = 0 and C = RG−0. Similarly, when the subject color is magenta Mg, C = 0
Becomes

That is, when the color is R, the color change signal C has the maximum value R, and becomes smaller as it approaches Ye or Mg. Furthermore, from Ye or Mg, G, Cy, B
When the color is in the direction of, R <G + B, and thus C = 0.

Also, when R = 1, G ≧ 1/2, B ≧ 1/2, C = 0 and C approaches R as G and B become smaller. From the above, in the subject color, the value of C increases as the ratio of the R component increases, that is, the purity of the R component increases.

Next, the color change signal C output from the color change signal generator 161 is input to the coefficient unit 162 indicated by the coefficient k, and is made to have a predetermined size by the control signal output from the color correction setting circuit 163. To be converted.

Further, the color correction setting circuit 163 controls the selection of the selection switches 164, 165 and 166. Here, consider a case where the hue of a subject close to R is corrected in the Ye direction (for example, when the color tone is in a fiberscope style). In this case, the color change signal C generated by the color change signal generator 161 may be set to a predetermined magnitude, added to the G signal, and output as a corrected G signal.

Therefore, when performing this correction, the color correction setting circuit 163 causes the switch 164 as shown in FIG.
To the contact a, the switch 165 to the contact a, and the switch 166 to the contact b, and the color change signal C having a predetermined magnitude by the coefficient unit 162 is added to the G signal selected by the adder 167. The corrected G signal that has been corrected is output. In this case, the B signal is output as it is.

Therefore, since the saturation of the B signal is not reduced,
Even if the saturation of the B signal component is low, the blue color tone can be maintained and the subject can be prevented from becoming dark. That is, when the color correction is performed in the specific color direction, it can be performed without changing the color tones of the other color components so much.

Similarly, when correcting the hue of a subject close to R in the Mg direction, the color correction setting circuit 163 switches the switch 164 to the contact point b, the switch 165 to the contact point b, and the switch 166 to the contact point a, and the coefficient unit 162. The color correction signal C having a predetermined magnitude is added to the B signal selected by the adder 167 and output as a corrected B signal corrected through the switch 166. In this case, the R signal itself is not corrected and the R signal is output as it is.

As described above, the color change signal C becomes large when the purity of the R signal is high, and Ye, Mg, G, Cy and B are obtained.
Since it is zero for other colors such as
It is possible to correct the hue of a subject having a high signal purity without affecting other colors. Therefore, the first color correction circuit 101
As a result, it becomes possible to perform color correction on blood or the like having a high R signal purity without affecting other subjects.

FIG. 3 shows an example of movement of each color on the color difference plane when the above color correction is performed (when R is corrected in the Ye direction). In FIG. 3, the arrow indicates the color-corrected color change direction and the magnitude of the color change amount.

In the above description, p = 1, q in the equation (1)
However, it is possible to change the area in which the color change signal C is zero and change the color correction range by appropriately selecting p and q. Also in this case,
In the case of R = 1, B = G = 0, that is, in the case of a pure R signal, C = R, so the correction amount is the same as in the case of p = 1, q = 1. Then, the RGB signal input to the first color correction circuit 101 is color-corrected by at least one of the G and B signals being color-corrected by the first color correction circuit 101 based on the color change signal C. Signals (shown as ROUT, GOUT, BOUT in FIG. 2) are output.

In this embodiment, an external adjusting means 58 for designating the setting of the control signal of the color correction setting circuit 163 is provided, and the external adjusting means 58 can set the color correction amount. . FIG. 6 shows a configuration example of the operation unit of the external adjusting means 58.

For example, in the case of setting the color correction setting circuit 163, as shown in FIG. 6A, adjusting means including a slide switch or the like which can be set in the Ye direction and the Mg direction around the preset portion is provided. . And if the adjustment means is at the preset position, do not perform the correction,
If it is set to the Ye direction, the switches 164, 1
65 and 166 are switched to the Ye direction correction position as described above, and as the adjusting means moves away from the preset position,
A color correction is performed by outputting a control signal so as to increase the correction amount (increase the gain by the coefficient multiplier 162). The same is done for the Mg direction.

The adjusting means is not limited to a knob such as a slide switch as shown in FIG. 6, but may be a method of determining a set value by a touch switch. In this case, the set value is displayed using an LED or the like. Further, even when the adjusting means is at the preset position, correction may be performed to some extent, and the set value of the adjusting means and the actual correction value may be shifted to some extent.

By using the external adjusting means 58 as described above, the correction amount can be arbitrarily set so that the operator can obtain a desired color, and the color correction suitable for the operator can be easily performed.

As described above, the RGB signal whose hue has been corrected by the first color correction circuit 101 is input to the second color correction circuit 102.

FIG. 4 shows the configuration of the second color correction circuit 102. Of the RGB signals input to the second color correction circuit 102, the R signal and the G signal pass through the R coefficient unit 175 indicated by the coefficient 1 and the G coefficient unit 176 indicated by the coefficient m, respectively,
Addition is performed by the adder 177, and further processing such as averaging is performed by the coefficient unit 178 indicated by the coefficient 1 / n.

The signal passed through the coefficient multiplier 178 is input to the switch 179 and the discrimination circuit 180. The input signal CE to the switch 179 and the discrimination circuit 180 is expressed by the following equation.

CE = (1R + mG) / n (2) The discrimination circuit 180 compares the magnitudes of the CE signal and the B signal and switches the switch 179. Here, the switch 179 is switched under the following conditions.

When CE ≦ B: Switch contact a When CE> B: Switch contact b (3) Then, the output signal of the switch 179 is adjusted to a predetermined magnitude through the coefficient unit 181 indicated by the coefficient r. Adder 1
At 82, the B signal is added and the corrected B signal is output.

Next, the operation of the second color correction circuit 102 will be described for the case of l = 1, m = 1, n = 2. Figure 5
Shows an example of the movement of each color on the color difference plane. In FIG. 5 as well, the direction of the color change and the magnitude of the color change amount are shown by the arrows.

In this case, CE = (R + G) / 2,
The boundary line (CE = 1) in the discrimination circuit 180 is a dotted line in FIG. 5 on the color difference plane. That is, according to the condition (3), the contact point b of the switch 179 is selected on the left half surface of the dotted line in FIG. 5, and the contact point a of the switch 179 is selected on the right half surface. Therefore, the left half surface of the dotted line in FIG. 5 is converted by the B signal, and the right half surface is converted by the CE signal.

Here, in FIG. 5, Mg, R, Ye,
In the vicinity of G, the B signal level is almost zero, so that the B signal is hardly converted. Further, in FIG. 5, since R and G are almost zero in the vicinity of B, the CE signal is also almost zero, and conversion by the CE signal is hardly performed. As described above, in the correction in the second color correction circuit 102, the R, G, B primary color signals and the vicinity of the Mg, Ye signals are hardly converted, and the colors near the white are largely converted. In other words, the second color correction circuit 102 can correct the color in the vicinity of white without changing the colors of the blue-dyed subject and blood.

Here, also regarding the setting of the coefficient unit 181,
It can be designated by the external adjusting means 58, and the color correction amount can be set.

For example, when the coefficient unit 181 is set, as shown in FIG.
Adjustment means including a slide switch that can be set in the direction Y and direction Ye is provided. When the adjusting means is at the preset position, the correction is not performed. When the adjusting means is set in the B direction, the gain of the coefficient unit 181 is increased in the positive direction, and when the adjusting means is set in the Ye direction. , Coefficient unit 18
The gain is set so that the gain of 1 is increased in the negative direction. In this case, the color correction is performed such that the correction amount is increased (the gain by the coefficient unit 181 is increased) as the adjusting unit moves away from the preset position.

This adjusting means is not limited to a knob such as a slide switch as shown in FIG. 6, but may be a method of determining a set value by a touch switch. Also in this case, the set value is displayed using the LED or the like. Further, even when the adjusting means is at the preset position, correction may be performed to some extent, and the set value of the adjusting means and the actual correction value may be shifted to some extent.

As described above, also in the second color correction circuit 102, the correction amount can be arbitrarily set so that the operator can obtain a desired color, and the color correction suitable for the operator can be easily performed.

Here, the case of l = 1, m = 1, n = 2 has been described, but by appropriately selecting l, m, n, the position of the dotted line dividing the area in FIG. The value changes, and a new color correction characteristic can be given.

The second color correction circuit 102 performs the color correction by correcting the B signal, but the same correction method can be applied to the R signal and the G signal, or a combination thereof can be used. it can.

Further, in the first color correction circuit 101 and the second color correction circuit 102, since the RGB signals can be processed as they are, a matrix circuit such as a processing system for converting into the color difference signals is not necessary, and therefore the circuit configuration is required. Has the advantage of being simple.

As described above, the RGB signal whose hue has been corrected by the second color correction circuit 102 is input to the third color correction circuit 103. The third color correction circuit 103 determines the distance to the subject and corrects the secondary reflected light due to the internal wall. FIG. 7 shows a first configuration example of the third color correction circuit 103.

The RGB signal input to the third color correction circuit 103 is converted into Y, RY, B- by the matrix circuit 104.
It is converted into a Y signal, and the size is converted by the coefficient units 105 and 106. On the other hand, the output signals of the dimming circuit 56 and the AGC control circuit 57 of the preprocessing section are also input to the far point determination circuit 107.

In the far point discrimination circuit 107, the dimming circuit 56,
The distance from the subject is determined by the dimming control signal and the AGC control signal respectively input from the AGC control circuit 57.

In the case of an electronic endoscope, the subject is irradiated with light from the emission end of the light guide 14 of the distal end portion 9 for observation. Therefore, when the distal end portion of the endoscope is close to the subject, the captured image becomes bright, and the dimming control is performed by the dimming circuit 56 so as to narrow the light emitted from the light source. vice versa,
When the distal end of the endoscope is farther from the subject, the image becomes darker, and therefore the light control is performed so that the light emitted from the light source is increased (the aperture of the light source is opened). By using the dimming control signal output from the dimming circuit 56, the distance between the subject and the tip can be detected.

Further, when the distance between the subject and the tip portion becomes large and the aperture of the light source is fully opened, the AGC circuit 5
5 works. As the distance between the subject and the tip portion increases, the video signal level decreases, so the AGC circuit 55
AGC control circuit 57 to increase the gain of the video signal with
Outputs the AGC control signal. The distance between the subject and the tip can be detected by this AGC control signal.

On the basis of the dimming control signal and the AGC control signal, the far point discriminating circuit 107 detects the distance to the subject and discriminates whether or not the subject is at the far point, and the far point discriminating circuit 107. Then, a control signal is output to the coefficient multipliers 105 and 106 to set the values of the coefficient multipliers 105 and 106.

The larger the distance between the subject and the distal end portion of the endoscope, the greater the influence of the secondary reflected light by the internal organ wall, and the effect of the color of the internal organ wall surface, the darker the subject color. Therefore, in this embodiment, as the distance between the subject and the tip portion increases, the color difference signals RY, Y
The size of BY is controlled to be small. This control is performed linearly or non-linearly depending on the magnitudes of the dimming control signal and the AGC control signal. As a result, the saturation is corrected in the case of far point observation.

Then, the luminance signal Y and the coefficient unit 105,
The color difference signals R-Y and B-Y output from 106 are converted into RGB signals by the inverse matrix circuit 108.
This RGB signal is output as an output signal of the color correction circuit 60.

As described above, when the far point is observed by performing the color correction by the third color correction circuit 103,
It is possible to reduce the influence of the secondary reflected light due to the visceral wall, and it is possible to always correct the color level optimally regardless of the distance.

FIG. 8 shows a second configuration example of the third color correction circuit 103. The second configuration example is an example in which a detector is provided in each of the R, G, and B signal circuits in addition to the components of the first configuration example.

The RGB signal input to the third color correction circuit 103 is converted into Y, RY, B- by the matrix circuit 104.
It is converted into a Y signal, and the size is converted by the coefficient units 105 and 106. Further, similarly to the first configuration example, the dimming circuit 56.
And a dimming control signal from the AGC control circuit 57 and A
Each of the GC control signals is input to the far point discriminating circuit 107. Also, the Y signal and the coefficient unit 105,
The R-Y and B-Y signals output from 106 are detected in magnitude (for example, an average value is calculated) by detectors 109, 110 and 111, respectively, and are input to the far point discriminating circuit 107.

The far point discrimination circuit 107 detects the distance between the subject and the tip based on the dimming control signal and the AGC control signal as described in the first configuration example. Here, when the distance between the subject and the tip is small, the influence of the secondary reflected light is small, and the color balance is not lost. Therefore, in the far point discriminating circuit 107, the output values of the detectors 109, 110, and 111 are held when the subject and the tip portion are close to each other by a predetermined distance. Then, even when the distance between the subject and the tip portion becomes large, the detectors 109, 11
The coefficient units 105 and 106 are controlled so that the ratio of 0 and 111 becomes the same as the ratio of the held detector outputs.

By controlling in this manner, the ratio of the Y, RY, and BY signals can be maintained as in the case where the distance between the subject and the tip is short, regardless of the distance to the subject. The influence of the secondary reflected light is reduced. Therefore, the color level can always be optimally corrected regardless of the distance.

Then, the luminance signal Y and the coefficient unit 105,
The color difference signals R-Y and B-Y output from 106 are converted into RGB signals by the inverse matrix circuit 108 and output as output signals of the color correction circuit 60.

In the first configuration example and the second configuration example of the third color correction circuit 103 described above, the RGB signal is generated from the Y, RY and BY signals in the inverse matrix circuit 108. However, in the matrix circuit 104, G, R-
You may convert into a Y, BY signal and the reverse matrix circuit 108 may synthesize | combine an RGB signal from a G, RY, and BY signal.

FIG. 9 shows a third configuration example of the third color correction circuit 103. The third configuration example is an example in which the matrix circuit is not provided. Of the RGB signals input to the third color correction circuit 103, the R and B signals are coefficient units 105 and 106.
Is input to and the size is converted. Further, similarly to the first configuration example, the dimming control signal and the AGC control signal from the dimming circuit 56 and the AGC control circuit 57 are input to the far point determination circuit 107, respectively. The G signal and the R and B signals output from the coefficient units 105 and 106 are
The magnitudes are detected (for example, the average value is calculated) by the detectors 109, 110, and 111, respectively, and the far point determination circuit 1
Enter in 07.

The far point discrimination circuit 107 detects the distance between the subject and the tip based on the dimming control signal and the AGC control signal as described in the first configuration example. In the far point determination circuit 107, as in the second configuration example, the detector 10 is activated when the subject and the tip are close to each other by a predetermined distance.
The output values of 9, 110 and 111 are held. And
Even when the distance between the subject and the tip portion becomes large, the coefficient unit 10 is adjusted so that the ratio of the detectors 109, 110 and 111 becomes the same as the ratio of the held detector outputs.
5, 106 are controlled.

By controlling in this way, the ratio of the G, R, B signals is maintained regardless of the distance to the subject, as in the case where the distance between the subject and the tip portion is short, and therefore 2
The influence of the secondary reflected light is reduced. Therefore, the color level can always be optimally corrected regardless of the distance.

In the case of the third configuration example, since the RGB signals can be processed as they are, there is no need for a matrix circuit such as a processing system for converting to the color difference signals, and therefore the circuit configuration can be simplified. Have. Furthermore, since the RGB signal ratio is controlled, it is possible to perform correction with higher accuracy than in a method that only controls saturation.

In the case of the third configuration example, R,
Although the magnitude of only the B signal is controlled, a coefficient multiplier may be inserted for the G signal to control the magnitudes of the three RGB signals.

Further, in the second and third configuration examples,
Although the signal level has been described as being controlled to be the same as the ratio of each signal when the subject is at a short distance, the ratio of each color may be controlled according to the distance.

In this embodiment, the first color correction circuit 10
First, second color correction circuit 102 and third color correction circuit 103
Are arranged in series in that order, but the order is not limited to this. Further, depending on the purpose, color correction may be performed by one or two of the first color correction circuit, the second color correction circuit, or the third color correction circuit. Further, by combining color correction circuits having different discriminant constants (p, q, l, m, n) of each color correction circuit, more complicated and precise color correction is possible.

Although the first embodiment has been described as the frame sequential system in which RGB primary color signals are processed as the primary signals, it is not limited to the frame sequential system, and may be applied to a simultaneous system in which a color filter array is mounted on the front surface of the solid-state image sensor. Applicable.

FIG. 10 shows an example in which the present embodiment is applied to the simultaneous method. Since it is a simultaneous type, the motor driver 25, the motor 23 and the rotary filter 24 in FIG. 1 are not provided. Regarding video signal processing, AGC
The circuit up to the circuit 55 has the same configuration as that of the first embodiment of FIG.
The description is omitted.

The output video signal of the AGC circuit 55 is A / D.
It is converted into a digital signal by the converter 34 and input to the color separation circuit 135. By the color separation circuit 135,
The video signal output from the solid-state image sensor 16 is separated into RGB signals, and after the signal processing such as white balance is performed, the respective RGB signals are converted into γ correction circuits 136a and 13a.
6b and 136c. Then, the γ correction circuit 13
6a, 136b and 136c respectively perform γ correction and input to the color correction circuit 60. The operation after the color correction circuit 60 is the same as in the first embodiment.

In FIG. 10, various signal processes are
Although the digital signals are converted from digital signals to digital signals, all analog signals may be used. Further, the γ correction circuit is not limited to the arrangement shown in FIG. 10, and may be arranged in the preceding stage of the color separation circuit.

In the case of the configuration of FIG. 10, the color signal processing is RGB.
Since the signal processing is performed by the signal, it is possible to perform processing such as color correction as in the first embodiment described above, but the signal processing is Y, R-.
When processed with Y, BY color difference signals, Y, R-
A matrix circuit for converting the Y, B-Y signals into RGB signals is required.

11 to 15 relate to the second embodiment of the present invention, FIG. 11 is a block diagram showing the configuration of the first color correction circuit, and FIG. 12 shows the area on the color difference plane determined by the area determination circuit. 13 is an explanatory view showing the operation of color correction by the first color correction circuit, FIG. 14 is a block diagram showing the configuration of the second color correction circuit, and FIG. 15 is an operation of color correction by the second color correction circuit. FIG.

The overall configuration of the signal processing system of the endoscope apparatus is the same as that of the first embodiment shown in FIG. 1. In this embodiment, the first color correction circuit 101 and the second color correction circuit in the color correction circuit 60 are used. Only the configuration of the circuit 102 is different.

FIG. 11 shows the configuration of the first color correction circuit 101. The RGB signal input to the first color correction circuit 101 is converted into an RY signal and a BY signal by the matrix circuit 61.

The RY signal is input to the positive part extraction circuit 84 and the adder 85. In the positive part extraction circuit 84, only the positive component of the input RY signal is taken out, and all other parts are set to zero. Next, the output signal of the positive part extraction circuit 84 is input to the coefficient unit 86 and the inverting circuit 87. Coefficient unit 8
At 6, the positive component of RY is converted to a predetermined magnitude and added to the BY signal by the adder 88. Further, the inversion circuit 87 inverts the output signal of the positive part extraction circuit 84, and inputs it to the area discrimination circuit 89 and the contact a of the switch 92.

On the other hand, the BY signal is input to the negative part extraction circuit 91, only the negative component is extracted, and the other parts are all set to zero. The output of the negative part extraction circuit 91 is input to the area discrimination circuit 89 and the contact b of the switch 92.

The area discriminating circuit 89 discriminates the area of the subject color on the color difference plane based on the signal Rm input from the inverting circuit 87 and the signal Bm input from the negative part extracting circuit 91. For example, a region where Rm <Bm (denoted by symbol A in FIG. 12) and a region where Rm ≧ Bm (denoted by symbol B in FIG. 12) are determined. The switch 92 is switched according to the determination result. The switching is performed so that contact point b is set when the subject color is in the area A in FIG. 12 and contact point a is set when the subject color is in the area B in FIG.

Then, the output signal of the switch 92 is converted into a predetermined size by the coefficient unit 93 and added to the RY signal by the adder 85.

R- converted by the adders 85 and 88
The Y signal and the BY signal are converted into RGB signals by the inverse matrix circuit 63 and become the output of the first color correction circuit 101.

Next, the operation of the first color correction circuit 101 will be described. First, B− corrected by the coefficient unit 86
Consider the Y signal. The signal input to the coefficient unit 86 is
The positive component of the RY signal affects the color of the upper half surface of the color difference plane in FIG. 12, and the larger the RY signal component, the larger the correction amount. Here, for example, when a negative coefficient is added by the coefficient unit 86, the correction by the adder 88 is illustrated in FIG.

Then, R-corrected by the coefficient unit 93
Consider the Y signal. The signal input to the coefficient unit 93 is
In the area A of FIG. 12, the negative component of the BY signal is shown, and in the area B of FIG. 12, the positive portion of the RY signal is inverted. Therefore, in the area A in FIG.
The larger the −Y signal component, the larger the correction amount.
In the area B, the larger the RY signal component, the larger the correction amount.

The output signal of the switch 92 is converted into a coefficient unit 93.
Thus, when the output is performed as it is, the correction by the adder 85 is illustrated in FIG. 13B. Actually, the above corrections of FIGS. 13A and 13B are combined, and the correction is as shown in FIG. 13C.

In the correction by the coefficient unit 86 and the coefficient unit 93, the color correction setting unit 94 controls the conversion amounts of the coefficient unit 86 and the coefficient unit 93 at the same time.
The red system color moves in a manner equivalent to hue adjustment (Hue adjustment) and does not affect other color systems. Also, no discontinuity occurs at the boundary of the region.

The RY and BY signals output from the adders 85 and 88 are combined with the G signal in the inverse matrix circuit 63.
To the RGB signal, which is then inversely converted into an RGB signal and is output from the first color correction circuit 101.

The first color correction circuit 101 of this embodiment is also used.
In the same manner as in the first embodiment, the setting of the coefficient unit 86 and the coefficient unit 93, that is, the setting of the color correction setting unit 94 can be designated by the external adjusting means 58, and the color correction amount can be set externally. .

For example, when the adjusting means that can set the Ye direction and the Mg direction around the preset portion similar to that of FIG. 6A is used and the adjusting means is at the preset position, the correction is not performed and the Ye direction is set. When set to, the gains of the coefficient units 86 and 93 are increased in the positive direction, and when set in the Mg direction, the gains of the coefficient units 86 and 93 are set to increase in the negative direction. In this case, the correction amount is increased as the adjusting unit moves away from the preset position (the gain by the coefficient units 86 and 93 is increased).
Color correction.

Incidentally, even when the adjusting means is at the preset position, some correction may be applied to shift the set value of the adjusting means and the actual correction value to some extent.

In this way, the first color correction circuit 1 of this embodiment is
Also in 01, the correction amount can be arbitrarily set so that the operator can obtain a desired color, and the color correction suitable for the operator can be easily performed.

Further, the negative part extraction is performed instead of the positive part extraction of the RY signal component, the positive part extraction is performed instead of the negative part extraction of the BY signal component, and the boundary for area discrimination is made different. As a result, correction of other colors and movements of other corrections are possible.

The RGB signal having the hue corrected by the first color correction circuit 101 is input to the second color correction circuit 102.

FIG. 14 shows the configuration of the second color correction circuit 102. The RGB signal input to the second color correction circuit 101 is
The matrix circuit 61 converts the signals into an RY signal and a BY signal and inputs them into the conversion table 62. In the conversion table 62, the RY signal and the BY signal are converted, for example, according to the following equation.

When x = (BY) / py = (RY) / q and (1) x ² + y ² > k ² R−Y = R−Y B−Y = B−Y (2 ) X ² + y ² ≦ k ² R−Y = q ((k−r) b / q + rk · sin (tan ⁻¹ (y / x))) / k B−Y = p ((k−r) a / p + rk · cos (tan ⁻¹ (y / x))) / k where r = (x ² + y ² ) ^1/2 (a, b) is a conversion vector p and q are non-zero arbitrary constants (( 4) In the case of p = 1 and q = 1, when the above conversion is performed, on the color difference plane shown in FIG. The color inside the radius k from the conversion vector (a,
Converted according to b).

In this case, by setting the conversion radius k to a predetermined level, only the low-saturation portion can be color-converted, so that the highly saturated dyed color and blood color are not converted. Only mucosal color with low saturation can be converted.
Therefore, the color tone of the blood color required at the time of the test can be maintained, and diagnosis is not difficult. Further, this color correction can be realized with a simple configuration.

In the present embodiment, the conversion is performed around the origin (white), but it may be performed around a predetermined color coordinate instead of the origin. For example, the color correction of blood or the like can be performed by performing the operation around red.

The conversion table 62 is a large-capacity ROM.
Alternatively, it can be easily realized by RAM. Also, p,
The conversion region can be changed by appropriately setting the value of q.

The R-Y signal and the B-Y signal output from the conversion table 62 are input to the inverse matrix circuit 63 together with the G signal, inversely converted to the RGB signal, and input to the third color conversion circuit 103. In the third color conversion circuit 103, the first
Color correction processing similar to that of the embodiment is performed, and the output of the color conversion circuit 60 is obtained.

The conversion formula in the conversion table 62 is not limited to the above formula, but a certain range is specified so that conversion of a specific color within the range is maximized, and at the boundary of the region,
It should be continuous.

Also, the second color correction circuit 102 of this embodiment.
In the same manner as in the first embodiment, the setting of the conversion table 62 can be designated by the external adjusting means 58.
The amount of color correction can be set externally.

For example, when the white color is corrected in the Ye direction and the B direction, the adjusting unit that can set the Ye direction and the B direction around the preset unit similar to FIG. 6B is used. If it is, the correction vector is not corrected, if it is set in the Ye direction, the conversion vector is set to the Ye direction, and if it is set in the B direction, the conversion vector is set to the B direction. Set. in this case,
Color correction is performed so that the correction amount increases (the size of the conversion vector increases) as the adjusting unit moves away from the preset position.

It should be noted that the set value of the adjusting means and the actual correction value may be shifted to some extent by making some correction even when the adjusting means is at the preset position.

As described above, the second color correction circuit 1 of this embodiment
Also in No. 02, the correction amount can be arbitrarily set so that the operator can obtain a desired color, and the color correction suitable for the operator can be easily performed.

Next, a first modification of the second color correction circuit 102 of this embodiment will be described. FIG. 16 shows a block diagram of the second color correction circuit of this modification.

As with the second color correction circuit of FIG. 14, RGB
The signal is converted into an RY signal and a BY signal by the matrix circuit 61. This RY signal and BY
The signal is input to the transform coefficient generator 64. The conversion coefficient generator 64 generates the RY conversion coefficient Rk and the BY conversion coefficient Bk according to the following equations.

When (1) x ² + y ² > k ² as x = (BY) / py = (RY) / q, Rk = 1 Bk = 1 (2) x ² + y ² ≦ k ² Then Rk = q ((k−r) b / q + rk · sin (tan ⁻¹ (y / x))) / (k (R−Y)) Bk = p ((k−r) a / p + rk · cos (tan ⁻¹ (y / x))) / (k (B−Y)) where r = (x ² + y ² ) ^1/2 (a, b) is the conversion vector p and q are any non-zero constants (5) Using the coefficients Rk and Bk obtained as described above, the RY signal and the BY signal are respectively multiplied and converted in the RY multiplier 65 and the BY multiplier 66. RY signal and BY output from the multipliers 65 and 66
The signal becomes equivalent to the output of the second color correction circuit 102 shown in FIG.

In this modification, since the signals are converted by using the multipliers 65 and 66, the conversion coefficient generator 64
The number of bits of the coefficient data output from is not necessarily as large as the number of bits of the original signal. Therefore, when the conversion coefficient generator 64 of the present modification is implemented by using the ROM or the RAM, it is possible to use one having a smaller capacity than the conversion table 62 of the second color correction circuit 102 of FIG.

The RY and BY signals output from the multipliers 65 and 66 are converted into RGB signals by the inverse matrix circuit 63 similarly to the second color correction circuit 102 of FIG. 14, and the second color correction is performed. It becomes the output of the circuit 102.

Also in this modification, color correction may be performed around an arbitrary point instead of centering on the origin on the color difference plane.

Also in the second color correction circuit 102 of this modification, the setting of the conversion coefficient generator 64 can be designated by the external adjusting means 58. The relationship between the external adjustment means and the correction amount is the same as in the case of the second color correction circuit 102 in FIG.

Next, the second color correction circuit 102 of this embodiment.
A second modified example will be described. FIG. 17 shows a block diagram of the second color correction circuit of this modification.

Similar to the second color correction circuit 102 of the second embodiment shown in FIG. 14, the RGB signal is converted into the RY signal and the BY signal by the matrix circuit 61. This RY
The signal and the BY signal are input to the saturation determination circuit 68.

The saturation discriminating circuit 68 calculates the saturation magnitude CC by the following equation, for example.

CC = ((RY) ² + (BY) ² ) ^1/2 (6) The CC signal output from the saturation determination circuit 68 is given a predetermined value by the subtraction circuit 69 at the next stage. Subtract from VR. next,
The limiter 70 limits the negative value of the output signal of the subtraction circuit 69 to zero and sets it as the control signal FC.

The control signal FC becomes zero when the saturation CC is equal to or larger than the predetermined value VR to be subtracted, gradually increases when the saturation CC becomes smaller than VR, and becomes the maximum value VR when the saturation CC is zero. Become.

The control signal FC is converted into a predetermined value by the coefficient units 71 and 72, and the outputs of the coefficient units 71 and 72 are added to the RY signal and the BY signal by the adders 73 and 74, respectively. R output from the adders 73 and 74
As shown in FIG. 18, from the characteristics of the control signal FC, the −Y signal and the BY signal are not converted for a color that is more than a predetermined value from the origin on the color difference plane, and the conversion amount increases as the color approaches the origin. Therefore, the origin becomes the maximum conversion amount.

R- converted by the adders 73 and 74
The Y signal and the BY signal are the second color correction circuit 102 in FIG.
Similarly to the above, it is converted into RGB signals by the inverse matrix circuit 63 and becomes the output of the second color correction circuit 102.

Also in this modification, as in the case of the second color correction circuit 102 of FIG. 14, only the low-saturation portion can be color-converted, so that the color of a highly saturated dyed object or blood is converted. No, only mucosal colors with low saturation can be converted. Further, also in the second color correction circuit 102 of this modified example, the setting of the coefficient units 71 and 72 is performed by the external external adjusting means 58.
It can be specified by. The relationship between the external adjustment means and the correction amount is the same as in the case of the second color correction circuit 102 in FIG.

In this modification, the formula for calculating the saturation CC is set to the formula (6), but the formula is not limited to the formula (6) as long as it is an arithmetic formula that changes depending on the distance from the origin on the color difference plane.

For example, if CC = | R−Y | + | B−Y | (7), it can be easily realized only by the adder circuit.
The entire circuit of the second color correction circuit 102 of the modified example can be easily realized by only an analog circuit.

In the second embodiment described above, the RGB signal is generated from the G, RY and BY signals in the inverse matrix circuit 63, but Y (luminance) and R- in the matrix circuit 61.
You may convert into a Y, BY signal and the reverse matrix circuit 63 may synthesize | combine an RGB signal from a Y, RY, and BY signal.

Also in the case of the second embodiment, the first color correction circuit 101, the second color correction circuit 102, and the third color correction circuit 103 are arranged in series in that order, but the order is limited to this. is not. Further, depending on the purpose, color correction may be performed by one or two of the first color correction circuit, the second color correction circuit, or the third color correction circuit.

In the case of the second embodiment, most of the color correction processing is performed by the color difference signals (RY, BY). Therefore, when each color correction circuit is connected, its input / output matrix circuit is used. Alternatively, the inverse matrix circuit may be omitted, and the color difference signals (RY, BY) may be directly input / output. For example, the third color correction circuit 103 includes the first configuration example and the second configuration example.
In the case of the method shown in the configuration example of 1, the inverse matrix circuit of the first color correction circuit 101, the matrix circuit and inverse matrix circuit of the second color correction circuit 102, and the matrix circuit of the third color correction circuit 103 are not necessary, and therefore the circuit configuration Has the advantage of being simple.

In the second embodiment, R is used as a frame sequential method.
Although the method of processing the GB primary color signal as the original signal has been described, the present invention is not limited to the frame sequential method but can be applied to a simultaneous method in which a color filter array is mounted on the front surface of the solid-state image sensor. Also in the second embodiment, the processing may be performed according to the block diagram shown in FIG. In the case of the configuration shown in FIG. 10,
Since the color signal processing is performed with the RGB signals, it can be processed as in the above-described embodiment, but the signal processing is performed by Y, R-.
In the case of Y, BY processing, the matrix circuit 61 in the color correction circuit of the second embodiment is unnecessary.

Further, the respective color correction circuits corresponding to the first and second embodiments can be interchanged.

19 to 23 relate to the third embodiment of the present invention, FIG. 19 is a block diagram showing the configuration of a signal processing system of an electronic endoscope apparatus, and FIG. 20 is a focus adjustment lens drive position and a specific high frequency. FIG. 21 is a characteristic diagram showing the relationship with the component size.
Is a block diagram showing a first configuration example of the third color correction circuit, FIG. 22 is a block diagram showing a second configuration example of the third color correction circuit, and FIG. 23 is a third configuration example of the third color correction circuit. It is a block diagram showing.

The third embodiment is a modification in which the control input for the far point discrimination to the third color correction circuit in the first embodiment is changed, and the same constituent elements as those in the first embodiment are shown in FIG. The same reference numerals are given and only different parts will be described.

The present embodiment is an example of an electronic endoscope apparatus having automatic focus control means for automatically adjusting the focus of an objective lens system.

In the electronic endoscope apparatus, the focus control circuit 150 is provided in the signal processing section, and the focus control means 151 is provided in the optical path of the objective lens system 15 at the tip 9 of the insertion section of the endoscope. . The focus control circuit 150 generates a focus control signal based on the output of the process circuit 33, and the focus control means 1
51 and the third color correction circuit 103.

Here, the automatic focus control operation will be briefly described. The video signal output from the solid-state image sensor 16 is preprocessed by the AGC circuit 55 and the process circuit 33. The video signal output from the process circuit 33 is input to the A / D converter 34 and at the same time, the focus control circuit 150.
To enter. The focus control circuit 150 separates a predetermined high frequency component from the input video signal and detects its magnitude.

The magnitude of this detection value increases as the subject image is brought into a focused state, and becomes maximum at the time of focusing. FIG. 20 shows the relationship between the focus adjustment lens drive position and the magnitude of a predetermined high frequency component. Therefore, the focus control circuit 150 sends a focus control signal to the focus control means 151 while monitoring the detection value, and the focus control means 151 moves the lens of the objective lens system 15 so that the detection value becomes maximum. Automatic focus control is possible.

Here, the focus control signal output from the focus control circuit 150 to the focus control means 151 changes depending on the distance from the distal end portion 9 of the endoscope to the subject. Therefore, in this embodiment, this focus control signal is sent to the third color correction circuit 103.
And used as a far point discrimination signal.

FIG. 21 shows a first configuration example of the third color correction circuit 103. This example is similar to the configuration shown in FIG. 7 of the first example, and the far point discrimination circuit 107 is adapted to receive the focus control signal from the focus control circuit 150. The distant point discrimination circuit 107 discriminates the distance from the subject based on the focus control signal, and outputs the control signal corresponding to the distance to the coefficient units 105 and 106 as in the first embodiment.
Output to. With this, depending on the distance from the subject,
For example, when the point is far from the predetermined distance, the color difference signal R-
The sizes of Y and BY are corrected.

FIG. 22 shows a second configuration example of the third color correction circuit 103. This example is similar to the configuration shown in FIG. 8 of the first example, and the far point determination circuit 107 is adapted to receive the focus control signal from the focus control circuit 150. Also in this example, based on the focus control signal and the outputs of the detectors 109, 110, 111,
Similar to the first embodiment, the color difference signal is corrected according to the distance from the subject.

FIG. 23 shows a third configuration example of the third color correction circuit 103. This example is similar to the configuration shown in FIG. 9 of the first embodiment, and the far point discrimination circuit 107 is adapted to receive the focus control signal from the focus control circuit 150. Also in this example, based on the focus control signal and the outputs of the detectors 109, 110, 111,
Similar to the first embodiment, the RGB color signals are corrected according to the distance from the subject.

As described above, by detecting the distance to the object using the focus control signal and performing the color correction in the third color correction circuit 103, the color changing depending on the distance of the observation point as in the first embodiment. Can be easily corrected,
The color level can always be optimally corrected regardless of the distance.

24 to 27 relate to the fourth embodiment of the present invention, FIG. 24 is a block diagram showing the configuration of the signal processing system of the electronic endoscope apparatus, and FIG. 25 is the first color correction circuit. 26 is a block diagram showing a configuration example, FIG. 26 is a block diagram showing a second configuration example of the third color correction circuit, and FIG. 27 is a block diagram showing a third configuration example of the third color correction circuit.

The fourth embodiment is also a modification in which the control input for the far point discrimination to the third color correction circuit in the first embodiment is changed, and in FIG. 24, the same constituent elements as in the first embodiment are shown. The same reference numerals are given and only different parts will be described.

The present embodiment is an example of an electronic endoscope device having a diaphragm control means of a light source device.

In the electronic endoscope apparatus, a diaphragm control circuit 152 is provided at a stage subsequent to the light control circuit 56 of the signal processing unit, and is arranged between the rotary filter 24 of the light source device and the incident end of the light guide 14. The diaphragm 154 is controlled according to the output of the dimming circuit 56. Further, an aperture position detection circuit 153 for detecting the position of the aperture 154 is provided, and the aperture position detection circuit 153 uses the detected aperture position information signal as a third signal.
The data is sent to the color correction circuit 103.

Here, the diaphragm control operation of the light source device will be briefly described. The video signal output from the solid-state image sensor 16 is input to the AGC circuit 55 and the dimming circuit 56 via the preamplifier 32. In the dimming circuit 56, the video signal is detected and filtered to generate a dimming signal, and this dimming signal is input to the aperture control circuit 152. The diaphragm control circuit 152 generates an operation signal for operating the diaphragm 154 based on the output signal of the dimming circuit 56. With this operation signal, the diaphragm 154 is driven so as to control the amount of light input to the light guide 14 so that a video signal having a predetermined brightness is obtained. The position of the diaphragm 154 driven by this operation signal is detected by the diaphragm position detection circuit 153 and output as a diaphragm position information signal.

The diaphragm position information signal becomes a signal that the diaphragm 154 is closed when the distance between the tip 9 and the subject is short, and the diaphragm 154 becomes longer as the distance between the tip 9 and the subject becomes longer.
Is an open signal. Therefore, in the present embodiment, this diaphragm position information signal is sent to the third color correction circuit 103 and used as a far point discrimination signal for performing far point discrimination.

FIG. 25 shows a first configuration example of the third color correction circuit 103. This example is similar to the configuration shown in FIG. 7 of the first example, and the far point determination circuit 107 is adapted to receive the aperture position information signal from the aperture position detection circuit 153. . Far point discrimination circuit 107
Determines the distance from the subject based on the diaphragm position information signal, and outputs a control signal corresponding to the distance to the coefficient units 105 and 106 as in the first embodiment. As a result, the magnitudes of the color difference signals R-Y and B-Y are corrected according to the distance from the subject, for example, when the point is farther than the predetermined distance.

FIG. 26 shows a second configuration example of the third color correction circuit 103. This example is similar to the configuration shown in FIG. 8 of the first example, and the far point determination circuit 107 is adapted to receive the aperture position information signal from the aperture position detection circuit 153. . Also in this example, the color difference signal is corrected in accordance with the distance from the subject based on the diaphragm position information signal and the outputs of the detectors 109, 110, and 111 as in the first embodiment.

FIG. 27 shows a third configuration example of the third color correction circuit 103. This example is similar to the configuration shown in FIG. 9 of the first example, and the far point determination circuit 107 is adapted to receive the aperture position information signal from the aperture position detection circuit 153. . Also in this example, the RGB color signals are corrected in accordance with the distance from the subject based on the diaphragm position information signal and the outputs of the detectors 109, 110, and 111, as in the first embodiment.

As described above, the distance to the object is detected using the diaphragm position information signal, and the color correction is performed in the third color correction circuit 103, so that the distance changes depending on the distance of the observation point as in the first embodiment. The color can be easily corrected, and the color level can always be optimally corrected regardless of the distance.

In the fourth embodiment, the far point discriminating circuit 107 performs the far point discrimination based only on the aperture position information. However, similar to the first embodiment, the aperture position information signal and the AGC control signal are used. Far point discrimination may be performed using both of the above.

The third and fourth embodiments are shown in FIG.
The field-sequential endoscope apparatus has been described so as to correspond to the configuration of the first embodiment shown in FIG. 10, but the same can be applied to the simultaneous-system endoscope apparatus shown in FIG.

The present invention is not limited to an electronic endoscope having an image pickup device built in at the distal end of the endoscope, but may be an endoscope device having a TV camera having an image pickup device built in an optical endoscope. It is clear that it can also be applied to.

[0183]

As described above, according to the present invention, it is possible to easily correct a color that changes depending on the distance of an observation point.

[Brief description of drawings]

1 to 9 relate to a first embodiment of the present invention,
FIG. 1 is a block diagram showing the configuration of a signal processing system of the electronic endoscope apparatus.

FIG. 2 is a block diagram showing a configuration of a first color correction circuit.

FIG. 3 is an explanatory diagram showing an operation of color correction by a first color correction circuit.

FIG. 4 is a block diagram showing a configuration of a second color correction circuit.

FIG. 5 is an explanatory diagram showing an operation of color correction by a second color correction circuit.

FIG. 6 is an explanatory view showing an operating section of an external adjusting means.

FIG. 7 is a block diagram showing a first configuration example of a third color correction circuit.

FIG. 8 is a block diagram showing a second configuration example of a third color correction circuit.

FIG. 9 is a block diagram showing a third configuration example of a third color correction circuit.

FIG. 10 is a block diagram showing a configuration example in the case where the first embodiment is applied simultaneously.

11 to 15 relate to a second embodiment of the present invention, and FIG. 11 is a block diagram showing a configuration of a first color correction circuit.

FIG. 12 is an explanatory diagram showing a region on a color difference plane discriminated by a region discrimination circuit.

FIG. 13 is an explanatory diagram showing the operation of color correction by the first color correction circuit.

FIG. 14 is a block diagram showing the configuration of a second color correction circuit.

FIG. 15 is an explanatory diagram showing the operation of color correction by the second color correction circuit.

FIG. 16 is a block diagram showing the configuration of a first modification of the second color correction circuit.

FIG. 17 is a block diagram showing the configuration of a second modification of the second color correction circuit.

FIG. 18 is an explanatory diagram showing the operation of color correction according to the second modification.

19 to 23 relate to a third embodiment of the present invention, and FIG. 19 is a block diagram showing a configuration of a signal processing system of an electronic endoscope apparatus.

FIG. 20 is a characteristic diagram showing the relationship between the focus adjustment lens drive position and the magnitude of a specific high frequency component.

FIG. 21 is a block diagram showing a first configuration example of a third color correction circuit.

FIG. 22 is a block diagram showing a second configuration example of the third color correction circuit.

FIG. 23 is a block diagram showing a third configuration example of a third color correction circuit.

24 to 27 relate to a fourth embodiment of the present invention, and FIG. 24 is a block diagram showing a configuration of a signal processing system of an electronic endoscope apparatus.

FIG. 25 is a block diagram showing a first configuration example of a third color correction circuit.

FIG. 26 is a block diagram showing a second configuration example of a third color correction circuit.

FIG. 27 is a block diagram showing a third configuration example of the third color correction circuit.

FIG. 28 is an overall view of a conventional electronic endoscope apparatus.

FIG. 29 is a block diagram showing a configuration of a signal processing system of a conventional electronic endoscope apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope 6 ... Video processor 9 ... Tip part 55 ... AGC circuit 56 ... Dimmer circuit 57 ... AGC control circuit 58 ... External adjustment means 60 ... Color correction circuit 101 ... First color correction circuit 102 ... Second color Correction circuit 103 ... Third color correction circuit 104 ... Matrix circuits 105, 106, 162, 175, 176, 178, 1
81 ... Coefficient device 107 ... Far point discriminating circuit 108 ... Inverse matrix circuit 161 ... Color change signal generator 163 ... Color correction setting circuit 164, 165, 166, 179 ... Switch 167, 177, 182 ... Adder 180 ... Discriminating circuit

Claims (4)

(57) [Claims] 1. An electronic endoscope apparatus comprising: an electronic endoscope including an image pickup means for converting light information from a subject into an electric signal; and a video signal processing means for processing a video signal of the electric signal of the image pickup means. In the video signal processing means, the distance determination means that determines the distance between the subject and the imaging means based on the electric signal of the imaging means, and the subject based on the determination result of the distance determination means
An electronic endoscope, comprising: a color correction unit that corrects a color signal such that the color density with respect to the subject becomes lighter as the distance from the imaging unit increases. apparatus. 2. Converting light information from a subject into an electric signal
An electronic endoscope having an image pickup means for
And a video signal processing means for processing the signal as a video signal.
In the endoscopic device, The video signal processing means, AGC control for adjusting the gain of the image signal of the image pickup means
Based on the AGC control signal output from the circuit,
Distance determining means for determining the distance between the body and the imaging means, Based on the discrimination result of the distance discrimination means,
As the distance from the imaging means increases,
Correct the color signal so that the color density for the body becomes lighter
Color correction means, An electronic endoscope apparatus comprising: 3. The correction by the color correction means is linear or
Is also nonlinear and adaptive.
Is an electronic endoscope apparatus according to 2. 4. A predetermined specific color of the color of the subject
It is equipped with a specific color correction unit that increases the correction amount.
The electronic endoscope according to any one of claims 1 to 3, characterized in that
apparatus.