JP2551644B2 - Image signal processing device for endoscope - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal processing circuit, and more particularly to an image signal processing circuit capable of adjusting the color tone of a color image.

[Prior Art] Generally, in an image signal processing circuit, the color tone is adjusted by changing the gain of the image signal for each color component. That is, input the image signal to the gain adjustment circuit,
The gain is variable for each color component. Then, during the manual adjustment, the gain of each color component is set so that the image has a preferable color tone while displaying the output of the automatic gain adjustment circuit.

[Problems to be Solved by the Invention] Here, conventionally, the color tone is adjusted while changing the gains of all color component signals, but in this case, the white balance reference is changed every time the gain of a certain color is changed. It changed and it was difficult to adjust.

[Problems to be Solved by the Invention] As described above, in the conventional image signal processing circuit, it is difficult to manually adjust the color tone.

The present invention has been made in view of such problems, and an object thereof is to provide an image signal processing circuit capable of manually adjusting the color tone of an image by a simple operation.

[Means for Solving the Problems] The image signal processing circuit according to the present invention sequentially picks up an image of a subject for each of three color components and sequentially outputs the first color component signal to the third color component signal. And a gain adjusting means that is capable of adjusting the gain by inputting the first color component signal to the third color component signal sequentially output from the image capturing means,
A first color tone setting switch for instructing increase or decrease of gain for the first color component signal output from the image pickup means, and an increase of gain for the second color component signal output from the image pickup means. Or a means for sequentially detecting the states of the second color tone setting switch, the first color tone setting switch, and the second color tone setting switch, and the gain for the first color component signal. First gain setting signal output means for outputting a first gain setting signal, second gain setting signal output means for outputting a second gain setting signal indicating a gain for the second color component signal, and the detecting means. The gain of the first gain setting signal is increased or decreased only during the period when it is detected that the first color tone setting switch is operated by Means for increasing or decreasing the gain of the second gain setting signal only during a period when it is detected that the setting switch is operated, and a means for showing a constant gain for the third color component signal output from the imaging means. Third gain setting signal output means for outputting a 3-gain setting signal, timing control means for outputting a signal synchronized with the first to third color component signals sequentially output from the image pickup means, and the timing One of the first gain setting signal, the second gain setting signal, and the third gain setting signal is sequentially input to the gain adjusting means according to the signal synchronized with each color component signal output from the control means, and the first gain setting signal is input. Switching means for sequentially adjusting the gains of the color component signals to the three color component signals according to the first gain setting signal, the second gain setting signal, and the third gain setting signal. That.

[Operation] According to the present invention, the gain setting means changes the gains of the other color component signals stepwise with reference to one color component signal, so that the gains among all the color component signals can be easily operated. The ratio of can be changed and the color tone can be adjusted.

[Embodiment] An embodiment of an image signal processing circuit according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment. Here, it will be described as an image signal processing circuit for an endoscope image pickup apparatus having a solid-state image pickup element built in at the tip of the endoscope. In such a case, the image signal processing circuit is integrated with the light source unit. The endoscope 10 transmits the illumination light emitted from the light source unit 12 to the tip and illuminates the subject with a light guide 16 formed of an optical fiber bundle, and an optical image of the subject obtained by an objective lens 18 at the tip of the endoscope. It has a CCD 20 as a solid-state imaging device for imaging. The light source unit 12 is a lamp that causes the illumination light to enter the light guide 16.
A rotary color filter 24 is provided on the front surface of the lamp 22, which is rotated by a motor 26. The rotating color filter 24 sequentially colors the illumination light incident on the light guide 16 during one rotation into component light of the three primary colors of red (R), blue (B), and green (G). CCD2 for one rotation period of the rotating color filter 24
0 corresponds to the image pickup period of 3 frames, and 1 coloring period corresponds to the image pickup period of 1 frame. As a result, the CCD 20 can perform color imaging by the frame sequential method. The output image signal of CCD20 is the automatic gain adjustment (AGC) circuit 2 in the light source unit 12.
Image processing circuit 3 after input to 8 and gain adjusted
It is supplied to the color monitor 14 via 0 and displayed.

On the other hand, on the operation panel on the surface of the light source unit 12, there are color tone setting switches 32a, 32b, 34a, 34b for instructing increase of R signal gain, decrease of R signal gain, increase of B signal gain, and decrease of B signal gain, respectively. It is provided. The color tone setting switches 32a, 32b, 34a, 34b are key switches which are covered with a drip-proof cover such as rubber as shown by a broken line in FIG. 1 and are turned on only while being pressed. Here, in the color tone of the color image, the gain of one color component signal (G color component signal) is fixed, and the gains of the other color component signals (color component signals of R and B) are varied, so that each color results. Adjust by changing the gain ratio between the component signals. The parts corresponding to the color tone setting switches 32a, 32b, 34a, 34b on the drip-proof cover are respectively
Letters indicating switch functions such as R up, R down, B up, and B down are written.

The color tone setting switches 32a, 32b, 34a, 34b are connected to the key scan circuit 36. The CPU 38 is connected to the key scan circuit 36, and the output of the CPU 38 is supplied to the first and second input ends of the multiplexer 44 via the D / A converters 40 and 42. It is supplied to the first and second input terminals of the multiplexer 44. A reference power supply 46 is connected to the third input terminal of the multiplexer 44. The multiplexer 44 is controlled by the output of the timing controller 48 and selectively supplies any of the signals supplied to the first, second and third input terminals to the AGC circuit 28 as a gain setting signal. The timing controller 48 also controls the rotation of the motor 26, and controls the switching of the multiplexer 44 in conjunction with this. That is, the multiplexer 44 switches in synchronism with the rotation of the rotary color filter 24, and switches from the CCD 20 to R,
The first, second, and third input terminals are connected to the AGC circuit 28 during the period in which the image signals of the B and G color components are output.

Next, the operation of this embodiment will be described. The illumination light to the subject is sequentially colored into R, B, and G by the rotation of the motor 26, and the R, B, and G color component image signals are sequentially output from the CCD 20 for each first screen.
Supplied to 28. The gain of this AGC circuit 28 is controlled as follows. The key scan circuit 36 is a color tone setting switch 32
A, 32b, 34a, 34b are sequentially scanned to detect the pressed key switch. This detection signal is supplied to the CPU38, and the CPU38
Operates as shown in the second flow chart. First, in step S1, it is determined based on the detection signal whether or not there is a key switch that is turned on. When it is determined that there is a key switch that is turned on (key input is present), it is determined in step S2 whether or not the switch is turned on is chattering. If it is determined that it is not chattering,
In step S3, it is determined whether this key input is a new key input. When it is determined that the key input is new, as shown in step S4, the digital data that increases or decreases corresponding to the key switch that is turned on is handled.
Output to D / A converter. Where multiplexer 44 is a CCD
When 20 is outputting R, B, and G color component image signals, the first, second, and third input terminals are connected to the AGC circuit 28, respectively. Since the third input terminal of the multiplexer 44 that provides the gain of the G signal is connected to the reference power supply 46, the color tones are R and B.
This can be adjusted by changing the gain of the color component signal. Therefore, when the tone setting switches 32a and 32b for changing the gain of the R signal are pressed, the digital data that increases or decreases according to the up / down of the switches is set in the D / A conversion circuit 40 to set the tone for changing the gain of the G signal. When the switches 34a and 34b are pressed, digital data which increases or decreases according to the up / down of the switches is output to the D / A converter 42. Here, it is assumed that the CPUB38 has a latch, and when the color tone setting switches 32a and 34a for increasing the gain are pressed, the latched digital data is increased by a predetermined amount and the data is output. . On the contrary, color tone setting switches 32b, 34 for gain reduction
When b is pressed, the latched digital data is reduced by a predetermined amount and the data is output. After step S4, it is determined in step S5 whether or not the process ends.
If not, step S1 is executed again. That is, while the color tone setting switch is pressed, the digital data is increased / decreased stepwise. When the determination in step S1 is NO, the determination in step S2 is YES, and the determination in step S3 is NO, step S5 is executed.

As described above, the gain of the G signal is not changed by turning on / off the key switches 32a, 32b, 34a, 34b, but it is possible to generate a gain setting signal that gradually changes the gains of the R and B signals, and It is possible to adjust the color tone by adjusting the gain ratio of the component signal.

Although the above description has been made with respect to the image signal processing circuit for the endoscope imaging apparatus, the present invention is not limited to this and various modifications can be made.

[Effect of the Invention] According to the present invention, the operation of the color tone setting switch causes the gain of another color component signal to be changed stepwise with reference to one color component signal. There is provided an image signal processing circuit capable of changing the gain ratio between the image signals and adjusting the color tone.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of an image signal processing circuit according to the present invention, and FIG. 2 is a flow chart for explaining the operation of this embodiment. 20: Solid-state image sensor, 22: Lamp, 24: Rotating color filter, 28: Automatic gain adjustment circuit, 30: Video process circuit, 32a, 32b, 34a, 34b ... Color tone setting switch, 36
...... Key scan circuit, 38 …… CPU, 40,42 …… D / A converter, 44 …… Multiplexer.

 ─────────────────────────────────────────────────── ─── Continuation of the Front Page Judge's Chief Judge Masuda Yamada Judge Kosaku Yosaku Judge Mitsuyama Murayama (56) References JP 55-25243 (JP, A) JP 56-56085 (JP, A) JP-A-56-90689 (JP, A) Actually opened 58-176472 (JP, U) Actually opened 58-77965 (JP, U) JP-B 58-34070 (JP, B1) JP-B 49-49248 (JP, B1)

Claims (1)

(57) [Claims] 1. A light source having a rotating color filter for sequentially irradiating a subject with three color component lights through an endoscope; and an image of the subject, which is provided in the endoscope, for each of the three color components. Then, a field-sequential imaging unit that sequentially outputs the first to third color component signals and the first to third color component signals sequentially output from the imaging unit are input, and the gain is Adjustable gain adjusting means, and for the first color component signal output from the imaging means,
A first increasing color tone setting switch configured by a key switch for instructing an increase in gain only when turned on, and a first color component signal output from the image pickup means,
A first decreasing color tone setting switch composed of a key switch for instructing a decrease in gain only when turned on, and a second color component signal output from the image pickup means,
A second increasing color tone setting switch composed of a key switch for instructing an increase in gain only when turned on, and a second color component signal output from the image pickup means,
A second decreasing color tone setting switch composed of a key switch for instructing a decrease in gain only when turned on, the first increasing color tone setting switch, the first decreasing color tone setting switch, and the second increasing color tone A drip-proof cover provided to cover the surfaces of the setting switch and the second decreasing color tone setting switch; the first increasing color tone setting switch, the first decreasing color tone setting switch, and the second increasing color tone setting A detection unit that sequentially detects an operating state of the switch and the second decreasing color tone setting switch; a first gain setting signal output unit that outputs a first gain setting signal indicating a gain with respect to the first color component signal; Second gain setting signal output means for outputting a second gain setting signal indicating a gain for the second color component signal; and the first increasing means by the detecting means. Only when it is detected that the color tone setting switch is operated, the gain of the first gain setting signal is increased, and only when the first decreasing color tone setting switch is detected by the detecting means. The gain of the first gain setting signal is decreased, and the gain of the second gain setting signal is increased only when the detecting unit detects that the second increasing color tone setting switch is operated, Means for decreasing the gain of the second gain setting signal only when the detection means detects that the second decreasing color tone setting switch is operated; and a third color component signal output from the image pickup means. Third gain setting signal output means for outputting a third gain setting signal indicating a constant gain, and a signal synchronized with the rotation of the rotating color filter. One of the first gain setting signal, the second gain setting signal, and the third gain setting signal is sequentially applied to the gain adjusting means in accordance with the timing control means and a signal synchronized with each color component signal output from the timing control means. And input the gains of the first color component signal to the third color component signal to the first gain setting signal and the second gain setting signal.
An image signal processing apparatus for an endoscope, comprising: a switching unit that sequentially adjusts the gain setting signal and the third gain setting signal.