JPS626592A - Picture signal processing circuit - Google Patents

Abstract

PURPOSE:To adjust a color tone with good durability and reliability by generating a gain setting signal digitally changing by the operation of a color tone setting switch. CONSTITUTION:An endoscope mirror 10 has a light guide composed of an optical fiber bundle transferring an illuminated light irradiated from a light source unit 12 to an end and illuminating an object to be photographed and a CCD 20 picking up the optical image of the object to be photographed obtained by an objective lens 18. On the surface panel of the light source unit 12, color tone setting switches 32a, 32b, 34a, 34b are provided. Herein, the color tone of a color picture can be adjusted by changing the gain of color component signals of R and B. The color tone setting switches 32a, 32b, 34a, 34b are respectively switches for indicating the increase and decrease of the gain of the R signal and for indicating the increase and decrease of the gain of the B signal. Accordingly, by the one and off of the key switches 32a, 32b, 34a, 34b, a digitally changing gain setting signal and the durability and reliability of a picture signal processing circuit capable of adjusting the color tone can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image signal processing circuit, and more particularly to an image signal processing circuit capable of adjusting the 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. Here, in order to continuously vary the color tone, an element that can continuously vary the output, such as a slide volume, is used as the gain setting element. Here, a slide volume that can continuously vary the output requires a movable member, but this movable member has the disadvantage of poor durability, and accurate fine adjustment is difficult with settings using a movable member. There are drawbacks. Furthermore, this movable member requires a portion of the 11 vessel that is open to the outside, resulting in incomplete drip-proofness. This becomes a problem in the case of image signal processing circuits for medical equipment that are often operated with wet hands. Furthermore, in the case of medical equipment, it is necessary to prevent internal circuits from being affected by chemicals, etc., and complete drip-proofing is required.

[Problems to be Solved by the Invention] As described above, in the conventional image signal processing circuit, the color tone of the image is adjusted using an element that requires a movable member such as a slide volume. There was a problem with sexuality.

The present invention was made in view of these problems, and an object of the present invention is to improve the durability and reliability of an image signal processing circuit capable of adjusting color tone.

[Means for Solving the Problems] The image signal processing circuit according to the present invention includes a gain adjustment means for receiving color component signals output from the imaging means and adjusting the gain for each color component signal, and for changing the color tone of the image. and a control means for detecting the operation of the color tone setting switch and supplying a digitally changing gain setting signal to the gain adjusting means.

[Function] In this device, by generating a gain setting signal that changes digitally by the operation of the color tone setting switch, the durability and reliability of the image signal processing circuit capable of adjusting color tone can be improved.

[Embodiment] An embodiment of the 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, the image signal processing circuit will be described as an image signal processing circuit for an endoscope imaging device that has a solid-state imaging device built into the tip of an endoscope. In such a case, the image signal processing circuit is integrated with the light source unit. The endoscope 10 includes a light guide 16 made of an optical fiber bundle that transmits illumination light emitted from the light source unit 12 to the tip and illuminates the subject;
It has a CCD 20 as a solid-state imaging device that captures an optical image of a subject obtained by an objective lens 18 at the tip of the endoscope. The light source unit 12 has a lamp 22 that makes illumination light enter the light guide 16. A rotating color filter 24 that is rotated by a motor 26 is provided in front of the lamp 22, and the illumination light that enters the light guide 16 is C0D2.
Red (R), blue (B) sequentially for each imaging period of one frame of 0
, green (G), which are the three primary color component lights. This allows the CCD 20 to perform color imaging in a frame-sequential manner.

The output image signal of the CCD 20 is input to an automatic gain control (AGC) circuit 28 in the light source unit 12 and the gain is adjusted, and then supplied to the color monitor 14 via the video processing circuit 30 for display.

On the other hand, color tone setting switches 32a, 32b, 34a, and 34b are provided on the front panel of the light source unit 12.The zero color tone setting switches 32a, 32b, 34a, and 34b are different from the conventional example and are shown by broken lines in FIG. It is a key switch that is covered with a drip-proof cover made of rubber, etc., and turns on only while it is pressed. Here, it is assumed that the tone of the color image is adjusted by varying the gains of the R and B color component signals, and the tone setting switches 32a, 32b, 34a,
34b are switches for instructing to increase the gain of the R signal, decrease the gain of the R signal, increase the gain of the B signal, and decrease the gain of the B signal, respectively. Therefore, the color tone setting switches 32a, 32b, 34a, 34 on the drip-proof cover
0 color tone setting switches 32a, 32b, 34a, and 34b, on which characters such as R up, R down, B up, and B down are written, are connected to the key scan circuit 36 at the portion corresponding to b. C to key scan circuit 36
The output of the CPU 38 is supplied to the first and second input terminals of the multiplexer 44 via D/A converters 40 and 42.

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 a timing controller 48, and the first . The AGC circuit 28 selectively receives either of the signals supplied to the second and third input terminals.
as a gain setting signal. The timing controller 48 also controls the rotation of the motor 26, and in conjunction with this controls the switching of the multiplexer 44. That is, the multiplexer 44 switches in synchronization with the rotation of the rotating color filter 24, and connects the first, second, and third input terminals to the AGC while the image signals of R, B, and G color components are output from the CCD 20. Connect to circuit 28.

Next, the operation of this embodiment will be explained. The rotation of the motor 26 sequentially colors the illumination light to the subject into R, B, and G.
RlB and G color component image signals are sequentially supplied from the CD 20 to the AGC circuit 28 for each screen. The gain of this A-GC circuit 28 is controlled as follows. The key scan circuit 36 includes color tone setting switches 32a, 32b, 34a, 3
4b is sequentially scanned to detect the pressed key switch. This detection signal is supplied to the CPU 38, and the CPU 38
performs the operations shown in the flowchart of FIG.

First, in step SL, it is determined whether or not there is a key switch that is turned on based on a detection signal. If it is determined that there is a key switch that is turned on, step S2
This switch-on determination determines whether chattering is occurring.

If it is determined that it is not chattering, it is determined in step S3 whether this key human power is a new key human power. If it is determined that a new key is manually operated, the digital data corresponding to the turned-on key switch is output to the corresponding D/A converter as shown in step S4. here,
When the CCD 20 outputs R, B, and G color component image signals, the multiplexer 44 outputs the first, second, and second color component image signals, respectively.
A third input terminal is connected to the AGC circuit 28.

Since the third input terminal of the multiplexer 44 that provides gain for the G signal is connected to the reference power source 46, the color tone can be adjusted by varying the R and B color components and signal gains. Therefore, the R signal gain B (when the edible color tone setting switches 32a and 32b are pressed, the digital data is sent to the D/A converter 40, and the G signal gain variable color tone setting switches 34a and 34b are pressed. At the time, the digital data is output to the D/A converter 42. Here, the CP
It is assumed that U38 is equipped with a latch, and when the gain increase color tone setting switches 32a and 34a are pressed, data obtained by increasing the latched digital data by a predetermined amount is output. Conversely, when the gain reduction color tone setting switches 32b, 34b are pressed, data obtained by reducing the latched digital data by a predetermined amount is output.

After step S4, it is determined in step S5 whether or not the process is finished. If not completed, step S1 is executed again. Step 51. If a negative determination is made in S2 and S3, step S5 is executed.

As mentioned above, the key switches 32a, 32b, 34a,
By generating a gain setting signal that changes digitally by turning on/off 34b, the color WRa! The durability and reliability of image signal processing circuits that can be adjusted can be improved. Furthermore, since the key switches 32a, 32b, 34a, and 34b are covered with a drip-proof cover, the drip-proofness of the image signal processing circuit is also improved. If you reduce the variation range of the data output to the D/A converter, the gain setting signal will change finely,
Fine adjustment of color tone is possible.

Note that although the above description has been made regarding an image signal processing circuit for an endoscope imaging device, the present invention is not limited thereto;
Various changes are possible.

[Effects of the Invention] According to the present invention, there is provided an image signal processing circuit that can adjust color tone with good durability and reliability by generating a gain setting signal that changes digitally according to the operation of a color tone setting switch.

[Brief explanation of the drawing]

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 flowchart explaining the operation of this embodiment. 20... Solid-state image sensor 22... Lamp 24... Rotating color filter 28... Automatic gain adjustment circuit 30... Image processing circuit 32a, 32b, 34a, 34 b... Color tone setting switch 36... ...Key scan circuit 38...CPU 40.42...D/A converter 44...Multiplexer

Claims (1)

[Claims] A gain adjusting means receives the color component signals output from the imaging means and adjusts the gain for each color component signal, a color tone setting switch changes the color tone of the image, and detects the operation of the color tone setting switch and digitally controls the color tone setting switch. An image signal processing circuit comprising control means for supplying a varying gain setting signal to the gain adjustment means.