JPH01279694A - White balancing circuit - Google Patents

Abstract

PURPOSE:To adjust colors even when automatic while balancing is used by providing an automatic white balancing means to automatically execute white balancing, a manual color adjusting means, and a means to switch the automatic white balancing means and the manual color adjusting means coexistently and selectively. CONSTITUTION:For example, when contacts S1 are selected by connecting change-over switches SW1-SW4, two outputs of an automatic white balancing(AWB) control circuit 53 are respectively inputted through the change-over switches SW1 and SW2 to adder circuits 54 and 55, variable voltages by variable resistors VR1 and VR2 are inputted to the adder circuits 54 and 55, and respective added results at the adder circuits 54 and 55 are inputted to a white balancing circuit 51 for R and another white balancing circuit 52 for B as gain control voltages. Namely, under this state, the state of the title device is a color adjustable AWB state. Further, when contacts S2 are selected in the change-over switches SW1-SW4, the state of the device becomes a manual color adjustable state.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is directed to
A small wide balance circuit is provided with a means to perform color adjustment.

"Prior art" In recent years, there has been a lot of research into inserting elongated insertion sections into living bodies.
Observe the inside of the body, and if necessary, treat f and treatment i? Optical endoscopes with large diameters have become widely used.

In addition, recently, optical endoscopes have been equipped with J-Level cameras that use solid-state image sensors as layer imaging means, and electronic endoscopes that do not use an image guide have been introduced. ” An electronic endoscope with a solid-state imaging element disposed on the focal plane of the Z=I object lens has been put into practical use.

In an electronic endoscope that uses the above-mentioned solid-state imaging device as an imaging means, ll1
H image 1. :If the signal is displayed as is on a color monitor, the actual color tone of the subject cannot be faithfully reproduced.

Therefore, in order to reproduce the color tone of the subject as faithfully as possible, some cameras are equipped with A-1 to 71\1 noise 1-balance circuits.

For example, FIG. 3 shows a conventional Δ-t, small-width, I-balance circuit.

Behind the R, G, and B color signals, the R and 13 color signals are input manually to the balance circuits 1 and 2, respectively, and are amplified and sent to the bow 1 to balance circuit 3. It is outputted from the output terminal of , and is also manually supplied to the A-to-why 1-balance converter 1 to L1-le circuit 4.

O1 above - White balance (hereinafter ΔW B ) T
- ] Roll circuit 4 is white balance circuit I.
When the switch 5 is turned on, the input color signals R and B are compared with the G color signal, and the compared control signals a and b are output from the two output terminals. These control signals a, b
is applied to the gain control terminals of the R and B white balance circuits 1 and 2 via the changeover switch 6.6', and the gains of the R and B white balance circuits 1 and 2 are set to white by the control signals a and b, respectively. Set the gain to a balanced value.

The above changeover switches 6 and 6' are interlocking switches, and when the contact S1 side is turned on, the operation is as in the case of needle 1~, and when the contact S2 side is on, the operation is as in the manual mode. is variable resistor VR1'
, VR2', then R and B why]-A gain setting voltage is applied to the balance circuit 1.2. In other words, in the case of a manual, the gains of the R and B color signals can be changed by adjusting the variable resistors VRI' and VR2' and changing the voltage applied to the gain control terminal ( I love that you can adjust the colors.

[Problems that the invention attempts to solve] The above conventional example has the following problems.

m: 4-topo 1 noise 1 ~ balance (1), there is a color preference that appears in medical images of doctors compared to endoscopic images,
Furthermore, the above-mentioned conventional example 4i1 is not compatible with the need for fine adjustment of colors.

(2) Furthermore, after fine-tuning 10, immediately return to the original A-1.
Although it is desirable to be able to easily return to the color of 1 to 1 to balance adjustment 11, the above conventional example does not have this function.

(3)Also, even if the selector switch is set to the side where color adjustment is possible, when you press the; It is desirable to cover the position so that the white balance cannot be maintained at the position where the adjustment is deviated, but the above-mentioned conventional example does not have this function.

(4) Also, when the changeover switch is set to the side where color adjustment is possible, it is convenient to make it so that there is no change even if you press the O1 - HNOI1 - Balance changeover switch. The conventional example does not have this function.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an easy-to-use white balance circuit that can eliminate the drawbacks (1) to (4) above. [Means and effects for solving the problem] The present invention is equipped with an automatic wide balance means for automatically adjusting the white balance, a manual color adjustment means, and a means for coexisting and selectively switching between these. Depending on the situation, the normal auto white balance state or the color adjustable
- The white balance circuit can be set to a balanced state and is easy to use.

[Example] Hereinafter, the present invention will be specifically explained with reference to the drawings.

1 and 2 relate to one embodiment of the present invention, FIG. 1 shows a construction diagram of one embodiment, and FIG. 2 shows an endoscope apparatus equipped with one embodiment.

Endoscope device V111 with one embodiment as shown in FIG.
is the fiber path scope 12 and this fiber path scope 1.
TV camera 13 attached to 2 and Fipass=! −
a video camera 16 that includes a light source section 14 that supplies illumination light to the video camera 12 and a signal processing section 15 that processes signals from the television camera 13; and a color monitor that displays the video signal output from the video camera 16. It consists of 17 parts.

The above fiber path]-112 is on the right side of the elongated insertion part 21,
A light guide 22 that transmits illumination light is inserted into the insertion section 21 and through a light guide cable 24 extending outside from an operating section 23 connected to the rear end of the insertion section 21. By connecting the light guide connector 25 at the tip of the light guide cable 24 to the connector number of the light source section 14, illumination light of, for example, red, green, and blue is supplied. That is, the lamp 28 is turned on by electric power supplied from the power source 27, and the white light from the lamp 28 is irradiated onto the rotating color filter 31 which is rotationally driven by the motor 29. This rotating color filter 31 has red, green, and horoscope color filters arranged in the circumferential direction (not shown).
, becomes light of each wavelength of red, green, and blue, is condensed from the connoun to the lunz 32, and then passes through the light guide connector 25.
is irradiated.

-1- The object illuminated by the illumination light transmitted by the light 1 to the guide 22 is placed at the tip of the insertion section 21 and placed at the focal plane of the single object lens 33. Tie the statue. The entrance end surface of the image guide 34 is disposed on this focal plane, and the image of this entrance end surface is transmitted to the output DA*i: surface. An eyepiece lens 36 is disposed in the eyepiece section 35 opposite to this end face, and -C can be observed with the naked eye through this eyepiece lens 36.

On the other hand, by equipping the eyepiece 35 with the television camera 13, the image transmitted to the exit end surface is transmitted to the imaging lens 37.
The image is formed on the CCD 38 via the . A signal line is connected to this CCD 38, and the signal line is passed through the signal coupler 39, and the Shintan connector 40 is connected to the signal connector receiver. connected. Then, the drive signal from the driver 41 is applied to the imaged CC1 38 under the sequential illumination of red, green, and blue light, and is sequentially read out and amplified by the amplifier 42. It is converted into a digital signal by the A/D converter 43, and converted to 1 via multiplexer +:JIll=1.
(.

For G and B (frame) go in and out of 45R, 45G, and 45B. For example, when illuminating with red illumination light, a signal that is photoelectrically converted by the CCD 38 and accumulated as a signal charge is read out by applying a drive signal when the red illumination ends.
The data is stored in the memory 45R.

In this way, R, G, B memories 45R, 45G, /
1.5B is inserted one frame at a time.

Therefore, the image data written to these memory cards /I5R, 45G, and 45B are simultaneously read out and converted into analog color signals R, G, and B via D/A converters 46a, /16b, and 46G, respectively. , are input to the white balance circuit 47 of the first embodiment, and are subjected to balance or color adjustment. Thereafter, the gamma correction circuit 48 performs gamma correction, and the image is displayed in color on the monitor 17 via the RGB output terminal /I-9.

The white balance circuit 47 is used to perform color adjustments such as auto white and balance on the operation panel 50, for example.

The configuration of the bowie 1 to balance circuit 47 is shown in FIG.

The R and B color signals are input to the R and B white balance circuits 51 and 52, respectively, and are amplified with a gain corresponding to the gain control voltage applied to the control ill@, respectively, and output from the output terminal. In addition, color signals such as G are manually input to an O1 to WhyI balance (AWB) control circuit 53.

To the above, the WB control circuit 53 compares the R color signal and the B color signal with the reference G color signal, and
Error signals a and b are output from a and 53b. These error signals a and b are input to adder circuits 54 and 55 through changeover switches SW1 and SW1, 3W2, respectively.

The adder circuit 54 is composed of resistors R1 and R2 and an operational pull amplifier (hereinafter referred to as an A pair amplifier) 56, and similarly the adder circuit 55 is composed of resistors R3 and R4 and an A pair amplifier 56.

The resistors R1 and R3 are the changeover switches SWl and S, respectively.
W2 is connected to a common contact, and three contacts S1. S2. S
It is connected to the selected contact 5l (I=1.2.3) at point 3.

Further, the resistors R2 and R4 are connected to the changeover switch SW3.
Connected to the common contact of SW4.

The switching contact 5w1-SW< is constituted by an interlocking switch, and is switched in conjunction with these switches.

The contacts 81 and 83 in the changeover switches SWI and SW2 are connected, and the output terminal 5 of the AWB: 1-1 to roll circuit 53 is connected.
3a and 53b, and each contact S2 is connected to a connection point between resistors R5 and R6, which divide the voltage VCC, and R7 and R8.

On the other hand, contact 81. of changeover switch SW3.8W4.
82 is connected to variable resistors VR1 and VR2 that variably divide voltage VCC, and contact S3 connects to resistors 1 and 9 and 10 that divide voltage VCC, and R11.
and R12.

By connecting the changeover switches SW1 to SW4 as described above, for example, the platform with contact S1 selected has an AW
The two outputs of B controller 1 to roll circuit 53 are connected to changeover switch SW1. Adder circuit 5/1. via SW2. ．． 55 respectively, the iU resistors VR1 and VR2 receive J.
: The variable voltages are input to adder circuits 54 and 55, and the added gain control voltages are input to R and B why 1 to balance circuits 51 and 52, respectively. In other words, this state is an AWB state in which μ color adjustment is possible.

Furthermore, when the contact S2 is selected using the changeover switches SW1 to SW4, a state is entered in which color adjustment using manual color is possible.

When contact S3 is roughly selected, the output of the A W B '171 control circuit 53 is added to the fixed voltage output, and the AWB state is set in which color adjustment is not possible. In addition, ΔW B
Turn switch 57 to the right and set this switch = 11
- You can let △WB by 5-7.

According to an embodiment configured as described above, the ΔWB state where color adjustment is possible, the manual color adjustment state, and the ΔWB state where color adjustment is not possible are set respectively for monkey J and sea urchin. .

For example, when SW1 to SW/I are set so that the contact S1 is selected, the output a of the AWB control circuit 53 and the voltage of the variable resistor VR1 are input to the adding circuit 5/1, and are added. This is the control voltage for the R Voitt balance circuit 51. The control voltage is set to a constant voltage 4, but the variable resistance V 11
By moving J, you can change the voltage, and J=
This allows you to adjust the color.

In this case, for example, the rectangular resistor VRI is connected to the center
Then, press switch 57 from △WB to A to select white.
Balance.

After this, adjust the variable resistor VR1 to the desired color tone.Also, turn the changeover switches SW1 to SW/l so that the contact S2 is selected, and the voltage generated by the resistors R5 and R6. , the voltage of the variable resistor VR1 is added to the control voltage of the R why 1 to the balance circuit 51 by 4. These resistors R5 and R6 are set, for example, in the relationship of R5<R6 and R6(R1.In this way, the voltage V1 at the common contact of the changeover switch SW1 is VccR6/(R5+R
6), and by appropriately selecting the resistors R5 and R6, the rectangular resistor VR1 can be brought into a state where the bowy 1 to 1 is balanced at the center (when the color temperature is constant).

When the changeover switches SW1 to SW4 are set so that the contact S3 is selected, the control voltage a and the resistances R9 and R10 are set to J,
The resulting voltage is added to the voltage generated by R, and becomes the control voltage to be applied to the balance circuit 51.

By setting the resistors R9 and R10 so that R9<R1, R1011, the voltage V2 at the common contact of the changeover switch SW2 is given by VccR10/(R9+R10). Resistance 1λ9. By appropriately selecting R10, the adjustment range of ΔWB can be made the same as when contact S1 is selected.

Although the above description has been made for the R color signal, the same operation will occur even if the B color signal is equal to i.

= 13- Note that in the above embodiments, for example, the contact S2 may be omitted from S3.

Also, resistors IR5 (or R6), R7 (or 1 or 8).

R9 (or R10) and R11 (or R12) should be made into I ~ Lima resistors, and an adjustment stage to adjust the voltage to an appropriate A1 level should be provided.1 The above first embodiment is, for example, as shown in Fig. 2. memory/l
5R, /15G,'l On the rear side of 5B,
It may also be installed on the front side.

It is also obvious that the method can be applied to color signals obtained by sequential illumination using a television camera with a built-in color filter. Furthermore, the present invention can be similarly applied not only to a television camera but also to an electronic scanner equipped with an image carrying means within the insertion section. Furthermore, it can be used commercially not only for endoscopes but also for general video cameras.

[Effects of the Invention] As described above, according to the present invention, since a means for performing color adjustment even when using heparance is provided, it is possible to achieve a desired color tone.

[Brief explanation of the drawing]

1 and 2 relate to one embodiment of the present invention, and FIG.
Figure 2 is a configuration diagram of the balance circuit of the first embodiment, Figure 2 is a configuration diagram of an endoscope apparatus equipped with the first embodiment, and Figure 3
1 is a configuration diagram of a conventional example. 11... Endoscope device 12... Fiber path probe 13... Television camera 15... Signal processing unit/'
17...Why (-balance circuit 51...R boy 1-balance circuit and 52...B
Bowie l-balance circuit 53...;4-1-white balance control circuit 5/1.55...addition circuit 5w1--SW4...changeover switch procedure manual (
spontaneous) 1. Display of the case 1988 Special YF Application No. 10974
No. 0 No. 2, Title of the invention White balance circuit 3, Relationship to the correction creator case Patent applicant address 2-43-2 Hatagaya, Shibuya-ku, Tokyo Name (037) Olympus Optical Industry Co., Ltd. Representative Satoshi Shimoyama, Department 4, Agent Address: 7-4-4-6 Nishi-Shinjuku, Shinjuku-ku, Tokyo;
Target of amendment In the 3rd line of page 13 of the specification in the column “Detailed explanation of the invention stated in the specification”, the text “1-<<R6 and...” has been replaced with “r<<R1 and...” First of all, please correct it.

Claims (1)

[Claims] In a white balance circuit that adjusts white balance by changing the gain of a color signal that forms a video signal, there is provided an auto white balance means that automatically adjusts white balance, and an auto white balance circuit that adjusts white balance by changing the gain of a color signal that forms a video signal. 1. A white balance circuit comprising: a color adjustment means that allows further color adjustment when the white balance circuit is set to the white balance circuit.