JPH0318765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a computer control system that is capable of controlling a plurality of controlled circuits without taking into account their mutual functional relationships.

[Conventional technology]

Color television receivers are equipped with a contrast control circuit to adjust the contrast of the image. The contrast control circuit that allows the gain to be varied is
In order to maintain white balance, it is necessary to vary the gain of an amplifier circuit as a controlled circuit provided for each primary color video signal in a certain relationship.

[Problem that the invention seeks to solve]

The conventional contrast control circuit described above has R, G,
Because an amplifier circuit for controlling the contrast is provided independently for each primary color video signal of B, 3.
There were problems such as difficulty in maintaining accurate white balance when the gains of two amplifier circuits were changed simultaneously.

[Means for solving problems]

The present invention solves the above problems, and includes a plurality of controlled circuits whose respective input/output ratios are defined by constants having a functional relationship with each other, and each input/output ratio of these plurality of controlled circuits. The calculations necessary to change the above while maintaining the functional relationship are performed, and based on the calculation results, the respective input/output ratios are sequentially designated to multiple controlled circuits using an address bus, and simultaneously. a microcomputer that generates a write pulse on a write pulse line and specifies the input/output ratio of the controlled circuit via a data bus; a plurality of data setting means in which specified values are latched; and a control signal conversion circuit that converts the outputs of the plurality of data setting means into predetermined signals in one-to-one correspondence and supplies the same to control terminals of the plurality of controlled circuits. The main point is that it has been established.

[Effect]

In this invention, when changing each input/output ratio of a plurality of controlled circuits whose respective input/output ratios are defined by constants having a mutual functional relationship, a microcomputer changes the constants while maintaining the functional relationship. , control the controlled object quickly and accurately.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of the computer control system of the present invention, and FIG. 2 is a diagram showing the input/output relationship of the amplifier circuit shown in FIG.

In FIG. 1, a computer control system 1 includes variable gain amplifier circuits 2r, 2g, and 2 provided as controlled circuits for each primary color video signal of red, green, and blue.
Each gain of b is controlled according to the control voltages C _VR , C _VG , and C _VB from the microcomputer 3, so that the contrast of the image can be adjusted without disturbing the white balance. Each amplifier circuit 2r, 2g, 2b and microcomputer 3
Between them, for example, a latch circuit 4, an address decoder circuit 6, and an AND gate circuit 7 are arranged as data setting means, and a DA conversion circuit 5, for example, is arranged as a control signal conversion circuit. A conversion circuit 5 is connected, and each latch circuit 4 has an AND gate circuit 7 closed by a corresponding address decoder circuit 6.
is connected. This AND gate circuit 7 is
When the address decoder circuit 6 is closed, a control pulse called a write pulse from the microcomputer 3 is transmitted to the latch circuit 4, and the data outputted to the data bus 9 at this time is latched to the latch circuit 4. do. The microcomputer 3 and the address decoder circuit 6 are connected by an address bus 8, and the microcomputer 3 and the latch circuit 4 are connected by a data bus 9.

Here, if the gains of each amplifier circuit 2r, 2g, 2b are represented by G _R , G _G , G _B , the outputs of each amplifier circuit 2r, 2g, 2b for input Xo are Y _RO , Y _GO ,
Y _BO is expressed as Y _RO =G _R X _O , Y _GO =G _G X _O , Y _BO = G _B X _O , and these relationships are as shown in FIG. In this case, as a condition for maintaining white balance, there is always a constant functional relationship between the gains G _R , G _G , and G _B as constants that determine the input/output ratio, that is, the ratio of G _R , G _G , and G _B . is required to be constant. In other words, the amplifier circuits 2r, 2g, 2
The control voltage C _VR that determines the gains G _R , G _G , G _B of b,
Regarding C _VG and C _VB , it is also required that the ratio of C _VR , C _VG and C _VB be constant.

Therefore, for example, in order to change the gain of the amplifier circuit 2g, the control voltage C _VG is changed by △C _VG ,
When C' _VG (=C _VG +△C _VG ), for the control voltages of other amplifier circuits 2r and 2b, for example, C' _VR , the relationship is C' _VG :C' _VR =C _VG :C _VR . It is necessary to set the value to maintain the value. That is, C′ _VR =C′ _VG /C′ _VG C
It is necessary to satisfy _VR = C _VR +C _VR /C _VG △C _VG , and also to satisfy C' _VB =C _VB +C _VB /C _VG △C _VG for the control voltage C' _VB of amplifier circuit 2b. .

Therefore, when the control voltage is changed by △C _VG with the green video signal as a reference, the microcomputer 3 uses the C _VR , C _VG , and C _VB stored as data before the change to calculate the above calculation formula. By executing the original calculation, data C′ _VR and C′ _VR necessary for maintaining white balance can be obtained quickly and accurately.

Therefore, the inaccurate contrast control that conventionally relied on manual adjustment can be performed quickly and accurately by taking advantage of the high-speed arithmetic processing capability of the microcomputer 3.

In this way, the computer control system 1
When changing the input/output ratios of the plurality of amplifier circuits 2r, 2g, and 2b whose respective input/output ratios are defined by constants G _R , G _G , and G _B that have a functional relationship with each other, the microcomputer 3 Since the constants G _R , G _G , and G _B are configured to be changed while maintaining the above-mentioned functional relationship, the amplifier circuits 2r and 2r as controlled circuits
As the number of 2g and 2b increases, the microcomputer 3 can process calculations that require more complex calculations at higher speed, and also have a proportional relationship (linear relationship).
Since it is possible to accurately determine a plurality of constants that have a nonlinear relationship in a short time, it is suitable for controlled objects that require quick and accurate control.

〔Effect of the invention〕

As explained above, according to the present invention, when changing the input/output ratios of a plurality of controlled circuits whose respective input/output ratios are defined by constants having a mutual functional relationship, the microcomputer Since the structure is configured to change constants while maintaining Multiple constants that are related to each other can be determined accurately in a short time.
It has excellent effects, such as being suitable for controlled objects that require quick and accurate control.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing one embodiment of the computer control system of the present invention, and FIG.
FIG. 3 is a diagram showing the input/output relationship of the amplifier circuit shown in the figure. 1... Computer control system, 2r, 2
g, 2b...Amplifier circuit, 3...Microcomputer, 4...Latch circuit, 5...DA conversion circuit, 6...Address decoder circuit, 7...And gate circuit, 8...Address bus, 9... data bus.

Claims (1)

[Claims] 1 A plurality of controlled circuits each having an input/output ratio defined by constants having a functional relationship with each other, and a method for changing each input/output ratio of the plurality of controlled circuits while maintaining the functional relationship. The necessary calculations are performed, and based on the calculation results, each of the above input/output ratios is sequentially designated to a plurality of controlled circuits using the address bus, and at the same time, a write pulse is generated on the write pulse line, and the above-mentioned input/output ratio is specified using the data bus. a microcomputer that specifies an input/output ratio of a controlled circuit; a plurality of data setting means that are sequentially specified by values on the address bus from the microcomputer and simultaneously latch specified values on the data bus by the write pulse; A computer control system comprising: a control signal conversion circuit that converts the outputs of the plurality of data setting means into predetermined signals in one-to-one correspondence and supplies the converted signals to control terminals of the plurality of controlled circuits.