JPH0582787B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention provides a control input for controlling a controlled circuit in a color television camera by a regulator that outputs a pulse number proportional to the rotation angle. This invention relates to improvements in adjustment devices for color television cameras.

[Technical background of the invention and its problems]

In recent years, it has become common for color television cameras to be equipped with an automatic adjustment function using a microcomputer. However, not all adjustments are necessarily operated according to the results of automatic adjustment, and manual adjustment is performed for control items other than automatic adjustment items. Although these are less troublesome, they are manual adjustments or adjustments that are performed anyway to obtain the best situation than automatic adjustment. A rotary encoder (hereinafter referred to as R/E) is used as a manual control input means for this purpose. Since the R/E has already been supplied to the market as a product, the details will be omitted, but it outputs a pulse train whose frequency is proportional to the angular velocity of the rotating shaft of the R/E, and the pulse train has two pulse trains to determine the rotation direction. A type that outputs something with a phase is common. Then, using one of the phases of these two pulses as a reference, if the phase of the other one is advanced by 90 degrees, it can be determined that the rotation is clockwise, and if it is delayed by 90 degrees, it is counterclockwise.

In this R/E adjustment, the pulse train is integrated, rotation angle information and rotation direction information are detected, and the corresponding control items are controlled based on this information. This control is performed faster if the R/E rotation shaft is turned faster, and slower if it is turned slower, and is proportional to the angular velocity of the rotation shaft.

In this kind of adjustment, the CPU reads the integration results of the R/E output pulse train at a constant cycle, so
The amount of change in the control amount for one pulse output of R and E is always constant. (In other words, the change in the control amount with respect to the rotation angle of the rotation axis is constant.) Therefore, in the case of "horizontal centering" shown in red, if the number of bits of the CPU digital signal is 10 bits, the resolution is 1/
The resolution is 1024, or approximately 1/1000. Assuming that the entire range is covered by R/E2 rotations, the quantization step will be 20/1000=0.02% when the horizontal centering variable range is ±20%. The detection limit based on the viewing angle of horizontal centering in the current broadcasting system is 0.05%.
Since the non-linearity of the D/A converter (normally ±
(1/2 to 1 bit), one quantization step can be considered to be slightly below the detection limit. As mentioned above, covering the entire range in 2 rotations means changing 1000 quantization steps in 2 rotations, so 500 quantization steps in 1 rotation and 1
The quantization step is obtained by a rotation of 360°/500=0.72°. In other words, the detection limit for the rotation angle of R and E becomes critical. In order to avoid this, it is possible to increase the rotation speed of R and E for the entire variable range, but this time, for the entire variable range,
Alternatively, when a large amount of change is desired, it is inconvenient to manually turn R and E many times.

[Purpose of the invention]

The present invention obviates the above-mentioned drawbacks, and R.E.
When the rotation axis is rotated by the same angle at different angular velocities, the pulse integration result corresponding to the rotation angle changes due to the change in angular velocity, so when the rotation axis is slowly rotated, the change in the control amount with respect to the rotation angle becomes smaller. It is an object of the present invention to provide an adjustment device for a color television camera, in which when the rotation angle is turned quickly, even if the rotation angle is the same as described above, the change becomes large, and a change amount over a wide range or the entire variable range can be obtained.

[Summary of the invention]

In the present invention, in an adjustment device for a color television camera that performs adjustment control by integrating the number of pulses proportional to the rotation angle from R and E, the integrated number of pulses is changed in accordance with the angular velocity.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIG.

1 is R and E, and as described above, two pulse train signals A and B are generated in accordance with the rotation of the rotary shaft, and these pulse train signals are supplied to the pulse integration and rotation discrimination circuit 2. Reference numeral 3 denotes an arithmetic circuit (hereinafter referred to as CPU) consisting of a microprocessor, which reads data from the circuit 2 and calculates control values.
4-1, 4-2,...4-n are switches for selecting control items, and when these switches are turned on, data corresponding to the control items is generated from the function selection matrix 4, and the control of the control items is performed. It is considered possible.

After a control item is selected by the switches 4-1, 4-2, . In the CPU 3, these pieces of information are read at a constant cycle T set based on clock pulses and the like. If the number of pulses accumulated in this period T is n, then in the CPU 3, if R.E1 is rotating at a constant angular velocity, the number of pulses n is read every T.

Also, reading to CPU3 like this is done using R.
A predetermined rotation angle of E1 may be detected and the process may be performed for each unit rotation angle. After reading the number n of pulses, the CPU 3 performs the following calculations.

m=n(n/N) ^c ...(1) D=A±∫mdt...(2) In equations (1) and (2), m is the cumulative number of pulses, N is a constant, and c is a constant (c> 1), A is the previous integrated value, D
is the control value.

Therefore, when n=N, m=n from equation (1), and when n<N, (n/N) ^c <1, so m<
When n>N, m>n due to (n/N) ^c >1. That is, when the rotation of R・E1 is slow and outputs fewer than N pulses per cycle T, m<n in the CPU 3.
is calculated and A is added to obtain the control value D ₀ .

Further, when R·E1 outputs more than N pulses at high speed, m>n, and the control value _D1 is obtained by adding A. In other words, the integrated value of the number of pulses n changes according to the rotational angular velocity of the rotating shaft of R・E1, and it is the same as reducing the number of output pulses by rotating slowly, and rotating quickly. This is equivalent to increasing the number of output pulses. Note that m is added to or subtracted from A depending on the rotation direction information of R and E1 determined by the circuit 2. The control value D calculated by the CPU 3 is applied to the conversion units 5-1, 5-2, ... 5-n, which correspond to the control items of the digital-to-analog converter groups 5 and 7 (hereinafter referred to as the D/A converter group). 7-1, 7-2,
...7-n to the controlled circuit for control. One of the D/A converter groups 5 is provided in a remote camera head or the like, and the control value D is transmitted thereto via a multiplexing circuit 8, a cable 9, and a multiplex demodulation circuit 10.

As mentioned above, the control of this controlled circuit can be varied with N as the boundary depending on the rotational angular velocity of the rotating shaft of R and E1, and when n<N, slow rotation, fine adjustment can be made.
At fast rotations where n>N, coarse adjustment occurs. This R.E.
The fine adjustment and coarse adjustment according to 1 are changed with c as a parameter and n=N as the boundary, as shown in FIG. By controlling R・E1 in this way, the controlled circuit is
It can be controlled as shown in the figure. In other words, the solid line in the figure shows conventional control, in which the entire variable range is controlled by two rotations of R and E, whereas the dashed line shows control by rotating R and E1 at a constant angular velocity where n>N. It can be controlled without making two rotations. Conversely, when rotating at an angular velocity of n<N, the entire range can be controlled with two or more rotations as shown by the broken line, allowing highly accurate control.Furthermore, the angular velocity of R/E1 can be changed midway through the rotation. By doing so, the control state can be changed as shown by the two-dot chain line. In addition, in this FIG. 3, the initial values, that is, A in equation (2) are all shown as zero.

〔Effect of the invention〕

As described above, according to the present invention, in the adjustment device for a color television camera that obtains a control value for controlling a controlled circuit with R/E, the control value for the rotation angle of R/E is Since the angular velocity of the rotating shaft is changed as a parameter, if you turn R and E slowly, you will get fine adjustment, and if you turn them quickly, you will get coarse adjustment, and you can quickly obtain a large amount of variation, so one R and E will make coarse adjustment. - A control circuit can be obtained that can be used for both fine adjustment and the switching is performed based on the natural reaction of humans, such as turning slowly when the operator is making fine adjustments and turning quickly when making coarse adjustments.

It is also possible to store in a memory circuit or the like such that N/C in equation (1) above is changed for each control item, and to perform control by reading out these values for the control item according to the selection of the switch. .

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing one embodiment of the adjustment device for a color television camera according to the present invention, and FIG.
3 are explanatory diagrams showing the operation shown in FIG. 1, respectively. 1...Rotary encoder, 2...Pulse integration, rotation discrimination circuit, 3...Arithmetic circuit, 5, 7...
Digital-to-analog converter group.

Claims (1)

[Claims] 1. In a color television camera adjustment device that uses a rotary encoder that generates a pulse signal proportional to the rotation angle and performs adjustment by integrating the number of output pulses, the output from the rotary encoder The number of output pulses is read, and if the rotational angular velocity of the rotary encoder is slowed down, the cumulative number of output pulses is decreased, and if the rotational angular velocity is increased, the cumulative number of output pulses is increased. A color television camera comprising: a first calculation means for deriving the number of pulses; and a second calculation means for generating a control value in accordance with the cumulative number of pulses derived from the first calculation means. Adjustment device. 2. The color television camera adjustment device according to claim 1, wherein the pulse number is integrated at predetermined intervals. 3. The color television camera adjustment device according to claim 1, wherein the pulse number is integrated at every predetermined rotation angle of the rotary encoder.