JPH08334673A - TV lens zoom adjustment device - Google Patents

Abstract

(57) [Summary] [Purpose] The television lens follows well to minute changes in zoom operation. A motor speed characteristic with respect to a tilt angle of a thumb ring is selected by a mode setting means between a linear mode a and a non-linear mode b, and an arbitrary characteristic is obtained according to a set constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom adjusting device for a TV lens, which is capable of remotely controlling the zooming operation of a zoom lens mounted on a TV camera.

[0002]

2. Description of the Related Art FIG. 6 shows an overall image when a photographing lens of a television camera is operated. Generally, a photographing lens 2 is attached to a tip of a television camera 1 and the whole thereof is mounted on a tripod mount 3.
It is often fixed and used. From this tripod mount 3, two bread bars 4a and 4b are projected rearward,
On one side, a zoom demand 6 for remotely operating the zoom unit 5 of the taking lens 2 is attached to the pan rod 4a, and on the other side, a focus demand 7 for remotely operating the focus unit is attached. These transmit signals to the taking lens 2 through the television camera 1 or directly in response to input by the photographer S's fingers or the like.

In such a system, the zoom section 5 of the taking lens 2 includes a driving means 8 such as a motor and the zoom section 5.
The zoom demand 6 is for providing a command signal to the driving means 8 and the servo control section 11 in the servo means for controlling the operation of the driving means 8 and the gear 10 for connecting the driving means 8 and the cam 9. Used for.

The zoom demand 6 is, as shown in FIGS. 7 and 8, a thumb ring 12 as a zoom operation means which is generally manually operated by a photographer S, and an electric power proportional to an operation amount which is an inclination angle of the thumb ring 12. It has a detection means 13 including a potentiometer for outputting a signal, and a body grip 14 for holding all of them.

The output signal of the detecting means 13 is converted into a servo command signal by the amplifier board 15, and the connector 16
6 to the servo control section 11 of the servo means, and the drive means 8 is operated based on this servo command signal to perform zooming in the range from the wide-angle end (WIDE) to the telephoto end (TELE). I am able to do it.

The servo command signal in this case controls the speed of the driving means 8, and generally, the relationship between the inclination angle of the thumb ring 12 and the speed of the driving means 8 changes linearly as shown in FIG. There are many. The portion of θ ₀ in FIG. 9 is called a dead zone, and is a portion in the vicinity of the mechanical midpoint of the thumb ring 12 where no signal is output.

[0007]

In such a television lens system, for example, when the photographer S performs zooming at an extremely slow speed, that is, in slow zoom,
It suffices to incline the thumb ring 12 by a small angle θ _{1 in} FIG. 9, for example. However, due to the presence of the dead zone described above, it is often unclear whether or not the thumb ring 12 is slightly inclined to perform zooming. .

However, if the tilt angle of the thumb ring 12 is too large, for example, θ ₂ in FIG. 9, the zoom may suddenly move for a moment, and the shooting state may be impaired. On the contrary, when performing zooming at an extremely high speed, the maximum speed cannot be obtained unless the fingers are tilted greatly, which is not convenient for the photographer S.

Further, since the dead zone is originally provided by allowing the middle point return error in the actual zoom adjusting device of the television lens, many photographers S do not feel the dead zone in the zoom adjustment of the television lens. It is possible that they are looking for a device.

A first object of the present invention is to provide a zoom adjusting device for a television lens which solves the above problems and is capable of following a minute change in the zoom operating means according to the photographer's intention. To provide.

A second object of the present invention is to provide a zoom adjusting device for a television lens which solves the above-mentioned problems and can obtain the stability of the zoom operation near the midpoint of the zoom operating means. .

[0012]

A zoom adjusting device for a television lens according to a first aspect of the present invention for achieving the above-mentioned first object detects an operation amount of a zoom operating means by a detecting means, and outputs the detection signal. When controlling the servo means for zoom operation based on the above, an A / D converter for converting an output signal from the detecting means into a digital signal, a mode setting means for setting a function mode, and an output signal from the detecting means And storage means for storing a constant for determining the relationship between the zoom operation and the output signal to the servo means, the signal from the mode setting means, the signal stored in the storage means, and the detection means from the detection means. Arithmetic means for calculating an output signal to the servo means using the output signal.

According to a second aspect of the present invention, there is provided a zoom adjusting device for a television lens according to the second aspect of the invention, wherein the detecting means detects the operation amount of the zoom operating means, and the servo of the zoom operation is performed based on the detection signal. An A / D converter for converting an output signal from the detection means near the midpoint of the zoom operation means into a digital signal when controlling the means;
Storage means for storing output data from the D converter, and calculation means for performing correction calculation of the midpoint data using the output signal from the A / D converter and the data stored in the storage means. It is characterized by having.

[0014]

In the zoom adjusting device for a television lens according to the first aspect of the present invention having the above-mentioned structure, the output voltage from the detecting means for detecting the operation amount of the zoom operating means is an A / D converter, a mode setting means, and a constant storage means. A non-linearization calculation is performed using the calculation means to arbitrarily set the relationship between the zoom operation amount and the zoom speed.

In the zoom adjusting device for a television lens according to the second aspect of the present invention, the output voltage near the midpoint of the detecting means for detecting the operating amount of the zoom operating means is A / D converted to the zoom operating amount near the midpoint. Correct the zoom speed relationship.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a block circuit configuration diagram of an embodiment. The output of the potentiometer 21 that outputs an analog voltage in conjunction with the thumb ring is connected to the CPU 23 via the A / D converter 22. The CPU 23 is connected to a mode changeover switch 24 for setting a calculation mode of a linear mode or a non-linear mode, a memory 25 for storing constants used during calculation, and an amplifier 26.
The data near the midpoint of the potentiometer 21 is connected to the CPU 23 via the amplifier 27 and the A / D converter 28, and the amplifier 26 is connected to the motor 29.

FIG. 2 is a flow chart showing an operation program of the CPU 23. The circuit operation of FIG. 1 will be described with reference to this flow chart. Memory 25 in step 1
Area boundary data X1 and X2 stored in, and non-linearization operation constants A, B and C in non-linear mode, adjustment area operation constants D and E, linearization operation constant F in linear mode, and maximum output data G Read the data. By operating the thumb ring 12 in step 2, the changed output voltage of the potentiometer 21 is A / D converted by the A / D converter 22, and the obtained digital data X is input to the CPU 23.

In step 3, the setting mode of the mode changeover switch 24 is input to the CPU 23. A / D in step 4
The digital data X input from the converter 22 is stored in the memory 25.
Compared with the area boundary data X1 input from, if X ≦ X1, the output data Y is set to 0 in step 5 as a dead zone area in the graph of FIG. 3, and the process proceeds to step 6. Since the output data Y is proportional to the zoom speed, the zoom speed by the motor 29 is 0 in the dead zone region, and zooming is not performed.

If X> X1 in step 4, step 7
And compare the digital data X with the area boundary data X2, and X ≤
If it is X2, the digital data X is processed in the following manner by using the constant groups A to G which are arbitrarily set and stored in the memory 25 as an arbitrary function area in the graph of FIG. If it is determined to be an arbitrary function region, it is determined in step 8 the data of the mode changeover switch 24 input in step 3, that is, whether it is the linear mode or the non-linear mode. If it is the linear mode, in step 9, Y = F ( X-X1) and in the non-linear mode, in step 10, Y = A (X-X1) ² + B (X-X1) + C is used to calculate the output data Y proportional to the zooming speed, and then Go to step 6.

If X> X2 in step 7, the adjustment area of the graph of FIG. 3 is set, and in step 11, the data of the mode changeover switch 24 is judged. In the linear mode, in step 12, Y = G is output data. If Y is set, and in the non-linear mode, the output data Y is calculated using Y = DX + E in step 13 and the process proceeds to step 6.

Note that examples of the rotation angle versus output data curve of the thumb ring 12 in the linear mode and the non-linear mode are shown in FIGS.

As described above, by setting the dead zone area by using the area boundary data X1 which is a constant that can be arbitrarily set, the dead zone width can be easily changed, and the zooming operation by the dead zone can be performed. You can eliminate the discomfort when rising. Also, arbitrary constants A, B, C, D,
By performing a non-linear calculation using E and realizing the rotation angle vs. output data curve intended by the operator, the change of the zooming speed at the time of slow zooming by the motor 29 becomes smooth and matches the operator's interval. Good slow zoom shooting is possible. In addition, by using the arbitrary constants F and G, it is possible to achieve the maximum speed without tilting the zoom operation means to the end, and it is possible to improve the feeling of operation at a fast zoom speed.

However, if the dead zone width is made smaller, the middle point tolerance of the potentiometer 21 becomes smaller and even if the thumb ring 12 is not operated, the potentiometer 21
A signal is output due to the static error, temperature change, and secular change, which easily causes a malfunction.

Therefore, 1 is added to the count value CT in step 6 of FIG. 2, the count value CT and the constant N are compared in step 14, and if CT <N, the process returns to step 2 to repeat the above-mentioned processing. If CT ≧ N, the voltage near the midpoint amplified by the amplifier 27 is A / D converted by the A / D converter 28 in step 15, the data DT _M is input, and in step 16, CP = Using (DT ₁ + DT ₂ + ... + DT _M ) / M, the average value CP of the midpoint data within a certain period of time is obtained and used as the midpoint data when the thumb ring 12 is not newly operated. , Correct errors and prevent malfunctions.

In the above embodiment, the constants that can be arbitrarily set are stored in the memory 25, and they are read into the CPU 23 for arithmetic processing. However, instead of storing the constants in the memory 25, a resistor or an encoder is used. It is also possible to use setting means such as.

Since all the constant groups stored in the memory 25 are arbitrary constants, the inclination of the straight line a and the shape of the curve b in FIG. 3 can be freely changed according to the photographer's intention. Further, as shown in FIG. 3, since the adjustment area is provided in each of the linear and non-linear modes, even when the arithmetic load of the CPU 23 is lightened by approximating the constant of the function in the arbitrary area to an integer, the error caused by the approximation is reduced. Since it can be absorbed in the adjustment area, the curve intended by the photographer can be realized almost accurately by relatively quick calculation.

FIG. 4 is a block circuit configuration diagram in the case of using a resistor for setting a constant that determines the dead band width among arbitrary constants, and FIG. 5 is a flowchart thereof. Note that FIG.
1 is different from the block circuit configuration diagram of FIG. 1 in that a dead band width setting means 31 composed of a resistor is connected to the CPU 23 via an A / D converter 30.

In the flow chart of FIG. 5, in step 1, the area boundary data X2 from the memory 25, the non-linear operation constants A, B and C in the non-linear mode, the adjustment area constants D and E, and the operation constant F in the linear mode are used. , G is read. In step 1 ', the output voltage X1 of the dead band width setting means 31
Is input via the A / D converter 30. After step 2, the process may be performed in the same manner as in the first embodiment. If the count value CT is larger than the constant N in step 14, the process returns to step 1'and the process is continued.

[0029]

As described above, in the zoom adjusting device for a television lens according to the first aspect of the present invention, the output voltage of the detecting means interlocked with the zoom operating means of the zoom adjusting device is nonlinear by the mode setting means, the storing means and the calculating means. By using the calculation, it is possible to arbitrarily set the relationship between the rotation angle of the zoom operation means and the output data proportional to the zoom speed, and it is possible to obtain a good zoom operation feeling for the photographer.

Further, in the zoom adjusting device for a television lens according to the second aspect of the present invention, by correcting the data in the vicinity of the midpoint of the zoom operating means, it is possible to suppress malfunction of the detecting means due to static error, temperature change, and secular change. It is possible to further reduce the dead zone width and further improve the operational feeling.

[Brief description of drawings]

FIG. 1 is a block circuit configuration diagram of a zoom adjusting device according to a first embodiment.

FIG. 2 is a flowchart of a processing process.

FIG. 3 is a graph showing a relationship between a tilt angle of a thumb ring and driving of a driving member.

FIG. 4 is a block circuit configuration diagram of a zoom adjusting device according to a second embodiment.

FIG. 5 is a flowchart of a processing process.

FIG. 6 is an explanatory diagram when operating a taking lens of a television camera.

FIG. 7 is a schematic cross-sectional view of a zoom adjusting device for a television lens.

8 is a cross-sectional view taken along the line AA of FIG.

FIG. 9 is a graph showing a relationship between a tilt angle and a speed of a driving unit in a conventional example.

[Explanation of symbols]

 21 Potentiometer 22, 28, 30 A / D Converter 23 CPU 24 Mode Changeover Switch 25 Memory 26, 27 Amplifier 29 Motor 31 Dead Band Width Setting Means

Claims (2)

[Claims] 1. When the operation amount of the zoom operation means is detected by the detection means and the servo means for zoom operation is controlled based on the detection signal, an output signal from the detection means is converted into a digital signal A / A D converter, a mode setting means for setting a function mode, a storage means for storing a constant for determining the relationship between the output signal from the detection means and the output signal to the servo means for the zoom operation, and It is characterized by further comprising: arithmetic means for arithmetically operating an output signal to the servo means using a signal from the mode setting means, a signal stored in the storage means and an output signal from the detection means. TV lens zoom adjustment device. 2. When the operation amount of the zoom operation means is detected by the detection means and the servo means for zoom operation is controlled based on the detection signal, an output signal near the midpoint of the zoom operation means is output from the detection means. A / D converter for converting into a digital signal, storage means for storing output data from the A / D converter, output signal from the A / D converter and storage in the storage means A zoom adjustment device for a television lens, comprising: a calculation unit that performs correction calculation of midpoint data using data.