JP2011139384A - Pan head camera apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To endlessly detect a rotational position of an imaging apparatus, and to further improve a resolution of position detection by using an inexpensive potentiometer for a pan head camera apparatus. <P>SOLUTION: A potentiometer for detecting the rotational position of the imaging apparatus has a resistance band for a low resolution and a resistance band for a high resolution. In the potentiometer, one or more resistance bands for the low resolution and two or more resistance bands for the high resolution are arranged on a concentric circle, and two or more resistance bands for the high resolution are separated from each other on the concentric circle. When the same voltages are applied to the resistance bands, variable ranges of output voltages of the low resolution and the high resolution from the potentiometer are made to be same, and with respect to the relation of an output voltage to a rotational angle, a change in the output voltage to the rotational angle in the high resolution is larger than that in the low resolution. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pan / tilt head camera apparatus, and more particularly to a pan / tilt head camera apparatus having excellent accuracy when stopping an imaging apparatus in which the imaging direction of a subject is set by horizontal rotation and vertical rotation.

Hereinafter, the configuration and operation of the pan / tilt head camera apparatus according to the related art will be described with reference to FIG.
FIG. 6 is a front view of a conventional pan / tilt head camera apparatus.

  As shown in FIG. 6, the conventional pan / tilt head camera apparatus includes a camera case 3, a horizontal rotating unit 2, and a fixed unit 1. The horizontal rotation unit 2 rotates left and right, and the fixing unit 1 fixes the horizontal rotation unit 2. The camera case 3 accommodates an imaging device including a camera and a camera lens, and rotates vertically outside the rotation axis of the horizontal rotation unit 2.

  Inside the horizontal rotation unit 2, a vertical rotation motor 5, a vertical rotation belt 13, a vertical rotation shaft 8 fixed to the camera case 3, a horizontal rotation motor 4, a horizontal rotation belt 7, and a fixed unit 1 Fixed shaft 6 for horizontal rotation, control circuit 10, motor driver 47 for vertical rotation, motor driver 46 for horizontal rotation, power supply unit 40 for motor control circuit, sensors 44 and 45 for reading origin position, rotary encoder 20 , 21 and a rotary encoder reading circuit 22 are housed.

  Control of the vertical rotation motor 5 is performed via the control circuit 10, the vertical rotation motor driver 47, and the vertical rotation motor cable 12. Similarly, control to the horizontal rotation motor 4 is performed via the control circuit 10, the horizontal rotation motor driver 46, and the horizontal rotation motor cable 11.

  The video output / control signal is input to the control circuit 10 via the video output / control cable 9, and the video output / control signal input to the control circuit 10 is supplied to the camera case 3 via the camera control cable 14. The Further, power is supplied to the power supply unit 40 for the motor control circuit through the AC power cable 43. The output of the power supply unit 40 is supplied to the horizontal rotation motor 4 and the vertical rotation motor 5 via the control circuit 10, the horizontal rotation motor driver 46, and the vertical rotation motor driver 47.

  The sensors 44 and 45 are sensors for reading the origin position at the time of initial operation. After the origin position is grasped, the rotary encoders 20 and 21 detect the current position with high resolution. The detection signal is read by the reading circuit 22 after removing glitches and chattering.

  Next, the operation of the pan head camera apparatus according to the prior art will be described.

  First, when the power is turned on, an initial operation is performed, and the origin is grasped by the sensors 44 and 45. When a preset operation for rotating to a specified position is performed after the initial operation, a horizontal rotation command including information on the horizontal rotation angle or horizontal rotation time is input to the control circuit 10 by the video output / control signal input / output cable 9. . In response to the input of the horizontal rotation command, the control circuit 10 generates a pulse, whereby the horizontal rotation motor 4 and the vertical rotation motor 5 rotate by the number of pulses.

  In the preset operation, the belts 7 and 13 do not stop at the same position every time because they are slightly bent. For example, when the preset operation is performed from the right side and the left side during horizontal rotation, the belts 7 and 13 stop at different positions due to the deflection. In addition, when an external load such as wind is applied, in the belt drive, the load is applied to the rotating shaft of the motor, so that the motor may be rotated to cause a position shift.

  The rotary encoders 20 and 21 detect this deviation at the final stage of the shaft, read the glitch and chattering by the reading circuit 22, and then read the current position in the control circuit 10, and the reading deviation from the current position is detected. If there is, the horizontal rotation motor 4 and the vertical rotation motor 5 are rotated to the proper positions.

  Patent Document 1 discloses a pan head camera device configured as described above, in which a rotary encoder is provided in each of the horizontal rotation motor and the vertical rotation motor, and the position of the motor rotation is detected.

Japanese Patent Laid-Open No. 2008-147886

  For example, in the case of a lens with a zoom ratio of 35 times and a horizontal angle of view of 2 °, detection of the rotational position of the imaging device by the pan head camera device appears as a deviation of about 10% on the screen even with a deviation of 0.2 °.

  In the above-described conventional pan / tilt head camera apparatus, when a rotary encoder is used, for example, a high-resolution one that outputs 1800 pulses per rotation at a resolution of 0.2 ° is expensive. .

  In addition, in the slightly cheaper magnetic type, for example, when the AD conversion is performed on the output voltage 5V in order to set the resolution to 0.2 °, 1LSB becomes a minute voltage of 5V / 1800 = 2.8 mV, so it is affected by noise and the like. In reality, it is difficult to read.

  When using a normal inexpensive potentiometer using a resistance band, there is a problem that the resolution cannot be increased as with the magnetic type described above, and the resistance band has a beginning and an end, and it is necessary to connect electrodes. Therefore, there is a part where there is no resistance band in a part of the rotation, and there is a problem that it cannot be continuously detected endlessly.

  The present invention has been made to solve the above-described problems, and its purpose is to be able to detect the rotational position of the imaging device endlessly by using an inexpensive potentiometer in the pan head camera device. And it is providing the pan head camera apparatus which can make the resolution of a position detection high.

  In the pan head camera device of the present invention, the rotation position of the imaging device is detected by a potentiometer, and has a resistance band for low resolution and a resistance band for high resolution. The insensitive part in the low resolution detection is supplemented with another low resolution or high resolution detection means, and the insensitive part in the high resolution detection is supplemented with another high resolution detection means.

  In a potentiometer, one or more resistance bands for low resolution and two or more resistance bands for high resolution are arranged on a concentric circle, and two or more resistance bands for high resolution are separated on the same circle. Yes.

  By applying the same voltage to the resistance band, the variable range of the potentiometer output voltage consisting of low resolution and high resolution is made the same, and the relationship between the rotation angle and the output voltage is higher with respect to the rotation angle than with the low resolution. The output voltage change is increased.

  According to the present invention, an inexpensive potentiometer can be used for the camera platform camera device, and the position of rotation of the imaging device can be detected endlessly, and the position detection resolution can be increased. A camera device can be provided.

It is a front view of the pan head camera device concerning a first embodiment of the present invention. It is a figure which shows the structure of the potentiometer which concerns on one Embodiment of this invention, and is a perspective view which shows a mode when it decomposes | disassembles into case 50a, the rotary body 50b, and the resistance band arrangement | positioning board 50c. It is a figure which shows the structure of the potentiometer which concerns on one Embodiment of this invention, and is a side view when assembling case 50a, the rotary body 50b, and the resistance band arrangement | positioning board 50c. It is a figure which shows the structure of the potentiometer which concerns on one Embodiment of this invention, and is a side view after assembling the case 50a, the rotary body 50b, and the resistance band arrangement | positioning board 50c. It is a figure which shows the example of the structure of the resistance band arrangement | positioning board of the potentiometer which concerns on 1st embodiment of this invention. It is the graph which showed the waveform of the voltage output of a potentiometer. It is a figure which shows the example of the structure of the resistance band arrangement | positioning board of the potentiometer which concerns on 2nd embodiment of this invention. It is a front view of the pan head camera apparatus which concerns on a prior art.

  Embodiments according to the present invention will be described below with reference to FIGS.

[Embodiment 1]
First, the configuration of the pan / tilt head camera apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 2C.
FIG. 1 is a front view of a pan / tilt head camera apparatus according to the first embodiment of the present invention.
2A to 2C are diagrams showing the structure of the potentiometer according to the first embodiment of the present invention.

  The pan head camera device of this embodiment differs from the pan head camera device of the prior art in that the rotary encoders 20 and 21 are potentiometers 50 and 51, and the rotary encoder reading circuit 22 reads the potentiometer. This is the circuit 52. Hereinafter, the potentiometer 50 will be described as an example, but the configuration and operation of the potentiometer 51 are the same.

  As shown in FIGS. 2A to 2C, the potentiometer 50 includes a case 50a, a rotating body 50b, and a resistance band arranging plate 50c.

  2A is a perspective view showing a state in which the potentiometer 50 is disassembled into a case 50a, a rotating body 50b, and a resistance band arranging plate 50c, and FIG. 2B is a case 50a, the rotating body 50b, and a resistance band arrangement. FIG. 2C is a side view after assembling the case 50a, the rotating body 50b, and the resistance band arranging plate 50c.

  The rotating body 50b is provided with a resistance band having a pattern, which will be described in detail later, and a VCC terminal and a GND terminal.

  As shown in FIGS. 2A and 2B, the rotating body 50b is rotatably mounted by inserting the shaft of the rotating body 50b into a hole provided in the center of the case 50a fixed to the apparatus body. Rotate according to the horizontal rotation by the horizontal rotation motor 4. The resistance band arranging plate 50c is fixedly attached to the four corners of the case 50a with screws. The rotating body 50b has brushes A, B, and C as viewed from the outside, and as shown in FIG. 2C, is in contact with the resistance band arranged on the resistance band arrangement plate 50c.

  The potentiometer reading circuit 52, the brushes A, B, and C, the VCC terminal, and the GND terminal are wired, and the voltage between the wirings can be read.

Next, the structure and principle relating to position detection of the pan / tilt head camera apparatus according to the first embodiment of the present invention will be described with reference to FIGS.
FIG. 3 is a diagram showing an example of the structure of the resistance band arranging plate of the potentiometer according to the first embodiment of the present invention.
FIG. 4 is a graph showing a waveform of the voltage output of the potentiometer.

  As shown in FIG. 3, the inside of the resistance band arrangement plate 50 c of the potentiometer 50 of the pan head camera apparatus of the present embodiment has a resistance band A, a resistance band B, and a resistance band C on a single plane and concentric circles. Has been placed. There is one break in the resistance band A, and the resistance band B and the resistance band C are in the same circle, respectively, and have five resistance bands B1 to B5 and C1 to C5, respectively. It is arranged to do. Further, the resistance band B is arranged so as to include the cut of the resistance band A. These three resistance bands have the same resistance from end to end of the elements of each resistance band. Also, VCC (power source) and GND (0 V) terminals are connected to both ends of each resistance band. As a potentiometer, a rotation position can be detected by the potentiometer reading circuit 52 when a voltage or the like changes depending on the position of the resistance band in contact with the brush by rotating the resistance band with a brush or the like. it can.

  FIG. 4 shows a voltage output waveform of the potentiometer having the structure shown in FIG. According to this, the voltage output by the resistance band A along with the rotation gradually rises to VCC, and the output stops at the break of the resistance band A. Similarly, the resistance band B and the resistance band C gradually increase in voltage up to VCC due to the rotation. However, because the resistance band B and the resistance band C are composed of five resistance bands, the change appears five times in one rotation (360 °). Similarly, the output of the resistance band B and the resistance band C disappears at the break. Here, since another resistance band is arranged so as to include each cut as described above, the output of the resistance band C may be detected even when there is no output of the resistance band B, for example.

  For example, when the brushes A, B, and C of the respective resistance bands A, B, and C are at the position P in FIG. 2, as shown in FIG. 3, the wires coming out from the brushes A, B, and C The potentiometer reading circuit 52 reads the voltage indicated by the intersection of the vertical line at the position P and the graph.

  Since the resistance band A is output from 0V to VCC when the break is ignored, for example, when an AD converter with a resolution of 10 bits is used, the resolution is about 0.35 °. When the break is ignored in the resistance bands B and C, 360 ° / 5 is output from 0 V to VCC, so that it is about 0.07 °. As described above, the resistance band A enables high-resolution detection by using the same power supply voltage with an approximate position in 360 ° and the resistance bands B and C.

  Further, the resolution can be further increased by increasing the number of breaks in the resistance bands B and C.

[Embodiment 2]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG.
FIG. 5 is a diagram showing an example of the structure of the resistance band arranging plate of the potentiometer according to the second embodiment of the present invention.

  In the resistance band arrangement plate of the potentiometer of this embodiment, as shown in FIG. 5, the non-resistance bands D and E to which the terminals of VCC and GND connected to each resistance band are connected are shown in FIG. The resistance bands A, B, and C are arranged concentrically. Here, the non-resistance band is made of a conductor whose resistance is close to zero.

  The rotating body 50b is provided with a brush D in contact with the non-resistance band D and a brush E in contact with the non-resistance band E on the outside of the brushes A, B, C, and the brushes A, B, C, Wiring the brushes D and E, the potentiometer reading circuit 52 detects the voltage between them. Thereby, it is possible to supply power to the resistance band endlessly.

A ... Resistance band A, B1-B5 ... Resistance band B, C1-C5 ... Resistance band C, C1-C5 ... Resistance band C, D ... Non-resistance band D, E ... Non-resistance band E,
DESCRIPTION OF SYMBOLS 1 ... Fixed part, 2 ... Horizontal rotation part, 3 ... Camera case, 4 ... Horizontal rotation motor, 5 ... Vertical rotation motor, 6 ... Horizontal rotation shaft, 7 ... Horizontal rotation belt, 8 ... Vertical rotation shaft , 9 ... Video output, control signal input / output cable, 10 ... Control circuit, 13 ... Vertical rotation belt, 14 ... Video output, camera control cable, 40 ... Motor power supply unit, 41 ... Control circuit power supply unit, 44, 45 ... Sensor for reading the origin position, 46 ... Motor driver for horizontal rotation, 47 ... Motor driver for vertical rotation, 33 ... Sensor for vertical rotation, 31 ... Sensor for horizontal rotation, 20 ... Potentiometer for horizontal rotation, 21: Potentiometer for vertical rotation, 22: Reading circuit.

Claims (1)

In the pan head camera device in which the imaging direction of the subject is set by horizontal rotation and vertical rotation and includes a rotation position detection unit,
With low and high resolution detection means,
By applying a voltage to each resistance band of the potentiometer, the variable range of the output voltage of the potentiometer consisting of low resolution and high resolution is made the same. A pan head camera device characterized by increasing the size of the camera.

Images