JP2000249514A - Motor position detection mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the load of software processing a step-out detection circuit and detect the origin by rotating a motor by 180 degrees. SOLUTION: A shading plate 16 is arranged at 0 degree position of a rotation plate 12a and a photosensor 14 is arranged on the opposite position of the shading plate 16. Also, a shading plate 17 is arranged apart from the shading plate 16 by x degree and a photosensor 15 is arranged at the opposite position of the shading plate 17. Also, a light shield plate 18 is arranged apart from the shading plate 16 by 90 degrees and a light shield plate 19 is arranged apart by 180 degrees and a light shield plate 20 is arranged apart by 270 degrees. The photosensors 14 and 15 inform the shading state by outside. By this, the position of the rotation state 12a is roughly identified from the outside by the light shield state from the photosensors 14 and 15 and an external software processing is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor position detecting mechanism for detecting the position of a motor, and more particularly to a motor capable of reducing the load on the host by outputting the detected position of the motor to the host with a simple signal. It relates to a position detection mechanism.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a configuration diagram of a television camera device using a camera platform incorporating a conventional motor position detection mechanism disclosed in Japanese Patent Application Laid-Open Publication No. H10-115,026. In the figure, 1 is a television camera, 2 is a tilt mechanism for rotating the television camera 1 in the vertical direction, 3 is a pan mechanism for rotating the television camera 1 in the horizontal direction, 4 is a pan head, 5 is an operation unit,
Reference numeral 6 denotes a motor for driving the tilt mechanism 2, and reference numeral 7 denotes a motor for driving the pan mechanism 3. 8 is a motor position detecting mechanism of the motor 6, 9 is a motor position detecting mechanism of the motor 7, 10
Is a motor control circuit, and 11 is a step-out detection circuit.

FIG. 5 shows a slip ring 3 shown in FIG.
1 is a configuration diagram, in which 311 is a cable connected to the TV camera 1 side, and 312 is a cable connected to the camera platform 4 side. The use of the slip ring 31 shown in FIG. 5 enables the pan mechanism 3 to perform endless rotation of 360 ° or more.

FIG. 6 is a block diagram of the motor position detecting mechanism 8 shown in FIG. In the figure, reference numeral 12 denotes a rotating plate which rotates in synchronization with a rotor (not shown) of the motor 6;
21 is a large slit and 122 is a small slit. Also,
Reference numeral 13 denotes a photo sensor that generates an interrupt in response to detection of the large slit 121 or the small slit 122.

Next, the operation of the television camera device shown in FIG. 4 will be described. For example, when an operator (not shown) controls the direction of the television camera 1, the control is performed by pressing a key arranged on the operation unit 5. Motor control circuit 1
Numeral 0 outputs a drive pulse to the motors 6 and 7 according to the amount of the key pressed by the operation unit 5.

For example, when the operator presses the up key U
Alternatively, when the down key D is pressed, the motor control circuit 10 outputs to the motor 6 a drive pulse corresponding to the pressed amount of the pressed key. As a result, the motor 6 rotates the tilt mechanism 2, so that the television camera 1 rotates in the vertical direction. When the operator presses the left key L or the right key R of the operation unit 5, the motor control circuit 10 outputs a drive pulse corresponding to the pressed amount of the pressed key to the motor 7. Thereby, the motor 7 rotates the pan mechanism 3, so that the television camera 1 rotates in the horizontal direction.

The motor control circuit 10 outputs the drive pulse output to the motor 6 or the motor 7 to the step-out detection circuit 11. Further, the motor position detecting mechanism 8 is configured such that the photo sensor 13 has a large slit 121 or a small slit 122.
Is output to the out-of-step detection circuit 11 in response to the detection of. As a result, the step-out detection circuit 11 compares the drive pulse from the motor control circuit 10 with the interrupt signal from the photosensor 13 and determines that a step-out has occurred if no interrupt signal corresponding to the drive pulse has been generated.

Next, a description will be given of the origin detection operation for eliminating step-out by the step-out detection circuit 11. Incidentally, in the motor position detecting mechanism 8 shown in FIG.
If 21 passes, an interrupt occurs three times in a row.
When the small slit 122 passes, one interruption occurs. The origin set in the motor position detection mechanism 8 is A. The step-out detection circuit 11 causes the motor control circuit 10 to output a drive pulse for rotating in the B direction. As a result, an interruption corresponding to the detection of the large slit 121 and the small slit 122 is output from the photosensor 13 to the out-of-step detection circuit 11.

In the step-out detection circuit 11, the photo sensor 13
When the interrupt is input three times in succession, and thereafter, the interrupt is input once, it is determined that the rotating plate 12 has passed the origin A, and the motor control circuit 10 is notified. That is, the step-out detection circuit 11 detects step-out and the origin of the motor 6 based on the interrupt signal from the motor position detection mechanism 8.

[0010]

The conventional motor position detecting mechanism is constructed as described above, and has the following problems. (1) The motor position detection mechanism 8 notifies the position of the motor 6 by outputting an interruption from the photo sensor 13 to the step-out detection circuit 11. That is, in the conventional motor position detecting mechanism 8, the structure having many slits requires the complicated rotating plate 12, and the step-out detecting circuit 11
In this case, it is necessary to respond to an interrupt from the motor position detecting mechanism 8, and there is a problem that software processing in the step-out detecting circuit 11 becomes heavy.

(2) Also, a predetermined processing time is required for the interrupt processing, and the step-out detecting circuit 11 becomes smaller as the interval between the driving pulses output by the motor control circuit 10 becomes shorter.
However, there is a problem that it is difficult to detect an interrupt in the system, and there is a case where a step-out is erroneously detected.

(3) The step-out detection circuit 11
When the out-of-step is detected, the origin A is detected by rotating the rotating plate 12 in the direction B and detecting a predetermined interruption pattern. For example, when the origin A is immediately to the left of the photosensor, the out-of-step is detected. Occurs, the origin A cannot be detected unless it is rotated about 360 °, and there is a problem that detection takes time.

A first object of the present invention is to provide a motor position detecting mechanism capable of reducing a load of software processing in a step-out detecting circuit. The second purpose is to use a motor of 18
An object of the present invention is to provide a motor position detecting mechanism that can detect the origin by rotating the motor by about 0 °.

[0014]

A motor position detecting mechanism according to the present invention comprises a plurality of light-shielding plates provided at equal intervals around an end of a rotor at a center of 0 °, and a plurality of light-shielding plates opposed to the 0 ° position of the rotor. A first photosensor that outputs a light-shielded state by the light-shielding plate, a 0 ° detection light-shielding plate provided at a predetermined angle from any of the plurality of light-shielding plates, and a 0 ° position of the rotor. And a second photosensor provided to face the 0 ° detection light-shielding plate and outputting a light-shielded state by the light-shielding plate.

In the motor position detecting mechanism according to the next invention, a third photosensor is provided at a position 180 ° away from the second photosensor facing the rotor.

Further, a motor position detecting mechanism according to the next invention outputs a light blocking state by a photo sensor by a port signal.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of a television camera device using a camera platform having a built-in motor position detection mechanism according to the first embodiment of the present invention. The same reference numerals as those in FIG. Omitted. In the figure, 4a is a camera platform, 8a is a motor position detecting mechanism, and 11a is a step-out detecting circuit. FIG. 2 is a configuration diagram of the motor position detection mechanism 8a shown in FIG. 1. In FIG. 2, 12a is a rotating body, 14 and 15 are photo sensors, 1
Reference numerals 6 to 20 denote light-shielding plates attached to the rotating body 12a. The photo sensors 14 and 15 are provided at intervals of x °, and the light shielding plates 16 and 17 are also provided at intervals of x °. Each of the light shielding plates 16, 18, 19, and 20 has 9
They are provided at 0 ° intervals.

Next, a motor position detecting mechanism 8a shown in FIG.
Will be described. The photosensors 14 and 15 output the light-shielded state by the light-shielding plates 16 to 20 to the out-of-step detection circuit 11, respectively. That is, for example, the photo sensor 14 is
When any one of the light-shielding elements 20 blocks light, the light-blocking state is output to the out-of-step detection circuit 11a as “present”, and in other cases, the light-shielding state is “not present” and output to the out-of-step detection circuit 11a. The photo sensor 15 also performs the same operation as the photo sensor 14.

Thus, in the out-of-step detection circuit 11a, it can be seen that when both the light-shielded states from the photosensors 14 and 15 are "present", they are the origins. Also, the photo sensor 1
The light blocking state of No. 4 is 90 by the light blocking plates 16 and 18 to 20.
°, the out-of-step detection circuit 11a outputs about 9
Rough step-out detection can be performed every 0 °. Also,
If the light-shielded state is transmitted to the out-of-step detection circuit 11a by a port signal, the out-of-step detection circuit 11a does not perform interrupt processing, and the load on software processing is reduced. Further, since the processing can be performed without shifting to the interrupt processing, step-out and detection are reduced by mistake.

In the configuration shown in FIG. 2, four light shielding plates 16, 1
By arranging 8, 19 and 20 at equal intervals every 90 °, 9
Although out-of-step detection can be performed at every 0 °, it goes without saying that out-of-step detection can be performed at every predetermined angle by arranging light shielding plates at equal intervals at every predetermined angle.

Embodiment 2 FIG. FIG. 3 is a configuration diagram of a motor position detection mechanism according to Embodiment 2 of the present invention. The same reference numerals as those in FIG. 2 indicate the same or equivalent functions, and a description thereof will be omitted. In the figure, 21 is 180 ° with the photo sensor 15
These are photosensors that are arranged apart. The photosensor 21 also outputs a light-shielding presence / absence signal to the step-out detection circuit 11a shown in FIG. 1 similarly to the photosensors 14 and 15.

Thus, the step-out detection circuit 11 shown in FIG.
In (a), (1) when both the light blocking states of the photo sensors 14 and 15 are “Yes”, the rotating body 8b is at the 0 ° position,
(2) When the light blocking states of the photo sensors 14 and 21 are both “presence”, it is understood that the rotating body 8b is at a position of 180 °. That is, if the rotating body 8b is rotated by 180 degrees at the maximum, the relative position of the rotating body 8b can be understood, and the origin can be detected more quickly.

[0023]

According to the present invention, in the motor position detecting mechanism, a plurality of light shielding plates are provided at equal intervals around 0 ° at the end of the rotor, and the first photo for outputting the light shielding state by the light shielding plates is provided. A sensor is provided opposite to the 0 ° position of the rotor, a 0 ° detection light-shielding plate is provided at a predetermined angle from any of the plurality of light-shielding plates, and a second photo for outputting a light-shielded state by the light-shielding plate is provided. Since the sensor is provided at the 0 ° position of the rotor so as to face the 0 ° detection light-shielding plate, the light-out state of the first photosensor can be roughly detected at the same intervals as the step-out state. The effect is that the structure can be simplified.

Further, according to the next invention, the motor position detecting mechanism detects the position of the second photo sensor from the second photo sensor in opposition to the rotor.
Since the third photosensor is provided at a position separated by an angle of 180 °, the position of the rotor can be specified by rotating the rotor by 180 °.

Further, according to the next invention, the motor position detecting mechanism outputs the light blocking state by the photo sensor by the port signal, so that the position of the motor can be known by looking at the port signal on the host side. This has the effect of reducing the load on the side.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a television camera device using a camera platform incorporating a motor position detection mechanism according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a motor position detection mechanism shown in FIG.

FIG. 3 is a configuration diagram of a motor position detection mechanism according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional television camera device using a camera platform having a built-in motor position detection mechanism.

FIG. 5 is a configuration diagram of the slip ring shown in FIG.

FIG. 6 is a configuration diagram of a pan-direction motor position detection mechanism shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Television camera 2 Tilt mechanism 3 Pan mechanism 4 Pan head 5 Operation part 6, 7 Motor 8, 8a, 8b Motor position detection mechanism 10 Motor control circuit 11, 11a Step-out detection circuit 12, 12a Rotating plate 13-15, 21 Photo Sensor 16-20 Light shield

Claims (3)

[Claims] 1. A plurality of light-shielding plates provided at equal intervals at an end of a rotor centered on 0 °, and provided opposite to a 0 ° position of the rotor,
A first photosensor for outputting a light-shielded state by the light-shielding plate, a 0 ° detection light-shielding plate provided at a predetermined angle away from any of the plurality of light-shielding plates, and a 0 ° detection at a 0 ° position of the rotor. A second photosensor that is provided to face the light-shielding plate for use and outputs a light-shielded state by the light-shielding plate. 2. The motor position detecting mechanism according to claim 1, wherein a third photosensor is provided at a position 180 ° away from the second photosensor so as to face the rotor. 3. The motor position detecting mechanism according to claim 1, wherein a light blocking state of the photo sensor is output by a port signal.