JP3039555B2 - Subject tracking control method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture video telephone apparatus for displaying a moving picture, and more particularly to a subject tracking control method in which a shooting angle of a camera of the moving picture video telephone apparatus follows a movement of a subject.

2. Description of the Related Art Conventionally, in a moving picture videophone device, the camera angle of photographing a speaker as a subject is fixed or semi-fixed, that is, the camera angle of camera is manually operated by a mechanism capable of tilting and swiveling. Can be changed.

[Problems to be Solved by the Invention] In the above-described conventional moving picture videophone device, since the shooting angle of the camera cannot follow the movement of the subject, the subject talks while adjusting the position of the subject itself to the shooting angle of the camera. In addition, there is a disadvantage that the image of the subject is deviated from the screen within the range that can be photographed by the camera depending on the movement of the subject during a call.

[Means for Solving the Problems] According to the subject tracking control method of the present invention, an infrared light emitting unit that emits infrared light of a certain level is provided in a handset of a moving picture videophone device, and an infrared light output from the infrared light emitting unit is provided. The infrared light receiving unit for detecting light is provided in the camera of the moving picture videophone device. Then, the intensity of the infrared light detected by the infrared light receiving unit is converted into digital data and stored in two registers alternately at a constant period, and the intensity of the infrared light is the maximum value compared with the previous stored value. A control mechanism is provided that controls the rotation of the motor so that the camera is turned in the direction of, and alternately repeats this in the tilt (TILT) direction and the swivel (SWIVEL) direction.

[Operation] By changing the shooting angle of the camera so that the intensity of the infrared light detected by the infrared light receiving unit becomes the maximum value,
An image of a subject holding the handset to which the infrared light receiving unit is attached can be constantly photographed in the center of the screen of the camera.

Embodiment Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a moving picture videophone device according to an embodiment of the subject tracking control system of the present invention.

1 is a handset (not shown) for a videophone device.
The infrared light emitting unit is mounted on the infrared light emitting diode 11 so that the infrared light emitting diode 11 outputs infrared light P having a constant intensity.

Reference numeral 2 denotes an infrared light reception peak detection unit provided in the moving picture videophone device.

Infrared receiver 21 mounted on camera (not shown)
Receives the infrared light P from the infrared light emitting diode 11 and outputs a level signal corresponding to the intensity of the infrared light P.

Note that the infrared light receiving section 21 is arranged so as to sense the central portion of the screen shot by the camera. Therefore, when the infrared light P output from the infrared light emitting diode 11 is detected with the highest intensity in the infrared light receiving section 21, that is, when the peak of the infrared light P is detected, the speaker holding the handset The image will be located at the center of the screen captured by the camera. The state in which the image of the speaker holding the handset is captured in the center portion of the screen of the camera in this manner is referred to as an optimum shooting state.

The level signal output from the infrared receiver 21 is amplified by the signal amplifier 22 and output to the A / D converter 23, where it is converted from an analog signal to a digital signal and output as level data.

The sampling clock is supplied from the sampling clock generator 27 to the signal level registers A24 and B25. Here, the signal level register A24
Are supplied with the sampling clock via the inverter 26, the phases of the sampling clocks supplied to the signal level registers A24 and B25 are shifted by half a clock. Therefore, the level data output from the A / D converter 23 is alternately stored in the signal level register A24 and the signal level register B25 every half clock of the sampling clock.

The comparator 28 sequentially compares the level data alternately supplied from the signal level register A24 and the signal level register B25, and compares the difference (including the direction), that is, the infrared light receiving unit.
A temporal change in the intensity of the infrared light P received at 21 is detected, and a difference control signal corresponding to the difference is output to the motor control unit 29.

The motor control unit 29 outputs a rotation control signal for instructing the X motor driver 31 and the Y motor driver 32 to rotate the X motor 30 and the Y motor 32, respectively, according to the difference control signal from the comparator 28. It has become.

The X motor 30 and the Y motor 32 are provided corresponding to the tilt direction and the swivel direction of the shooting angle of the camera.
The camera rotates in accordance with drive signals from the motor driver 31 and the Y motor driver 32 to change the shooting angle of the camera. Therefore, the shooting angle of the camera is
30 and the Y motor 32 are set by a combination of two motors.

 Next, the operation will be described.

When the speaker picks up the handset and starts a call,
A predetermined control signal is input from a predetermined control unit (not shown) to the motor control unit 29, and the X motor 30 is rotated to change the shooting angle of the camera. At this time, since the Y motor 32 is stationary, only the component in the direction set by the rotation of the X motor 30 changes in the shooting angle of the camera.

The intensity of the infrared light P output from the infrared light emitting diode 11 attached to the handset held by the speaker is converted into level data via the infrared light receiving unit 21, the signal amplifier 22, and the A / D converter 23. After that, it is stored in the signal level register A24 and the signal level register B25. The infrared light P stored in the signal level registers A24 and B25
Are sequentially compared by the comparator 28, and the difference is detected.

As long as the difference detected by the comparator 28 is not 0, that is, as long as the peak of the infrared light P is not detected, the comparator 28 outputs a difference control signal to the motor control unit 29.
The motor control unit 29 outputs a rotation control signal for instructing the X motor driver 31 to rotate the X motor 30 according to the difference control signal. The X motor driver 31 outputs a drive signal to the X motor 30 according to the rotation control signal to change the shooting angle of the camera. As a result, when the difference detected by the comparator 28 becomes 0, that is, when the peak of the infrared light P is detected, the difference control signal output from the comparator 28 to the motor control unit 29 stops. Then, the rotation control signal output from the motor control unit 29 to the X motor driver 31 stops. As a result, the X motor 30 is fixed, and the shooting angle of the camera at the angle set by the X motor 30 is fixed.

Next, the same operation as described above is performed for the angle set by the Y motor 32. That is, a predetermined control signal is input from a predetermined control means (not shown) to the motor control unit 29, and the Y motor 32 is rotated to change the shooting angle of the camera. At this time, since the X motor 30 is stationary, only the component in the direction set by the rotation of the Y motor 32 changes in the shooting angle of the camera. Thereafter, the same operation as the above-described series of operations for fixing the shooting angle of the camera at the angle set by the X motor 30 is performed for the Y motor 32, but the description thereof is omitted.

In this way, the image of the speaker holding the handset is captured in the center of the camera screen when the camera shooting angle is determined by the combination of the two directions of the X motor 30 and the Y motor 32. Will be.

In addition, since the above control operation is performed in real time even during a call, control is performed so that the image of the speaker holding the handset is always captured in the central portion of the screen of the camera, that is, in an optimal shooting state. Will be done.

[Effects of the Invention] As described above, according to the subject tracking control method of the present invention, the shooting angle of the camera is changed so that the intensity of the infrared light detected by the infrared light receiving unit becomes the maximum value. In addition, an image of a subject holding a handset to which an infrared light receiving unit is attached can be constantly photographed at the center of the screen of the camera. Therefore, even if the speaker, who is the subject, moves and deviates from the center of the camera screen, the shooting angle of the camera changes and the optimal shooting state is achieved. There is an advantage that it will not be lost.

Further, according to the subject tracking control method of the present invention, only one infrared light receiving unit is required and only one control mechanism is required, so that the number of components can be reduced, so that the required space is reduced and the cost is reduced. There is an advantage that can be.

[Brief description of the drawings]

FIG. 1 is a block diagram of a moving picture videophone device according to an embodiment of the subject tracking control system of the present invention. 1 ... infrared light emitting section, 2 ... infrared light receiving peak detecting section,
21 ... Infrared light receiving section.

Claims (1)

(57) [Claims] An infrared light emitting section provided on a handset and an infrared light receiving section provided on a camera, wherein the infrared light emitted from the infrared light emitting section is received by the infrared light receiving section and the camera is directed to the infrared light emitting section. A video videophone device having control means for photographing a subject at the center of a screen by means of: a means for converting the intensity of infrared light detected by an infrared light receiving unit into digital data; a means for storing the digital data; Control means for comparing the obtained value with the newly obtained value to change the shooting angle in the tilt (TILT) direction and the swivel (SWIVEL) direction of the camera in a direction in which the intensity of the infrared light is maximized; This control means alternately controls the shooting angle of the camera in the tilt direction and the swivel direction.