JPH05328189A - Object automatic tracking device for video camera - Google Patents

Abstract

PURPOSE:To allow the video camera to pick up an object through automatic tracking. CONSTITUTION:An ultrasonic wave generator 11 generating intermittently ultrasonic wave is provided at an object 10 or its vicinity. The intermittent ultrasonic wave radiating from the ultrasonic wave generator 11 is detected at two points orthogonal to an optical axis L of the camera 1 in the vicinity thereof and the optical axis L of the video camera 1 is turned horizontally so as to be in matching with the object 10 based on an arrival time difference of the intermittent ultrasonic wave reaching the two points of the video camera 1. Since the video camera 1 is automatically tracked with a motion of the object 10 at all times, the horizontal turning speed is optionally set the camera work in an easy manner is attainable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subject automatic tracking type automatic photographing apparatus for a consumer video camera such as a home video.

[0002]

2. Description of the Related Art Conventionally, in order to control a video camera (including a conventional TV camera) so as to always face a subject (tracking target), an advanced technique using an image processing technique is used. ..

Further, by detecting the sound generated on the subject side,
Others detect the direction of the subject and control the video camera so that it points in the direction of the sound.

[0004]

What is called a conventional TV camera automatic tracking system or the like is a flying object such as an industrial or rocket or missile used in an unmanned surveillance device in a special field such as a crime prevention system. It is a large-scale device for the purpose of munitions tracking.

Recently, TV cameras have been widely used for general consumers, such as home video cameras, and therefore, there is a demand for a photographing device which allows the photographer himself to be a subject. That is, conventional home video is always shot in a family with insufficient video of the photographer, and in order to photograph the whole family, the camera should be fixed and the photographing range should be set in advance, or other than the family. There was no other way to shoot than to ask someone to shoot.

For the above purpose, an automatic tracking type photographing apparatus is desired, but the one for tracking an object by the image processing is complicated and expensive and is not suitable for consumer use. In addition, a type that responds to a sound or the like generated on the subject side becomes unable to follow when the subject side remains silent. Therefore, the followability of the camera is enhanced so that it responds quickly to a few independent sounds. An image captured by a camera having a high tracking capability as described above becomes an uncomfortable image because the moving speed for moving the subject to the center of the frame is too fast. If the moving speed of the camera is limited, the reaction to the independent sound becomes slow, and the camera becomes uncontrollable as in the continuous silent state.

The present invention is to solve the above-mentioned problems by automatically moving the optical axis of a video camera toward a subject with a follow-up speed suitable for viewing with a simple device.

[0008]

[Means for Solving the Problem] Ultrasonic wave generating means for intermittently generating ultrasonic waves provided on a subject, and a horizontal optical axis of the video camera, which are provided symmetrically with respect to the horizontal optical axis, are provided on a base for fixing the video camera. A pair of ultrasonic wave receiving means, a motor for horizontally rotating a base for fixing a video camera, and a phase difference between ultrasonic waves received by a pair of ultrasonic wave receiving means are detected, and the phase difference is reduced. The above problem is solved by providing the motor drive control means for controlling the motor.

[0009]

An ultrasonic wave generator for intermittently generating ultrasonic waves is provided in or near an object to be photographed, and intermittent ultrasonic waves emitted from the ultrasonic wave generator are provided near the video camera by the camera. Detected at two points orthogonal to the optical axis of, and based on the arrival time difference (phase difference) of the intermittent ultrasonic waves that reach these two points, horizontally rotate the optical axis of the video camera so as to match the subject, Since the video camera automatically tracks the movement of the subject, you can set the horizontal turning speed arbitrarily,
You can get a relaxed camera work.

[0010]

FIG. 1 shows an embodiment of the present invention.
The video camera (1) is fixed to a platform (3) which is horizontally rotated by a motor (2). Motor (2) is a tripod
(4) It is fixed to the platform (5) at the top.

On the platform (3) of the motor (2), arm members (6) and (6) extending horizontally in the horizontal direction are provided, and the arm members (6).
Ultrasonic microphones (7) and (7) are provided at the tip of (6).

A microphone (7) on the arm members (6) (6)
(7) is equidistant from the center of rotation of the motor (2), and the optical axis (L) of the video camera (1) is the microphone (7).
(7) It is orthogonal to the line connecting the two in a plan view. In other words, the microphones (7) and (7) are provided symmetrically with respect to the optical axis (L) of the video camera (1).

The microphones (7) and (7) are connected to the amplifier circuits (8) and (8) respectively, and the outputs of both amplifier circuits (8) and (8) are fed to the motor control circuit (9). It has been entered. The output of the motor control circuit (9) is connected to the motor (2).

The subject (10) that is tracked and photographed by the video camera (1) is the subject (10) or the subject (10).
An ultrasonic transmitter (11) is provided in the vicinity of. Subject (10)
And the ultrasonic transmitter (11) are provided so as to move together.

The ultrasonic transmitter (11) intermittently emits ultrasonic waves of a required frequency. For example, when an ultrasonic wave of about 40 KHz is transmitted for a period of 0.3 ms, the ultrasonic wave is stopped for a period of 3 ms, which is repeated.

The microphones (7) and (7) respectively receive intermittent ultrasonic waves emitted from the subject (10) side, and the reception signals (12) and (13) of both microphones (7) and (7) are The phase difference is detected in the motor control circuit (9).

Since both microphones (7) and (7) receive ultrasonic waves from the same source, the reception signal (12) or (13) closer to the ultrasonic transmitter (11) is far. Received signal (13)
Alternatively, from (12), the phase of the signal waveform is advanced (see FIG. 2).

The motor control circuit (9) receives the received signal (12) or
When the motor (3) is rotated in the direction of the microphone (7) from which the advance signal of (13) is obtained and the phase difference between both reception signals (12) and (13) disappears, the video camera (1) The optical axis (L) faces the direction of the subject (10), at which time the motor (3) is stopped.

In this motor control, the rotation speed of the motor (2) can be gently rotated until the subject (10) is caught in the center of the frame of the video camera (1).
This makes it possible to perform tracking gently by transmitting the transmission signal of the ultrasonic wave transmitter (11) intermittently and continuously with finely divided ultrasonic waves without interruption.

Further, by intermittently chopping the sounding portion of the ultrasonic wave, the detection accuracy of the phase difference can be improved and the chances of detecting the phase difference can be discontinuous (non-analog) at multiple points.

That is, both microphones (7) and (7) are almost at the same time.
Since the ultrasonic waves that are input to 1) originate from one sound source, they have the same frequency and the same duration, and differ only in the phase difference of the delay caused by the difference in the distance of spatial transmission. Therefore, the phase difference can be detected with high accuracy by both digital processing and analog processing.

Further, as described above, since there is an opportunity to detect the phase difference in each sounding section, gentle tracking is enabled, and the horizontal rotation speed of the video camera (1) is moderated to create an uncomfortable photographed image. Absent.

[0023]

According to the present invention, the following effects can be obtained. (a) By attaching an ultrasonic wave transmitter to the required subject or placing it near the subject, it is possible to easily perform automatic photography that matches the subject with the center of the video camera. (b) The tracking speed of the video camera can be set slowly. (c) It has a simple structure and can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a required subject block diagram showing an embodiment of the present invention.

FIG. 2 is a time chart showing signal waveforms of respective parts of FIG.

[Explanation of symbols]

(1) Video camera (2) Motor (3) (5) Head (4) Tripod (6) Arm member (7) Microphone
(Ultrasonic receiving means) (8) Amplifying circuit (9) Motor control circuit (10) Subject (11) Ultrasonic transmitter (12) (13) Received signal (L) Optical axis

Front page continuation (72) Inventor Kazuhiko Okamoto 1-13-16 Higashi Owada, Ichikawa City, Chiba Prefecture

Claims (1)

[Claims] 1. A pair of ultrasonic waves provided on a base for fixing a video camera symmetrically to the horizontal direction optical axis of the video camera and an ultrasonic wave generation means for intermittently generating ultrasonic waves on a subject. The phase difference between the receiving means, the motor that horizontally rotates the table for fixing the video camera, and the ultrasonic wave received by the pair of ultrasonic wave receiving means is detected, and the motor is controlled so that the phase difference is reduced. A subject automatic tracking device for a video camera, comprising: