JPS62243480A - Automatic zooming tracking camera and range - Google Patents

Abstract

PURPOSE:To attain the effective automatic tracking focus zooming by allowing a receiver provided to a camera to trace an object provided with an ultrasonic wave oscillation source, finding the range up to the object, setting the size of the pickup of the object from the distance and applying the succeeding range fiding movement. CONSTITUTION:The phase difference of ultrasonic waves reaching receivers 2a-2c provided to a universal head 4 is detected, the direction of the universal head 4 is changed so as to make the phase of the sound waves of the receivers 2a,2c equal to each other thereby matching the direction of the camera 3 on the universal head 4 with the object having the oscillation source 1. The distance (x) is obtained from equation, where (x) is the range from the oscillation source l, (l) is the distance between the receivers 2a and 2b and between the receivers 2b and 2c and DELTA tsec is the phase difference of waves reaching the receivers 2a,2b. The object 5a shown in figure shows that the distance x1 from the camera 3 is at a point A and the object 5b shows that the distance x2 is at a point B, and the ratio of elevating angles representing the ratio of the sizes of the object at the points A,B is obtained as a ratio of the distances x1 to x2. Thus, the automatic focusing and tracking zooming are applied effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic tracking camera that can automatically track and image a subject.

[Conventional technology]

, 4.

Conventional devices include a method of determining only the distance between an oscillation source and a receiving source using sound waves and radio waves, as in Japanese Patent Application Laid-Open No. 54-110784, and a method of determining only the distance between an oscillation source and a receiving source, as in Japanese Patent Application Laid-Open No. 59-200318.
There was a way to control the sound timing of a sound source using radio waves and determine the distance. However, in order to automatically capture a subject with a camera, in addition to a tracking function (direction detection) and a focusing function, the camera must also have an automatic zooming mechanism that maintains a constant size when the subject is photographed. It is necessary to have various functions.

The problem with the above-mentioned conventional techniques is that they do not take into account the possibility of photographing a subject with a home-use camera, and only have a single function, such as distance detection.

[Problems to be Solved by the Invention] ``Therefore, the present invention provides an automatic zoom function that has a simple configuration, allows to know the direction and distance, and keeps the size of the photographed subject constant regardless of the distance to the subject. The problem to be solved is to provide an automatic zooming and tracking device that is optimal for use as a home camera.

[Means for solving problems]

The above object is achieved by adding an automatic zoom function in addition to the automatic tracking and automatic focusing functions, and by devising an oscillation source provided to the subject.

[Effect]

The automatic zoom function determines the size of the subject at a certain arbitrary distance and resets it. At this time, the distance to the subject is memorized. If the subject moves, the tracking mechanism operates first, and then the focusing mechanism operates. By operating the focusing mechanism, the distance to the subject is known, so by calculating the ratio with the distance at the time of resetting, and moving the zoom mechanism,
You can easily keep the size of the subject constant.

Also, if the subject moves freely, rotates, etc.
If the oscillation source is in only one direction, it may be lost. In such a case, in the present invention, a plurality of oscillation sources are provided in the form of a belt, and these are used as a subject.

In this way, it will not look unnatural when attached to the subject,
Even if the subject moves, it will not easily separate from the subject, and the oscillation source will always be in the direction of the receiving source, so the receiving source will never lose sight of the subject, making it suitable as a subject device for home cameras. Optimal.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1(α) and 1(h) show diagrams of the principle in which an ultrasonic oscillation source is attached to a subject and the imaging unit measures the direction and distance of the subject.

First, a method for detecting direction will be explained.

In FIG. 1 (α), 1 is an ultrasonic oscillation source held by a subject (not shown). 2α, 2b, 2c
is an ultrasonic receiver. 3 is camera, 4 is 2α.

This is a pan head on which receivers 2h and 2c and camera 3 are mounted. The sound waves oscillated from the ultrasonic oscillation source are transmitted to the receiver 2
a, 2A, and 2c are reached. Therefore, receivers 2α and 2
If the phase difference of the sound waves reaching c is detected, the direction has been detected. If the direction of the pan head 4 is changed so that the phases of the sound waves of the receivers 2α and 20 are equal, the camera 3 on the pan head will face the direction of the ultrasonic oscillation source 1. next,
As for the distance to the ultrasonic oscillation source 1, as shown in Fig. 1 (α), the distance to the ultrasonic oscillation source 1 is x1
7. If the interval between instruments 2α and 2A and 2b and 2c is t, and the phase difference between the ultrasonic waves that reached the ultrasonic receivers 2a and 2b is converted to time and Δ is seconds, then the sound waves are transmitted at intervals of 334 seconds. Therefore, the distance X to be found is roughly expressed by the following formula.

“2X334XJt”)・・・・・・・・・(1)
(The phase difference Δ in seconds can be easily determined from the speed of sound and the ultrasonic oscillation frequency.) Although the value obtained from equation (1) does not indicate the exact distance to the ultrasonic oscillation source, It shows sufficient performance as an automatic focusing function when taking pictures. The method described above allows automatic tracking and automatic focusing.

Some specific examples of the distance measuring device will be described below.

FIG. 2 is a block diagram showing a specific example of a distance measuring device, and FIG. 3 is a diagram of important waveforms thereof. In FIG. 2, 31 is a first periodic signal generator, 32 is an ultrasonic transmitter, 33 is an ultrasonic receiver, 34 is a demodulator, 35 is a phase difference detector, and 36 is an ultrasonic receiver.
37 is a second periodic signal generator and a distance indicator. The operation will be explained below. 1st, 8.

The periodic signal generator 31 generates a first periodic signal (f) having a period τ, and the ultrasonic transmitter 32 modulates this periodic signal (f), converts it into an ultrasonic signal, and transmits it. . The ultrasonic receiver 33 receives the ultrasonic signal and converts it into an electrical signal, and the demodulator 34 demodulates this and outputs a demodulated signal (y). Further, the second periodic signal generator A generates a second periodic signal <h having the same period τ as the first periodic signal (f).
> is generated. However, the first periodic signal (f) and the second
The phase of the periodic signal (A) is aligned. The phase difference detector 35 detects the phase difference between the demodulated signal (,V) and the second periodic signal (A), and the distance indicator 37 detects the ultrasonic wave from the ultrasonic transmitter 32 based on this phase difference. The distance to the receiver 33 is determined and displayed. Here, the propagation time of the ultrasonic wave is used to calculate the distance. This principle will be explained with reference to FIG. The propagation time of the ultrasonic wave is equal to the time difference T between the first periodic signal (1) and the demodulated signal (, q). If the time difference between the first periodic signal (f) and the second periodic signal (A) is ΔT, and the time difference between the second periodic signal (A) and the demodulated signal (q) is T', then 17"-7'l=ΔT (1,
4), and T'#T 121 is approximately established by making ΔT extremely small. Therefore, T' becomes an approximate propagation time.

If the speed of sound is V, the required propagation distance is Le, VT
/ ill can be obtained. What should be noted here is the first
And the period τ of the second periodic signal is set to be sufficiently larger than the propagation time T.

τ>T t41 The phases of the first periodic signal U) and the second periodic signal (A) must be aligned in advance before distance measurement.

This specific means will be explained using FIGS. 4 and 5. FIG. 4 shows an example of the internal circuit of the first periodic signal generator 1 and the second periodic signal generator 36 in FIG. 2, and FIG. 5 is a diagram of essential waveforms thereof. In FIG. 4, 101 is a first original oscillation circuit, 102 is a first frequency dividing circuit, 601 is a second original oscillation circuit, 602 is a second frequency dividing circuit, 603 is a differentiating circuit, and the wings are switches. be. The operation will be explained below. The first original oscillation circuit 101 and the second original oscillation circuit 601 output a first original oscillation signal (α) and a second original oscillation signal (d) having the same frequency. 1st
The frequency dividing circuit 102 and the second frequency dividing circuit 602 divide the first original oscillation signal (, ) and the second
The original oscillation signal (d) is frequency-divided to output a first periodic signal (A) and a second periodic signal (1). Before distance measurement, in order to align the phase with the first periodic signal (Al, !: second periodic signal (1)), the first periodic signal (Al, !:
A) is differentiated by the differentiating circuit 603 via the switch 38 to generate the reset signal (1), and then the second frequency dividing circuit 602
input to the reset terminal. In this way, as shown in FIG. 5, the phases of the first periodic signal (A) and the second periodic signal (1) can be aligned.

As described above, according to the specific examples shown in FIGS. 2 to 5, the distance between the ultrasonic transmitter 32 and the ultrasonic receiver 33 can be displayed on the distance display 37.

Next, another specific example is shown in FIG. In Figure 6, 3
9 is a switch; 201. 202 and 203 are ultrasonic transmitters, and the others are the same as in FIG. 2, with an angle of 11 degrees. The operation will be explained below. The switch 39 periodically switches the contact points, so that the ultrasonic transmitter 201,
Ultrasonic waves are transmitted from 202 and 203 in a time-division manner. Other operations are similar to those in FIG. 2.

As described above, according to the specific example shown in FIG. 6, the ultrasonic transmitter 201,
Either 202 or 203 and the ultrasonic receiver 3
Even if there is an obstacle between the camera and the camera, the distance can be measured.

Next, yet another specific example is shown in FIG. In FIG. 7, 204. 205 and 206 are ultrasonic transmitters; 401. 402 and 403 are demodulators;
is a switch, and the other parts are the same as in FIG. □The operation will be explained below. Ultrasonic transmitter 204. 205 and 206 each transmit ultrasound at different carrier frequencies. Demodulator 401. 402 and 403 are the ultrasonic transmitters 204. and 403, respectively, from the received signals. Frequency components corresponding to the transmission frequency bands 205 and 206 are separated and demodulated. The switch 40 selects and extracts the one with the highest signal-to-noise ratio among the output signals of the demodulators 401, 402, and 403. The other operations, 12°, are similar to those in FIG.

As described above, according to the specific example shown in FIG. 7, the ultrasonic transmitter 204,
Either 205 or 206 and the ultrasonic receiver 3
This has the effect of being able to measure the distance even if there is an obstacle between the two.

Next, FIG. 8 shows an example in which the distance measuring device described above is applied to an automatic focusing function of a camera. In Figure 8, 4
1 is a camera, and the others are the same as in FIG. The first periodic signal generator 31 and the ultrasonic transmitter 32 are attached to the subject. The distance information obtained by the phase difference detector 35 is input to the camera 41 to focus on the subject.

Next, returning to FIG. 1(A), the automatic zoom function will be explained using this figure. 5α and 5b are objects. 5a is at the 0 point when the distance from camera 3 is X,
5h indicates when the distance is to the point of X. The automatic zoom function is to take an image with the camera 3 so that the size of the object at the 0 point is the same as the size of the object at the 0 point. If the elevation angle of the camera when photographing the subject 5a is taken at 0 point is θ, then the purpose can be achieved by making the elevation angle θ1 even at 0 point. The ratio of θ and θ is equal to the ratio of distances and X. However, the distance between tl and the town has already been measured in order to activate the automatic focusing function. Therefore, this can be achieved by moving a zoom mechanism built into the camera 3 according to the ratio of the measured distances. When operating this, for example, if the size at the 0 point shown in FIG. 1(A) is to be maintained, the zoom mechanism is preset at the 0 point.

Calculations for operating the automatic zoom function can be performed using a microcomputer or the like.

By the method described above, it is possible to realize a camera that automatically tracks a subject, adjusts focus, and performs automatic zooming without manual intervention.

FIG. 9 shows a shape diagram of an ultrasonic oscillation source worn by a subject (here, a person is considered). 6 is a belt, 7 is a battery, 8 is a microphone, and 9 is a circuit. Ultrasonic oscillation sources 1 are attached to the four sides of the belt 6. A belt 6 is attached to a person who is a subject. If you wear it on your waist, it won't feel strange to the person you're photographing, and it won't give you any unnatural appearance. Further, even when the person who is the subject moves, it does not interfere with the movement, and when the person moves, the camera does not easily separate from the person. Further, there is an advantage that the place where the device is worn can be selected from a wide variety of options, such as wearing it on the head as a hair band or wearing it like a shoulder bag. Further, as shown in FIG. 9, by providing the ultrasonic oscillation sources 1 on all sides, even if the subject rotates, one ultrasonic oscillation source always faces the imaging section. By integrating the battery 7 that serves as the power source for the ultrasonic oscillation source 1 and the circuit 9 that performs necessary processing, as shown in FIG. 9, it is possible to obtain an ultrasonic oscillation source that is extremely easy to operate. can. A microphone 8 was also attached to the belt 6. Conventionally, the microphone for recording audio was attached to the camera, so it was not used to record audio from the vicinity of the subject. Audio from the vicinity of the camera was recorded. In the present invention, at the same time as the ultrasonic oscillation source l is attached to the subject, the microphone 8 is also attached, and the sound recorded by the microphone 8 is modulated by the circuit 9, and the ultrasonic oscillation source l is
Oscillate from 5° source 1. For example, set the ultrasonic oscillation frequency to 70
If KHz is selected, modulation is applied with 10f#z audio. In this way, it is possible to record sounds from the vicinity of the subject, making it ideal for use as a home camera. Incidentally, if the four ultrasonic emitting sources 1 shown in FIG. 9 oscillate at the same time, there will be a problem when the ultrasonic receiving section detects the phase and uses it for azimuth detection. Therefore, the circuit 9 performs control so as to oscillate sequentially in a time-division manner.

FIGS. 10(α) and (b) show an imaging condition diagram and an ultrasonic reception level change diagram. The ultrasonic receivers 2α, 2A, 2c receive signals from the ultrasonic oscillation sources 1a, IA, 1c, and ld provided on the upper part of the belt 6 worn by the subject 5, and send the signals to the camera platform 4.
The camera 3 performs controls such as changing the direction of the camera 3 and captures the subject on the camera 3. At this time, the ultrasonic oscillation sources 1α to 1d sequentially oscillate in a time-division manner. Figure 10 (h) shows the state in which this is received.
Shown below. The ultrasonic reception level varies greatly over time. At time T1, the ultrasonic oscillation source 1α directly facing the pan head 4 oscillates, so the reception level is high.

Time T.

- At 16° and T4, the oblique ultrasonic oscillation sources 1h and 1d oscillate, so the reception level slightly decreases.At time T, the ultrasonic oscillation source 1o located behind the subject 5 oscillates. The ultrasonic reception level becomes low. During the time T, which is the sum of the oscillation times 11 to T4 of the four ultrasonic oscillation sources, the direction of the mounting table 4 and the focusing mechanism and zooming mechanism of the camera 3 are operated depending on the signal level at time T1, which indicates the maximum reception level. If you do so, you can operate with a signal with a good ψ, and the operation will be stable. Specifically, first, a cycle TI showing the maximum level among all cycles T is detected. If the received signal level is detected only during T1 period in the next full cycle T,
This can be realized with a simple circuit.

FIG. 11 shows the configuration of a general video camera 3.

A main body of the camera 3 that performs an imaging unit and video signal processing,
It consists of 11 lens units that perform focus adjustment and zooming operations, and a viewfinder that monitors the image capture screen. In the fully automatic camera described in the present invention, there is no need for a person to operate the camera 3, and there is no need to always look at the image capture screen. The only time you see the photo screen is when you operate the zoom mechanism that temporarily keeps the size constant. Therefore, there is no problem even if the viewfinder 10, which consumes a large amount of power during imaging, is stopped. When photographing a subject with a video camera, it is more likely to be photographed outdoors than indoors, and power is supplied from a battery. This battery is used to operate the VTR and video camera, but it is necessary to save power so that images can be taken for a long time with a small amount of batteries, and being able to omit power for the viewfinder is a great advantage.

FIGS. 12(α) and (h) show configuration diagrams of a specific embodiment in which a zoom operation is performed in accordance with the focus function using a simple method. As shown in FIG. 12 (α), the zoom function is based on the elevation angle θ at the 0 point where the subject 5 is located at a distance of 3e1.
1 and the elevation angle at the point at which distance X is reached should be equal. When not zooming, the height of the subject is 4
, and the same is true when the 0 point is reached, so camera 3
The elevation angle of is θ8. In order to equalize the elevation angles at the 0 point, the objective can be achieved by making the object size equal to 4.

t-decoration θ, = 4 = 4 (5
)xI! 1 4=34 ・・・・・・・・・(6)xI As shown in equation (6), zooming is performed using distances X,
The optimum value can be obtained by setting according to the ratio of . In order to obtain such an optimal value, some kind of calculation is required, and it cannot be said that it is suitable for practical use. Since this is a home-use camera and its range of use is relatively limited, and there is no need to zoom accurately, we decided to use the motor that moves the focusing mechanism to move the zoom mechanism. A specific example is shown in FIG. 12(A).

The specific operation will be described below. The camera in item 3 must have an automatic focusing function and a zoom function. The focus detection unit 13 is configured to focus on the subject 5.
The motor 14 rotates according to the signal of Boo IJ15,
17. The focusing mechanism 12 operates via the belt 16. In this embodiment, the focus detection section uses an infrared detection method, but any method such as a method using sound waves may be used.

If you want to focus at the 0 point shown in Figure 12 (α) and operate the zoom mechanism to maintain the size of the subject at this point and increase the angle to 19 degrees, then as shown in (b), at this time, , 22, the gear wheel moves in the {circle around (2)} direction and is connected to the autofocus motor 14. When the subject 5 moves to the point shown in FIG.
1B, move the zoom mechanism 11 via the belt 19; In this way, an automatic zoom function can be realized with a simple configuration. If you do not need the automatic zoom function, return the automatic zoom switch to its original position and move the pulley in the direction of for manual zoom.

In the above embodiment, a camera with a manual zoom function was described, but a camera with an electric zoom function has a dedicated motor for driving the zoom mechanism. In such a case, automatic zooming can be easily achieved by applying the drive voltage of the motor that moves the focusing mechanism to the motor that moves the zooming mechanism.

Note that an infrared detection automatic focusing device may automatically focus on an obstacle such as a telephone pole when the angle is 20 degrees, where there is an obstacle such as a telephone pole between the subject and the camera.

Therefore, in order to recognize a specific subject and eliminate the inconvenience, an ultrasonic oscillation source is provided on the subject as in the present invention.

〔Effect of the invention〕

As described above, according to the present invention, the automatic tracking and zooming operations required by a home video camera can be realized with a simple configuration, and the home video camera can be fully automated in a simple manner.

[Brief Description of the Drawings] Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing a specific example of a distance measuring device, Fig. 3 is a diagram of important waveforms thereof, Fig. 4 is a block diagram showing an example of the internal circuit of the first periodic signal generator 1 and the second periodic signal generator 6 in FIG. 2, FIG. 5 is a diagram of its essential waveforms, and FIGS. 9 is a block diagram showing a specific example of the ultrasonic oscillation source of the present invention, FIG. 10 is a block diagram of the oscillation source and receiver of the present invention, and FIG. 11 is a configuration diagram of a video camera. FIG. 12 shows a configuration diagram in which the autofocus mechanism and autozoom function operate simultaneously. Explanation of symbols 1...Ultrasonic oscillation source 2...Ultrasonic receiver 3.
... Camera 4 ... Panhead 5 ... Subject
6...Belt 7...Battery
8... Microphone 31... First periodic signal generator 32, 201-206... Ultrasonic transmitter...
Ultrasonic receivers 34, 401 to 403... Demodulator 35... Phase difference detector 36... Second periodic signal generator 37... Distance indicator 3a to 3 40... Switch 41... ...Camera Figure 1 (b) Figure 71] @ Figure 8 Figure 9 Figure 10 <b) Figure 11 M 12 Figure e1= p= 1z zl 22

Claims (1)

[Claims] 1) A camera equipped with an imaging device, comprising: a distance measuring means to a subject; a means for automatically tracking the imaging device toward the subject; and a distance to the subject measured by the distance measuring means. An automatic zooming tracking camera characterized by comprising means for setting the size of an image of the object by setting a distance as a specific distance, and thereafter operating a zoom mechanism of the imaging device as the distance changes. 2) In the automatic zooming tracking camera according to claim 1, the zoom mechanism of the imaging device is linked to a drive source that moves a focusing mechanism, or is driven by the same driving source as the focusing mechanism. Automatic zooming tracking camera. 3) In the automatic zooming tracking camera according to claim 1, the distance measuring means includes an ultrasonic oscillation source attached to the subject side and an ultrasonic receiving device attached to the imaging device side. , the automatic tracking means includes means for detecting a phase difference of ultrasonic waves transmitted from the subject and received by the imaging device, and the ultrasonic oscillation source is shaped like a pants belt and includes a plurality of ultrasonic oscillation sources. 1. An automatic zooming tracking camera comprising: an ultrasonic oscillation source, the plurality of ultrasonic oscillation sources sequentially oscillating one by one in a time-sharing manner. 4) In the automatic zooming tracking camera according to claim 3, the ultrasonic oscillation source has a built-in microphone,
The ultrasonic oscillation source is modulated by the sound collected by the microphone, and the ultrasonic receiving device demodulates the sound contained in the ultrasonic wave and obtains it as an audio output. Zooming tracking camera. 5) In the automatic zooming tracking camera according to claim 3, the ultrasonic receiving device detects the direction and distance based on the phase difference and time difference of only the oscillation source having the maximum level among the time-division oscillation sources. An automatic zooming tracking camera characterized in that the camera is configured to control the direction of the imaging device and the zoom mechanism. 6) The automatic zooming tracking camera according to claim 1, wherein the imaging device stops an imaging signal monitoring function of an electronic viewfinder or the like during automatic operation. camera. 7) In a distance measuring device for an automatic zooming tracking camera, a first periodic signal generator that accompanies a subject and generates a periodic signal, and an ultrasonic wave modulated by the output signal of the first periodic signal generator. an ultrasonic transmitter that transmits a signal from the subject; an ultrasonic receiver that receives the ultrasonic signal;
a demodulator that demodulates the output signal of the ultrasonic receiver, and a second periodic signal generator that generates a signal having the same period as the first periodic signal generator.
and a phase difference detector for detecting a phase difference between the output signal of the second periodic signal generator and the demodulated signal of the demodulator. A distance measuring device comprising means for presetting a phase difference between the output signal of the first periodic signal generator and the output signal of the second periodic signal generator to a constant value. 8) In the distance measuring device according to claim 7, the first periodic signal generator and the second periodic signal generator both operate an original oscillation circuit of the same frequency at the same frequency division ratio. The output signal of the first and second periodic signal generators is configured to perform frequency division, and is provided with means for controlling the frequency division timing in the other periodic signal generator using the output signal of one of the periodic signal generators. A distance measuring device characterized by presetting a phase difference to a constant value. 9) In the distance measuring device according to claim 7 or 8, a plurality of the ultrasonic transmitters are provided, and the distance measurement is characterized in that the ultrasonic transmitters transmit data in a time-sharing manner. Device. 10) In the distance measuring device according to claim 7 or 8, a plurality of the ultrasonic transmitters are provided, and the carrier wave frequency of each ultrasonic transmitter is set to a different numerical value, and The number of demodulators equal to the number of ultrasonic transmitters is provided to separate and demodulate the transmitted signals from each ultrasonic transmitter, and to extract the signal with the maximum signal-to-noise ratio among the demodulated signals of each demodulator. A distance measuring device comprising means for selectively inputting the selected information to the phase difference detector. 11) In the distance measuring device according to any one of claims 7 to 10, the ultrasonic receiver, the demodulator, the second periodic signal generator, and the phase difference detector A distance measuring device characterized in that the first periodic signal generator and the ultrasonic transmitter are attached to a camera, and the first periodic signal generator and the ultrasonic transmitter are attached to a subject, and are used for an automatic focusing function of the camera.