JPH04149532A - Tracing type camera - Google Patents

Abstract

PURPOSE:To speedily and accurately trace the motion of an object with simple circuit constitution by detecting the position of the object while receiving a remote control signal emitted from the object and controlling the rotational direction and rotational speed of a camera main body so that the object is at a specific position in a photographing screen. CONSTITUTION:The camera main body 100 is fixed on an up/down rocking plate 101. A light receiving window 102a for receiving the remote control signal from an infrared-light emission unit 3 and four red LEDs 8a - 8d for displaying the position of the object are provided in the front of a main body box 102. While KEYs 1 - 9 of the infrared-light emission unit 3 except a downward key KEY 5 are depressed, the camera main body 100 is moved in directions corresponding to the depressed keys. When the KEY 5 is depressed, the camera enters a tracing mode to detect the position of the object and traces the object. When the position of the object crosses the center of the photographing screen, the rotational direction of the camera main body is reversed and the rotational speed is reduced to make the camera main body face the object speedily and accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tracking camera that receives a signal from a subject and tracks the subject by directing the camera toward the subject.

(Prior art) Cameras have a long history, and if we look only at still cameras, until now the photographer held the camera facing the subject to compose the photograph and take the picture, and even today, many cameras still use this method. I'm using it like this. However, recently, the camera has been fixed on a tripod, the subject is standing in front of the camera within the shooting range (angle of view), and the remote control transmitter that the person carries sends the release signal. The so-called "
A camera with a remote control has been developed and put into practical use.

However, with this camera equipped with a remote control, the photograph is taken without the subject knowing exactly whether or not the subject is completely within the angle of view of the camera, so it may not be possible to take a satisfactory photograph.

Therefore, like a camera with a remote control, the person who is the subject carries a transmitter, the camera receives the signal from this transmitter, and the position of the subject is detected from the received signal.
A so-called tracking camera is considered, which automatically moves the camera so that the camera is approximately in the center of the subject or angle of view.

Although this type of tracking type camera has not been known in the field of still cameras, tracking type cameras are known in the field of video cameras and industrial television cameras. In order to track objects and targets in these fields, image recognition technology using CCD is used. CCD is indispensable for capturing image information of video cameras, and many are equipped with it. However, since the technology for processing the captured image information is technically advanced, the circuit configuration is complex and requires a large space, making it difficult to make it into a J\ type at low cost. It is difficult to apply the above-described method of newly equipping a CCD and processing image information to still cameras as is.

When it receives a pattern signal emitted from a signal generating means carried by the subject, it generates a position signal corresponding to the position of the subject, detects the pattern of the pattern signal, and generates a position signal in synchronization with the detected signal pattern. It may be a subject position detection device configured to read the information and detect the position of the subject.

If a tracking camera is configured using the subject position detection device according to this proposal, the subject position can be detected with a simple circuit configuration without using advanced image recognition technology, and a small and inexpensive tracking camera can be created. It would be desirable if this kind of tracking camera could quickly and reliably follow the movements of the subject.

(Purpose and Structure of the Invention) The present invention has been made in view of the above points, and an object of the present invention is to shorten the time required for tracking a subject in a tracking camera as much as possible, and to track the subject reliably. In order to achieve this, the position of the subject is detected by receiving a signal emitted from the subject, and the direction and speed of rotation of the camera body is adjusted so that the detected position of the subject is at the center of the camera's shooting screen. Configured to control.

(Example) The present invention will be explained below based on the drawings.

Figure 1 shows a tracking camera using the present invention attached to a tripod, where l is the tracking camera;
2 is a tripod, and 3 is an infrared light emitting unit carried by the subject.

The tracking camera 1 includes a normal camera body 100 and a drive mechanism provided under the camera body 100 for vertically swinging the camera body 100 for tracking purposes or rotating it in a horizontal plane. and a platform device 110, this platform device 1
Reference numeral 10 denotes a vertical swing plate 101 for vertically moving the camera body lOO, and further below the vertical swing plate 101, the camera body 100
It is composed of a main body box 102 housing a drive mechanism for vertically swinging the camera and horizontally rotating it horizontally, and a pedestal 103 screwed to the tripod 2 below the main body box 102.

The camera body 100 includes a photographic lens 100a, a flash device 100b, a release button 1ooc, and a power button 10.
It is a normal camera equipped with 0d, etc., and a pan head device 110.
is fixed on a vertically swinging plate 101. Vertical swing plate l
ot is formed of a resin member with a U-shaped opening facing downward, and a position detection unit for detecting the position of the subject is built in one end in the longitudinal direction (the left end in the figure), and 101a is a light receiving unit. The main body box 102, which is a window, has a vertically swinging plate 101 pivotably supported at both ends in the longitudinal direction of a ridge-shaped upper surface that slopes from the center to both sides. A light receiving window 102a for receiving a remote control signal and four red LEDs 8a to 8d for displaying the position of the subject are provided at the top and bottom of both left and right ends.

On the other hand, the infrared emitting unit 3 is basically the same as a normal remote control used for home televisions and industrial air conditioners, and has nine keys KEY1 on the top surface of the resin case 3a.
-KEY 9 are provided, and an infrared light emitting diode 3b is provided at the tip facing toward the camera body 100. Each key has the function of moving the camera body 100 in the direction indicated by the arrow on the key in FIG.
When you press EY8, the camera moves downwards toward the subject.
In this way, KEY1 to KEY9 excluding key KEY5 (
direction key) is the camera body 10 while you hold it down.
0 moves in the direction corresponding to the key pressed, but KEY5
(hereinafter referred to as the "tracking key"), the camera enters tracking mode, detects the subject's position through the process described later, and moves to track the subject. Infrared light having a light emission pattern is emitted. Here, infrared emitting unit 3
The movements of the camera when each of the keys KEY1 to KEY9 are pressed are described below.

Lower right with the camera facing the subject. move it to

Point the camera downwards toward the subject. move quickly.

Lower left when facing the camera toward the subject. move it to

Turn the camera to the right when facing the subject. move it in the direction.

The camera becomes the subject by tracking operation. Move it in the direction of.

Turn the camera toward the subject and look to the left. move it in the direction.

Top right with the camera facing the subject. move it to

KEY8: Move the camera downward toward the subject.

KEY9: Move the camera to the bottom left toward the subject.

KEY4: KEY2: EYI: KEY3: KEY7: KEY5: (Tracking key) KEY6: FIG. 2 shows the infrared light emitting circuit of the infrared light emitting unit 3. The infrared light emitting circuit includes an IC 31 that outputs a remote control signal with an infrared light emission pattern corresponding to a pressed key, a switching transistor 32 that turns ON10FF in response to this remote control signal, and an infrared light emitting diode 3b. I
The infrared emission pattern of the remote control signal output from C31 is unique for each key as shown in FIG. The remote control signal has a length of 8 msec modulated at 38 KHz.
The interval between the remote control signal of c and the remote control signal is short (1,
5m5ec) is set as "L", and long case (2,5m5ec) is set as "H", and a 3-bit start signal consisting of only "L" and only "H" or only "L" or "H"
5-bit data consisting of a combination of " and L" and "
It is a 10-bit signal (this series of signals is called one frame) consisting of a 2-bit stop signal consisting only of "L", and has a unique light emission pattern with different signal intervals depending on the key. If you keep pressing the button, the same flash pattern will repeat over and over again.

Next, the mechanism and circuit configuration on the camera side will be explained.

Figure 4 shows a tracking circuit provided on the camera side, and 4 is an infrared light receiving unit for receiving the remote control signal emitted from the infrared light emitting unit 3, which includes a photodiode and a signal processing circuit (amplifier 38KHz bandpass). filter,
It has a circuit configuration consisting of an integrator circuit, a comparator), etc.
When a KHz signal is received, it outputs an “H (High)” level signal, and when it is not received, it outputs an “L (L)” level signal.
o w )" level signal. 5 is a subject position detection unit that uses a photodiode divided into four as a two-dimensional position detection element to detect the position of the subject in two dimensions. Red External light unit 3
The infrared light from
(see figure), different position signals are output from the four-division photodiode 5d depending on the position of the light spot.

FIG. 5 shows an example of this subject position detection unit 5, in which a support frame 5a is provided with a filter 5b for cutting visible light,
A condenser lens 5C and a four-part photodiode 5d are arranged side by side on the optical axis. The visible light cut filter 5b and the condensing lens 5c may be formed integrally.

As shown in FIG. 6, the four-division photodiode 5d is divided horizontally and vertically through the center of one screen to form four regions MM, PM, MP, and PP. Further, the long and short sides of the four-division photodiode 5d are proportional to the photographing screen, so that the light receiving area detected by the four-division photodiode 5d and the photographing screen of the camera almost match. Furthermore, a zoom lens can be used as the condenser lens 5C so that the detection screen can be changed. Also, the condenser lens 5
The distance between C and the 4-split photodiode 5d may be adjusted depending on the distance between the camera and the subject to keep the size of the focused light spot constant.Infrared light focused by the focusing lens 5c is made larger than the width between the photodiodes so that the light spot straddles adjacent photodiodes. In addition, the F number should be as bright as possible without increasing aberrations, etc. The subject position detection unit 5 uses a two-dimensional position detection element without division (so-called two-dimensional PSD) instead of a four-division photodiode.
Although it is possible to use the device, this is not preferable because the element itself is expensive and the signal processing circuit becomes much more complicated.

Returning to FIG. 4 again, reference numeral 6 indicates four areas PM and P of the four-division photodiode 5d of the subject position detection unit 5.
This is a detection circuit that inputs two diagonal position signals among the four position signals output from P, MM, and MP, processes the signals, and detects the position of the subject.The circuit configuration is shown in Figure 7. It becomes like this. That is, the detection circuit 6 is
Four areas PM and PP of the 4-division photodiode.

A differential amplifier circuit 6a that performs current-to-voltage conversion by taking the difference between the position signals PM signal S and MP@ signal output from two diagonal areas PM and MP among the four position signals output from MM and MP, and Frequency components of 38 KHz or less are obtained from the outputs of the differential amplifier circuit 6a2, which performs current-to-voltage conversion by taking the position signal PP signal output from the regions PP and MM and the MM-fold signal difference, and the differential amplifier circuits 6a+E and 6a, respectively. The outputs from the filter circuits s b , g and 6 b to be cut, and the filter circuits 6 b and 6 b 2 are compared with the reference value, and if the output is higher than the reference value, the output is H (High).
It is composed of a comparator 6c and 6c2, which converts the voltage to an "L (Low)" level when the level is low.

The detailed circuit configuration of this detection circuit 6 is shown in FIG.
It consists of two circuits in which 62, 63; 61' and 62' and 63' are connected in series, and since the signals are processed digitally, these operational amplifiers do not need to be of low precision.
Moreover, no circuit adjustment is required.

! @ In Figure 4, the CPU 7 controls the position of the camera based on the signal from the infrared light receiving unit 4, displays the position of the subject based on the signal from the detection circuit 6, and tracks the subject. make judgments and calculations,
This CPU 7 receives a signal (1) from the infrared light receiving unit 4 and a position signal (2) from the subject position detection unit 5.
a 3-bit remote control signal input port PX that receives a signal (bit), a 4-bit LED output port P2 that outputs a lighting signal to the subject position display unit 8, and a signal that directs the camera toward the infrared light emitting unit 3. Output 4
A bit motor output port P3 and an 8-bit hardware counter 7 that is decremented every 64 psec.
a, and an interrupt function every 10m5ec.

The subject position display unit 8 is the main body block 102 (1!
It consists of four red LEDs 8a to 8d arranged 2 (1) on the front left and right of the camera (see figure s1).When viewed from the subject or camera side, the LED 8a is located at the upper right position, and when it is located at the lower right, the LED 8a is located at the right position. If the LED 8b located at the bottom position lights up, the LED 8c located at the upper left position lights up when it is located at the upper left position, and the LED 8d located at the lower left position lights up when the LED 8b located at the lower left position lights up.

Reference numerals 9a and 9b denote a motor M, which constitutes a drive mechanism for rotating the camera body 100 in a horizontal plane and swinging it up and down, and an xtll motor driver and a Y-axis motor driver for driving MY.

FIG. 9 shows the drive mechanism of the pan head device 110, which is responsible for so-called tracking operations, such as swinging the camera body 100 up and down and rotating it left and right in a horizontal plane.

Bins 101a and 101b extend horizontally inward from opposing surfaces at both longitudinal ends of the U-shaped inner surface of the vertically swinging plate 101, and one of the bins 101b has a sector-shaped gear 101 at its tip.
c or fixed.

Furthermore, three receivers 11102b and 102c are formed on the top surface of both longitudinal ends of the main body box 102 to receive the bins 101a and 101b of the vertically swinging plate 101. Rocking plate 10
A motor Mx, which serves as a drive source for rotating the motor (not shown) fixed on the display panel 1 from side to side in a horizontal plane, and a motor My, which serves as a drive source for swinging it up and down, are built-in. The rotation of the motor Mx is caused by a gear 104 fixed to the rotating shaft of the motor, and a two-ohm gear 1 meshing with this gear 104.
05, ohm gear 106 that meshes with this ohm gear
, is transmitted to a pedestal 103 disposed below the main body box 102 via a shaft 107 fixed to this gear 106.

On the other hand, the rotation of the motor My is controlled by a gear 10B fixed to the rotating shaft of the motor MY, a two-ohm gear 109 that meshes with this gear 108, and a two-ohm gear 109 that is fixed to the tip of the bottle 1olb of the vertically swinging plate 101. It is transmitted to the vertically swinging plate 101 via the sector-shaped gear 101c.

When the motor Mx of the drive mechanism rotates, the pedestal 103 does not rotate because it is fixed to the tripod 2 (see FIG. 81), and as a reaction, the camera body 100 rotates left and right in the horizontal plane. On the other hand, when motor My rotates, sector gear 1
01c rotates by a predetermined amount, and the vertically swinging plate 101 swings up and down.

Next, the operation of the tracking camera will be explained.2Prior to that, the basic idea of the present invention will be explained with respect to (I) detection of the subject position and (n) tracking operation.

(I) Detection of subject position The principle of detecting the subject position using the output from the subject position detection unit 5 will be explained using FIG. 1O.

In this embodiment, as described above, a four-segment photodiode 5d as shown in FIG. 6 is used as the two-dimensional position detection element of the subject position detection unit 5.
Four areas PM, PP, of the four-division photodiode 5d,
Among MM and MP, two areas PP and M on the diagonal line
The difference between the two position signals output from M and the areas PM and MP
The position of the subject is detected from the difference between two position signals output from the camera.

The position of the subject is determined based on the position of the infrared light spot of the 4-split photodiode 5d, and the 4-split photodiode 5 is determined based on the position of the infrared light spot of the 4-split photodiode 5d.
Since there are nine position signals from d as shown in FIG. 5(b), it is possible to know where the subject is located among the nine positions within the camera's field of view from the output of the four-division photodiode 5d. This 4
The operation of determining the position of the infrared light spot, that is, the position of the subject, from the output of the divided photodiode 5d is executed in a <current position detection routine> to be described later.

By the way, in the present invention, infrared light from the infrared light emitting unit 3 is used to detect the subject position, thus preventing false detection due to the influence of extraneous light (for example, fluorescent light or the sun) in the shooting environment. Therefore, the reading timing of the position signal output from the four-division photodiode 5d is determined as follows.

FIG. 11 shows four areas PM of the four-division photodiode 5d,
When infrared light hits area MM among PP, MM, and MP (left column) (a) (this corresponds to the case where the subject is at the bottom left of the angle of view as seen from the camera), and when area PP hits The signal waveforms at each part of the detection circuit 6 shown in Fig. 7 are shown in the case of infrared light (right column (b) (this corresponds to the case where the subject is at the upper right of the angle of view when looking at the camera). It is something that

In both cases (a) and (b), the signal A undulates significantly due to the influence of induced noise from the AC power supply and external light such as fluorescent lights. Since the differential amplifier circuit 6aI takes the difference between the regions PP and MM of the four-division phototire auto 5d, light components and induced noise that equally hit the regions PP and MM are canceled. At this stage, output signal B is output.

B' is offset from the reference level by the difference between the external light hitting areas PP and MM, and there is 38KH.
The signal of z is on.

The filter 6b is configured to pass only a 38 KHz signal and can remove the offset (DC component). It is also possible to remove noise with a frequency higher than 38 KHz. Here, by making the circuit configuration as shown in Fig. 8, when a 38KHz signal like signal B is input to the filter circuit 6b, which is higher than the signal when there is no signal, the 38KHz signal is interrupted and for a while,
The output signal C of the filter circuit 6b becomes a signal lower than the reference level and slightly exceeds the reference level after a certain period of time. On the other hand, when the 38 KHz signal is lower than when there is no signal like signal B', the open signal C becomes a signal higher than the reference level for a while after the 38 KHz signal is interrupted.
After a certain period of time, it slightly exceeds the standard level.

Is it possible to detect the position of these signals c and c' using an A/D converter or the like? Since the circuit would be complicated and the processing would take time, here, it is simply converted into two values.

That is, when the signals c and c' are inputted to the comparator 6c, signals separated by whether they are above or below the reference level are output.

However, as mentioned above, the output of the signal C slightly exceeds the reference level after a while after the 38 KHz signal is discontinued, so the output of the filter circuit 6b changes like α of the signal. If the light is strong enough, it is possible to detect the signal pattern from the falling edge of the signal, or if the light is weak, the α part will be affected by even a small amount of noise, and the signal will contain noise. , the pattern cannot be detected with just the signal. On the other hand, the infrared light receiving unit 4 can output a correct signal even with fairly weak light, so 1. ．． The above-mentioned problem can be solved by reading the signal at the timing of 12 and performing statistical processing to detect the position.

Specifically, the timing for reading the output of the detection circuit 6 is determined using the output signal E from the infrared light receiving unit 4 at its fall and rise timings tag and t2. At these two timings t1 and t2, the detection circuit 6
For example, when the output level changes from "H" to "L", the first
When it is determined that the infrared light is hitting the position of the area PP as shown in Figure 1 (in), and the output level changes from "L" to "H", the infrared light is detected as shown in Figure 11 (b). is the area MM
By determining that the infrared light is hitting the position, the position where the infrared light is hitting can be detected.

As described above, by detecting the signals from the four-divided photodiodes in synchronization with the signal pattern from the infrared light receiving unit 4, position detection can be performed reliably even over long distances with a simple circuit configuration.

On the other hand, since the output from the infrared light receiving unit 4 may be contaminated with external noise such as noise from a fluorescent lamp, in the present invention, the count period of the hardware counter 7a built in the CPU 7 is set to 647 zsec. The interval between remote control signals is 64 x 2 gsec = 128
Signals shorter than psec are treated as noise by software to eliminate the influence of noise.

(II) Tracking operation Next, the basic concept of tracking operation will be explained.

In this embodiment, the camera tracking operation is performed using a motor M for rotating the camera body left and right in a horizontal plane and a motor MY for swinging it up and down.
Since the concept of motor control for tracking is the same for both motors, only motor M will be explained here.

(a) Tracking control is performed using the tracking key KEY of the infrared light emitting unit 3.
5 is pressed and the remote control signal is received by the infrared light receiving unit 4, and the camera is moved to the position or center of the light spot based on the position of the light spot of the infrared light on the 4-division photodiode 5d. A tracking operation is performed. In this embodiment, the rotation of the motor is not stopped until a certain period of time (50 m5ec in this embodiment) has elapsed since no remote control signal was received. This is to avoid jerky camera movements if you stop the motor immediately when the signal is interrupted for a short time due to noise mixed in with the remote control signal, etc., and to make the camera tracking movement smooth. This is to do so. The above-mentioned tracking control is executed in <one frame reception routine> which will be described later.

(b) Since a 4-split photodiode is used as the subject position detection element, the subject, that is, the infrared light spot,
It is only possible to detect which region it is in. Therefore, the infrared light continuously output from the infrared light emitting unit is received by the four-division photodiode 5d, the subject position is detected by the signal processing circuit, and the position information is sequentially stored in the CPU 7. The currently detected position information is compared with the previously detected position information to determine the direction in which the vehicle should be tracked.

The light spot of infrared light on the 4-division photodiode 5d takes one of three positions: positive, zero, or negative when viewed in the X-axis direction, so the position of the infrared light from the previous light spot position and the current light spot position is Now that we know the direction of movement of the light spot, we can think of the following five ways.

(1) When changing from zero position or positive position to positive position (2) When changing from zero position or negative position to negative position (3) When remaining at zero position (4) Negative position (5) When the light point changes from a positive position to a zero position or a negative position For these five ways of movement of the light spot, for (1) and (4) For (2) and (5), motor M is rotated in the forward direction; for (3), motor M is rotated in the reverse direction;
Stop x.

The speed of the motor M8 is controlled by changing the duty ratio, and in this embodiment, the duty ratio is set to 100% and 50%.
It is set in 5 levels: %, 30%, 20%, and 10%.

Every time the light spot passes the zero position, the motor M is reversed and at the same time the duty ratio is lowered one step at a time by referring to the speed table, for the following reason.

In other words, if the camera is tracked at a very slow speed, it is not possible to stop the camera body reliably so that the light point reaches the zero position, but it takes too much time. On the other hand, when tracking at high speeds, the light spot cannot be reliably stopped at the zero position due to the inertia of the camera body, the play of the drive mechanism, and the time lag between detection and control, resulting in a hunting phenomenon. At first, the light point is moved quickly, and when the light point passes the zero point, the duty ratio is lowered by one step in the opposite direction to reduce the speed. Accurate tracking without hunting can be achieved. Further, tracking control for zero or more in which the same control as that for the X-axis is performed for the Y-axis is executed as an <X-axis movement determination routine> and (Y-axis movement determination routine), which will be described later.

(C) Another way of thinking about tracking control is that if the light point or zero position is not passed through after starting tracking and the zero position is not passed again even after a certain period of time (1 second in this example) has elapsed, the duty ratio is Increase the speed by one step, and then perform speed increase control in the same way. This is due to the following reason.

In other words, once the infrared light spot passes the zero position, the motor is controlled to reverse, so it should pass the zero position sooner or later, but if there is play in the drive mechanism or the subject is tracked by the camera. If it moves in the same direction, it may not pass through the zero position again even after a certain period of time. In this case, increase the tracking speed, or the subject may be nearby.
If the speed is increased too rapidly, the light spot will pass the zero position and go too far, so tracking control above zero can avoid overshooting by increasing the duty ratio one step at a time and increasing the speed. This is executed in the tracking routine described below.

Now, the operation of the tracking camera will be explained below using the flowcharts shown in Appended Tables 1 to 13.

The tracking camera operates by the tracking circuit CPU shown in Figure 4.
First, the algorithm will be explained.

The program is realized by several routines as shown in Attached Table 1.The constants used in this program are shown in Attached Table 2 along with their explanations, and the variables are shown in Attached Table 3.Algorithm description methods in Attached Tables 5 to 13 is attached table 4
It is as follows.

As shown in FIG. 1, a tracking camera 1 is fixed on a tripod 2, a power switch 100d is turned ON, and a person, who is a subject, stands in front of the camera holding an infrared light emitting unit 3.

Figure 12 shows the operation of the tracking camera using the present invention.
A flowchart of the main processes of tracking operation related to the present invention is shown, including distance measurement, photometry, lens drive, release,
This is performed separately and independently from a series of shooting operations such as film winding.

Immediately execute <Initialization routine> (Sl) (F-1
). This routine initializes various variables shown in Attached Table 3. When the initialization routine is completed, the next <I frame reception routine> (S2) is executed (F-2).
In this routine, one frame of the remote control signal from the infrared light emitting unit 3 is received, and for this purpose, <remote control signal boat input routine> (F-3), <counter value reading routine> (F-4), (Routine for determining light emission interval> (S3) (F-5) is executed.

<Remote control signal boat input routine> (F-3)
Read the signal from the infrared light receiving unit 4 and the position signal (PP/MM signal and MP/PM @ number) from the subject position detection circuit 6 from the remote control signal input port PI of PU7 and set it to the variable (cur-port). (Counter value reading routine> In (F-4), the value of the 8-bit counter is decremented by 1 every 64 psec and the value of the 8-bit counter is decremented by 1.
Routine for Determining Light Emission Interval> In (F-5), it is determined which key has been pressed from the time interval of the remote control signal received by the infrared light receiving unit 4.

After completing these routines, it is determined whether or not the reception of the 1 frame has been completed (F-6). If it has been completed, the next current position detection routine> (S4) is executed (F-6).
-7), this routine determines the current position of the subject from the various variables determined in step (F-5).

Next, execute (LED boat output calculation) and F-
8), the content of the variable (1ed-output-data) is output to the LED output port P2 of the CPU 7 and output to the four LEDs 8a to 8d (No. (See Figure 1).

Next, from the results of the above (l frame reception routine) and <routine for determining light emission interval>, the infrared light emitting unit 3
Determine whether or not the key is pressed (F-9), and if it is not pressed, execute the <standby routine> (S5) (F-10). After that, the LED is turned off, and the control variables for motors M and My are set to stop (that is, motors M and MY are stopped, and the speed variable (cur++ x
s p e e d ) and (car yspe
ed) to maximum speed) Waits until the next key press.

When it is determined that a key has been pressed in step (F-9) or when the standby routine has ended, it is determined whether the tracking key (KEY5) has been pressed or not (F-11).
, tracking routine when it is determined that it is pressed>
(S6) is executed (F-12).

In the <tracking routine>, the movements of the motors M and M are determined from the current position and previous position of the subject detected in the <current position detection routine, and the subject is tracked.

In other words, execute the <standby routine) and turn on the LEDs 8a to 8.
d and set the motor control variable to stop (F-13), then execute the <X-axis movement determination routine> (F-13).
-14) (S7) and <Y-axis movement determination routine>
(F-15) Execute (S8).

In this routine, the rotation direction and speed of motors Mx and MY that move the camera in the X-axis direction and Y-axis direction are determined from the current position of the subject and its previous position.

When it is determined that the tracking key (KEY5) is not pressed in step (F-11) or when the Y-axis movement determination routine is completed, the direction keys (KEY1 to KEY9) except the tracking key (KEY5) It is determined whether or not is pressed (F-16), and if it is pressed, set the motor control variables in each direction (F-17), and if it is not pressed, return to step (F-2). Execute the <l frame reception routine> again.

Figure 13 shows a 10 m
It shows a <timer interrupt process> that is executed every s e c. It is determined whether or not a timer interrupt has been made (P-1), and when the interrupt has been made, the motor l port output routine is executed (P-2), and this routine sets the variable (a+otor move) for the motor 81B. The contents are output to the motor output capo-4P of the CPU 7. If there is no timer interrupt, return to step (P-1).

Next, each routine executed in the above-mentioned main process will be explained in detail.

(Initialization Routine) This routine initializes various variables shown in Attached Table 3, and the details are shown in Attached Table 5.

Variable (xduty-di) representing the moving direction of motor Mx
Assign the constant [MV-XP] that instructs normal rotation to the current speed of motor M and the current speed of motor My, and substitute the constants [XDUTY-MAXI and [YDUTY-MAXI] that instruct the maximum speed to the current speed of motor M and the current speed of motor My. Sl-1).

Furthermore, a table (xtable) for controlling the speed of motor Mx in order to gradually slow down and gradually speed up the speed of motors Mx and MY.

(xtable r) and the constants of the speed control table (ytable) and (ytable r) of the motor M"t are set as shown in Attached Table 5 (Sl-2). Here, the variables (xtable[10]) and means that the duty ratio is 100%, (xtable[5]) means that the duty ratio is 50%, (xtable[3]) means that the duty ratio is 30%, and (xtable[2]) means that the duty ratio is 30%.
The ratio is 20%, and (xtable 1) means that the duty ratio is 10%.

In addition, a constant [FALSE] indicating that the key of the infrared light emitting unit 3 is not pressed should be substituted into the variable (1s-key-push) indicating whether the key of the infrared emitting unit 3 is pressed.5l-3
), a variable indicating the previous detection position (old-pos),
Variables indicating the current detection position (cur, pos), variables indicating the bit count (biLcnt), variables indicating the received data (key-result), variables indicating the previously received data (key-result)
Assign 0 to each of 1d), 5l-4), and 1 to the variable (1eve I) that indicates the current state of received data, 5l-5), the time when the infrared signal fell, and whether it is an infrared signal or not. Variables (td) and (to) representing the falling time interval and the definitely rising time interval, respectively.

8 each for (tu), (t+), (wo), (wr)
Constant representing the maximum value of the bit variable [BYTE-MAXI
(Sl-6).

In addition, the four regions PM and P of the four-division photodiode 5d
Variables (dir-pp), (dir-pm), (dir-m) for determining how infrared light hits P, MM, and MP
p).

Assign 0 to (dir-am) (S1-7).

Furthermore, O is assigned to the variable (ρLdata) that indicates the boat value when the infrared signal has a positive edge and the variable (pOJata) that indicates the boat value when the infrared signal has a negative edge (S
l-8).

(One frame reception routine) This routine receives one frame of the infrared signal emitted from the infrared light emitting unit 3.
is shown.

First, assign a constant [FALSE] indicating that no key is pressed to the variable (1s-key-push) that indicates whether or not a key of the infrared emitting unit 3 is pressed.S2-
1) Next, a variable (tiger-no-key) that measures the time since infrared signals cease to arrive is set (S2-2). This variable is 10m in the interrupt routine.
It is incremented by 1 every s e c. It is also reset when a key is pressed, and represents the time since the key was no longer pressed.

Next, execute the <infrared signal boat input routine>. That is, the value of the infrared signal input port P1 of the CPU 7 is set as a variable (p
ort) (S2-3).

Next, the <counter value reading routine> is executed. In other words, the count value of the CPU built-in hardware counter 7a, which is decremented every 64 Bsec, is expressed as a variable (co
(S2-4).

Next, the infrared signal from the infrared light emitting unit 3 becomes “HIG”.
S2-5), if it is HIGH, then “
The count value of the hardware carantuff of the CPU 7 when it changes from "HIGH" to "LOW" is read into the variable (td) representing the time when the infrared signal falls (S2-6).
, if the infrared signal is “LOW”, from “LOW” to “
The count value of the hardware counter 7a when it becomes HIGHHH is expressed as a variable (t
u) (S2-7). An example of the above operation along with the count value of the hardware counter 7a for reception of an infrared signal is shown in FIG. 14(a).

Next, the level of the infrared signal is 64 psec x 2 = 128 p
When the infrared signal remains "LOW" for more than sec (S2-8) and more than 128ILsec has passed since the infrared signal rose (S2-9), a variable representing the current reception state is assumed to have arrived as a correct infrared signal. Assign "1" to (level) (S2-10), and substitute the rising time data (tu) that was assigned in step (S2-7) to the variable (tl) representing the time when the infrared signal fell. (S21
1). By doing this, it is possible to remove noise mixed into the infrared signal. Furthermore, in order to find the signal interval of the infrared signal, the variable (w2) representing the signal interval is replaced with a variable (w,) representing the time interval when the infrared signal was "LOW" two times before, and a variable (w,) representing the time interval when the infrared signal was "HIGHH" last time. Assign the variable (w,) representing the time interval in which the current state is
2-12), from the variable (to) to the variable (w,),
Substitute the time difference (to) - (t,) by subtracting tl).5
2-13), a variable (PIJa) representing the value of the infrared signal input port PI when the infrared signal is -HIGH''
The value of the infrared signal input port P1 when the infrared signal rises is substituted into ta) and saved (S2-14). In step (S2-8), the level of the infrared signal is 128 μs.
becomes HIGH'' within ec, that is, the variable (level
) becomes 1 and the infrared signal falls, 128uLs
If ec or more has passed (S2-15), the variable (lev
Set el) to 0, assign the time difference (tl) - (td) obtained by subtracting the variable (td) from the variable (t□) to the variable (冑, ), and assign the variable (td) to the variable (to). and the infrared signal input boat P when the infrared signal is “LOW”,
Infrared signal input boat P to the variable (POJata) representing
A concrete example of the operation of substituting the value of I (S2-16) for 0 or more is shown in FIG. 14 (b).

It is determined whether or not the key of the infrared light emitting unit 3 is pressed (S2-17), and if it is pressed, a variable (keyJata ) and return to the main process (S2-18), set a variable (ti Er no
-key) is reset in step (S2-2), and then in the <interrupt routine> 10 msec
Since it is incremented every time, it indicates the elapsed time since the start of execution of this <1 frame reception routine.

Then, it is determined whether this variable (tii+er no-key) is 5 or more (S2-19), that is, whether 50m5ec has elapsed since entering this routine, and if it has elapsed, it represents the data received last time. Variable (key-re
sult-old), clear it by assigning a constant [KEY NUL L] indicating that no key is pressed to the variable (k6y data) representing the key code being received, and then clearing the variable (key). [KEYN
ULL] and exit from this routine (S2-20
).

(Routine to find the light emission interval) This routine uses the variable (W2) representing the signal interval found in the above-mentioned 1 frame reception routine for 1 frame of the infrared signal emitted from the infrared light emitting unit 3. The time interval between each signal, that is, the emission interval is “L” or “H”
This is a routine to find ``, and the details are shown in Attached Table 7.

The variable (W2) representing the signal interval determined by the above-mentioned frame reception routine is 16 or less, that is, 16X64.
psec=1024. It is determined whether the interval is less than or equal to ccsec (S3-1).
．． 5m5ec, long interval "H" or 2.5m5ec, so 1024 is even shorter than this short interval "L"
Signals below psec are to be ignored, and w
When 2<16 (1024ILsec), variables (dir-pp), (dir-pm+
), (dir-mp), (dir-mm) and a variable (bit-cnt) representing the count number of the infrared signal (S3-2). Next, the signal "L" should ideally be 9.
12=23(23X64gsec'-, 1500gs
ec) or W2 or 16 (16x64=1024pse) with a little convergence considering the variation in signal intervals
c) to 31 (31×64=1984p, 5ec), it is determined that the signal interval is “L” (S3-3). 16≦w2<3
When it is 1, the variable (key-
Enter (key-result)×2+O in result). In other words, it shows the result (key result
) is shifted one bit to the right (S3-4).

Next, the signal “H” is ideally w2=39 (
39X64gsec=2496psec=2500uL
sec), but in this case as well, the variable (w2) that represents the signal interval is given a width in consideration of the variation in the signal interval.
(31X64=1984psec) ~60 (
60x64=38407zsec), the signal interval is determined to be "H" (S3-5), and furthermore, the variable (tp-cnt) representing the count number of the infrared signal is 0.
In the case of 1.2, it is a start signal of "L", and in the case of 8.9, it is a stop signal of "L", so the variable (bit
S3 to determine whether cnt) is 3 or less or 7 or more.
-6), if so, all the infrared signals should be "L". However, since they were recognized as "H" in step (S3-5), they are regarded as noise and the variable (bit-cnt
), (dir-pp), (dir-pw+).

All of (dir-p) and (dir-ms) are cleared (S3-7). At this time, (key-result) is set to the variable (key-result) representing the received data.
t) Enter x 2 + 1.

That is, shift the result (key-result) one bit to the right and set bit O to "H" (S3-8)
.

When it is determined in step (S3-5) that the variable (tp) representing the time interval between signals is tp≧60, this is the end of l frame or abnormal data, so the variable (bi
Lcnt), (dir-pp), (dir-pm).

(dir-mp) and (dir @II) are all cleared (S3-9).

Next, if the 20 o'clock position signal PP/MM signal is "H" and the 21 o'clock position signal PP/MM signal is "L" (S3-10), the area of the 4-division photodiode 5d A variable (dir-p) that represents how infrared light hits PP
Substitute (dir-pp)+1 for p) (S3-11
). On the other hand, if the PP/MM signal at 20 o'clock is "L" and the PP/MM signal at 21 o'clock is "H" (S3-
12), (dir-am) + variable ('dir-am)
Substitute 1 (S3-13), similarly MP/ at 20:00
PM signal is “H” and MP/PM signal at 21:00 is “L”
” (S3-14), the 4-split photodiode 5
A variable (dir
Substitute (dir mp) + l for mp) (S3-
15), Similarly, if the MP/PM signal at 20 o'clock is "L" and the MP/PM signal at 21 o'clock is "H", (S3-16
), and (dir-Pa)+1 is assigned to the variable (dir-mp) (S3-17).

When calculating one signal interval in this way, the count number (bit cnt) can be counted up (53-18)
, if the signal interval data is obtained for this count number (biLcnt) or lO, that is, one frame (lO bit), the infrared signal is correct only if the frame is received twice and the signal interval data is the same both times. I recognize that. Therefore, the received signal interval data is changed to a variable (key-result-) representing the previously received signal interval data.
old) and compares it with the current signal interval data, and if they are the same (S3-19), it is recognized as a correct signal and a variable (is-key-p
Assign constant [TRUE] to ush) (S3-20)
. There is also a variable (tig) that represents the time since the key was pressed.
er-push-key) (S3-21
). For later position detection, position determination counters (djr J) I)), (dir-pm), (dir
-mp) and (dir-ms) respectively.
), (dir-up), (dir am) (
S3-22).

If the data of the previous signal interval and the data of the current signal interval are different, the current data (key-resu
lt) is a variable (key-res
ulLold) (S3-23), and various variables (tp-cnt) and (tp dir-
pp), (tp-dir p 鳳), (tp-dir m
p), (tp-dir am) is cleared (S3-2
4).

(Current position detection routine) This routine uses a variable (dir-p
p), (dir-pm), (dir-mp)
This routine detects the current position of the subject from , (d ir-gg), and the details are shown in Appendix 8.

First, a variable p is used to find the position of the subject.

(8 bits) is initialized to 0 (S4-1).

Next, in order to save the subject position, the data contained in the variable representing the current subject position (cur-pos) is transferred to the variable representing the previous subject position (old-pos).
(S4-2). Pre-existing constant [LEVEL]
(for example, 5), and the variable (
S4-3) to determine whether the data of dir-pp) is greater than or equal to the constant [LEVEL]. If it is greater than or equal to [LEVEL], it is assumed that infrared light is hitting the area PP of the 4-split photodiode 5d, and the variable is changed. Set 1" in the 4th bit of pO (S4-4), and similarly, set the 4-divided photodiode 5d.
Whether infrared light is applied to the area PM is data of a variable (dir-pm) representing the subject position [LEVEL]
S4-5), [LEVEL]
] If it is above, set the variable pO no 3 and 1n for the Udo eyes (
S4-6), and the following four-divided photodiode 5 in the same manner.
To determine whether or not the infrared light is hitting the area MP of d
4-7), if it is correct, the 2nd bit of variable pO is set to 1'''
is set (S4-8), and if the infrared light is hitting the area MM, "l" is set at the 1st bit of the variable pO (S4-10).
.

In this way, depending on which bit of the variable pO is set to "1", it is possible to determine the position of the infrared light in 16 ways shown in Appendix 8 (S4-11). The following nine types of subject position data are assigned to a variable (cur-pos) representing the current position.

Po5ZZ, Po5MM, PosMP, P
osMZ, PosPM, Po51M, Po
5PP.

Po5ZP, Po5PZ After that, array variables (1ec
Ltable) (S4-12) and passes the value to <LED output calchin), which will be described later.
The LEDs 8a to 8d provided at 02 are turned on.

(Standby Routine) This routine waits until a key on the infrared light emitting unit 3 is pressed, and the details are shown in Appendix 9.

First, if the time from when a key is pressed and an infrared signal is received is within 100m5ec, the system returns without doing anything and returns to 100m5ec.
When more than msec has elapsed (Sl-5), the current speed variables (cur xspeed) 3 and (cur-ys) of motors Mx and MY are changed to increase the tracking speed.
peed) is a constant that specifies the maximum speed [XDUTY-M
AX] and [YDUTY-MAX, and (S5-
2), a variable (
xduty-direc) and (yduty-dir
ec) to 0 (S5-3), then LED8a-8
Set the constant [LED-OFF] to turn off d as a variable ()
ed-output-data) and (S5-4
)<LED output calculation).

(Tracking routine) This routine uses the tracking key (KE) of the infrared light emitting unit 3.
Details of the routine for pointing the camera toward the subject when Y5) is pressed are shown in Appendix 1O.

First, the standby routine described above and the X-axis motion determination routine and Y-axis motion determination routine described later are executed (S6-1).

Thereafter, it is determined whether one second or more has elapsed since the position of the light spot of the infrared light crossed the zero point of the X-axis that horizontally divides the light receiving area into two on the 4-split photodiode 5d (S6-2).
, when the elapsed time has elapsed, a variable (ti■e
r-xcross) and reset (S6-3
), X of motor M, based on the current speed of motor Mx
The value obtained by referring to the axial braking table (xtable-r) is set as the new speed in the X-axis direction of the new motor Mx (S6-4). As a result, the speed of motor Mx gradually increases. The same applies to motor MY (S6
-5), the speed of motor MY gradually increases.

After that, the X value obtained using the X-axis braking table (xtableC) and the Y-axis braking table (ytable)
A variable (xduty-speed) that indicates the speed in the X-axis direction and the speed in the Y-axis direction by changing the duty ratio of the speed data in the axial direction and the speed data in the Y-axis direction, respectively.
and (yduty-speed) (S6-6
).

(X-axis movement determination routine) This routine determines the direction in which the motor M is moved from the current position (cur-pos) of the infrared light spot on the 4-division photodiode 5dp and the previous position (old=pos). This is a routine to determine the speed, and the details are shown in Attached Table 11.

First, when looking in the X-axis direction, the position of the subject, that is, the position of the light spot of the infrared light on the 4-split photodiode 5d, is between the normal position (i.e., areas PM and PP) and the zero position N (i.e., areas PM and MM). On the border and in areas PP and MP
) and negative M (i.e. areas MM and MP
).

First, reset the variable (x-cross) that indicates whether the point of infrared light has passed through the zero position on the X-axis.
1), next, processing is performed to obtain only information on movement in the X-axis direction (S7-2). Variables (ol+Lpos) and (cur
-pos) bit2 jll; and bit3 indicate the position in the X-axis direction, so the variable (x
Bit 2 and bit 3 of p) indicate the previous position of the subject,
Furthermore, bit 1 represents the current position of the subject.

Therefore, the position of the subject, that is, the position of the light spot of the infrared light,
It is determined whether the axial direction has changed from the zero position to the positive direction or from the normal position to the positive direction (S7-3). If it has changed, the variable (xduty-direction) representing the moving direction of the motor Mx is
Insert a constant [MV-XM] to move in the positive direction of the X-axis in c) 6 (S7-4), so that the motor M moves in the positive direction of the X-axis so that it is at the light spot position or the zero position. Camera tracking is done. Similarly, when the position of the light spot changes from the zero position to the negative direction in the X-axis direction or from the negative position to the negative direction, the motor M is moved in the negative direction of the X-axis.
7-5), when the light spot remains at the zero position, the variable (x
duty Jirec) to 0 to stop the movement of the motor M in the X-axis direction (S7-6); conversely, when the position changes from a negative position to a positive position or a zero position, set the variable (xcross) to zero and set the variable ( Substituting constant [MV-XPI in S7-7), -11=-ta Mx is moved in the positive direction of the X-axis to track the camera so that the position of the light spot becomes the zero position. When the position of the light spot changes from a positive position to a negative position or zero position in the X-axis direction, the variable (
xcross) and set the variable (xduty
, -direc) and substitute the constant [MV-XM] in S7.
-8) Move the motor M in the negative direction of the X-axis to track the camera so that it is at the subject position or at the zero position.

Finally, it is determined whether the variable (xcross) is set or not (S7-9), and if it is set, the current speed variable (cur=xspeed) or if it is not 0, the current speed is used as the referenced x table. Motor M with value
The current speed of x is determined (S7-10). As a result, the tracking speed of the camera gradually slows down, and a variable (timer) that measures the time after the light point crosses the zero position on the
-xcorss) (S7-11).

(Y-Axis Movement Determination Routine) This routine is a routine for determining the direction and speed of moving the motor MY in the same way as the X-axis movement determination routine described above, and details are shown in Appendix 12.

This routine is "X-axis movement determination routine".
This routine is exactly the same as the X-axis movement determination routine except that the "X-axis direction" is changed to the Y-axis direction and the motor to be controlled is y instead of M, so a description thereof will be omitted. However, bits 2 and 3 of the variable (yp) represent the previous position of the subject, and bits O and bitl represent the current position. Processing is in progress (S8
-1).

(Infrared signal input port input routine) This routine includes the infrared signal input port P1 of the CPU7.
The following data input to the cur-port is read and set to a variable (cur-port) representing the current port value.

Bit 7: Infrared signal from infrared receiving unit 4 Bit 6: PP/MM signal b from detection circuit 6
it 5: MP/PM signal from detection circuit 6 (L
Variable for displaying the camera position (Ied-outp)
When bits 0 to 3 of utJata) are 0, the following LEDs are lit.

bit O: Upper right LED bit when viewed from the subject
1: LED bit on the lower right when viewed from the subject 2:
LED bit 3 on the lower left when viewed from the subject: LED on the upper left when viewed from the subject (motor boat output routine) A routine that outputs rotation direction and speed instructions for the motors Mx and MY to the motor output boat P, The following motor control is performed depending on the output to each bit of l.

(Leaving space below) bit3 bit2 bitl bit0 Motor Mx stop (MV-XZ) Motor Mx forward rotation (MV-XP) Motor M, reverse rotation (MV-XM) Motor MY stop (MV-YZ) Motor MY forward rotation (MV-YP) ) Motor MY reverse rotation (MV-YM) Motor M, forward rotation means clockwise rotation when looking at the camera from above, and motor My forward rotation means the camera faces upward.

(Counter value reading routine) This routine sets the count value of an 8-bit eight-way counter that is decremented every 64 Bsec to a variable (cur-counter).
The count value becomes 255 after 0.

(Interrupt routine) This routine interrupts 10m, s by timer interrupt.
Executed every e c.

This routine sets the following variables to B as shown in Appendix 13.
The following time can be measured by increasing by l as long as YTE-MAX is not exceeded.

tiger-no-key: Time since infrared signal no longer arrives (S9 tiIIer-push-key: Time since infrared signal arrives (S9-2) tiger-x cross: Subject position Time since passing the center of the axis (point f) (S9-3) tiger-y cross: Time since the position of the subject has passed the center of the Y-axis (point ff) (S9-4) Also a variable (xduty-count), (xdut
, y-speed), the speed of the horizontal motor Mx is controlled by changing the duty ratio of the energization time of the motor.

Here, the variable (xduty-count) is decremented by 1 each time the interrupt routine is called (S9-5
). If the initial value of the variable (xduty-count) is K, then (xduty, -count) or 0 to (xd
Please keep the motor running during Uty, 5peed-1).
9-7), The duty ratio of the motor Mx is changed by stopping the motor Mx from (xduty 5peed) to K (S9-6). Also, the variable (xdu
ty-count) or 0, a constant [XDUTY-MAX
] and stop the motors M x and M y (S9
-8).

Similarly, the vertical motor MY has a variable (xdut
y-count), (yduty-speed).

The actual rotation control of the motor is performed using the variable (■otor
(move), the following constant MV-XP: Normal rotation of motor Mx MV-XZ: Motor 9MX (7) stop MV-XM:
One of the reverse rotations of motor Mx and the following constant MV-YP: 9MY (7) Normal rotation MV-Y
Z: (=9 My I) Stop MV-YM: Performed by substituting the logical sum with either of the reverse rotations of motor My and executing the <motor boat output routine.

The present invention has been described above with reference to one embodiment. However, in the present invention, the multi-segment position detection element constituting the subject position detection unit 5 is not limited to a four-segment photodiode, but at least two
Any photoelectric conversion element with more than one division is sufficient. Furthermore, the two subject position signals to be differentially amplified are not limited to outputs from two diagonal areas, but may also be position signals from two areas that are not in line contact with each other among a plurality of divided areas that make up the element. Good too.

Furthermore, the signal emitted from the subject to the camera is not limited to infrared light, but can also use sound waves, radio waves, etc.

As a tracking camera, as shown in the above embodiments, is it preferable to have a camera body that can swing up and down and rotate left and right in a horizontal plane to follow the movement of the subject in all directions? Needless to say, it is sufficient to have only one that can be rotated from side to side within a horizontal plane.

Further, in the above embodiments, the tracking mechanism of the camera body is configured as a part of the camera, but the present invention is not limited to this, and the tracking mechanism may be incorporated inside the pan head device that fixes the camera.
In this way, a tracking type camera can be realized simply by attaching a normal camera to a pan head device.

(Effects of the Invention) As explained above, the present invention detects the position of the subject in response to a signal emitted from the subject in a camera that tracks a subject by rotating the camera body left and right within at least a horizontal plane. The camera body is configured to control the rotation direction and rotation speed so that the position of the subject is at the center of the camera's shooting screen, so it is possible to use a simple circuit configuration without using advanced image recognition technology. It is possible to create a tracking camera that can quickly and accurately follow the movement of a subject. In particular, by reversing the direction of rotation of the camera body and reducing the rotation speed when the position of the subject crosses the center of the photographic screen, the camera body can be quickly and precisely directed toward the subject. Also, if the direction of rotation of the camera body is reversed when the subject's position crosses the center of the shooting screen, the subject's position should eventually cross the center of the shooting screen again, but there may be variations in the tracking mechanism of the camera. 2 If the subject (for example, a child) moves on its own, the subject's position may not cross the center of the shooting screen even after a certain period of time has passed. By increasing the distance, it is possible to focus on the subject without going too far, and quick tracking becomes possible.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the tracking camera according to the present invention in use, FIG. 2 is an example of an infrared light emitting circuit of an infrared light emitting unit used in the present invention, and FIG. 3 is a diagram showing each key of the infrared light emitting unit. Diagrams showing different infrared signal patterns, FIG. 4 is an example of the tracking circuit of the tracking camera according to the present invention, FIG. 5 is a sectional view showing the internal structure of the subject position detection unit, and FIG. 6 is a diagram showing the internal structure of the subject position detection unit. An example of the light-receiving area of a 4-division photodiode, FIG. 7 is a block &! of an embodiment of the detection circuit.
8 is an example of a detailed circuit configuration of the detection circuit shown in FIG. 87, and FIG. 9 is a partially cutaway view of the drive mechanism incorporated in the pan head device of the tracking camera according to the present invention. The perspective view, Fig. 10 (a) shows the position of the infrared light spot on the four-split diode, and (b) shows the waveform diagram of the position signal corresponding to the light spot, Figs. 11 (a) and (b). ) is a waveform diagram of the position signal in each part of the detection circuit when a light spot of infrared light hits different areas on the 4-split photodiode, and Figure 12 is a flowchart showing the main process of operation of the tracking camera according to the present invention. , Fig. 13 is a flowchart showing the timer interrupt process in a tracking camera, Fig. 14 (a)
and (b) are diagrams showing data of each variable in the actual operation of the one-frame reception routine of the present invention. l... Tracking camera, 2... Tripod, 3... Infrared light emitting unit, 4... Infrared light receiving unit, 5... Subject position detection unit, 6... Detection circuit, 7... -CP
U. 7a...Hardware counter, 8...Subject position display unit, 100...Camera body, 110-...
Panhead device

Claims (3)

[Claims] (1) position signal output means for outputting a position signal corresponding to the position of the subject upon receiving a signal emitted from the subject;
a position detection means for detecting the position of the subject based on the position signal; a rotation mechanism for rotating the camera body at least within a horizontal plane; A tracking camera characterized in that it has a control means for controlling the rotation operation of the camera body by the rotation mechanism. (2) The tracking camera according to claim 1, wherein the control means reverses the direction of rotation of the camera body and reduces the rotation speed when the position of the subject crosses the center of the photographic screen. (3) When the position of the subject does not cross the center of the photographic screen within a predetermined time after reversing the rotational direction of the camera body, the control means adjusts the rotational speed and time of the tracking type camera according to claim 2. .