JPH0717050Y2 - Focus control device for camera - Google Patents

Description

[Technical Field] The present invention relates to a focus control device for a camera that automatically detects a distance to a subject and drives an autofocus mechanism based on the distance data.

“Prior art and its problems” In a general camera that has been used conventionally, the distance measuring zone is located in the center of the viewfinder field. By aligning this distance measuring zone with the subject and performing a predetermined operation, ,
The autofocus mechanism can be driven to bring it into focus.

For this reason, if you want to take a deliberately stray portrait of the subject you want to focus on from the center of the viewfinder, press the release switch halfway while the camera is facing the subject to focus, then after this focus lock. It is necessary to determine the composition again and shoot.

However, such an operation is sometimes very complicated even for a person who is familiar with the camera. There is a problem that a user who is not familiar with such an operation cannot effectively use even the function thereof, which is particularly inconvenient when the subject is a moving body.

[Purpose of Invention] The present invention has been made in order to solve such a conventional problem, and no matter what composition the photographer takes, the photographer does not have to perform any operation. An object of the present invention is to obtain a focus control device for a camera that can automatically perform focusing on the camera.

[Summary of the Invention] The present invention that achieves the above object is a focusing control device including a receiver provided in a camera having an autofocus mechanism and a receiver formed separately from the main body of the camera. A light emitting means provided in the receiver for emitting a specific coded optical signal intermittently; and a sound wave emitting means for emitting a sound wave signal intermittently in synchronization with the emission of the optical signal; A light receiving section for receiving the optical signal and a sound wave receiving section for receiving the sound wave signal; a code identifying means for identifying a code included in the optical signal; and a code identifying means for identifying the code based on the code identifying means. Distance measuring means for detecting a time difference between the optical signal received by the light receiving section and the sound wave signal received by the sound wave receiving section, and calculating the distance from the camera body to the receiver based on the detected data; By distance measuring means And a control means for driving the automatic focusing mechanism based on the distance data calculated as described above.

With the above configuration, the autofocus mechanism provided on the camera body side can accurately focus on the subject based on the optical signal and the sound wave signal from the transmitter carried by the subject. Needless to say, this focusing is performed regardless of the composition of the camera. Therefore, the image pickup operation becomes very simple, and even a person unfamiliar with the camera can effectively use the function. In particular, this is a very effective function when the subject is moving.

Further, the present invention is a focusing control device comprising a receiver provided in a camera having an autofocus mechanism and a transmitter formed separately from the main body of the camera, and a specific code provided in the transmitter. A radio wave emitting means for intermittently emitting a converted radio wave signal, and a sound wave emitting means for intermittently emitting a sound wave signal in synchronization with the emission of the radio wave signal; the radio wave signal provided in the receiver A radio wave receiving section for receiving the sound wave signal; a code identifying means for identifying a code included in the radio wave signal; and a radio wave signal received by the receiving section based on code identification by the code identifying means. A distance measuring means for detecting a time difference between the sound wave signals received by the sound wave receiving section and calculating the distance from the camera body to the transmitter based on the detected data; Characterized in that it comprises a; based on the distance data and control means for driving the autofocus mechanism.

Therefore, the autofocus mechanism provided on the camera body side can perform accurate focusing on the subject based on the radio wave signal and the sound wave signal from the transmitter held by the subject.

[Embodiment of the Invention] The present invention will be described below with reference to illustrated embodiments. FIG. 6 is a perspective view showing a transmitter 30 and a camera 30 equipped with a receiver which constitutes the focusing control apparatus according to the present invention.

The camera body 32 of the camera 30 includes an ultrasonic signal receiver 22 that receives the ultrasonic signal from the ultrasonic transmitter 13, and an IRED.
It has a light receiver 21 for receiving the optical signal emitted from 12. In addition, the camera body 32 has a viewfinder 39 and a strobe 4
It has 0, a release switch 34, a mode changeover switch 36, and a code selection switch 37.

The mode changeover switch 36 functions as a photographing mode changeover means and can be switched between the specific photographing mode and the selected photographing mode by sliding the mode to the left or right.

The code selection switch 37 functions only when the mode switch 36 is switched to the specific shooting mode. The code selection switch 37 can be freely slid to the left and right, and is biased to return to the central position when released. Corresponding to this sliding operation, it is possible to specify which code of the optical signals emitted from the plurality of transmitters 10 causes the control circuit 20 to respond.

The transmitter 10 has a case 33 in which an ultrasonic transmitter 13 and an IRED 12 are incorporated. A mounting pin 35, which serves as a mounting means for mounting the transmitter 10 on a subject, is attached to the back surface of the case 33. Further, the case 33 has a shape as shown in FIG. 3 and is configured as a brooch-shaped accessory.

On the substrate 33a, a circuit in which the IRED 12, the ultrasonic signal transmitter 13, the microcomputer 11 (hereinafter referred to as a microcomputer), and the drive amplifier 14 for driving the IRED 12 and the ultrasonic signal transmitter 13 are integrated in order from the top. 31, and power supply
16 is installed. The case 33 is not limited to the brooch type, but may be configured as a necklace, a name tag, earrings, a tie pin, a bracelet, or the like.

FIG. 1 is a schematic configuration diagram showing a control circuit of the oscillator 10, and FIG. 2 is an output timing chart of an optical signal and an ultrasonic signal output from the oscillator 10. Microcomputer
11 works by connecting power switch 15 to power supply 16.

When the microcomputer 11 functions, the IRED 12 emits light at a certain cycle, as shown in FIG. In this embodiment, the IRED 12 emits light at a cycle of, for example, about 100 ms, and a coded signal is output during the light emission period. Also, an ultrasonic signal is output in synchronization with the light emission cycle of IRED12.

A plurality of transmitters 10 are prepared, and the optical signals emitted from the IREDs 12 of the plurality of transmitters 10 are each assigned a unique code. This unique code is set by changing the combination of ON and OFF (1,0) of the pulse during the light emission period (p part in the figure). The unique code may be set by changing the frequency of the optical signal.

FIG. 4 is provided on the camera body side and is used for the subject (transmitter 1
FIG. 3 is a schematic configuration diagram of a control circuit 20 that activates and focuses an autofocus mechanism based on distance measurement data obtained by calculating a distance to 0).

The control circuit 20 has a microcomputer 40 (hereinafter referred to as a microcomputer). This microcomputer 40, transmitter 10
Receiver 21 for inputting the light emitted from, ultrasonic signal receiver 22 for inputting the ultrasonic signal emitted from transmitter 10, mode changeover switch 36, code selection switch 37, and AF
The motor 25 is connected. Microcomputer 40 is position calculation unit 2
3, it has an AF control unit 24, a code identification unit 41, and a mode switching unit 42.

The position calculation unit 23 functions as a distance measuring unit, and calculates the distance to the transmitter 10, that is, the object based on the data of the optical signal and the ultrasonic signal from the light receiver 21 and the ultrasonic signal receiver 22.

The AF control unit 24 drives the AF motor 25 based on the signal output from the position calculation unit 23 to operate the focusing lens functioning as an automatic focusing mechanism to focus on the subject.

Upon receiving the mode switching signal from the mode switching switch 36, the mode switching unit 42 switches between the specific shooting mode and the selective shooting mode. The specific shooting mode is a transmitter 10 that emits an optical signal having a specific code among the plurality of transmitters 10.
This is a mode in which the control circuit 20 is operated so as to focus only on. The selective shooting mode is a control circuit 20 for focusing on the transmitter 10 located at the shortest distance as a result of distance measurement of all the transmitters 10 corresponding to a plurality of optical signal codes.
Is a mode for operating. Although it is possible to set the subject at the rearmost position or the subject in the middle so that the subject is in focus, focusing on the subject at the closest distance results in a deep depth of field to the rear. This selection was adopted in this embodiment because it is effective.

The code identifying section 41 receives signals from the code selection switch 37 and the mode switching section 42 and sets which code the control circuit 20 responds to when the specific photographing mode is set. Then, the code identifying section 41 inputs the data based on the optical signal received by the light receiver 21, and identifies the set code. Further, when the set code is identified, a command is issued to the position calculation unit 23 to start the distance measurement to the transmitter 10 having this code.

The focus control device for a camera of the present invention configured as described above operates as follows.

For example, when a plurality of people who are the subjects attach the transmitters 10 each having a unique code to the chest etc. with the wearing pin 35 and are lined up, if you want to focus on a particular person, first, The mode selector switch 36 is operated to switch to the specific shooting mode. Further code selection switch
37 is operated to set the control circuit 20 so as to identify the code of the oscillator 10 worn by a specific person.

Then, as shown in FIG. 6, the camera 30 is aimed at the subject.
At this time, optical signals and ultrasonic signals as shown in FIG. 2 are emitted from the plurality of transmitters 10, respectively.
Then, the plurality of optical signals are received by the light receiver 21 and input to the code identifying unit 41 as optical signal data. This optical signal is
Since the code is different depending on each transmitter 10, the code identifying unit 41 identifies the optical signal having the set specific code. Then, a command is issued to the position calculation section 23, and the distance is measured so that the person who possesses the transmitter 10 which has emitted the optical signal of this code is in focus.

This distance measurement is performed by the optical signal data of a specific code input from the light receiver 21 to the position calculation unit 23 via the code identification unit 41, and the ultrasonic signal input from the ultrasonic signal receiver 22 to the position calculation unit 23. This is performed based on the ultrasonic signal from the transmitter 13.
At this time, the signal data from the photodetector 21 and the ultrasonic signal receiver 22 are input with a temporal shift, as shown in FIG. 5, because the transmission speed in space differs between light and ultrasonic waves. It The position calculator 23 calculates the distance to the subject based on the detection delay time (time T in FIG. 5) of both detection signals. Then, the position detector 23 outputs a signal according to the calculated distance data to the AF control unit 24.

Based on this signal, the AF control unit 24 drives the AF motor 25 to move the focusing lens to the in-focus position and bring it into focus. Therefore, a person who has the specific transmitter 10 is focused and photographed regardless of the overall composition.

When the mode changeover switch 36 is operated to switch to the selective shooting mode, the code identifying section 41 issues a command to focus the closest object.

If the focusing control device according to the present invention is applied to a video camera, even if the subject is moving within the angle of view from the distance measuring zone, the subject is automatically focused by following the movement. Therefore, a clear image can be easily obtained.

Another embodiment according to the present invention will be described with reference to FIG. This embodiment is almost the same as the above-mentioned embodiment, but the following points are different.

That is, in the above-described embodiment, the IRED12 is adopted as a means for obtaining the distance measurement data by comparing the time difference with the sound wave signal, but in the embodiment according to FIG. 7, the radio wave transmitter 51 is used instead of the IRED12. Is provided in the transmitter 10. Further, the camera 30 is provided with a radio wave receiving section 50 instead of the light receiver 21.

Therefore, the position calculator 23 calculates the distance to the transmitter 10 based on the radio signal received by the radio receiver 50 and the ultrasonic signal data received by the ultrasonic signal receiver 22. Then, focusing control is performed based on the distance measurement data.
Further, the code identifying section 41 inputs the data of the radio wave signal received by the radio wave receiving section 50 and identifies the code set in the radio wave signal.

"Effect of Device" As is clear from the above description, according to the focus control device of claim 1, the transmitter is attached to the subject, and the subject is always reliably attached to the subject regardless of the composition. It is possible to focus on it, and you can easily take pictures of various compositions. Moreover, since the optical signal emitted from the transmitter has a distinguishability by a specific code, it is possible to easily focus on an arbitrary subject simply by designating this code. Further, since the control is performed based on the signal emitted from the transmitter, there is no problem such as loss of reflected distance measuring light during distance measurement by the conventional active method, and reliability can be improved.

Further, according to the focus control device described in claim 2, it is possible to obtain the same effect as that of the focus control device described in claim 1.

Furthermore, according to the focus control device of the third aspect, the transmitter can be easily attached to the subject, so that the person who is the subject does not need to have the transmitter in his hand during shooting.
You can wear it without being aware of its existence. For this effect to be effective, the transmitter is required to be small, but it may be incorporated into accessories such as brooches, necklaces, name tags, earrings, tie pins, bracelets, etc.

According to the focus control device of the fourth aspect, the photographing mode can be easily changed only by operating the photographing mode switching means. Then, when switching to the specific photographing mode, it is possible to identify one of a plurality of subjects having a transmitter and focus only on this subject.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a control circuit of an oscillator in a focus control device for a camera according to the present invention, and FIG. 2 is a timing showing a signal output state of light and an ultrasonic signal output from the oscillator. FIG. 3 is a diagram showing an embodiment in which the oscillator according to the present invention is configured as a brooch type, and FIG. 4 is a schematic diagram showing a control circuit in the focusing control apparatus for a camera according to the present invention, FIG. 5 is a timing chart showing a state in which the light output from the transmitter and the ultrasonic signal are input to the control circuit shown in FIG. 4, and FIG. 6 is a view from the transmitter to the camera. FIG. 7 is a perspective view showing a state in which signals of light and ultrasonic signals are being output, and FIG. 7 is a schematic view showing a control circuit in another embodiment of the focusing control apparatus for a camera according to the present invention. 10 ... Oscillator, 11 ... Microcomputer, 12 ... IRED (light emitting means), 13 ... Ultrasonic signal transmitter (sound emitting means), 20
... Control circuit (control means), 21 ... Light receiver (light receiving part), 22 ...
Ultrasonic signal receiver (sound wave reception unit), 23 ... Position calculation unit (distance measuring unit), 24 ... AF control unit (control unit), 25 ... AF motor,
30 ... Camera, 32 ... Camera body, 33 ... Case, 35 ... Mounting pin, 36 ... Mode selector switch (shooting mode selector),
37 ... Code selection switch, 40 ... Microcomputer,
41 ... Code identifying section (code identifying means), 50 ... Radio wave receiving section, 51 ... Radio wave emitter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 2-97908 (JP, A) JP-A 61-97615 (JP, A) JP-A 3-58624 (JP, U)

Claims (4)

[Scope of utility model registration request] 1. A focusing control device comprising a receiver provided in a camera having an autofocus mechanism and a transmitter formed separately from the main body of the camera, wherein a specific code provided in the transmitter. A light projecting means for intermittently emitting a converted optical signal, and a sound wave emitting means for intermittently emitting a sound wave signal in synchronization with the emission of the optical signal; A light receiving section for receiving the sound wave signal; a code identifying means for identifying a code included in the optical signal; an optical signal received by the light receiving section based on code identification by the code identifying means; Distance measuring means for detecting a time difference between the sound wave signals received by the sound wave receiving section and calculating the distance from the camera to the receiver based on the detected data; and based on the distance data calculated by the distance measuring means. Focus control device for a camera, characterized in that it comprises a; and control means for driving the autofocus mechanism. 2. A focusing control device comprising a receiver provided in a camera having an autofocus mechanism and a transmitter formed separately from the body of the camera, wherein a specific code provided in the transmitter. A radio wave emitting means for intermittently emitting the converted radio wave signal, and a sound wave emitting means for intermittently emitting a sound wave signal in synchronization with the emission of the radio wave signal; the radio wave signal provided in the receiver for receiving the radio wave signal A radio wave receiver for receiving the sound wave signal; a code identifying means for identifying a code included in the radio wave signal; a radio wave signal received by the radio wave receiving portion based on the code identification by the code identifying means And a distance measuring means for detecting a time difference between the sound wave signals received by the sound wave receiving section and calculating the distance from the camera to the transmitter based on the detected data; And control means which distance based on the data to drive the autofocus mechanism; focus control device for a camera, characterized in that it comprises a. 3. The focus control device for a camera according to claim 1, wherein the transmitter has a mounting means for mounting the transmitter on a subject. 4. The transmitter according to claim 1, wherein a plurality of transmitters that emit different optical code signals are prepared, and the camera body emits an optical signal having a specific code among these transmitters. A focusing control device for a camera, which has a photographing mode switching means for switching to a specific photographing mode in which the camera only responds to.