GB2265019A

GB2265019A - "remote control auto-focus camera"

Info

Publication number: GB2265019A
Application number: GB9305117A
Authority: GB
Inventors: Yongjun Jeong; Taekyeong Yoon
Original assignee: Samsung Aerospace Industries Ltd
Current assignee: Hanwha Aerospace Co Ltd
Priority date: 1992-03-14
Filing date: 1993-03-12
Publication date: 1993-09-15
Also published as: KR970006009B1; FR2688603A1; JPH0688937A; CN1083227A; GB9305117D0; DE4307953A1; KR930020206A

Description

2265019 REMOTE CONTROL CAMERA AND CONTROL METHOD THEREFOR 1 The present

invention relates to a remote control camera and method therefor. More particularly, this invention relates to a remote control camera which can carry out a remote control by together using a light receiving circuit capable of sensing a necessary signal in an automatic focus control circuit instead of an extra remote receiving apparatus.

An apparatus capable of making a remote control of a camera is very convenient. Because a user can take a photograph of an object by controlling the camera remotely at a necessary time, and can take the photograph of himself, taking a pose freely.

moreover, there is an advantage that the user can automatically and simply operate the camera without working the camera manually whenever he takes the photograph of the object.

Referred to Fig. 1, an operation of a prior art remote control camera will be explained.

The prior art remote control camera includes a remote transmitting apparatus 1 for outputting a remote control signal to carry out a remote control and a remote receiving apparatus 2 for receiving the signal from the remote transmitting apparatus 1 and taking a photograph of a wanted photograph in the remote control operation.

The remote transmitting apparatus includes a remote shutter switch S1 an infrared ray emitting diode IRED1 an information display 12 and a remote transmitting and information display 11 for transmitting a control signal to the remote receiving apparatus 2 through the infrared ray emitting diode IRED1 in response to the operation of the remote shutter switch S1, and at the same time displaying an operation state of the remote transmitting apparatus 1 on the information display 12.

The remote receiving apparatus 2 includes a central processing unit CPU 21 to control peripheral circuits by using the received control signal so as to carry out the remote control of the camera, an automatic focus control circuit 22, connected to the CPU 21, a position sensitive device PSD and 'an infrared 2 ray emitting diode IRED, for automatically controlling a focus of the camera by using an incidence angle of the infrared ray 5w which, after being emitted from the infrared ray emitting diode, is reflected from the object and become incident to the PSD, a remote receiving circuit 23, connected to the CPU 21, for sensing the infrared ray transmitted from the remote transmitting apparatus 1 by a silicon photo diode SPD and making the CPU 21 perceive the remote control operation, a motor driving circuit 24, connected to the CPU 21, and for driving a motor to control a focus in response to the operation of the automatic focus control circuit 22, and a shutter 25, connected to the motor driving circuit 24, for controlling the focus in response to the operation of the motor.

Fig. 2 shows a detailed circuit diagram of the remote receiving circuit. AS shown in Fig. 2, the remote receiving circuit 23 includes a silicon photo diode SPD, a resistance R1 with one terminal thereof connected to the SPD, a voltage regulator 230 connected to a power terminal Vc, a current-to- voltage converter 231 connected to the resistance R1 and the voltage regulator, a low cut filter 232 connected to the currentto-voltage converter, an amplifying circuit 233 connected to the low cut filter, and a comparator 234 connected to the amplifying circuit 233, and having a hysteresis characteristic.

The current- to -voltage converter 231 includes an operational amplifier Q11 with an inverting terminal thereof connected to the resistance Rl and with a non-inverting terminal connected to the voltage regulator 230, a resistance R11 with one terminal thereof connected to the inverting terminal of the operational amplifier Q11, a resistance R12 with one terminal thereof connected to the other terminal of the resistance R 11 and with the other terminal thereof connected to an output terminal of the operational amplifier Q11, a resistance R13 with one terminal thereof connected to a common terminal of the resistances R11 and R12, a capacitor C11 with one terminal thereof connected to the other terminal of the resistance 13 and with the other terminal thereof connected to ground.

4 A 1OW Cut filter 232 includes a capacitor C21 with one terminal thereof connected to the output terminal of the operational amplifier Q11 in the current-to-voltage converter, and a resistance R21 with one terminal thereof connected to the other terminal of the capacitor C21 and with the other terminal thereof connected to the power terminal.

The amplifying circuit 233 includes an operational amplifier Q31 with a non-inverting terminal thereof connected to the other terminal of the capacitor C21 in the low cut filter 232, a resistance R31 with one terminal thereof connected to the inverting terminal of the operational amplifier Q31 and with the other terminal thereof connected to the power terminal, and a resistance R32 with one terminal thereof connected to the inverting terminal of the operational amplifier Q31 and with the other terminal thereof connected to the output terminal of the operational amplifier Q31.

A comparator 234 includes an amplifier Q41 with a non- inverting terminal thereof connected to the output terminal of the operational amplifier Q31 in the amplifying circuit 233 and with the output terminal thereof connected to the CPU 21, a resistance R41 with one terminal thereof connected to the non- inverting terminal of the amplifier Q41 and with the other terminal thereof connected to the inverting terminal of the amplifier Q41, and a capacitor C41 with one terminal thereof connected to the inverting terminal of the amplifier Q41 and with the other terminal thereof connected to the power terminal.

The operation of the prior art remote control camera is as f ollows.

First, if a user separates a remote transmitting apparatus 1 attached to a camera to carry out a remote control, a state switch set up in the remote receiving apparatus 2 and turned ONIOFF in accordance with a connection state of the remote receiving apparatus 2 and the remote transmitting apparatus 1 is turned ON, and the CPU 21 senses that the camera is placed in a stand by state to do the next operation.

Therefore, if the user separates the remote transmitting 6 t apparatus 1 from the remote receiving apparatus 2 as the above and turns ON the remote shutter switch SI attached to the remote transmitting apparatus 1 to carry out the remote automatic photograph, the infrared ray is emitted from the infrared ray emitting diode IRED1 by the operation of the remote transmitting and information display driving circuit 11.

The infrared ray emitted from the infrared ray emitting diode IRED1 senses the signal transmitted only from the remote transmitting apparatus 1 by a silicon photo diode SPD attached to the remote receiving circuit 23 in the remote receiving apparatus 2, so that the CPU 21 can carry out the automatic photograph of the object without any operation of the extra switch for photographing the object by the CPU 21.

First, if the infrared ray emitting diode IRED1 in the remote transmitting apparatus 1 emits a frequency of a predetermined size, the silicon photo diode SPD of the remote receiving circuit 23 in the remote receiving apparatus 2 senses the received infrared ray, and outputs an corresponding current to this to the current-to-voltage converter.

After the current is converted to the voltage in the current-to-voltage converter 231 including the operational amplifier Q11 and the resistances Rll-R13, the low cut filter 232 constituted with the resistance R21 and the capacitor C21 removes an external noise signal, namely, a direct current element from a input signal raised by the infrared ray emitted from the remote transmitting apparatus 1.

After the noise signal is removed by the low cut filter 232, the input signal is amplified as much as a predetermined size in the amplifying circuit 233 in accordance with a gain value determined by the values of the resistances R31 and R32. Also, 1-he input signal is shaped to a square wave by the comparator Q41 having the hysteresis characteristic, and outputted to the CPU 21.

If the remote control operation is sensed by the operation of the remote receiving circuit 23 as the above, the release switch SW2 is turned ON by the operation of the CPU 21, and the 8 object is photographed in the photograph operation, the CPU 21 outputs the object W distance measurement signal to the automatic focus control circuit 22. In response to this signal, the automatic focus control circuit 22 measures the distance from the object which the user wants to trigonometric levelling.

photograph, using the principle of As shown in Fig. 3 illustrating the principle of trigonometric levelling by the projection of the infrared ray, the PSD is placed at a predetermined interval from the infrared ray emitting diode IRED, an emitted beam collimation lens 4 is placed between the infrared ray emitting diode IRED and the object 3, and a PSD beam forming lens 5 is placed between the PSD and the object 3 on a common axis with emitted beam collimation lens 4.

Therefore, the infrared rays projected from the infrared ray emitting diode IRED are emitted to the object 3 through the emitted beam forming lens 4, and the reflected infrared rays 9 become incident on the PSD through the PSD beam forming lens 5.

Thus, the PSD outputs a current corresponding to the incident angle of the infrared rays inputted to the PSD. Therefore, the trigonometric levelling controls a focus by moving a light receiving circuit for two current amounts 1,, 12 outputted from the PSD becoming the same amount.

Namely, supposing that a distance between the object 3 and centre of the emitted beam collimation lens 4 on an optical axis is "L", a distance between centres of the emitted beam collimation lens 4 and the PSD beam forming lens is "W", a distance between centre of the emitted beam collimation lens 4 and the PSD is "F", and a distance between the centre of the PSD beam forming lens 5 and a forming point of the object at the PSD is "V, since L:W = F:T can be established, a distance L can be given by (FxW)/T.

The signal corresponding to the distance from the object 3 measured by the inputted current values 1,. 12 by the PSD through the above -mentioned method is 'converted to a digital signal by 1-0 an A/D converter (not shown) in the CPU 21.

The distance signal converted to the digital signal is stoed in a memory (not-shown), and the CPU 21 operates a moto"r driving circuit 24 in response to the distance signal by using the stored distance signal. A shutter driving motor of the shutter 25 in accordance with the output of the motor driving circuit 24 is rotated, and a focus is adjusted in response to the measured distance signal.

However, the prior art remote control camera operated as the above has to equip the remote receiving apparatus 2 with the extra remote receiving circuit to sense the infrared ray emitted from the infrared ray emitting diode IRED1 of the remote transmitting and information display driving circuit 11 in the remote transmitting apparatus Accordingly, there has been difficulty of making a small-sized camera and a cause for increase of production cost in the prior art remote control camera.

1 -3- Accordingly, it is an object of the invention to provide a remote control camera which can carry out a remote control by together using a light receiving circuit capable of sensing a necessary signal in an automatic focus control circuit instead of an extra remote receiving apparatus.

To accomplish the above-mentioned object, there is provided a remote control camera having a remote transmitting apparatus for emitting a first remote infrared ray signal to carry out remote control, and a camera body to carry out a remote control photograph and an ordinary photograph, the camera body comprising inf rared-emitting means for sequentially emitting a first infrared ray signal to an object for an automatic focus control; light receiving means for outputting two channel currents respectively in response to the first remote infrared ray signal emitted from the remote transmitting apparatus and a second infrared ray signal reflected from the object, automatic focus control and remote receiving means for driving the infrared ray emitting means, detecting a remote control signal from one-current of the two channel currents output on the basis of the f irst remote infrared ray signal through the light receiving 12 means, and outputting a measured distance signal by sequentially handling the two channel currents output on the basis of the second infrared ray received sequentially; control means for determining wnether the remote control signal instructs to carry out a remote control photograph by comparing a frequency and a duty rate of the remote control signal with a reference value, transmitting an automatic focus control signal to the focus control and remote receiving means by operating a release switch in case of the remote control photograph instruction, outputting the control signal for operating the motor of a shutter so that the two channel currents are equal to each other on the basis of the measured signal outputted from the automatic focus control and remote receiving means, and controlling a following photograph operation; and a motor driving circuit for driving the motor in response to the motor driving control signal from the control means.

In accordance with the present invention, there is provided 13 a photograph control method for a remote control camera having a camera body and a remote receiving apparatus united detachably coupled to the camera body comprising the steps of: deciding whether a release switch is operated in the case where the remote transmitting apparatus is not separated, and placing the camera body in a stand by for the remote control in the case where the remote transmitting apparatus is separated from the camera body; comparing the detected remote control signal with a reference value through the light receiving means equipped in the automatic focus control and remote receiving means of the camera body in the case where the remote control signal is emitted from the remote transmitting apparatus; operating the release switch after the predetermined time in the case where the remote control photograph signal is inputted on the basis of said comparison result, and being placed in the stand by status in the case where the remote control signal is not inputted; emitting an infrared ray to an object by driving an infrared ray emitting diode equipped in the automatic focus control and remote receiving 14 means of the camera body in the case where the release switch is operated; the automatic focus control and remote receiving means -Elected from the object through the' receiving the infrared ray rel light receiving means; and carrying out the automatic focus control on the basis of the received data and taking a photograph.

The object of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings wherein:

Fig. 1 is a block diagram illustrating a construction of a prior art remote control camera;

Fig. 2 is a detailed circuit diagram illustrating a remote receiving circuit in the prior art remote control camera;

Fig. 3 is a diagram for illustrating the principle of trigonometric levelling; Fig. 4 is a block diagram illustrating a. remote control camera in accordance with an embodiment of the invention; X 5 r Fig. 5 is a block diagram illustrating an automatic focus control and remote receiving circuit in accordance with the embodiment of_the invention; j Fig. 6 is an operational waveform chart of the remote control camera in accordance with the embodiment of the invention; and Fig. 7 is a flow chart illustrating a sequence of operation of the remote control camera in accordance with the embodiment of the invention.

Referring to Fig. 4, a remote control camera comprises a remote transmitting apparatus 1 for outputting a remote control signal to carry out a remote control, and a remote receiving apparatus 20, namely, a camera body, for taking a photograph in a remote control operation by receiving a signal from the remote transmittipg apparatus 1 through an existing position sensitive device without using an extra remote receiving circuit.

An construction of a remote transmitting apparatus 1-is the 3-6 same as that of an existing remote transmitting apparatus, accordingly, an explanation for the remote transmitting apparatus 1 is omitted.

The remote receiving apparatus 20 comprises a central processing unit 201 to control to carry out the remote control for the camera and an ordinary photographing in response to th remote control signal in case of a remote mode and by the operation of a release switch SW2 in case of an ordinary mode; an infrared ray emitting diode IRED for emitting an infrared ray to an object to automatically adjust a focus; an automatic focus control and remote receiving circuit 202 for sensing the remote control signal emitted from the remote transmitting apparatus 1 by the position sensitive device PSD connected to the CPU 201 and for adjusting automatically the focus of the object by using an incident angle of the infrared ray which is emitted from the infrared ray emitting diode IRED, is reflected from the object and become incident; a motor driving circuit 24 connected to the CPU and for driving a motor in response to a control signal from 17 the CPU 201 to adjust the focus in accordance with the operation of the automatic focus control and remote receiving circuit 202; and a shutter 25 connected to the motor driving circuit 24 and for adjusting the focus by the operation of the motor.

The remote control camera is operated in accordance with the successive steps shown in Fig. 7.

Referring to Fig. 7, the operation of the remote control camera comprises a step 100 of starting the operation after power applied; a step 200 of deciding whether a present mode is a remote control mode, a step 300 of deciding whether the operation for an ordinary photographing, namely, a release switching operation is made in the case where the present mode is the remote control mode, a step 400 of deciding whether the remote control signal is received in the case where the present mode is the remote control mode, a step 450 of operating a release switch after a predetermined time passes by if the remote control signal is received, a step 500 of adjusting a focus from an object in response to the operation of the release switch, a step 600 of X 8 il taking a photograph of the object, and a step 700 of terminating all the operations.

Referring to Fig. 5, the automatic focus control and remote receiving circuit 202 comprises a head amplifying circuit 221 connected to the position sensitive diode PSD, a multiplexer 222 connected to the head amplifying circuit 221 and the CPU 201, a band-pass filter 223 connected to the multiplexer 222, an amplifying circuit 224 connected to the band-pass filter 223; an integrator 225 connected to the amplifying circuit 224 and the multiplexer 222; and a comparator 226 connected to the integrator 225 and the CPU 201.

The operation of the remote control camera made as the above will be explained in detail.

First, when the power is applied, the CPU 201 starts the operation. The CPU 201 decides a state of the release switch SW2 attached in the remote receiving apparatus 10 because the object is photographed by that operation in the state of the general camera, in the case where the present modd is the ordinary mode :L 9 in which a remote mode switch SW1 is not operated because the remote transmitting apparatus 1 is not separated from the camera body.

If the release switch SW2 is turned ON, the CPU 201 first measures the distance from the object by the automatic focus control and remote receiving circuit 202, carries out the operation for adjusting the focus, and takes the photograph on the basis of that operation.

However, if the user separates the remote transmitting apparatus 2 from the remote receiving apparatus 20 to operate the camera in the remote control operation, the remote mode switch swi is turned ON as shown in Fig. 6A and the remote receiving apparatus 20, namely, the camera is in the remote mode.

if a remote shutter switch S1 in the remote transmitting apparatus 1 is operated by the user, the infrared ray having a predetermined frequency and duty rate is emitted from the remote transmitting apparatus 1 as shown in Fig. 6B. This infrared ray is converted to an electric signal in the position sensitive device PSD of the automatic focus control and remote receiving circuit 202. Namely, the infrared ray is outputted from the position sensitive device PSD in two channel currents 1,, 12 The head amplifying circuit 221 receives the two channel currents 1,, 121 converts the inputted current to a corresponding voltage, and amplifies the voltage as much as a predetermined size.

The amplified voltage is inputted to the multiplexer 222, and the multiplexer 222 selects a corresponding input terminal of two input terminals by a channel selection signal CIS from the integrator 225 and the CPU 201. Accordingly, the amplified voltage of one channel is inputted to the band-pass filter 223 through the output terminal, and of note, only the signal emitted from the remote receiving apparatus is passed.

The signal filtered in the band-pass filter 223 is amplified and integrated as much as the predetermined size in the amplifying circuit 224 and the integrator 225, respectively. If the integrated signal is inputted to the comparator 226 and the 21 integrated signal reaches to a predetermined setting level, the comparator 226 outputs a corresponding digital signal to the CPU 201.

If the CPU 201 monitors the input of the comparator 226 and the integrated voltage is more than the predetermined voltage, the CPU 201 outputs the control signal CTR to the integrator 225 to suspend the integral operation and measures an integral period. At this time, in the case where the measured integral period has the frequency and the duty rate similar to the infrared ray emitted from the infrared ray emitting diode IRED1 in the remote transmitting apparatus 1 as shown in Fig. 6C, the CPU 201 perceives that the remote control signal requests the remote control operation, outputs the ON signal of the release switch SW2 after the predetermined time, for example, 2 seconds as shown in Fig. 6C, and the focus of the object is adjusted in the automatic focus control and remote receiving circuit 202.

on the other hand, to adjust the focus automatically in the automatic focus control and remote receiving circuit 202, the position sensitive device PSD senses the infrared ray reflected from the object thereto the infrared ray is emitted from the infrared ray emitting diode IRED in the same operation as the position sensitive device PSD senses the remote control signal from the remote transmitting apparatus 1, and outputs a pair of current 1,, 12 Then, the automatic focus control and remote receiving circuit 202 handles one signal selected of two channels applied to the multiplexer 222 by the channel selection signal from the CPU 201 in the same as the operation processing the remote control signal, measures the integral period and stores it. And then the integration terminating signal from the integrator 225 and the channel selection signal CIS from the CPU 201 to the multiplexer 222 are outputted to select the other channel in 'he U multiplexer 222. The above-mentioned operation is repeated to measure the integral period. Accordingly, the CPU 201 operates the motor in the shutter 25 by operating the motor driving circuit 24 to have two measured integral periods be equal to each other.

However, the CPU 201 continues to be in a stand by to sense the remote control signal from the remote transmitting apparatus 1 in the case where the remote control signal is not sensed because the remote shutter switch S1 in the remote transmitting apparatus 1 is not operated.

If the focus is automatically adjusted by operating the lens by the operation of the motor, the CPU 201 carries out the next operation for taking the photograph of the object.

The CPU 201 carries out the photographing operation in the predetermined time after sensing the remote control signal emitted from the remote transmitting apparatus 1 as shown in Fig.

6C for the user to pose for his picture and so take the natural photograph.

As described in the above, the automatic focus control and remote receiving circuit 202 can be used as the light receiving element PSD or SPD for sensing the signal emitted from the remote transmitting apparatus 1 because the automatic focus control and 24 z remote receiving circuit 202 can more exactly sense the signa from the remote transmitting apparatus 1 and the reflected signal from the object by using a charge coupled device CCD as well as the silicon photo diode SPD. Also, the automatic focus control and remote receiving circuit 202 can sense the signal transmitted from the remote transmitting apparatus by using a photoconductor of which internal characteristic is changed in accordance with an applied light intensity.

The invention thus provides effects in which the user can embodies the small-sized camera and the reduction of the production cost, as a result, can embody a high-class camera by applying middle and low class cameras because the remote transmitting signal can be sensed by the light receiving element PSD or SPD for sensing the infrared ray equipped for the automatic focus control without equipping the extra remote receiving apparatus for sensing the remote control signal, accordingly the operation of the camera can be carried out in the remote control mode.

Also, the remote control in longer distance than the sensing range in case of sensing the reflected signal from ' the object can be embodied because the remote transmitting signal is directly applied to the light receiving circuit for sensing only a reflected wave reflected from the object.

Claims

1 1 A remote control camera having a remote transmitting apparatus for emitting a first- remote infrared ray signal to carry out remote control, and a camera body to carry out a remote control photograph and an ordinary photograph, said camera body comprising:

infrared ray emitting means for sequentially emitting a f irst infrared ray signal to an object f or an automatic focus control; light receiving means f or outputting two channel currents respectively in response to the f irst remote infrared ray signal emitted from said remote transmitting apparatus and a second infrared ray signal reflected from said object; automatic focus control and remote receiving means for driving said infrared ray emitting means, detecting a remote control signal f rom one current of the two channel currents output on the basis of said first remote infrared ray signal through said light receiving means, and outputting a measured d-istance--s-i.gnal by sequentially handling the two channel currents output on the basis of the second 27 W infrared ray received sequenly; control means for determining whether said remote transmitting apparatus instructs to carry out a remote control photograph by comparing a frequency and a duty rate of said remote control signal with a reference value, sending an automatic focus control signal to said focus control and remote receiving means by operating a release switch in the case where there is the remote control photograph instruction, outputting a motor driving control signal for operating a motor of a shutter to have the two channel currents be equal to each other on the basis of the measured signal outputted from said automatic focus control and remote receiving means, and controlling a following photograph operation; and a motor driving circuit for driving the motor in response to the motor driving control signal from said control means.

2. A remote control camera as set forth in claim 1 wherein said automatic focus control and remote receiving mean 1 compri'ses:

c head amplifying means for converting two channel currents outputted from said light receiving means to a corresponding voltage and amplifying the voltage; a multiplexer for selectively outputting two voltage signals inputted from said head amplifying means in response to a channel selection signal from said control means; a band-pass filter for removing a noise from the signal inputted from said multiplexer; amplifying means for amplifying said filtered signal; an integrator for integrating said amplified signal in response to a control signal from said control means; and a comparator for outputting a digital signal to said control means in a case where the output of said integrator becomes more than a predetermined level.

3. A remote control camera as set forth in claiia 1 wherein said control means operates a release switch after a predetermined time when the remote control signal from the remote transmitting apparatus is received.

4. A remote control camera as set forth in claim 1 wherein said light receiving means is one selected from a position sensitive device, a charge coupled device and a photoconductor.

5. A method for controlling a remote control camera having a camera body and a remote receiving apparatus detachably coupled to the camera body, comprising the steps of:

deciding whether a release switch is operated in the case where the remote transmitting apparatus is not separated, and placing said camera body in a stand by for the remote control in the case where the remote transmitting apparatus is separated from the camera body; comparing the detected remote control signal with a reference value through the light receiving means equipped in the automatic focus control and remote receiving means of said camera body in the case where the remote control signal is emitted from said remote_ transmitting apparatus; operating the release switch after the predetermined time in the case where the remote control photograph signal is 3 0 inputted on the basis of said comparison result, and being placed in the stand-by state in the case where the remote control signal 1 is not inputt.ed; emitting an inf rared ray to an object by driving an inf rared ray emitting diode equipped in said automatic focus control and remote receiving means of the camera body in the case where said release switch is operated; receiving the infrared ray reflected from the object for said automatic focus control and remote receiving means through said light receiving means; and carrying out the automatic focus control on the basis of said received data and taking a photograph.

6. A photograph control method for a remote control camera as set forth in claim 5 wherein the step of comparing said detected remote control signal with the reference value is made on the basis of a frequency and a duty rate of the remote control signal.

7. A remote control camera substantially as herein described with reference to Figures 4 to 7 of the accompanying drawings.

i

8. A method for controlling a remote control camera substantially as herein described with reference to Figures 4 to 7 of the accompanying drawings.

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