DETACHABLE UNIT ELECTRONIC CAMERA

Abstract: A detachable unit electronic camera which includes three detachable units, namely, a photographing unit (100), a record/playback unit (200) and a picture monitor unit (300). The photographing unit (100) has the function of converting an output signal from a camera means into a luminance signal and colour difference signals. The record/playback unit (200) has the function of magnetically recording an output signal from the photographing unit on a magnetic disc and also the function of reading a signal which is previously recorded on the magnetic disc. The picture monitor unit (300) has the function of displaying a picture in response to an output signal from the photographing unit (100) or a signal which is reproduced from the record/playback unit (200).

Description: The invention relates to an electronic camera which performs a photoelectric conversion of an image of an object being photographed for recording on a magnetic recording medium, and more particularly, to a detachable unit electronic camera which comprises detachable units including a camera or photographing unit, a record/playback unit and a picture monitor unit. There is already known (US-A- 507689) a detachable unit electronic camera for photo-electrical conversion of an image of an object being photographed to feed a picture monitor or to be recorded magnetically, comprising: a photographing unit which includes a camera means which converts into an electrical signal an image of an object being photographed, which is focussed by an optical system, and a signal processing circuit for producing a luminance signal and colour difference signals in response to an output signal from the camera means; a record/playback unit which includes an image recording means responsive to an output signal from the signal processing circuit for magnetically recording on a magnetic medium a video signal which is based on said output signal, and magnetic reproducing means for reading a signal previously recorded on the magnetic medium; and a picture monitor unit which includes a reproduced signal processing circuit responsive to a signal reproduced by the magnetic reproducing means for producing a reproduced luminance signal and reproduced colour difference signals and encoder responsive to an output from the reproduced signal processing circuit for producing a composite colour video signal, and a display for displaying a picture based on an output signal from the encoder; the photographing unit, the record/playback unit and the picture monitor unit being formed as detachable units which can be coupled together by a cooperating coupling means provided in each unit. A disadvantage of the known camera system is that only two of the units can be connected together at a time so that the flexibility of the known system is very limited. It is an object of the present invention to provide a detachable unit camera in which this disadvantage is eliminated. In accordance with the present invention, each of the photography unit, the record/playback unit and the picture monitor unit has at least two coupling means, each of said at least two coupling means being capable of coupling to the associated coupling means of a different one of the other units connectible therewith, and a control means being provided in only one of said units for selectively activating the other units connected therewith to operate to record signals when in a first state and to play back recorded signals when in a second state. An electronic camera in accordance with the invention may thus may be used in one of the several manners including "electronic camera having a record/playback capability", "devoted playback unit", or "video camera". A required minimum number of units may therefore be selectively coupled together, affording a greater convenience in use. The capability and the ease of operation of the picture monitor unit are enhanced, removing the drawbacks of the prior art in this respect and providing for the extendability of the system. In addition, the picture monitor unit is capable of directly receiving the luminance signal and the colour difference signals both during recording and playback operation to provide a display of the picture. In this manner, the arrangement of the photographing unit and the record/playback unit can be simplified. In the electronic camera of the invention, either an optical or an electronic viewfinder can be selectively mounted on the body of the electronic camera, thus providing for an extended range of uses. By way of example, when it is desired to minimize the dissipation of the battery or to reduce its size, the optical viewfinder may be mounted on the body. On the other hand, when a playback capability is required or when a colour balance of the recorded image is to be recognized, the electronic viewfinder may be mounted on the body. In addition, each of the connectors which enables a coupling between individual units can house internally a sync signal generator to permit the size of each unit to be minimized. This contributes to the practical implementation of the detachable unit electronic camera by allowing a minimum number of required units to be combined, depending on the intended use. The power supply of the electronic camera of the invention is preferably provided by a small battery which is coupled to the electronic camera when the electronic camera is used alone. In the event that the electronic camera is combined with an external item of equipment such as a VTR, the electronic camera is fed from a power supply of a greater capacity which is associated with the external equipment, thus allowing the useful life of the small battery coupled to the electronic camera to be increased advantageously. The use of a mechanical switch or an electrical switch circuit which switches between the small battery and the external power supply is avoided, thus eliminating or minimizing the resulting failure rate. The electronic camera of the invention may include a dubbing unit which is provided as a simple and inexpensive arrangement, using a minimum number of components, and which affords a greater convenience in use and extends the applicability of the electronic camera while retaining the combination capability thereof. The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings, in which:- Fig. 1 is an exploded, perspective view of a detachable unit electronic camera according to a first embodiment of the invention; Fig. 2 is a schematic view of the electronic camera shown in Fig.1 when assembled; Fig. 3 is a circuit diagram of various electrical circuits contained in individual units of the detachable unit electronic camera shown in Figs. 1 and 2; Fig. 4 is a schematic view of the electronic camera shown in Figs. 1 and 2 in which an optical viewfinder is substituted for the picture monitor unit thereof; Fig.5 is a block diagram of a devoted playback unit formed by coupling the record/playback unit and the picture monitor unit of the electronic camera shown in Figs. 1 and 2; Fig.6 is a block diagram of the electrical circuit of a video camera which is formed by coupling the photographing unit and the picture monitor unit of the electronic camera shown in Fig.1; Fig.7 is a circuit diagram of the electrical circuit of the electronic camera shown in Fig.4 in which the photographing unit, the record/playback unit and an optical viewfinder are coupled together; Fig. 8 is a perspective view of a connector which is used in an electronic camera according to a second embodiment of the invention; Fig. 9 is a perspective view of a relay connector used in a detachable unit electronic camera according to the second embodiment of the invention; Fig. 10 is a wiring diagram of the connector shown in Fig. 8; Fig. 11 is a wiring diagram of the connector shown in Fig. 9; Fig. 12 is a circuit diagram of the electrical circuit within the individual units of electronic camera according to the second embodiment of the invention; Fig. 13 is a circuit diagram of the electrical circuit of a devoted playback unit which is formed by coupling the record/playback unit and the picture monitor unit of the electronic camera shown in Fig. 12; Fig. 14 is a circuit diagram of the electrical circuit of a video camera which is formed by coupling the photographing unit and the picture monitor unit of the electronic camera shown in Fig. 12; Fig. 15 is a circuit diagram of the electrical circuit of the electronic camera formed by coupling together the photographing unit and the record/playback unit of the electronic camera shown in Fig. 12 with an optical viewfinder; Fig. 16 is a circuit diagram of the electrical circuits within the individual units of a detachable unit electronic camera according to a third embodiment of the invention; Fig. 17 is a circuit diagram of the electrical circuit of a devoted playback unit which is formed by the electronic camera of Fig. 16 from which the photographing unit is removed; Fig. 18 is a circuit diagram of the electrical circuit of a video camera formed by the electronic camera of Fig. 16 from which the record/playback unit is removed; Fig. 19 is a circuit diagram of the electrical circuit of the record/playback unit of a detachable unit electronic camera according to a fourth embodiment of the invention; Fig. 20 is a circuit diagram of a dubbing unit which may be combined with the record/playback unit of Fig. 19; Fig. 21 is a circuit diagram of the photographing unit of the detachable unit electronic camera of the fourth embodiment; Fig. 22 is a circuit diagram of the electrical circuit of the picture monitor unit of the electronic camera of the fourth embodiment; Fig. 23 is a circuit diagram of the electrical circuit of a dubbing apparatus formed by a combination of the record/playback unit and the dubbing unit of the electronic camera of the fourth embodiments; and Fig. 24 is a circuit diagram of the electrical circuit of the electronic camera which comprises the photographing unit, the record/playback unit and the picture monitor unit. Referring to the drawings, several embodiments of the invention will now be described. Referring first to Fig. 1, there is shown a detachable unit (modular) electronic camera according to the invention including a photographing unit 100, a record/playback unit 200 and a picture monitor unit 300 which may be selectively coupled together in various combinations. A taking lens 1 is mounted on the front surface of the photographing unit, the top of which is provided with a mount 101 for an associated optical viewfinder 500 (see Figs. 4 and 7) to be described later. The mount 101 is normally covered, and can be opened when the optical viewfinder 100 is to be mounted. Both the top surface and a back surface of the photographing unit 100 are formed with substantially elongate angular recesses in which connectors CN1A, CN2A are disposed which allow an electrical interconnection with the record/playback unit 100 and the picture monitor unit 300 when the latter are coupled. Along one lateral side, the unit 100 carries a group of operating buttons 102, while a grip 400 having operating buttons 401 may be detachably mounted on the unit along the other lateral side thereof. The record/playback unit 200 is adapted to be closely mounted against the bottom and the back surface of the photographing unit 100. In its front and top surfaces, the unit 200 is formed with recesses in which connectors CN2B, CN3B are disposed for electrical interconnection, the connector CN2B mating with the connection CN2A. The picture monitor unit 300 is adapted to be detachably coupled with the top surface of the photographing unit 100 and with the top surface of the record/playback unit 200, and is provided with a recess in its bottom surface in which connectors CN1B, CN3A are disposed for electrical interconnection with the connectors CN1A, CN3B, respectively. On its lateral side, the unit 300 carries a set of output terminals 40 (see Fig. 3) from which an NTSC color video signal is derived. When the units 100, 200 and 300 are coupled together, the various connectors are electrically interconnected as pairs CN1A and CN1B, CN2A and CN2B, and CN3A and CN3B, thus achieving an electrical and a mechanical coupling between the various units (see Fig. 2). As shown in Figs. 2 and 3, the taking lens 1 of the photographing unit 100 functions to focus an image of an object being photographed, and an iris 2 and a shutter 3 are disposed along the optical path of the taking lens 1. Disposed on the imaging plane of the taking lens 1 is a camera means, for example, CCD4, which converts a light image into a two dimentional array of electrical signals. A space 101 is defined between the taking lens 1 and the CCD4 for receiving a half mirror 501 of an optical viewfinder 500 (see Fig. 4) which can be detachably coupled to the photographing unit 100. As shown in Fig. 3, a two dimensional scanning of CCD4 takes place in response to a horizontal scan drive signal H₁ and a vertical scan drive signal V₁ which are fed from a sync signal generator 5. The output of CCD4 is coupled through a preamplifier 6 to the input of a signal processing circuit 7. In response to an output signal from CCD4 and a sync signals S from the sync signal generator 5, the signal processing circuit 7 produces a luminance signal Y₁ and color difference signals (R-Y)₁ and (B-Y)₁. Y₁ signal output from the circuit 7 is connected to a terminal d of the connector CN2A, (R-Y)₁ signal output is connected to a terminal e of the connector CN2A and (B-Y)₁ signal output is connected to a terminal f of the connector CN2A. It will be noted that these terminals d , e and f are also connected to corresponding terminals d , e and f of the connector CN1A. The combination of CCD4, preamplifier 6 and signal processing circuit 7 constitute together a camera circuit. The unit 100 also includes a unit select signal generator 8, the output of which is connected to a terminal a of the connector CN1A and to a terminal i of the connector CN2A. The connector CN2A includes a terminal a which is adapted to receive various display data D₂₀₀ such as an exposure period which is to be used within the unit 100, and also includes a terminal b which is connected to a supply bus ℓ₂₀₀ which feeds the various circuits disposed within the unit 100. The generator 8 develops a signal of H level when the bus ℓ₂₀₀ assumes a given voltage. Additionally, the unit 100 includes a mode switching circuit 9, the output of which is connected to a terminal c of the connector CN1A and to a terminal c of the connector CN2A. The circuit 9 produces an output which changes its level in accordance with a record mode or a playback mode which may be established by a manual switch, not shown. Specifically, when the record mode is established, the output assumes an H level, and when the playback mode is established, the output assumes an L level. An output terminal of the generator 5 which delivers a horizontal sync signal H₂ is connected to a terminal g of the connector CN2A while an output terminal which delivers a vertical sync signal V₂ is connected to a terminal h of the connector CN2A. Finally, the output terminal of the generator 5 which delivers a subcarrier signal SC₁ is connected to a terminal b of the connector CN1A. The connector CN2B of the record/playback unit 200 includes a terminal d which is connected to the input of a luminance signal modulator 11, a terminal e which is connected to (R-Y)₁ signal input of a line sequencing circuit 12, and a terminal f which is connected to (B-Y)₁ signal input of the circuit 12. The output of the circuit 12 is coupled through a chroma signal modulator 13 to one input of a summing circuit 14, the other input of which is connected to the output of the luminance signal modulator 11. The output of the summing circuit 14 is coupled through a record amplifier 15 to a normally off terminal 16a of a switch circuit 16, which also includes a normally on terminal 16b which is in turn connected through a preamplifier 17, forming a playback circuit, to a terminal e of the connector CN3B. The combination of the circuits 11 to 15 constitutes together a recording circuit. The preamplifier 17 has a supply input which is connected through a line ℓ₁₇ to a terminal c of the connector CN3B. The switch circuit 16 has a common terminal 16c which is connected to a magnetic recording/playback head 18. It is to be understood that the magnetic head 18 is supported by an actuator, not shown, so as to be movable in the radial direction of a magnetic disc 19. The disc 19 is centrally formed with a chuck, which allows the disc to be mounted on a motor 21. The chuck is formed with a pulse generator yoke (hereafter abbreviated as PG yoke). A detecting coil 22 is disposed adjacent to the chuck to detect the location of the PG yoke 20, and is connected to one control input of a motor drive control circuit 23, a control output of which is fed to the motor 21. The unit 200 also includes a sync signal generator 24 having an output terminal which delivers a vertical sync signal V₃ which is connected to a normally on terminal 25b of a switch circuit 25. The circuit 25 has a normally off terminal 25a which is connected to a terminal h of the connector CN2B. The circuit 25 has a common terminal 25c which is connected to the other control input of the motor drive control circuit 23. An output terminal of the sync signal generator 24 which delivers a subcarrier signal SC₂ is connected to a terminal b of the connector CN3B. The connector CN2B includes a terminal i which is connected to the control input of the switch circuit 25, a terminal g which is connected to an input terminal for the horizontal sync signal H₂ of the line sequencing circuit 12, and a terminal c which is connected to the control input of the switch circuit 16. The unit 200 contains a battery 41 which serves as a power supply, and its output terminal is connected to a supply bus ℓ₃₀₀ which feeds various circuits within the unit 200 other than the preamplifier 17 and to a terminal d of the connector CN3B and to a terminal b of the connector CN2B. The unit 200 also includes a display control circuit 42 having a first data input connected to a terminal a of the connector CN2B, and a second data input to which various display data D₃₀₀ such as data indicating the number of recorded tracks and operational mode is supplied. The output of the display control circuit 42 is connected to a terminal a of the connector CN3B. The picture monitor unit 300 which is adapted to be coupled to other units of the electronic camera has an electronic viewfinder 35. The connector CN1B of the unit 300 includes terminals d , e and f , which are connected to normally off terminals 30a, 31a, and 32a, respectively, of switch circuits 30, 31, and 32, common terminals 30c, 31c, and 32c of which are connected to Y signal input, R-Y signal input and B-Y signal input, respectively, of an NTSC encoder 33. The encoder 33 has a terminal to which a subcarrier signal SC is supplied and which is connected to the common terminal 34c of a switch circuit 34 having a normally off terminal 34a which is connected to a terminal b of the connector CN1B and a normally on terminal 34b which is connected to a terminal b of the connector CN3A. The circuit 34 has a control terminal which is connected to a terminal a of the connector CN1B. The output of the NTSC encoder 33 is connected to an NTSC video output terminal 40 and to an input of an NTSC display 35 which comprises CRT. The connector CN3A includes a terminal e which is connected to the input of a color separation circuit 36. The circuit 36 has an output terminal from which a luminance signal component is delivered and which is coupled through a luminance signal demodulator 37 to feed Y₂ signal to a normally on terminal 30b of the switch circuit 30. The color separation circuit 36 has another output terminal from which a chroma signal component is delivered and which is coupled through a chroma signal demodulator 38 to the input of a time coincidence circuit 39. The circuit 39 functions to achieve a time coincidence of R-Y signal and B-Y signal which are input in a line sequential manner, in a manner well known in the art. The circuit 39 has an output terminal from which (R-Y)₂ signal is delivered and which is connected to a normally on terminal 31b of the switch circuit 31, and also has another output terminal from which (B-Y)₂ signal is delivered and which is connected to a normally on terminal 32b of the switch circuit 32. The control terminals of the switch circuits 30, 31, 32 are connected in common and connected to a terminal c of the connector CN1B. The unit 300 also includes a finder indicator 43 which is located adjacent to the NTSC display 35 and which has an input terminal connector to a terminal a of the connector CN3A. The connector CN3A also includes a terminal d which is connected to a supply bus ℓ₄₀₀ which feeds the various circuits within the unit 300. The terminals c and d of the connector CN3A are connected in common to feed the preamplifier 17 in the playback circuit. The operation of the electronic camera described above will now be described. In the present embodiment, the individual units 100, 200 and 300 can be coupled together in four different combinations as indicated below: (1) The three units 100, 300 and 200 may be coupled together to use the combination as an electronic camera capable of recording and playback operation. (2) The units 200 and 300 may be coupled together to use the combination as a devoted playback unit. (3) The units 100 and 300 may be coupled together to use the combination as a video camera. (4) The units 100 and 200 may be coupled together to use the combination as an electronic camera which is for devoted use in the recording operation. In this instance, it is necessary to employ the optical viewfinder 500 to monitor the picture being taken. The operation for the combination (1) will now be described with reference to Fig. 3. In this instance, the terminals a to f of the connector CN1A are electrically connected to the terminals a to f of the connector CN1B, respectively, as are the terminals a to i of the connectors CN2A, CN2B and the terminals a to e of the connectors CN3A, CN3B. In addition, the units 100, 200, 300 are physically coupled together with the grip 400. When a power switch, not shown, is closed, the voltage across the battery 41 is applied to the preamplifier 17 through a path including the bus ℓ₃₀₀, the terminals d of the connectors CN3B, CN3A, the terminals d , c of the connector CN3A, the terminals c of the connector CN3B and the line ℓ₁₇. At the same time, the various circuits within the unit 200 are fed from the bus ℓ₃₀₀, and the various circuits within the unit 300 are fed from the bus ℓ₄₀₀. In addition, the various circuits within the unit 100 are fed from the battery 41 through the terminals b of the connectors CN2B, CN2A and the bus ℓ₂₀₀. If it is now assumed that a switch or the like is used to establish a record mode, the mode switching circuit 9 develops an output of H level, which is applied through the terminals c of the connectors CN1A, CN1B to the switch circuits 30, 31, 32, and is also fed through the terminals c of the connectors CN2A, CN2B to activate the switch circuit 16. As the photographing unit 100 is fed with power, the unit select signal generator 8 develops an output of H level, which is applied to the switch circuit 34, through the terminal c of the connectors CN1A, CN1B, to activate it, and is also fed through the terminals a of the connectors CN2A, CN2B to activate the switch circuit 25. Accordingly, each of the switch circuits 16, 25, 30, 31, 32, 34 are operated to establish a connection between the common terminal and the normally off terminal thereof. Under this condition, the shutter 3 is open, and accordingly, an image of an object being photographed is focussed by the taking lens 1 onto the light incident surface of CCD4. The amount of incident light upon CCD4 is controlled by the iris 2. The image focussed on CCD4 is subject to a two dimensional scan which takes place in response to the horizontal scan drive signal H₁ and the vertical scan drive signal V₁ which are supplied from the sync signal generator 5, thus producing an electrical signal which corresponds to the image, at the output of CCD4. This signal is amplified to a given level by the preamplifier 6 and thence fed to the signal processing circuit 7 which then produces Y₁ signal, (R-Y)₁ signal and (B-Y)₁ signal in response to the sync signal S also fed from the sync signal generator 5. These three signals are fed through the terminal pairs d , e and f of the connectors CN1A, CN1B to the picture monitor unit 300. These signals are then fed through the switch circuits 30, 31, 32 to be input to the NTSC encoder 33, which then operates to produce a color video signal in accordance with the given NTSC standard in response to the subcarrier signal SC₁ which is delivered from the sync signal generator 5 and fed through the terminals b of the connectors CN1A, CN1B and the switch circuit 34. The video signal is applied to the output terminal 40, and is also applied to the NTSC display 35 which then displays the picture corresponding to the image focussed upon CCD4. At the same time, display data D₂₀₀ such as an exposure period which is determined within the unit 100 as well as display data D₃₀₀ such as the number of recorded tracks which is determined within the unit 200 are fed to the display control circuit 42, the output of which is fed through the terminals a of the connectors CN3B, CN3A to the finder indicator 43, which then indicates such data. Under this condition, a distance adjustment and an adjustment of the focal length of the taking lens 1 as well as the set-up of the photographic composition are made while visually observing the display 35. A release button, not shown, is then operated, whereupon the picture which is displayed by the display 35 is recorded. Specifically, the recording operation takes place as follows: As the release button is operated, the shutter 3 is closed once, and subsequently an exposure of CCD4 takes place during a given exposure period. At the same time as the exposure, a two dimensional scanning of CCD4 takes place in response to the horizontal scan drive signal H₁ and the vertical scan drive signal V₁ fed from the sync signal generator 5. An output signal from CCD4 is amplified by the preamplifier 6 and is then input to the signal processing circuit 7. The circuit 7 develops at its outputs Y₁ signal, (R-Y)₁ signal and (B-Y)₁ signal, which are delivered through the terminal pairs d , e and f of the connectors CN2A, CN2B. Y₁ signal is subject to an emphasis by the luminance signal modulator 11, which then applies a frequency modulation. (R-Y)₁ signal and (B-Y)₁ signal are then converted into a chroma signal in which (R-Y)₁ signal and (B-Y)₁ signal occur for each horizontal scan line, by the operation of the line sequencing circuit 12 which responds to the horizontal sync signal H₂ fed from the sync signal generator 5. The chroma signal is then subject to an FM modulation and an emphasis by the chroma signal modulator 13. The summing circuit 14 mixes the output signals from the luminance signal modulator 11 and the chroma signal modulator 13, and the mixed output is fed to the record amplifier 15. The amplifier 15 performs various processing such as a record equalization and white peak clipping, and the resulting signal is then fed through the switch circuit 16 to the magnetic head 18 for recording. The vertical sync signal V₂ from the sync signal generator 5 is fed through the terminal pair h of the connectors CN2A, CN2B and through the switch circuit 25 to the other control input of the motor drive control circuit 23 as a vertical sync signal V. Accordingly, the motor 21 rotates at a rate of one revolution per period (1/60 second) of the vertical sync signal V₂. In this manner, the magnetic disc 19 is driven for rotation while maintaining a phase control of the relative position of the disc with respect to the magnetic head 18 which is accomplished by the signal from the detecting coil 22 which develops a signal indicating the position of the PG yoke 20. In this manner, a magnetic recording is achieved as referenced to the position of the PG yoke 20. When a signal which is previously recorded on the magnetic disc 19 is reproduced, a switch, not shown, may be operated to change the output from the mode switching circuit 9 from its H level to its L level. Thereupon, the switch circuits 16, 30, 31, 32 are deactivated, whereupon each of these switches return to their positions in which the common terminal is connected to the normally on terminal. The rotation of the magnetic disc 19 is controlled in the same manner as it occurred during the recording operation, whereby a reproduced signal from the magnetic head 18 is fed through the switch circuit 16 to the preamplifier 17, which amplifies it to a given level while simultaneously performing a playback equalization and de-emphasis, thus producing a reproduced signal PB. The reproduced signal PB is fed through the terminals e of the connectors CN3B, CN3A to the picture monitor unit 300. In this unit, the reproduced signal PB is separated into the luminance signal component and the chroma signal component by the color separation circuit 36. The luminance signal component is demodulated by the luminance signal demodulator 37 which also performs a de-emphasis, thus producing Y₂ signal, which is fed through the switch circuit 30 to the NTSC encoder 33. The chroma signal component is demodulated by the chroma signal demodulator 38 which also performs a given de-emphasis, thus producing concurrent (R-Y)₂ and (B-Y)₂ signals. (R-Y)₂ signal is fed through the switch circuit 31, and (B-Y)₂ signal is fed through the switch circuit 32, the both being input to the NTSC encoder 33 as (R-Y) and (B-Y) signals. The encoder 33 responds to the subcarrier signal SC which is delivered from the sync signal generator 5 and fed through the terminal pair b of the connectors CN1A, CN1B and through the switch circuit 34 to develop a given NTSC color video signal. The video signal is then applied to the output terminal 40 and is also fed to the NTSC display 35 which displays the reproduced image corresponding to the signal recorded on the magnetic head 19. As before, display data D₂₀₀, D₃₀₀ such as the exposure period or the number of recorded tracks are indicated by the finder indicator 43. The operation of the electronic camera in the manner (2) mentioned above, namely, when it is used as a devoted playback unit by coupling the record/playback unit 200 and the picture monitor unit 300 together, will now be described. In this instance, an H level signal from the unit select signal generator 8 (see Fig. 3) is not applied to the terminal a of the connector CN1B and to the terminal i of the connector CN2B, as will be noted from Fig. 5, and hence the both switch circuits 25, 34 remain deactivated, whereby the common terminal and the normally on terminal of each of these switch circuits 25, 34 are connected together as shown by solid line. A signal from the mode switching circuit 9 (see Fig. 3) is not applied to the terminal c of the connector CN1B and to the terminal c of the connector CN2B, and hence the switch circuits 16, 30, 31, 32 remain deactivated, and accordingly, in each of these switch circuits, a connection is established between the common terminal and the normally on terminal as indicated by solid line. Therefore, the rotation of the motor 21 is controlled in accordance with the vertical sync signal V₃ delivered by the sync signal generator 24 which is contained in the record/playback unit 200, in distinction from the manner (1) mentioned above. The signal previously recorded on the magnetic disc 19 is reproduced in the same manner as the playback mode of the combination (1), and Y 2, (R-Y)₂ and (B-Y)₂ signals are fed through the switch circuits 30, 31, 32 to be input to the NTSC encoder 33. It is to be noted that the subcarrier signal SC which is input to the encoder 33 is the subcarrier signal SC₂ from the sync signal generator 24 within the record/playback unit 200 which is fed through the terminal pair b of the connectors CN3B, CN3A and the switch circuit 34, in distinction to that of the combination (1). The encoder 33 produces an NTSC color video signal while using the subcarrier signal SC₂, and a video signal is applied to the output terminal 40 and also supplied to the NTSC display 35 which allows an image reproduced from the signal recorded on the magnetic disc 19 to be displayed. When it is desired to record such a reproduced image in separate equipment, for example, a video tape recorder, a video input of such video tape recorder may be connected to the output terminal 40 of the picture monitor unit 300. When the reproduced image is to be displayed on a large size picture monitor television set, a video input of such set may be connected to the output terminal 40. In this manner, an output available at the output terminal 40 can be utilized in various ways. The operation of the electronic camera in the combination (3) mentioned above, namely, when the photographing unit 100 and the picture monitor unit 300 are coupled together to operate as a video camera, will now be described with reference to Fig. 6. An H level output from the unit select signal generator 8 activates the switch circuit 34, whereby the common terminal 34c is connected to the normally off terminal 34a as indicated by broken lines. When a switch, not shown, is used to establish a record mode, the mode switching circuit 9 produces an output of H level, which activates the switch circuits 30, 31, 32. Accordingly, the common terminal is connected to the normally off terminal of each of these circuits. Accordingly, a picture corresponding to an image of an object being photographed is displayed by the NTSC display 35 in the same manner as it occurs during the record mode of the manner (1) mentioned above. The output terminal 40 now delivers the NTSC color video signal, and hence such terminal may be connected to a video input of a video tape recorder, not shown, thus allowing a motion picture to be recorded. In the operation of the electronic camera in the combination (4) mentioned above, namely, when the photographing unit 100 and the record/playback unit 200 are coupled together with the optical viewfinder 500 mounted thereon to provide an electronic camera which is devoted for recording purpose, reference is made to Figs. 4 and 7 for description. As shown, the photographing unit 100 and the record/playback unit 200 are coupled together through the connectors CN2A, CN2B, and the optical viewfinder 500 is assembled with the combination by inserting the half mirror 501 with the space 101, with a connector CN3AO of the viewfinder 500 being coupled with the connector CN3B of the record/playback unit 200. An H level output from the unit select signal generator 8 activates the switch 25, whereby the common terminal 25c is connected to the normally off terminal 25a as indicated by broken lines. When a switch, not shown, is used to establish the record mode, the mode switching circuit 9 develops an output of H level which activates the switch circuit 16 to connect the common terminal 16c with the normally off terminal 16a, as indicated by broken lines. It is to be noted that terminals c and d of the connector CN3AO are not connected together, preventing the output from the battery 41 from being supplied to the line ℓ₁₇ and hence to the preamplifier 17, thus preventing a wasteful power dissipation. A picture signal is recorded on the magnetic disc 19 as it occurs during the record mode in the manner (1) mentioned above. However, in this instance, the half mirror 501 of the optical viewfinder 500 is inserted into the space 101, whereby the light flux which passed through the taking lens 1 is divided into two portions, one being fed to CCD4 and the other fed to a finder screen 502. The light which has been transmitted through the half mirror 501 impinges upon CCD4 to enable a recording of a picture signal on the magnetic disc 9 in the same manner as in the combination (1) mentioned above. The light flux which is reflected upward by the half mirror 501 is focussed upon the finder screen 502 and is then converted into an erect image by a pentaprism 503, which erect image can be viewed through an eyepiece 504, thus allowing an adjustment of the focal length, a distance adjustment and the set-up of the photographic composition. As described, with this embodiment, the units 100, 200 and 300 can be selectively coupled together. When reproducing the signal which is previously recorded on the magnetic disc 19, the signal from the head 18 is amplified by the preamplifier 17 which is located adjacent thereto before delivering it to the picture monitor unit 300, thus advantageously improving the signal-to-noise ratio. Both the photographing unit 100 and the record/playback unit 200 include the sync signal generators 5, 24, respectively. When the photographing unit 100 is used, the sync signal generator 5 included therein delivers various sync signals to both the record/playback unit 200 and the picture monitor unit 300. When the unit 100 is not used, the sync signal generator 24 in the unit 200 delivers various sync signals, which are fed to the picture monitor unit 300. In this manner, there is obtained a video signal which is free from jitters caused by the eccentricity of the magnetic disc 19 during the playback mode. In the described examples of possible combinations, the photographing unit 100 is provided with the space 101 in which the optical viewfinder 500 is received. However, it is to be understood that the unit 100 may be modified by removing the space 101 and avoiding the use of the viewfinder 500. Also it will be appreciated that the NTSC encoder 33 which is contained within the picture monitor unit 300 may be replaced by a PAL or SECAM encoder or other similar encoders. In addition, the shutter 3 may be located in front of the image plane such as formed by CCD4. Alternatively, instead of using the shutter 3, the camera means such as CCD4 may be electrically controlled. Finally, when selectively coupling the units 100, 200 and 300 in the described embodiment, the connectors CN1A, CN1B, CN2A, CN2B, CN3A and CN3B may be coupled through relay cables rather than coupling them together. In another embodiment of the invention, the sync signals are supplied to various electrical circuits within the plurality of divided units by utilizing connectors which are originally used to enable a detachable coupling of selected units. In this embodiment, the connectors of selected units are coupled together by utilizing two kinds of relay connectors 600 or 700, shown in Figs. 8 and 9, respectively. The relay connector 600 shown in Fig. 8 comprises a first connector 601 and a second connector 602 between which a coupler 103 is integrally connected. As shown in Fig. 10, the coupler 103 internally houses a sync signal generator 604 and a crystal oscillator 605. The other relay connector 700 comprises a first connector 701 and a second connector 702 which are integrally formed by having their electrical terminals connected in common, as indicated in Figs. 9 and 11. Referring to Figs. 10 and 11, the electrical circuits of these relay connectors 600, 700 will now be described. The first connector 601 includes a plurality of terminals a₁ to a n , +, -, b , c . . . . . , and the second connector 602 similarly includes a plurality of terminals a₁ to a n , +, -, b , c . . . . . which are connected to corresponding terminals of the first connector by lead wires. In addition, the "+" and "-" terminals are connected across the power supply terminals of the sync signal generator 604 which is in turn connected to the crystal oscillator 605 operative to determine a reference oscillation frequency of the generator 604. The generator 604 includes a plurality of output terminals which are connected to the terminal a₁ to a n of the first and the second connector 601, 602, respectively. The horizontal scan signal, the vertical scan signal, the subcarrier signal, CCD scan signal or like sync signals are applied to the terminals a₁ to a n . On the other hand, each of the first and the second connectors 701, 702 of the other relay connector 700 also includes a plurality of terminals a₁ to a n , +, -, b , c ..... which are connected together by lead wires. When the relay connectors 600, 700 are used with the electronic camera capable of recording and playback operation as mentioned above in connection with the combination (1) (see Fig. 3), the resulting circuit arrangement will be as shown in Fig. 12. Specifically, the terminals a₁ to a n and b to f of the connector CN1A are electrically connected to the corresponding terminals a₁ to a n and b to f of the connector CN1B, respectively, through the relay connector 700. Similarly, the terminals a₁ to a n and e the connector CN3A are connected electrically to the corresponding terminals a₁ to a n and e of the connector CN3B through the relay connector 700. In addition, the terminals a₁ to a n and b to f of the connector CN2A are electrically connected to corresponding terminals a₁ to a n and b to f of the connector CN2B through the relay connector 600, and the terminals a₁ to a n of the connectors CN2A, CN2B are connected to the sync signal generator 604 of the relay connector 600. The connectors are coupled together in this manner, and with the grip 400 (see Fig. 1) are physically coupled to the units 100, 200 and 300. When a power supply, not shown, is fed to the units, the terminals a₁ to a n of the relay connector 600 feed various sync signals to the individual units 100, 200 and 300 through sync signal lines S₁₀₀, S₂₀₀ and S₃₀₀, respectively. Accordingly, the same operation as described before takes place. When the relay connectors 600 and 700 are used with the devoted playback unit (see Fig. 5) mentioned above in connection with the combination (2) or which comprises the record/playback unit 200 and the picture monitor unit 300 physically coupled together, there results a circuit arrangement as shown in Fig. 13. In this instance, the relay connector 600 is coupled between the connectors CN3A and CN3B in order to couple the units 200 and 300 together. Because the photographing unit 100 is not coupled, the terminal c of the connector CN1B and the terminal c of the connector CN2B remain at their L level. Accordingly, the switch circuits 30, 31, 32 and 16 remain deactivated, and in these switch circuits, the common terminal is connected to the normally on terminal as indicated by solid lines. As a result, in distinction to the electronic camera of Fig. 12, the outputs from the sync signal generator 604 are delivered through the sync signal lines S₂₀₀, S₃₀₀, the vertical sync signal on the line S₂₀₀ driving the motor 21 for rotation. The signal which is previously recorded on the magnetic disc is separated into Y₂, (R-Y)₂ and (B-Y)₂ signals, which are supplied through the switch circuits 30, 31, 32, respectively, to the NTSC encoder 33 in the similar manner as during the playback mode in the manner (1). In this instance, the subcarrier signal fed to the encoder 33 is supplied by routing the output from the sync signal generator 604 in the relay connector 600 through the terminals a₁ to a n of the connector CN3A and the sync signal line S₃₀₀, in distinction from the electronic camera mentioned above in connection with the combination (1). The encoder 33 produces an NTSC color video signal in response to the subcarrier signal, and such video signal is applied to the output terminal 40 and also fed to the NTSC display 35, allowing a reproduced image from the magnetic disc 19 to be displayed. As mentioned previously, the output terminal may be connected to a video input of a video tape recorder or a large size picture monitor television set whenever it is desired to record the image on a video tape recorder or when the reproduced image is to be displayed on a large size picture monitor television set. When the connector 600 is used with the video camera (see Fig. 6), which comprises the photographing unit 100 and the picture monitor unit 300 coupled together, there results a circuit arrangement as shown in Fig. 14. In this instance, the relay connector 600 is coupled between the connectors CN1A and CN1B. Thereupon, the terminals b , c , d and f of the connectors CN1A, CN1B are connected together, and various sync signals from the sync signal generator 604 within the relay connector 600 are fed to the units 100, 300 through the terminals a₁ to a n and the sync signal lines S₁₀₀, S₃₀₀. When a switch, not shown, is operated to establish a record mode, the mode switching circuit 9 develops an output of H level, which activates the switch circuits 30, 31, 32. Thus, in these switch circuits, the common terminal is connected to the normally off terminal, as indicated by broken lines. Accordingly, the image corresponding to a photographic image of an object being photographed can be displayed on the NTSC display 35, in the same manner as during the record mode with the video camera of Fig. 6. The output terminal 40 delivers the NTSC color video signal, which may be fed to a video tape recorder, not shown, for recording a motion picture. When the relay connector 600 is used with the electronic camera for the devoted recording purpose shown in Fig. 7, which comprises the photographing unit 100 and the record/playback unit 200 coupled together with the optical viewfinder 500 mounted thereon, there results a circuit arrangement as shown in Fig. 15. The relay connector 600 is coupled between the connectors CN2A and CN2B. Corresponding terminals of the connectors CN2A, CN2B are then connected together, and various sync signals from the sync signal generator 604 within the relay connector 600 are fed to the units 100, 200 through the terminals a₁ to a n and the sync signal lines S₁₀₀, S₂₀₀. When a switch, not shown, is operated to establish the record mode, the mode switching circuit 9 develops an output of H level, which activates the switch circuit 16 to connect its common terminal 16c to the normally off terminal 16a, as indicated by broken lines. Accordingly, a static or still image can be recorded on the magnetic disc 19 in the same manner as it occurs during the record mode with the electronic camera of Fig. 7. It will thus be seen that in any combination of the units 100, 200 and 300, the various sync signals produced by the sync signal generator 604 which is internally contained within the relay connector 600 can be fed to the electrical circuits within the units 100, 200 and 300, thus simplifying the construction. It is also to be noted that instead of using the relay connector 600 to provide a relay connection among the connectors CN1A, CN1B, CN2A, CN2B, CN3A and CN3B of the individual units, the sync signal generator which has been described above as contained within the relay connector 600 may be contained in one of the connectors CN1A to CN3B of a selected unit which is chosen depending on the frequency of use of a particular combination of the units 100, 200 and 300. It is also to be understood that the sync signals delivered by the sync signal generator are not limited to those described above. Alternatively, the generator may only produce a reference signal, which is received by each unit to develop a necessary signal as by frequency division. The electronic camera of the invention which is divided into plurality of units which can be coupled together in a detachable manner can be fed from a battery unit so that when an item of external equipment such as video tape recorder is connected to the electronic camera, the latter can be fed from a power supply associated with that equipment. In this embodiment, the electronic camera comprises a photographing unit 100, a record/playback unit 200, a picture monitor unit 300, and a battery unit 800, as shown in Fig. 16. These four units can be selectively and detachably coupled together. The electrical coupling between the photographing unit 100 and the picture monitor unit 300 takes place by physically coupling the connector CN1A on the photographing unit 100 with the connector CN1B on the picture monitor unit 300. The electrical coupling between the unit 100 and the record/playback unit 200 takes place by physically coupling the connector CN2A on the unit 100 with the connector CN2B on the unit 200. The electrical coupling between the units 300 and 200 takes place by physically coupling the connector CN3A on the unit 300 with the connector CN3B on the unit 200. The record/playback unit 200 also includes another connector CN5A, which can be physically and electrically coupled with a connector CN5B that is disposed on the battery unit 800. The connector CN5B can also be physically and electrically coupled with a connector CN6A disposed on the photographing unit 100. The picture monitor unit 300 also includes a connector CN4A, which can be physically and electrically coupled with a connector CN4B disposed on a video tape recorder (hereafter abbreviated as VTR), representing an item of external equipment, the connector CN4B being connected with a power supply associated with the video tape recorder. It is to be understood that the mechanical coupling means which permits a selective coupling between the units 100, 200 300 and 800 is not specifically illustrated. A circuit arrangement for the power supply will now be described. Each of the connectors CN1A, CN2A, CN6A on the photographing unit 100 includes a terminal j , which is connected in common among these connectors and which is grounded to the casing of the unit 100. These connectors also include a terminal k which is connected in common to a bus ℓ₁ which is in turn connected to a power supply circuit 10 to feed the various electrical circuits within the unit 100 through a bus ℓ₁₀₀. The purpose of the power supply circuit 10 is to feed the electrical circuits within the photographing unit 100, and is suitably constructed, including a constant voltage circuit, a voltage booster circuit (not shown) or the like. It is to be understood that power supply circuits 26, 44, to be described later, are similarly constructed. The connectors CN2B, CN3B, CN5A on the record/playback unit 200 include a terminal j , which is connected in common among these connectors and which is grounded to the casing of the unit 100, these connectors also include a terminal k , which is connected in common by a bus ℓ₂, which is in turn connected to a power supply circuit 26 to feed the various electrical circuits within the unit 200 through a bus ℓ₃₀₀. Similarly, the connectors CN1B, CN3A, CN4A on the picture monitor unit 300 include a terminal j which is grounded to the casing of the unit 300, and another terminal k which is connected in common by a bus ℓ₃, which is in turn connected to a power supply circuit 44 to feed the various electrical circuits within the unit 300 through a bus ℓ₄₀₀. The battery unit 800 is provided with the connector CN5B which can be coupled with the connector CN5A. It contains a battery 41 such as a dry cell, nickel-cadmium battery or the like. The negative terminal of the battery 41 is connected to a terminal j of the connector CN5B while the positive terminal is connected to a terminal k of the connector CN5B through a bus ℓ₄. The connector CN4A on the picture monitor unit 300 is adapted to be coupled to the output of a power supply which is associated with VTR 900 through a cable and a connector CN4B. The connector CN4B has a terminal j which is connected to the negative terminal of the power supply, and a terminal k which is connected to the positive terminal of the power supply. In this manner, it is possible for the electrical circuits within the units 100, 200 and 300 to be fed from the battery unit 800. Accordingly, when the three units 100, 200 and 300 are coupled together to define an electronic camera which is capable of recording and playback operation, with the battery unit 800 electrically coupled to the combination, as shown in Fig. 16, the terminals a to f , k and j of the connector CN1A are electrically connected to the corresponding terminals a to f , k and j of the connector CN1B. Similarly, the terminals c to k of the connectors CN2A, CN2B are electrically interconnected as are the terminals b , e , j and k of the connectors CN3A, CN3B. In addition, the terminals j and k of the connectors CN5A, CN5B are electrically connected. As a consequence, the negative and the positive terminals of the battery 41 are connected to the record/playback unit 200 through the pair of connectors CN5B, CN5A, and also connected to the picture monitor unit 300 through the pair of connectors CN3B, CN3A, and further connected to the photographing unit 100 through the pair of connectors CN2B, CN2A. The positive voltage from the battery 41 feeds the power supply circuits 10, 26, 44 through the buses ℓ₁ to ℓ₄, and these power supply circuits feed the electrical circuits within the individual units 100, 200, 300 through the buses ℓ₂₀₀, ℓ₃₀₀, ℓ₄₀₀, respectively. Accordingly, there can be achieved the same operation as that of the electronic camera described in connection with Fig. 3. It will be appreciated that the recording and playback operation mentioned above takes place under the power supply from the battery 41 of the battery unit 800. However, during the recording mode, when it is desired to record a static or still image signal on the magnetic disc 19 as well as in VTR 900, the battery unit 800 is disconnected from the record/playback unit 200 while the connector CN4B on VTR 900 is coupled with the connector CN4A on the picture monitor unit 300. The output terminal of the unit 300 is connected to a video input, not shown, of VTR 900. In this manner, the units 100, 200 and 300 can be fed from the power supply associated with VTR 900, thus recording a static or still image signal on both the magnetic disc 19 and VTR 900. Also, during the playback mode, when VTR 900 is connected in the same manner as mentioned above, the still image signal which is obtained by a reproduction from the magnetic disc 19 can be recorded in VTR 900. When the units 200 and 300 are coupled together to define a devoted playback unit, the battery unit 800 may be coupled with the combination as indicated in Fig. 17 to achieve entirely the same operation as mentioned above in connection with Fig. 5. Again, if the battery unit 800 is disconnected and VTR 900 is connected instead, the power supply associated with VTR 900 may feed the electrical circuits within the units 300, 200 through the buses ℓ₃, ℓ₂, thus allowing the still image signal reproduced from the magnetic disc 19 to be recorded in VTR 900. When the photographing unit 100 and the picture monitor unit 300 are coupled together to define the video camera, a circuit arrangement results as shown in Fig. 18. In this instance, the unit select signal generator 8 develops an output of H level, which activates the switch circuit 34 to connect its common terminal 34c to its normally off terminal 34a, as indicated by broken lines. When a switch, not shown, is operated to establish the record mode, the mode switching circuit 9 develops an output of H level, which activates all of the switch circuits 30, 31, 32. Accordingly, in each of these switch circuits, the common terminal is connected to the normally off terminal. Accordingly, an electronic image corresponding to a photographic image of an object being photographed can be displayed on the NTSC display 35 in the same manner as it occurs during the record mode using the video camera shown in Fig. 6. It will be seen that the output terminal 40 also delivers the NTSC color video signal, which can be supplied to a video input, not shown, of VTR 900, thereby allowing a motion picture signal to be recorded in addition to a still image signal. In the various combinations described above, the battery unit 800 is attached to the record/playback unit 200. However, the battery 41 of the unit 800 may be connected to the connector CN6A of the photographing unit 100. Alternatively, the battery 41 may also be connected to the connector CN4A of the picture monitor unit 300. Instead of connecting an external power supply such as the power supply associated with VTR 900, for example, to the connector CN4A, it may be coupled to the connector CN5A or the connector CN6A. It is also possible that the record/playback unit may be provided with a dubbing feature, which may be combined with a devoted dubbing unit to enable a dubbing operation. Such an embodiment of the invention is illustrated in Fig. 19 which shows a record/playback unit 200A. The unit 200A may be coupled through a connector with a devoted dubbing unit 50 shown in Fig. 20. The combination of the units 200A and 50 is shown in Fig. 23 as a dubbing apparatus. It is also to be noted that the record/playback unit 200A is adapted to be coupled with a photographing unit 100A shown in Fig. 21 through a connector to define a circuit arrangement shown in Fig. 24. In addition, the record/playback unit 200A is also adapted to be coupled with a picture monitor unit 300A shown in Fig. 22 on its top side, through another connector, thus defining an electronic camera having a circuit arrangement as shown in Fig. 24. The photographing unit 100A (See Figs. 21 and 24) includes a taking lens 1 which functions to focus an image of an object being photographed. A diaphragm 2 and a shutter 3 are disposed on the optical path of the taking lens 1. Disposed on the focussing plane of the taking lens 1 is a solid camera element 4, for example, CCD4, which is subject to a two dimensional scan in response to a horizontal and a vertical sync drive signal H₁, V₁ delivered from a sync signal generator 5 to convert the light image into a two dimensional array of electrical signals. The output of CCD4 is connected through a preamplifier 6 to the input of a signal processing circuit 7. In response to an output signal from CCD4 and a sync signal S from the generator 5, the signal processing circuit 7 produces luminance signal Y₁ and color difference signals (R-Y)₁ and (B-Y)₁, which are delivered to connector terminals Ta, Tb, Tc associated with the record/playback unit 200A and to connect terminals Ti , Tj, Tk associated with the picture monitor unit 300A. The sync signal generator 5 delivers a horizontal and a vertical sync drive signal H₂, V₂ to connector terminals Td, Te associated with the record/playback unit 200A, and also delivers a subcarrier signal SC₁ to a connector terminal Th associated with the picture monitor unit 300A. The construction of the record/playback unit 200A will now be described with reference to Figs. 19 and 24. The connector terminal Ta associated with the photographing unit 100A is connected to the input of a luminance signal modulator 202 while connector terminals Tb, Tc, Td are connected to (R-Y)₁, (B-Y)₁ inputs and horizontal scan drive signal H₂ input of a line sequencing circuit 203. The output of the line sequencing circuit 203 is connected to the input of a chroma signal modulator 204, the output of which is connected to a summing circuit 205 together with the output from the luminance signal modulator 202, thus forming a signal which is suitable for recording on a magnetic disc. The combination of the luminance signal modulator 202, the line sequencing circuit 203, the chroma signal modulator 204 and the summing circuit 205 constitute together a first signal processing circuit 201. The output of the summing circuit 205 is connected to a normally on terminal of a first switch circuit 206, which also has a normally off terminal connected to the output of a second signal processing circuit 220. The common terminal of the switch circuit 206 is connected to the input of a record amplifier 207, the output of which is connected to a connector terminal Tco associated with the dubbing unit 50, to be described in detail later, and to the normally on terminal of a third switch circuit 208. The switch circuit 208 has a normally off terminal connected to the input of a preamplifier 209, the output of which is connected to a connector terminal Tbo associated with the picture monitor unit 300A which will be described later. The common terminal of the switch circuit 208 is connected to a magnetic head 210 which is used in a recording and playback operation. The head 210 is supported by an actuator, not shown, so as to be movable in the radial direction of a magnetic disc 211. The disc 211 is centrally formed with a chuck which permits it to be mounted on a motor 212. The chuck is provided with a pulse generator yoke or PG yoke 213. A detecting coil 214 is located adjacent to th Pg yoke to detect the position thereof, and is connected to one control input of a motor drive control circuit 215. The output of the control circuit 215 is connected to the spindle motor 212. The unit 200A includes a sync signal generator 218. The generator 218 has an output connected to the normally off terminal of a fourth switch circuit 216, the normally on terminal of which is connected to the common terminal of a fifth switch circuit 217. The normally on terminal of the switch circuit 217 is connected to a connector terminal Te associated with the photographing unit 100A while the normally off terminal of the switch circuit 217 is connected to an input terminal Tg which receives a dubbing vertical sync drive signal V₄ as from an external recorder. The common terminal of the fourth switch circuit 216 is connected to the input of the motor drive control circuit 215 and to a connector terminal Teo associated with the dubbing unit 50. The second signal processing circuit 220 has a input connected to the common terminal of the second switch circuit 219 having a normally off terminal connected to a dubbing signal input terminal Tf from an external recorder or the like, and a normally on terminal connected to the output of the preamplifier 209. The picture monitor unit 300A will now be described with reference to Figs. 22 and 24. The connector terminals Ti, Tj, Tk of the picture monitor unit 300A which are associated with the photographing unit 100A are connected to the respective normally off terminals of switch circuits 301, 302, 303, respectively, which have their common end connected to Y signal input, (R-Y) signal input and (B-Y) signal input, respectively, of NTSC encoder 304. The encoder 304 has another input which receives a subcarrier signal and which is connected to the common terminal of a switch circuit 305. The switch circuit 305 has a normally off terminal connected to a connector terminal Th associated with the photographing unit 100A and a normally on terminal connected to a connector terminal Tao associated with the record/playback unit 200A. The output of the encoder 304 is connected to an NTSC video signal output terminal 306 and also connected to the input of an NTSC display 307 which may comprise CRT or liquid crystal display. The unit 300A includes a connector terminal Tbo associated with the record/playback unit 200A which is connected to the input of a color separation circuit 308. The circuit 308 has an output terminal which delivers a luminance signal component and which is connected to a luminance signal modulator 309, which in turn delivers Y₂ signal to the normally on terminal of the switch circuit 301. The color separation circuit 308 has another output terminal which delivers a chroma signal component and which is connected to a chroma signal demodulator 310. The demodulator 310 is connected to a time coincidence circuit 311, which is constructed in a well known manner to achieve a time coincidence in the occurrence of (R-Y) and (B-Y) signals which are inputted thereto in a line sequence. An output terminal of the circuit 311 which delivers (R-Y)₂ signal is connected to the normally on terminal of the switch circuit 302 while an output terminal of the circuit 311 which delivers (B-Y)₂ signal is connected to the normally on terminal of the switch circuit 303. The dubbing unit 50 will now be described with reference to Figs. 20 and 23. It includes a connector terminal Tco associated with the record/playback unit 200A which is connected to a magnetic head 51. It will be understood that the head 51 is supported by an actuator, not shown, so as to be movable in the radial direction of a magnetic disc 52. The disc 52 is centrally formed with a chuck member which permits it to be mounted on a spindle motor 53. The chuck member is also formed with a PG yoke 54, the position of which is detected by a detecting coil 55. The coil 55 is connected to one control input of a motor drive control circuit 56. The output of the control circuit 56 is connected to the spindle or stepping motor 53. The control circuit 56 has another input which is connected to a connector terminal Tdo associated with the record/playback unit 200A. The electronic camera which is thus constructed in divisible units can operate in several different manners, illustrated below as combinations involving the record/playback unit 200A. (11) The photographing unit 100A, the record/playback unit 200A and the picture monitor unit 300A may be combined together to provide an electronic camera capable of recording and playback operation and which additionally includes an electronic finder (See Fig. 24). (12) The photographing unit 100A and the record/playback unit 200A may be combined to provide an electronic camera which is devoted for recording purpose only. (If required, an optical viewfinder may be combined.) (13) The record/playback unit 200A and the picture monitor unit 300A may be combined to provide a playback unit. (14) The record/playback unit may be combined with another record/playback unit of a similar kind or with an external video unit so as to receive a dubbing input signal therefrom to achieve a dubbing recording. (15) The record/playback unit 200A may be combined with the dubbing unit 50 to provide a dubbing apparatus (see Fig. 23). In addition, the photographing unit 100A and the picture monitor unit 300A may be combined to provide a video camera. Initially, the operation of the combination (11) will be described. In this instance, the photographing unit 100A and the picture monitor unit 300A are physically coupled with the record/playback unit 200A, with their connector terminals electrically coupled together. When power is fed, the photographing unit 100A is capable of performing a photographing operation. The shutter 3 is opened, and an image of an object being photographed passes through the taking lens 1 to be focussed on the light incident surface of CCD 4. The amount of incident light on CCD4 can be adjusted by the diaphragm 2. The image which is focussed on CCD 4 is subject to a two dimensional scan in response to a horizontal sync drive signal H₁ and a vertical sync drive signal V₁ delivered by the sync signal generator 5, whereby an electrical signal corresponding to the image is output from CCD4. This signal is initially amplified to a given level by the preamplifier 6, and is then fed to the signal processing circuit 7. The signal processing circuit 7 then forms and delivers the luminance signal Y₁, and the color difference signals (R-Y)₁ and (B-Y)₁ in response to a sync signal S from the sync signal generator 5. These three signals are fed through the connector terminals Ti, Tj, Tk to the NTSC encoder 304 through the switch circuits 301, 302, 303 which are activated by a signal from a mode switching circuit, not shown. The subcarrier signal SC₁ is supplied through the connector terminal Th from the sync signal generator 5, and in response thereto, the encoder produces an NTSC color video signal, which is then applied to the output terminal 306 and also fed to the NTSC display 307 such as a liquid crystal display or CRT, thus allowing the focussed image on CCD4 to be displayed. By observing the image displayed by the electronic viewfinder, a distance adjustment and an adjustment of the focal length of the taking lens may be made as well as the set-up of the photographic composition. Subsequently when a release button is operated, the image on the display 307 can be recorded. Specifically, the shutter 3 is closed once, and an exposure of CCD4 then takes place during a given exposure period. At the same time as the exposure occurs, a two dimentional scan of CCD4 takes place in response to the horizontal and the vertical sync drive signal H₁, V₁ supplied from the generator 5, and the output signal from CCD4 is amplified by the preamplifier 6 and then fed to the signal processing circuit 7. In this manner, the luminance signal Y₁ and the color difference signals (R-Y)₁ and (B-Y)₁ are developed at the output of the circuit 7, and are delivered through the connector terminals Ta, Tb, Tc to the luminance signal modulator 202 and the line sequencing circuit 203 within the first signal processing circuit 201 of the record/playback unit 200A. The luminance signal Y₁ is subject to an FM modulation and an emphasis by the modulator 202. The color difference signals (R-Y)₁ and (B-Y)₁ are converted into a line sequenced chroma signal by the line sequencing circuit 203 which receives a horizontal sync drive signal H₂ from the generator 5 through the connector terminal Td so that (R-Y)₁ and (B-Y)₁ signals occur for alternate horizontal scan lines. The resulting chroma signal is subject to an FM modulation and an emphasis by the chroma signal modulator 204. The output signals from the modulators 202 and 204 are mixed by the summing circuit 205, and the resulting mixture is fed through the first switch 206 to the record amplifier 207. The amplifier 207 performs a processing such as an equalization for recording to provide a signal of a given level which is suitable for magnetic recording, the signal being then fed through the third switch circuit 208 to the head 210. It will be noted that at this time, the vertical sync drive signal V₂ from the generator 5 within the photographing unit 100A is fed through the connector terminal Te, the fifth switch circuit 217 and the fourth switch circuit 216 to the other control input of the motor drive control circuit 215. In this manner, the rotation of the spindle motor 212 is controlled to achieve one revolution per period (1/60 second) of the vertical sync drive signal V₂. During the rotation of the disc 211, the relative position between the head 210 and the disc 211 is subject to a phase control which responds to the position of the PG yoke 213 as detected by the detecting coil 214. In this manner, a magnetic record on the magnetic disc 211 is referenced to the position of the PG yoke. On the other hand, when the signal which is previously recorded on the magnetic disc 211 is to be reproduced, the sync signal V₂ from the generator 5 within the photographing unit 100A is fed through the fifth switch circuit 217 and the fourth switch circuit 216 to the motor drive control circuit 215 for driving the magnetic disc 211. A weak signal from the head 210 is fed through the switch circuit 208 to the preamplifier 209 which performs an amplification to a given level as well as a playback equalization. The reproduced RF signal is fed through the connector terminal Tbo associated with the picture monitor unit 300A to the color separation circuit 308 where it is separated into the luminance signal component and the color difference signal component. The luminance signal component is subject to an FM demodulation and a given de-emphasis by the luminance signal demodulator 309 to provide Y₂ signal which is fed through the switch circuit 301 to the encoder 304. The color difference signal component is subject to an FM demodulation and a given de-emphasis by the chroma signal demodulator 310, and a time coincidence circuit 311 produces (R-Y)₂ signal and (B-Y)₂ signal which occur simultaneously. (R-Y)₂ signal is fed through the switch circuit 302 to the encoder 304 as (R-Y) signal while (B-Y)₂ signal is fed through the switch circuit 303 to the encoder 304 as (B-Y) signal. The subcarrier signal SC₁ from the sync signal generator 5 is fed through the connector terminal Th associated with the photographing unit 100A and the switch circuit 305 to the encoder, which then produce an NTSC color video signal. This video signal is applied to the output terminal 306 and is also fed to the NTSC display 307, allowing an image corresponding to the reproduced signal from the magnetic disc 211 to be immediately displayed. It will be noted that the combination (12) is devoid of the picture monitor unit 300A. Such combination is utilized to provide a portable electronic camera. The optical viewfinder 500 as shown in Figs. 7 and 15 may be detachably mounted on the combination. The record/playback unit 200A serves only the record operation, which is entirely similar to the record operation of the combination (11) and hence will not be described. The combination (13) removes the photographing unit 100A from the combination (11), and the record/playback unit 200A serves only the playback operation. It is to be noted that in the combination (11), the operation is based on the vertical sync drive signal V₂ from the generator 5 which is contained in the photographing unit 100A, but in the combination (13), the operation is based on the vertical sync drive signal V₃ and the subcarrier signal SC₂ from the sync signal generator 218 which is contained within the record/playback unit 200A. Specifically, when the picture recorded on the magnetic disc 211 is to be reproduced, the switch circuit 216 is activated to the position indicated by broken lines to feed the vertical sync drive signal V₃ from the generator 218 to the motor drive control circuit 215 for driving the spindle motor 212 for rotation. A weak signal reproduced by the head 210 is fed through the switch circuit 208, which is then switched to the broken line position, to the preamplifier 209, which then amplifies it to a given level and which also performs a processing such as a playback equalization. The reproduced RF signal is fed through the connector terminal Tbo to the picture monitor unit 300A where a video processing such as the color separation is performed in the same manner as the playback operation for the combination (11), and the signal is then input to the encoder 304. The subcarrier signal SC₂ from the generator 218 is supplied through the terminal Tao and the switch circuit 305 to the encoder 304, which then produces an NTSC color video signal, which can be immediately displayed on the NTSC display 307 to allow the reproduced image to be viewed. Also the output terminal 306 may be connected to an external television set to be viewed thereon. For the combination (14) where the record/playback unit 200A is used to perform a dubbing operation, the dubbing signal input terminal Tf and the dubbing vertical sync drive signal input terminal Tg are connected to an external record/playback apparatus. The switch 217 is activated to its broken line position while the switch circuit 216 is maintained in its solid line position, allowing the vertical sync drive signal V₄ to be fed to the motor drive control circuit 215. Consequently, the rotation of the spindle motor 212 is synchronized with the signal V₄. On the other hand, the signal supplied to the terminal Tf is fed to the second signal processing circuit 220 through the switch circuit 219 which is then activated to its broken line position. While not shown, the processing circuit 220 comprises a filter, an equalizer and a limiter to derive from the input signal an output signal which is similar in construction to the output from the first signal processing circuit 201. This output signal is fed to the record amplifier 207 through the switch 206 which is then activated to its broken line position. The amplifier 207 amplifies the output signal to a level which is suitable for recording, and the amplified signal is fed through the switch circuit 208 to the magnetic head 210. In this manner, an image which is previously recorded on the external recorder can be dubbed on the disc 211. For the combination (15), the dubbing unit 50 shown in Fig. 20 is combined with the record/playback unit 200A. A magnetic disc which has a signal previously recorded thereon is loaded into the record/playback unit 200A, whereupon it is mounted on the spindle motor 212 through the chuck member for rotation. The switch circuit 216 is now activated to its broken line position, whereby the vertical sync drive signal V₃ from the sync signal generator 218 contained within the record/playback unit 200A is fed to the motor drive control circuit 215. A signal reproduced by the head 210 is fed through the switch circuit 208, which is then activated to its broken line position, to the preamplifier 209 which amplifies it to a given level. The reproduced RF signal is fed through the switch circuit 219 to the second signal processing circuit 220. In the signal processing circuit 220, the reproduced signal is separated into the luminance signal component and the color difference signal component, which are equalized to signals suitable for recording and then mixed by a summing circuit to derive a signal which is similar to the output from the first signal processing circuit 201. The switch circuit 206 is activated to its broken line position, whereby this signal is fed to the record amplifier 207 to be amplified therein and then fed through the terminal Tco to be applied to the magnetic head 51 of the dubbing unit 50. On the other hand, the vertical sync drive signal V₃ from the generator 218 is fed through the switch circuit 216, which is then activated to its broken line position, and through the terminal Tdo to the motor drive circuit 56 within the dubbing unit 50. The disc 52 is driven for rotation at a rate of one revolution per period of the sync signal V₃. The rotation of the disc 52 is also controlled through a phase control which responds to the relative position of the head 51 with respect to the disc 52 as detected by the combination of the PG yoke 54 and the detecting coil 55. In this manner, a magnetic record is made on the magnetic disc 52 as referenced to the position of the PG yoke. The dubbing unit 50 disclosed is constructed as a simple arrangement including the spindle motor, the motor drive control circuit which drives the magnetic disc, the magnetic recording head and the chuck member, for ease of use of the electronic camera in extended applications. It should be noted that the individual switch circuits may be switched by a manual operation. Alternatively, a mode switching circuit may be used to achieve an automatic switching depending on the record or the playback mode. As a further alternative, an automatic switching may also be achieved depending on the particular combination of individual units as coupled together.

Claims: A detachable unit electronic camera for photoelectrical conversion of an image of an object being photographed to feed a picture monitor or to be recorded magnetically, comprising: a photographing unit (100) which includes a camera means which converts into an electrical signal an image of an object being photographed, which is focussed by an optical system, and a signal processing circuit (7) for producing a luminance signal (Y₁) and colour difference signals [(R-Y)₁ , (B-Y)₁] in response to an output signal from the camera means; a record/playback unit (200) which includes an image recording means responsive to an output signal from the signal processing circuit (7) for magnetically recording on a magnetic medium (19) a video signal which is based on said output signal, and magnetic reproducing means for reading a signal previously recorded on the magnetic medium (19); and a picture monitor unit (300) which includes a reproduced signal processing circuit (36, 37, 38, 39) responsive to a signal reproduced by the magnetic reproducing means for producing a reproduced luminance signal (Y₂) and reproduced colour difference signals [(R-Y)₂ , (B-Y)₂], an encoder (33) responsive to an output from the reproduced signal processing circuit for producing a composite colour video signal, and a display (35) for displaying a picture based on an output signal from the encoder; the photographing unit (100), the record/playback unit (200) and the picture monitor unit (300) being formed as detachable units which can be selectively coupled together by cooperating coupling means provided in each unit, characterised in that each of said units (100, 200, 300) has at least two coupling means (CN 1A , CN 2A ; CN₂ B , CN₃ B ; CN 1B , CN 3A , each of said at least two coupling means being capable of coupling to the associated coupling means of a different one of the other units connectible therewith; and in that a control means is provided in only one of said units (100, 200, 300) for selectively activating the other units connected therewith to operate to record signals when in a first state and to play back recorded signals when in a second state. A detachable unit electronic camera as claimed in claim 1, in which the camera means within the photographing unit (100) comprises a lens (1), an iris (2), a shutter (3) and CCD (4) on which an image of an object being photographed is focussed. A detachable unit electronic camera as claimed in claim 1 or 2, in which the signal processing circuit (7) within the photographing unit (100) comprises a circuit which receives an output from the camera means and a sync signal from a sync signal generator (5) for producing the luminance signal Y₁ and colour difference signals (R-Y)₁ and (B-Y)₁. A detachable unit electronic camera as claimed in claim 1, 2 or 3, in which the image recording means within the record/playback unit (200) comprises a luminance signal modulator (11), a line sequencing circuit (12), a chroma signal modulator (13), a summing circuit (14) which combines an output signal from the chroma signal modulator with an output signal from the luminance signal modulator, a record amplifier (15) for amplifying an output signal from the summing circuit, a recording and reproducing magnetic head (18) to which and from which a signal is fed from or to the amplifier, and a magnetic disc (19) on which a signal is magnetically recorded by the head. A detachable unit electronic camera as claimed in claim 1 in which the magnetic reproducing means within the record/playback unit (200) comprises a recording and reproducing magnetic head (18) which reproduces a recorded signal from the magnetic medium (19), and a preamplifier (17) for amplifying a reproduced signal from the head. A detachable unit electronic camera as claimed in any of claims 1 to 5, in which the reproduced signal processing circuit within the picture monitor unit (300) comprises a colour separation circuit (36), a luminance signal demodulator (37), a chroma signal demodulator (38) and a time coincidence circuit (39). A detachable unit electronic camera as claimed in any of claims 1 to 6, in which each coupling means includes means for electrically connecting the unit in which the coupling means is provided to an associated unit to thereby provide electrical connections therebetween. A detachable electronic camera as claimed in claim 7 wherein each unit is provided with a plurality of coupling means for simultaneously releasably electrically coupling each unit to a plurality of other units. A detachable unit electronic camera as claimed in claim 8 wherein selected signals developed in each of said units are electrically coupled in common to a plurality of coupling means provided in said unit.

Inventors: FUKUDA, YOSHIO, HARADA, HISAYUKI, IDA, MASATOSHI, INOUE, MANABU, KATOH, AKIRA, YUNOKI, YUTAKA
Applicants: OLYMPUS OPTICAL CO., LTD.
Application year: 1985
Main classification: H04N5
IPC codes: H04N5, H04N9, G11B27, G11B31