JP2616909B2 - Electronic still camera - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic still camera that records a video signal indicating a still image of a subject on a rotating recording medium such as a magnetic disk on each track of the rotating recording medium.

[Background of the Invention]

Recently, a combination of an imaging device such as a solid-state imaging device or an imaging tube, and a recording device using a magnetic recording medium such as a magnetic disk having a relatively large storage capacity as an inexpensive recording medium,
2. Description of the Related Art An electronic still camera has been developed in which a still image of a subject is captured, a still image thereof is recorded on a magnetic recording medium, and an image is reproduced by a separate reproducing device or the like.

In such an electronic still camera, for example, one track is formed of a plurality of tracks formed on a magnetic disk.
A video signal indicating a still image for a frame is recorded. For example, a moving image is shot in a single shooting mode in which a shooting operation is completed for each frame, and one frame of the moving image is recorded as a still image on one track or continuously shot for a predetermined number of frames at a predetermined time. It is possible to reproduce a moving image to some extent by shooting in a transfer mode in which the operation is performed and recording the moving image continuously on a plurality of tracks.

By the way, in a conventional electronic still camera capable of shooting in the transfer mode, the image recording of each track is performed by moving the magnetic head from the home position set at the outermost circumference of the magnetic head to the innermost circumference side of the magnetic head during shooting and recording. Track search for returning the magnetic head to the home position again, and then moving the magnetic head to the first consecutive empty track. For this reason, there is a problem that a long time is required for the track search, and the photographing cannot be performed immediately.

[Object of the invention]

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electronic still camera that can reduce the time required for track search.

[Summary of the Invention]

In order to achieve the above object, the present invention drives a rotary recording medium such as a magnetic disk to rotate, and moves a magnetic head by a predetermined pitch from an outer peripheral side to an inner peripheral side in a radial direction of the rotary recording medium, An electronic still camera that magnetically records a video signal representing a still image of a subject concentrically on each track of a rotary recording medium, and a single shooting mode in which a shooting operation is terminated for each frame and a predetermined number of frames continuously. A magnetic head moving means for moving a magnetic head in a radial direction of a rotary recording medium, and detecting presence / absence of image recording of each track from a signal obtained from the magnetic head. Recording state detecting means for detecting the home position of the magnetic head further inside the innermost track of the rotating recording medium; And a photographing mode selecting means for selecting one of the photographing modes from the continuous shooting mode, and the output signals of the magnetic head transfer means, the recording state detecting means and the position detecting means, and the rotating recording medium is stored in the camera body. When the video head is loaded at a predetermined position and the continuous shooting mode is selected by the shooting mode selection means, the magnetic head is moved to the outer peripheral side from the home position prior to the recording operation when recording a video signal. The presence or absence of continuous empty tracks equal to or more than the number of frames is detected. When it is detected that there are continuous empty tracks and the first image recording track is detected, the track is returned to the inner peripheral side by one track, and And control means for controlling the magnetic head transfer means so as to be in a standby state.

〔Example〕

Hereinafter, preferred embodiments of an electronic still camera according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the configuration of an embodiment of the electronic still camera according to the present invention. In FIG. 1, the imaging unit of the electronic still camera mainly includes an afocal lens 10, an aperture 12, a master lens 14, a shutter 16, and a solid-state image sensor (CC in this embodiment).
D is used), an imaging optical system composed of 18;
An aperture drive device 20 drives the aperture 12, a shutter drive device 22 drives the shutter 16, and an automatic exposure control circuit 24 controls the aperture drive device 20 and the shutter drive device 22.

The solid-state imaging device 18 has a vertical drive circuit 28 that operates in response to a pulse signal output from the timing pulse generation circuit 26,
Driven by a drive signal from the horizontal drive circuit 30. The timing pulse generation circuit 26 is a circuit that generates various pulse signals for controlling each circuit section of the electronic still camera.

Further, the imaging unit samples the primary color signals R, G, and B obtained from the solid-state imaging device 18 and amplifies the signals to a predetermined level, and converts the color temperatures of the primary color signals R, G, and B output from the preamplifier 32 to white. A process circuit 34 that adjusts to a predetermined value based on the output signal from the balance circuit 44,
A gamma correction circuit 36 for performing color signal processing for gamma correction of the primary color signals R, G, and B output from the process circuit 34, and a predetermined signal based on the primary color signals R, G, and B output from the gamma correction circuit 36 luminance signal Y _H has a bandwidth, and Y _L -Y _H,
Matrix circuit for generating color difference signals R-Y _L and B-Y _L
Based on these signals output from the matrix circuit 38, the NTSC video signal NTSC, the luminance signal Y + S including the composite synchronization signal S, and the color difference signals RY, B-
And an encoder 40 for synthesizing Y and Y.

The NTSC signal output from the encoder 40 is output to the electronic viewfinder 43 via the high voltage generation circuit 42, so that the subject image is displayed on the screen of the electronic viewfinder 43.

On the other hand, the recording system circuit includes a pre-emphasis circuit 48 for performing a predetermined frequency correction on the luminance signal Y + S among the signals synthesized by the encoder 40, and an FM modulation circuit for FM-modulating the luminance signal Y + S output from the pre-emphasis circuit 48. 50
And the color difference signal R-
A line-sequential circuit 52 for converting Y and BY into a line-sequential color difference signal
A pre-emphasis circuit 54 for performing predetermined frequency correction on the line-sequential color difference signal output from the line-sequential circuit 52, an FM modulation circuit 56 for FM-modulating the line-sequential color difference signal output from the pre-emphasis circuit 54, Differential phase shift keying (DPSK) for recording data according to a predetermined format (for example, converting shooting data into a data signal having a frequency of about 200 KHz)
A circuit 58, an FM luminance signal output from the FM modulation circuit 50,
FM line sequential color difference signal output from FM modulation circuit 56, DPSK
A mixer 59 that mixes three signals with various data signals output from the circuit 58 to create a recording FM video signal, and a preamplifier that sets the recording FM video signal output from the mixer 59 to a predetermined level 86 and FM output from preamplifier 86
And a magnetic head 64 for recording video signals.

The preamplifier 86 is described as having two components, a recording amplifier and a reproduction amplifier described later, and performs a switching operation in response to a gate signal output from the gate circuit 84 for a predetermined period.

The magnetic head 64 can be moved in the radial direction along the recording surface of the magnetic disk 66 by the head drive motor 62 as conceptually indicated by the one-dot chain line 65. Head drive motor
62 is supplied with drive pulses of four layers A, B for performing 1-2 phase excitation by a motor drive circuit 60 which operates in response to a motor drive signal consisting of 8 bits output from a control circuit 82. . The transfer direction of the magnetic head 64 is determined by the rotation direction of the head drive motor 62, and the transfer distance of the magnetic head 64 is proportional to the rotation angle. For example, the head drive motor 62 rotates about 18 ° per one pulse of the shift pulse of the head drive motor 62, whereby the magnetic head
64 is transferred about 5 μm. Therefore, the transfer of 100 μm (one track) is performed by the 20 shift pulses.

A home position is set further on the inner circumferential side of the innermost track in the recording area of the magnetic disk 66.
This home position is not a position attached to the magnetic disk 66, but is an extreme position allocated on the movement path of the magnetic head 64. This home position is detected by the number of shift pulses. The transfer of the magnetic head 64 from the home position to the outer peripheral side is forward feeding, and the transfer in the reverse direction is reverse feeding.

On the other hand, the magnetic disk 66 is a rotating shaft of the spindle motor 70.
It is removably mounted on 68, and is regularly rotated in a predetermined direction by a spindle motor 70, a frequency generator (FG) 72, a PG detection coil 74, a waveform shaping circuit 76, a servo control circuit 78, and a motor drive circuit 80.

The PG detection coil 74 detects a magnetic PG yoke (not shown) embedded in the rotating shaft of the magnetic disk 66, and a PG signal obtained with the detection passes through a waveform shaping circuit 76 and a servo control circuit. 78, the gate circuit 84, and the timing pulse generation circuit 26.

The gate circuit 84 outputs a gate signal to the preamplifier 86 based on the PG signal detected by the PG detection coil 74 and the recording / reproduction command signal output from the control circuit 82.

When the power switch SW3 is closed, the aperture drive circuit 20
Is supplied with power, and the aperture 12 is driven and controlled, and the solid-state imaging device 18 is also driven.

Preamplifier 32, process circuit 34, gamma correction circuit
36, matrix circuit 38, encoder 40, high voltage generation circuit
Power is supplied to the electronic viewfinder 43, the electronic viewfinder 43, and the like. As a result, the subject image can be monitored by the electronic viewfinder 43.

After the power switch SW3 is closed, the spindle motor 70
It is activated by the operation of the shutter release button 90. That is, in this embodiment, the shutter release button 90 operates in a two-step stroke, and the switch SW is operated in the first stroke of the pressing operation.
1 is closed, and power is supplied to each circuit unit of the recording system including the motor drive circuits 60 and 80. As a result, the servo control circuit 78
Outputs a drive signal for driving the spindle motor 70 via the motor drive circuit 80 to the spindle motor 70.
Further, the switch SW2 is closed in the second stroke of the pressing operation of the shutter release button 90, whereby the control circuit 82 controls the operation of each circuit unit so as to perform shutter release, photographing, and recording. With such a configuration, the power consumption of a power source such as a battery is configured to be avoided.

Reference numeral 88 denotes an envelope detection circuit. The envelope detection circuit 88 reproduces the reproduced signal output through the preamplifier 86.
The envelope detection of the FM video signal is performed, and the detection output is output to the control circuit 82. The control circuit 82 performs a track search for checking the presence / absence of recording on each track of the magnetic disk 66 based on the detection output of the envelope detection circuit 88, or determines the presence / absence of a dropout generated on the magnetic disk 66.

The NTSC video signal output from the encoder 40 is visualized by the electronic viewfinder 43 via the high voltage generation circuit 42, passes through the buffer amplifier 46, and is output to the outside via the video signal output terminal T1.

The control circuit 82 is a circuit that controls and controls the operation of the entire apparatus including a memory device such as a ROM in which various interfaces and control programs are stored. ) To set the continuous shooting speed setting switch 92, the number of shots during transfer,
Alternatively, various controls are performed based on a switch group 93 or the like for instructing a mode of photographing and recording. The control circuit 82 is provided with a frame counter for counting the number of frames shot in the continuous shooting mode, and stores the number of unrecorded tracks on the magnetic disk 66, that is, the number of frames that can be shot.
A memory such as a RAM is provided.

Further, in the control circuit 82, there is provided an auto power off timer for automatically turning off the power when the release operation is not performed for a fixed time or more from the time when the power is turned on. .

The continuous shooting speed setting switch 92 is provided with eight contacts (contacts a, b, c, d, e, f, g, and h) that are manually selected. Is determined. In the present embodiment, for example, shooting at 15 frames / sec is performed by selecting the contact a, and thereafter, by selecting the contact b to the contact h, 10 frames / sec.
Frames / second (contact b), 5 frames / second (contact c), 2 frames /
Second (contact d), 1 frame / second (contact e), 1 frame / 2 seconds (contact f), 1 frame / 5 seconds (contact g), 1 frame / 10 seconds (contact h) are performed. It has become.

A key group 93 includes, for example, a shooting mode selection switch 94 for selecting a single shooting mode for terminating a shooting operation for each frame or a continuous shooting mode for continuously shooting a predetermined number of frames at a predetermined time, and a shooting mode selection switch 94 based on these shooting modes. Mode switch 95 for instructing field recording or frame recording of still images shot by camera, shooting number setting switch 96 for setting the number of shots during continuous shooting, and increasing / decreasing the setting value of the number of shots And an up / down switch 97 for instructing the operation. The shooting mode selection switch 94 is configured to select, for example, in the open state, the single shooting mode, and in the closed state, the continuous shooting mode.The recording mode switch 95 is, for example, in the open state. When the field recording is in the closed state, the frame recording is performed respectively.

The number-of-frames setting switch 96 is a push switch, and when the up-down switch 97 is switched to the contact UP side, if the number-of-frames setting switch 96 is kept pressed, the set value of the number of frames increases and the contact DOWN side If the switch 96 is kept depressed while the up / down switch 97 is switched, the set value of the number of frames to be shot is decreased. The set value of the number of shot frames is displayed on the liquid crystal display device 98.

Reference numeral 99 denotes a buzzer for issuing a warning when there is no unrecorded track on the magnetic disk, that is, when the number of photographable frames is zero.

Next, the operation when the continuous shooting mode is selected by the shooting mode selection switch 94 will be described with reference to the flowchart of FIG. Note that the magnetic head 64 counts the number of shift pulses output from the motor drive circuit 60 as described above by the initial processing executed by the control circuit 82 when the power switch SW is turned on, and
64 is returned to the home position further provided on the inner circumferential side of the innermost track of the recording area of the magnetic disk. In the figure, after the power switch SW3 is turned on to supply power to the reproducing system, the magnetic disk pack containing the magnetic disk 66 is loaded at a predetermined position in the camera body, and the magnetic disk pack is continuously operated by the photographing mode selection switch 94. When the photographing mode is selected, a drive command for forward transfer for transferring from the home position provided on the inner peripheral side of the magnetic disk 66 to the outer peripheral side is given to the motor drive circuit 60, and the magnetic head
64 are sequentially transferred to the outer peripheral side (step 104). When the magnetic head 64 is moved to the outer peripheral side, the detection output of the envelope detection circuit 88 is sequentially taken into the control circuit 82 in accordance with the movement of the magnetic head 64, and the presence or absence of image recording of each track is detected based on the detection output. Is performed (step 106). Then, it is determined whether or not there is a continuous empty track based on the detection (step 108).

If there is a continuous empty track, it is determined whether or not the next track is an image recording track (step 11).
0). This process is continuously performed until a continuous track is detected and then an image recording track is detected. When an image recording track is detected after the continuous empty track, a command for temporarily stopping the magnetic head 64 is given to the motor drive circuit 60, and the magnetic head 64 is temporarily stopped (step 112). Thereafter, a command to transfer the magnetic head 64 in the reverse direction is given to the motor drive circuit 60, and the magnetic head 64 is transferred to the inner peripheral side (step 114). When an empty track is detected by this transfer (step 116), the magnetic head 64 is stopped at the position of the first empty track (step 118), and the magnetic head 64 waits at this position. That is, when an image recording track is detected after a continuous empty track, the magnetic head is returned from the image recording track to the inner circumferential side of one track, and the magnetic head 64 waits at a position of an empty track adjacent to the image recording track. .

As described above, in the present embodiment, when the continuous shooting mode is set, the magnetic head 64 does not need to be moved from the home position provided on the outermost peripheral side of the magnetic disk to the innermost peripheral side, so that the magnetic head 64 is continuously moved to the empty track. Can be transported to the position of the first designated track, so that the time required for track search can be reduced.

〔The invention's effect〕

As described above, according to the present invention, in an electronic still camera having a continuous shooting mode, it is necessary to perform a track search from a home position to detect a continuous empty track required for continuous shooting. The home position is provided further inside than the position of the innermost track, and the track search is performed from this home position (that is, the direction in which recording is sequentially performed by the magnetic head, the direction in which the track search is performed from the home position, and the direction in which the track search is performed). Therefore, the time required for performing the track search and thereafter transferring the magnetic head to a required empty track can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the electronic still camera according to the present invention, and FIG. 2 is a flowchart showing the contents of a program executed by the control circuit in FIG. 62 ... header drive motor, 66 ... magnetic disk, 82 ...
Control circuit, 88: Envelope detection circuit, 90: Release button, 92: Continuous shooting speed setting switch, 94: Magnetic mode setting switch, 95: Recording mode switch, 96
…… Shooting frame number setting switch, 97 …… Up / down switch.

Continued on the front page (72) Inventor Kazuya Oda 2-26-30 Nishiazabu, Minato-ku, Tokyo Fuji Photo Film Co., Ltd. (72) Inventor Kimihide Takahashi 2-26-30 Nishiazabu, Minato-ku, Tokyo Fuji Photo Film (56) References JP-A-59-52473 (JP, A) JP-A-59-71102 (JP, A) JP-A-59-42670 (JP, A)

Claims (1)

(57) [Claims] A rotating recording medium such as a magnetic disk is driven to rotate, and a magnetic head is moved by a predetermined pitch from an outer peripheral side to an inner peripheral side in a radial direction of the rotating recording medium to show a still image of a subject. An electronic still camera that magnetically records a video signal concentrically on each track of a rotating recording medium,
In an electronic still camera having a single shooting mode in which a shooting operation is completed for each frame and a continuous shooting mode in which a predetermined number of frames are continuously shot, a magnetic head transfer for transferring a magnetic head in a radial direction of a rotary recording medium Means, a recording state detecting means for detecting the presence or absence of image recording of each track from a signal obtained from the magnetic head, and a position detection for detecting a home position of the magnetic head further inside the innermost track of the rotary recording medium. Means, a photographing mode selecting means for selecting one of the photographing modes from the single photographing mode and the continuous photographing mode, and taking in the output signals of the magnetic head transferring means, the recording state detecting means and the position detecting means, and A video signal is output when a recording medium is loaded at a predetermined position in the camera body and a continuous shooting mode is selected by the shooting mode selecting means. Together at the time of recording for transferring the magnetic head before a recording operation on the outer peripheral side of the home position, and detecting the presence or absence of empty trucks which the predetermined number of frames or more continuously was during the transfer,
Control means for controlling the magnetic head transfer means to return to the inner peripheral side by one track when it is detected that there are continuous empty tracks and to detect the first image recording track, and to wait at the track; An electronic still camera comprising: