JPS60105383A - Electronic still camera - Google Patents

Abstract

PURPOSE:To prevent that the data record of the final track is destructed by detecting that the track for recording the unrecorded image signal is one final track only, by inhibiting the operation of the frame photographing and by switching to the field photographing. CONSTITUTION:The signal preserved at a solid-state pickup element 7 is read with a signal processing circuit 8 and is outputted to a magnetic head 10 as an image signal. A selective change-over switch 15 selects the frame photographing or the field photographing, and in case of the frame photographing, for two tracks, and in case of the field photographing, only for 1 track, a magnetic head 10 is shifted toward the center of a magnetic sheet 12. A track counter 18 counts the number of the recorded tracks. When a head 10 reaches the position corresponding to one track ahead of the final track, the prescribed signal is outputted. The frame photographing is inhibited and is switched to the field photographing with the signal.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention relates to an electronic still camera using a magnetic recording method.

Conventional electronic still cameras using the magnetic recording method complete one frame of image by recording one or two fields of video signals, similar to the interlaced scanning method used in broadcast television.
One track on the magnetic sheet is used for field recording, two tracks provide one space, and the 51st track is used for recording rt data and the like.

Therefore, when photographing is performed with two fields and one frame, it is possible to photograph 25 frames, which corresponds to one 25-frame photograph using silver halide film. By the way, when recording a video signal for one field, the number of scanning lines is half of the normal number, but since that alone constitutes one screen, it is possible to record it as one photograph if you accept some roughness in the image. It is possible, and in some cases it is sufficient, and sometimes you want to record as many screens as possible on a single magnetic sheet, but with magnetic recording electronic still cameras, it is possible to record only one field by switching. Shooting and 2 Feel 1.1
You can select any frame to shoot.

By the way, when using an electronic still camera like the one mentioned above, if you mix field shooting or shooting two fields and one frame, two tracks (the 500th and 51st tracks in the upper part) may remain at the end. be. in this case,
The last shooting should only be possible for one field shooting, but if you accidentally select frame shooting, the last 5
The second field is recorded on the first track,
There was a fear that the records of the photographic data that had already been recorded would be destroyed.

Furthermore, as mentioned above, if the 500th and 51st tracks remain, if frame recording is selected, recording will not be performed on the 51st track even though the recorded information will be destroyed. In this configuration, it is necessary to switch from frame recording to field recording to take a picture, which complicates the operation and may lead to a missed photo opportunity.

Purpose The present invention provides a tracker capable of recording video signals (even if you accidentally select l-frame shooting when there is only one remaining track, only one field's worth of shooting is performed and the data of the last track is saved). The objective is to provide an electronic still camera that does not destroy records, is easy to operate, and does not let you miss a photo opportunity.

Structure According to the present invention, when it is detected that the last unrecorded track among the video signal recording tracks on the magnetic sheet, the operation of photographing one frame is prohibited by the detection signal, and the operation of photographing one frame is prohibited. The present invention is characterized in that one-field photographing is performed even when the above is selected, or in that a warning is displayed in that case.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The figures show one embodiment of the present invention. First, an overview of the electronic still camera itself will be explained using FIG. 1 in Figure 1
is the camera body, 2 is the shooting lens, 3 is the lens aperture, and 4
is the shutter. Reference numerals 6 and 6 are mirrors for the finder, and 13 is an eyepiece lens for the finder. 5 is the release button of the camera; when this is pressed, the shutter 4 opens for a predetermined period of time. 7 is a solid-state image sensor, which is installed at the focal position of the photographic lens 2. When the shutter 4 is opened for a predetermined time, the solid-state imaging device 7 is exposed to light, and the device integrates the current during exposure and holds a photoelectric conversion signal. A signal processing circuit 8 reads out the signal held in the solid-state image sensor 7 and outputs it to the magnetic head 10 as a video signal. 11 is a magnetic sheet pack with a disc-shaped magnetic sheet 12
The magnetic sheet 12 is rotated by a drive motor 14. For example, magnetic heads come in sets of two, and in the case of 1-frame photography, a video signal is input to the first magnetic head during the first revolution of the magnetic sheet, and the first field is recorded on a track of one circumference. In the next rotation, the video signal is input to the second magnetic head, and the second field is recorded on the inner track of the first field.

In the case of one-field imaging, a video signal is input to the first magnetic head and only the first field is recorded.

9 is a magnetic head moving device, and 15 is a selector switch for selecting 1-frame shooting or 1-field shooting.When recording of one shooting is finished, in the case of 1-frame shooting, 2 trunks are selected,
(2) In the case of field photography, move the magnetic head lO toward the center of the magnetic sheet 12 by ltrough 0 minutes. As mentioned at the beginning, the magnetic sheet has space for 51) ranks concentrically in one track per circumference, and the last trunk is for recording photographic data.

This concludes the general description of the electronic still camera, and examples will be described. FIG. 2 is a block diagram of the magnetic recording circuit in the embodiment. In this figure, reference numeral 16 denotes a synchronization signal generator that sends a horizontal synchronization signal and a vertical synchronization signal to the solid-state image sensor 7 to drive the solid-state image sensor 7. Synchronous signal generator 1
The vertical synchronization signal (b) from 6 is input to a recording start/end signal generator 17 for controlling the start and end timing of recording on the magnetic sheet, and the recording start/end signal generator 17 is input to the release button 5. A recording start signal (C) is generated at a timing corresponding to the vertical synchronization signal (b) by the trigger signal (a) of the switch SW, which is closed upon completion of the exposure operation started by pressing the button.

The video signal processing circuit 8 reads the output of the solid-state image sensor 7 in response to the recording start signal (c) and starts supplying it to the magnetic head IO. Reference numeral 18 denotes a track counter within the camera body, which advances the count and displays the counted value each time the magnetic head 1o records one field of the magnetic sheet 121j.sub.l, that is, one track. This display allows you to know which track number has been photographed.

The track counter 18 outputs a final track detection signal when the outer head of the two magnetic heads arranged in parallel in the radial direction of the loaded magnetic sheet is moved to a position corresponding to the 500th track. , and when the head on the outer circumferential side is moved to a position corresponding to the 51st track, a track end signal is output. Both the final track detection signal and the track end signal are input to the recording start/end signal generator 17.

Specifically, the track counter 18 is a mechanical counter having a rotor that rotates by one scale for driving one track in conjunction with the magnetic head drive mechanism 9. It is also possible to manually move the magnetic head 10 over any trunk by manually turning the knob, and it returns to the count 1 position when a new magnetic sheet pack is attached to the camera. Therefore, the number displayed by this counter is the number of the track on which video recording is to be performed, and the signal emitted at count 50 is a signal indicating that there is only one last track that can be recorded. The signal emitted at count 51 is a signal indicating the end of photographing one magnetic sheet pack. These signals are sent to a recording start/end signal generator 17.

FIG. 3 is a time chart illustrating the normal operation of the above-mentioned @formation. In the figure, A shows the operation in the case of 1-field photography, and B shows the operation in the case of 1-frame photography. In both cases, b is the vertical synchronizing signal output from the synchronizing signal generator, and a is the switch Sw (second The trigger pulse formed by the Fig. In the case of 1-field photography in A, at the first fall of the vertical synchronization signal during the presence of the tri-force pulse a, the output of the recording start/end signal generator 17 becomes high level as shown in c in the same figure, and the next vertical synchronization Returns to low level at the falling edge of the signal. While the recording start signal C output from the recording start/end signal generator 17 is at a high level, the video signal is recorded on the magnetic sheet, and the recording of the video signal of the field is completed by one cycle of the vertical synchronizing signal. From, 7
A signal indicated by d in the figure is sent to the magnetic head drive mechanism 9, and the magnetic head 10 is driven by one track. In the case of shooting one frame of B, as shown by C in FIG. 3B, the output C of the recording start/end signal generator 17 becomes high level at the first vertical synchronization signal while the signal a is high, and the next It returns to a low level with the next vertical synchronization signal, during which recording for two fields and one frame is performed, two magnetic head drive signals d are issued, and the magnetic head is moved by two tracks.

FIG. 4 shows the internal groove of the recording start/end signal generator 17. When the switch Sw closes upon completion of the exposure operation, the differential circuit 2
0, a set pulse is applied to the RS flip-flop 21, the Q output of the flip-flop becomes high, and the AND gate 22 is opened. Open Antogenide 22
Through this, the first vertical synchronization signal VSync is applied to the first trigger flip-flop 23, and the Q output of the flip-flop becomes high. This high level output is sent to the changeover switch circuit 28. The switch circuit is switched by selecting either 1 frame shooting or 1 field shooting, and in the case of L field shooting, the contact A side is conductive;
When shooting one frame, the contact port is conductive. In the case of one-field photography, the Q output of the T flip-flop 23 is sent to the AND gate 27 through the changeover switch circuit 28.

A 51st track detection signal (imaging end signal) is applied to the gate. This signal is normally high level and becomes low level when the last track is detected, so the AND gate 27 is normally open and the third
A recording start signal indicated by C in Figure A is output. This signal opens the AND gate 29, and while the gate is open, seven vertical synchronizing signals VSync pass through, and this becomes the signal d in FIG. 3A, and the magnetic head 10 Only one track is driven. Since the AND gate 27 is closed when the last track is detected, even if the Q output of the T flip-flop 23 is applied, the output of the AND gate 27 is at a low level and the image is displayed on the last track (51st track). No signal is recorded.

When photographing one frame, the contact port side of the changeover switch 28 is conductive. In this case, when the second vertical synchronization signal causes the Q output of the first T flip-flop 23 to go low, the second T flip-flop 24 is triggered and its Q output goes high; The output is outputted through the AND gate 27 and becomes the signal shown as C in FIG.
The magnetic head is moved by two trunks in response to the signal shown by . In the case of 1 frame photography, the selector switch 15 for selecting either 1 frame photography or 1 field photography comes into contact with the upper contact point to set the 10,000 input terminal of the AND gate 25 at a high level. The 500th track detection signal is applied to the other input terminal of the AND gate 25 through the inverter 30. This signal is normally low level and becomes high level when the 50th detection detector is detected. Therefore and gate 2
5 is normally open, and when one frame photographing is selected, a high level signal is sent to the selector switch circuit 28 to set the switch to the one frame photographing mode, that is, the state in which contacts A and B are both conductive. Even if you select l-frame shooting when the 50th trunk is detected, the AND gate 25 is closed, so the high-level signal for l-frame shooting selection is not sent to the changeover switch circuit 28, and the same process occurs. The changeover switch is for l-field photographing mode, and in the end, only l-field recording is performed on the 50th track, thereby achieving the object of the present invention.

Note that 19 is a warning lamp, and if one frame shooting is selected while the 50th track is detected, the output of the AND gate 26 becomes high level and the lamp lights up.
Displays that only one field shooting is possible. Also l
Whether it's field shooting or single frame shooting,
The inverted signal of the recording start signal, which is the output of the AND gate 27, is differentiated by a differentiating circuit 31, and the differential pulse, that is, the fall of the recording start signal, resets the RS flip-flop 21 and returns the circuit to its original state.

Effects The electronic still camera of the present invention has the above-described configuration, and even if one frame shooting is selected on the final track for recording video signals, it automatically switches to one field shooting and the data recording on the data recording track is saved. Therefore, the user can shoot without worrying about selecting between 1-frame shooting and 1-field shooting.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a longitudinal cross-sectional side view of the camera body, Fig. 2 is a block diagram of the magnetic recording circuit, and Fig. 3 is a block diagram of the magnetic recording circuit.
The figure is a time chart of the operation, and FIG. 4 is a block diagram showing the inside of the recording start/end signal generator. 1...Camera body, 2...Photographing lens, 7...
Solid-state image sensor, 8--Signal processing circuit, 10--Magnetic head, 12--Magnetic sheet, 15--Selection switch, 16--Synchronization signal generator, 17-- Recording start/end signal generation vessel. Representative Patent Attorney Kosuke Agata

Claims (2)

[Claims] (1) Selection switching means between 1-frame shooting and 1-field shooting, and for recording video signals on magnetic recording media! - It has a means for detecting that the magnetic head is located at a position facing the final track in the rack, and when the above detection signal is output from the detecting means, the video signal of the second field in 1 frame shooting is detected. An electronic still camera characterized by having a prohibition means for prohibiting recording. (2) The electronic still camera according to claim 1, further comprising warning means activated by a detection signal emitted from means for detecting the presence of the magnetic head at a position facing the final track.