JPS61262381A - Electronic still camera - Google Patents

Abstract

PURPOSE:To prevent the flow of over current at one time and to fasten the speed of a continuous photographing by starting up a charge motor during the pause period of conduction to move a head while the head is moved by two tracks in a frame recording. CONSTITUTION:After the completion of a recording, the conduction to a head driving solenoid is made and a ratchet is rotated by a driving circuit 15 as shown at figure (g) and the head is moved by one track. And after that, the conduction to the solenoid is cut and the conduction is paused for a prescribed time necessary to return the ratchet to a fixed position. And as shown at figure (h), a charge motor 17 is started up by a charge motor driving circuit 16 during the pause period and the charging operation of a shutter is started. After the completion of the conduction pause period stated above, the conduction to the solenoid is made again and the head is moved to the next recording track position. In the continuous photographing, after a charging, the conduction is made again to a relay magnet, magnets for trailing shutter and leading shutter and thereafter, the above stated operation is repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electronic still camera that records instantaneous images of a subject.

Conventional technology Generally, video signals are recorded on a recording medium such as a magnetic sheet,
One of the major features of playback electronic still cameras is that, unlike cameras that use silver halide film, recorded footage can be instantly played back and viewed. The ability to erase images and re-record them any number of times.

An example of a conventional electronic still camera will be described below with reference to the drawings. FIG. 2 shows an example of the configuration of an electronic still camera. Figure 3 is a timing diagram showing the signals of each part of a conventional electronic still camera.
is the vertical synchronization signal, (value) is the release signal, (6) is the release magnet drive signal, (a is the front curtain magnet drive signal, (e) is the rear curtain magnet drive signal, (is the recording gate signal, (ml is the head The drive signal (h) is a charge motor drive signal.

When the release signal shown in FIG. 3(b) is sent to the system control circuit 2 by pressing the release button 1, aperture information is sent to the aperture control circuit 3 and the aperture υ4 is set to a predetermined aperture value. It is narrowed down to At the same time, the front curtain magnet drive signal and the rear curtain magnet drive signal shown in FIG. 3(d) and (+5) are sent from the shutter drive circuit 6 to the shutter 6 to drive the front curtain magnet (not shown) and the rear curtain magnet. (not shown) is energized to hold the leading and trailing curtains, and at the same time, the release magnet drive signal shown in FIG. 3(C) is sent, and the shutter 60 locking lever (not shown) is released. The shutter becomes ready for operation. When the aperture 4 has stopped down, etc. and the exposure level has been reached, the power to the front curtain magnet is cut off in synchronization with the vertical synchronization signal shown in FIG. 3 (11), the shutter 6 begins to open, and the lens optical system 7 A subject image is formed on the imaging surface of the solid-state image sensor 8. After the shutter 6 is opened, when a preset shutter time or a shutter time obtained by photometry or the like elapses, the power to the trailing curtain magnet is cut off, the shutter 6 is closed, and the exposure is completed. The image sensor 8 is composed of mxn COD elements arranged in a two-dimensional array on an IJ hook, and is time-series in synchronization with a reference signal that has accumulated charge according to the brightness of the picture element corresponding to each division. The video signal processing circuit 9 outputs the video signal as a video signal. This video signal is shown in Figure 3 (IL)
A frame image is recorded on two adjacent tracks of a recording medium 11 such as a magnetic sheet by a recording circuit 10 in response to a recording gate signal f synchronized with a vertical synchronization signal shown in FIG. Note that 12 is a magnetic head, 13 is a disk motor, and 14 is a disk motor drive circuit. After recording is completed, since the head 12 must move two tracks during frame recording, the head drive circuit 16 energizes a head drive solenoid (not shown) as shown in FIG. 3(g).
Rotate the ratchet (not shown) to move the head one track. Then, the solenoid is de-energized, and after the energization is stopped for a predetermined time required for the ratchet to return to the fixed position, the solenoid is energized again to move the head one more track and move the head to the next recording track position.

After the head movement is completed, the charge motor 17 is driven by the charge motor drive circuit 16 as shown in FIG. 3(h), the shutter is initialized (hereinafter referred to as charge), and the -th photographing operation is completed. During continuous shooting, after charging is completed, the release magnet, front curtain magnet, and rear curtain magnet are energized again, and the above-mentioned operation is then repeated to perform continuous shooting.

Problems to be Solved by the Invention However, with the above configuration, since charging is performed after the head has finished moving, the time required for -times of shooting becomes long, and continuous shooting speed cannot be increased. There is. Also, in order to increase the continuous shooting speed, it is possible to move the head and charge it at the same time, but since the current required for head drive and charging is large, if you try to do it at the same time, the current required will be too large. Since current cannot be supplied unless a power source with a large capacity is used, battery operation becomes impossible, and this becomes a major obstacle to miniaturizing devices.

In view of the above-mentioned problems, the present invention has been developed by starting the charge motor during the pause period in which the head moving solenoid is not energized while the head moves two tracks during frame recording, thereby reducing the large starting current when starting the charge motor. To provide an electronic still camera that prevents excessive current from flowing at once by preventing the timing of solenoid energization from overlapping with the timing of energization of the solenoid, which can be driven by batteries, and which can increase continuous shooting speed. .

Means for Solving the Problems In order to solve the above-mentioned problems, the electronic still camera of the present invention includes an imaging system that forms a subject image on the imaging surface of an image sensor and generates a video signal corresponding to the subject image. means, an exposure control means for controlling the exposure amount of the imaging surface, a recording means for recording the video signal on a recording medium via a recording head, and after energizing the head drive section for a first predetermined period, Second
head moving means for moving the recording head to the next recording position by suspending energization of the head drive unit for a first predetermined period and then energizing the head drive unit again for a first predetermined period; The apparatus further includes a charging means for performing an initial setting of the control means, and is configured to start operation of the charging means during a second predetermined period when power supply to the head moving section is suspended.

Effect of the Invention With the above-described configuration, the present invention starts the charge motor during the period when the head drive section is not energized when the head is moved.
Since the timings at which the current flows to the head drive unit do not overlap, a large current does not flow at once, and the continuous shooting speed can be increased by battery drive.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a timing diagram in one embodiment of the present invention.

In Figure 1, (1) is a vertical synchronization signal, (b) is a release signal, (C) is a release magnet drive signal, (d
) is a leading curtain magnet drive signal, (6) is a trailing curtain magnet drive signal, (f) is a recording gate signal, (g) is a head drive signal, and (h) is a charge motor drive signal.

The operation will be explained below using the first factor and FIG. 2. When the release button 1 is suppressed, the release signal shown in FIG. The aperture is narrowed down to the predetermined aperture value. At the same time, the shutter drive circuit 6 (d) in FIG.
The front curtain magnet drive signal and the rear curtain magnet drive signal shown in (6) are sent to the shutter 6, and the front curtain magnet and the rear curtain magnet are energized to hold the front curtain and the rear curtain, and at the same time, as shown in FIG. The release magnet drive signal shown in (0) is sent, the locking lever of the shutter 6 is released, and the shutter becomes ready for operation. When the diaphragm 4 has completed its aperture 4 and is ready for exposure, the power to the front curtain magnet is cut off, the shutter 6 begins to open, and the registration optical system 7 causes an image to be captured on the imaging surface of the solid-state image sensor 8. Form an image of the subject.

When a preset shutter time or a shutter time obtained by photometry or the like elapses after the shutter 6 is opened, power to the trailing curtain magnet is cut off, the shutter 6 closes, and the exposure ends. The accumulated charge of the image sensor 8 is extracted in time series in synchronization with a certain reference signal, and output as a video signal to the video signal processing circuit 9t. This video signal is recorded on a magnetic sheet or the like by a recording circuit 10 via a magnetic head 12 consisting of two adjacent heads in response to a recording gate signal f synchronized with a vertical synchronization signal shown in FIG. 1 (IL). Field images are recorded on two adjacent tracks of the medium 11.

After recording is completed, the head drive circuit 16 energizes the head drive solenoid to rotate the ratchet and move the head one track, as shown in FIG. 1(g). Then, the solenoid is de-energized, and the energization is suspended for a predetermined period of time required for the ratchet to return to the fixed position. Then, as shown in FIG. 1(h), during this pause period, the charge motor drive circuit 16 starts the charge motor 17 and starts charging the shutter. After the power-off period has elapsed, the solenoid is energized again, the head is moved one more track, and the head is moved to the next recording track position. During continuous shooting, after charging is complete, the release magnet, first curtain magnet, and second curtain magnet are energized again.
Thereafter, the above operation is repeated to perform continuous shooting.

As described above, in this embodiment, during frame recording, frame signals are recorded on two adjacent tracks using two adjacent recording heads.
This method focuses on the fact that although it is necessary to move the head by a track, there is a period during which the head driving section is not energized during this head movement period. Conventionally, if you tried to start charging while the head was moving, the current to be supplied would be too large, requiring a large-capacity power source and making it impossible to use battery power, so charging was started after the head had finished moving. However, in this embodiment, the head movement starts after recording is completed, and the charge motor is started during the period when the head drive unit is not energized while the head is moving. Since the power supply and the start-up of the charge motor do not occur at the same time, a large current is not required at once even though the head is being charged while the head is moving, and continuous shooting speed can be maintained even when powered by batteries. It can be done quickly.

In the above example, a case was explained in which a focal plane shutter was used, but the same applies, of course, to a case where a shutter having another structure such as a lens shutter is used.

Effects of the Invention As described above, in the present invention, the head is moved after recording is completed, and the charge motor is started during the period when power is not supplied to the head drive unit during the head movement. By charging the
Although the time required for the sequence is shortened and the continuous shooting speed is increased, excellent effects such as no large current being required at once and battery operation possible can be obtained.

[Brief explanation of drawings]

Fig. 1 is a timing diagram when an electronic still camera according to an embodiment of the present invention takes a picture, Fig. 2 is a block diagram showing an example of the configuration of an electronic still camera, and Fig. 3 shows a timing diagram when a conventional electronic still camera takes a picture. FIG. 6... Shutter drive circuit, 15...
Head drive circuit, 16...Charge motor drive circuit, g...Head drive signal, h...
Charge motor drive signal.

Claims (1)

[Claims] an imaging means for forming a subject image on an imaging surface of an imaging element and generating a video signal corresponding to the subject image; an exposure control means for controlling the amount of exposure of the imaging surface; and recording the video signal. After energizing the recording means that records on the medium via the recording head and the head drive unit for a first predetermined period, the power supply to the head drive unit is stopped for a second predetermined period, and then the power supply to the head drive unit is stopped again for the first predetermined period. The apparatus includes a head moving means for moving the recording head by one recording unit by energizing the head driving section, and a charging means for initializing the exposure control means, and a charging means for initially setting the exposure control means, and stopping the energization to the head moving section. An electronic still camera characterized in that the operation of the charging means is started during a second predetermined period during which the charging means is in use.