JPH037318B2 - - Google Patents

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 configuration and its problems In general, one of the major features of electronic still cameras that record and reproduce video signals on recording media such as magnetic sheets is that, unlike photographic cameras that use silver halide film, the recorded images You can instantly replay and check the recorded image, and if it is a failed or unnecessary image, you can erase the recorded image and rerecord it as many times as you like.

FIG. 1 shows an example of the configuration of an electronic still camera. FIG. 2 is a timing diagram showing the signals of each part, where a is a vertical synchronization signal, b is a release signal, c is a release magnet drive signal, d is a front curtain magnet drive signal, e is a rear curtain magnet drive signal, and f is a recording gate signal, g is a recording head drive signal, and h is a charge motor drive signal. Figure 1 below,
The configuration of a conventional electronic still camera will be explained using FIG. By pressing the release button 1,
A release signal shown in FIG. 2b is sent to the system control circuit 2, aperture information is sent to the aperture control circuit 3, and the aperture 4 is narrowed down to a predetermined aperture value. At the same time, the shutter drive circuit 5 sends the front curtain magnet drive signal and the rear curtain magnet drive signal shown in FIG. 2) is energized to hold the leading and trailing curtains, and at the same time, the release magnet drive signal shown in FIG. becomes. When the aperture 4 has been stopped down and exposure is possible, the power to the front curtain magnet is cut off.
The shutter 6 begins to open, and the lens optical system 7 forms a subject image 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 has elapsed, 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 constructed by two-dimensionally arranging m×n CCD elements in a matrix type, and the image sensor 8 is composed of m×n CCD elements arranged in a two-dimensional matrix. was taken out,
The video signal processing circuit 9 outputs it as a video signal. This video signal is recorded on 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. 2a. Note that 12 is a magnetic head, 13 is a disk motor, and 14 is a disk motor drive circuit. After the recording is completed, the head drive signal shown in FIG. 2g is sent to the head drive circuit 15, and the magnetic head 12 is moved. After the head is sent, the charge motor drive circuit 16 energizes the charge motor 17 as shown in FIG. 2h, and the shutter 6 is initialized (hereinafter referred to as charge).
One shooting operation ends. In the continuous shooting mode, after charging is completed, the release magnet, front curtain magnet, and rear curtain magnet are energized again, and the above-mentioned operation is repeated thereafter to perform continuous shooting.

In the above example, since charging is performed after the head movement is completed, the time required for one photographing operation becomes longer, and there are problems such as the inability to increase the continuous photographing speed. Also, in order to increase the continuous shooting speed, it is possible to move the head and charge at the same time, but since the current required for head drive and charging is large, if you try to do both at the same time, the current required will be too large and the capacity will be reduced. Unless a large power source is used, current cannot be supplied, which is a major obstacle to miniaturizing devices.

Purpose of the Invention The present invention is intended to improve such conventional drawbacks, and enables battery drive and charge operation by starting head movement when the current flowing through the charge motor drops below a predetermined value. To provide an electronic still camera that can increase the continuous shooting speed by moving the head during the process.

Structure of the Invention The electronic still camera of the present invention uses an optical system to form a subject image on the imaging surface of a solid-state imaging device that has both a power conversion function and a charge transfer function, and corresponds to each pixel on the imaging surface. an exposure control means for controlling the exposure amount of the imaging surface; a recording means for recording the video signal onto a recording medium via a recording head; It has a head moving means for moving the recording head to have a plurality of recording tracks, and an initial setting means for initializing the exposure control means, and after the recording is completed, the initial setting means is operated, The recording head moving means is configured to operate when the current flowing through the initial setting means falls below a predetermined value, and the head movement is started after the current flowing through the charge motor falls below a predetermined value. Therefore, a large current does not flow at once, and battery operation is possible.Also, since the head moves during the charging operation, the time required for one shooting operation can be shortened, and the continuous shooting speed can be increased. It is something that can be done.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a block diagram showing the configuration of an electronic still camera according to an embodiment of the present invention, and FIG. 4 is a timing diagram showing signals of each part.
Components that are the same as those shown in FIGS.

After the recording of the video signal is completed, the current is transmitted from the charge motor drive circuit 16 to the current detection circuit 18 as shown in FIG.
As shown in the figure, the charge motor 17 is energized and charging of the shutter 6 is started. After starting charging, the current detection circuit 18 detects the charge motor 1.
When it is detected that the current flowing through the head 7 has decreased below a certain predetermined value, a head movement start command signal is sent to the system control circuit 2, and a head drive signal is sent to the head drive circuit 15 as shown in FIG. Head 1
Move 2. In the continuous shooting mode, after charging is completed, the release magnet, front curtain magnet, and rear curtain magnet are energized again, and the above operations are then repeated to perform continuous shooting.

Generally, in electronic still cameras, a DC motor is used as the charge motor, and a stepping motor or solenoid is used to drive the head.
In stepping motors and solenoids, the current flowing during operation is almost constant, but the current flowing in a DC motor is large at startup, but then decreases significantly as the rotation speed increases. In this way, this embodiment focuses on the fact that although the current flowing through the charge motor is large at startup, the current decreases significantly after that. The current flowing through the charge motor becomes too large, so instead of starting charging after the head has finished moving, it is now possible to start charging first after recording has finished, and the current flowing to the charge motor becomes The system detects when the battery has fallen below a certain value that allows battery operation even when the head is moved at the same time, and starts moving the head.Since the head is sent during the charge operation, one sequence of shooting This makes it possible to shorten the time required for continuous shooting and increase the continuous shooting speed.

In the above embodiment, when the current flowing through the charge motor is detected to have decreased below a predetermined value, the head movement is started. The time required is almost the same, so measure the time after the start of charging, and after the predetermined time required for the current flowing through the charge motor to become below the predetermined value,
Alternatively, the head movement may be started.

In addition, in the above example, the head movement is started when the current flowing through the charge motor falls below a predetermined value, but it is important to note that as the rotation speed of the charge motor increases, the current flowing through the charge motor decreases. The same effect can be obtained by detecting the rotational speed of the charge motor and starting the head movement when the rotational speed exceeds a predetermined value.

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

Effects of the Invention As described above, the present invention starts the charge operation after recording ends, and starts moving the head when the current flowing to the charge motor drops below a certain value to enable battery drive. Since the head is moved during the charge operation, the time required for one photographing sequence can be shortened, which is extremely advantageous in increasing the continuous photographing speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional electronic still camera, FIG. 2 is a timing diagram of the conventional electronic still camera when shooting, and FIG. 3 is a diagram showing the configuration of an electronic still camera according to an embodiment of the present invention. The block diagram in FIG. 4 is a timing chart during photographing by an electronic still camera according to an embodiment of the present invention. 2...System control circuit, 6...Shutter,
12...Head, 15...Head drive circuit, 16
...Charge motor drive circuit, 17...Charge motor, 18...Current detection circuit.

Claims (1)

[Scope of Claims] 1. A subject image is formed by an optical system on an imaging surface of a solid-state imaging device having both a photoelectric conversion function and a charge transfer function, and a video signal corresponding to each pixel on the imaging surface is generated. 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 a plurality of tracks on the recording medium. The recording head preferably has a head moving means for moving the recording head, and a charging means for initializing the exposure control means, and after the recording is completed, the charging means is operated, and after the start of the charging operation, the charging means is operated. An electronic still camera characterized in that the head moving means is operated after the flowing current falls below a predetermined value. 2. The electronic still according to claim 1, wherein the head moving means is operated after a predetermined time required for the current flowing through the charge motor to become equal to or less than a predetermined value after the start of the charge operation. camera. 3. The electronic still camera according to claim 1, further comprising means for detecting that the current flowing through the charging means has become less than a predetermined value. 4. The charging means has an electric motor as a driving source,
further comprising means for detecting the rotational speed of the electric motor, and after the rotational speed detection means detects that the rotational speed of the electric motor exceeds a predetermined value and the current flowing through the electric motor decreases; An electronic still camera according to claim 1, characterized in that a head moving means is operated.