KR900004955B1 - Electronic still camera - Google Patents

Abstract

An electronic still camera comprises an imaging means for sensing image of an object and generating a corresponding image signal, an exposure control means for controlling the quantity of exposure, a recording means for recording the image signal on the recording medium, a head transfer means for transfering a recording head on the recording medium, a charge meams for setting the exposure control means, and a detecting means that current through charge motor drops below predetermined value.

Description

Electronic still camera

1 is a block diagram showing the configuration of a conventional electronic still camera.

2 is a timing diagram at the time of photographing a conventional electronic still camera.

3 is a block diagram showing the configuration of an electronic still camera according to an embodiment of the present invention.

4 is a timing diagram at the time of photographing the electronic still camera according to the embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

2: system control circuit 6: shutter

12: head 15: head drive circuit

16: charge motor drive circuit 17: charge motor

18: current detection circuit

The present invention relates to an electronic still camera for recording an instant image of a subject.

In general, one of the great features of an electronic still camera that records and reproduces a video signal on a recording medium such as a magnetic sheet is different from that of a photo camera using a silver salt film. If it is possible to confirm or fail or an unnecessary image, the recorded image can be erased and recorded again and again.

An example of the structure of an electronic still camera is shown in FIG. 2 is a timing diagram showing signals of respective parts, (a) is a vertical synchronization signal, (b) is a release signal, (c) is a release magnet drive signal, and (d) is a front curtain ( The former is a magnet drive signal, (e) is a rear film magnet drive signal, (f) is a recording gate signal, (g) is a recording head drive signal, and (h) is a charge driving signal. Hereinafter, the structure of the conventional electronic still camera is demonstrated using FIG. 1 and FIG. By the pressing operation of the release button 1, the release signal shown in FIG. 2 (b) is sent to the system control circuit 2, and the aperture information is sent to the aperture control circuit 3, whereby the aperture ( 4) is tightened to a predetermined aperture value.

At the same time, the front curtain magnet drive signal and the rear curtain magnet drive signal shown in Figs. 2 (d) and (e) are sent from the shutter driver circuit 5 to the shutter 6, and the front curtain magnet (not shown) and the rear curtain The magnet (not shown) is energized so that the front curtain (not shown) and the thick film (not shown) are maintained, and the release magnet drive signal c shown in FIG. ), The connection lever (not shown) is released, and the shutter operation state is enabled. When the diaphragm 4 is tightened and the like is exposed, energization to the front curtain magnet is interrupted, the shutter starts to open, and the subject optical image is picked up by the lens optical system 7 on the image pickup surface of the solid state image pickup device 8. Image it. After the shutter 6 is opened, when the shutter initial time obtained by a predetermined shutter initial time or photometry passes, the energization to the thick film magnet is cut off, the shutter 6 is closed, and the exposure ends. do. The image pickup device 8 is constituted by two-dimensional arrays of m × n CCD devices in a matrix form, and is accumulated in time series in synchronism with a reference signal in which accumulation charges different from the luminance of pixels corresponding to the respective divisions are synchronized with a certain reference signal. And are output as a video signal by the video signal processing circuit 9. This video signal is recorded on the recording medium 11 such as a magnetic sheet by the recording circuit 10 in accordance with the recording gate signal f in synchronization with the vertical synchronizing signal shown in FIG. 12 denotes a magnetic head, 13 a disk motor, and 14 a disk motor drive circuit. After the end of the recording, the head drive signal shown in FIG. 2 (g) is sent to the head drive circuit 15, and the magnetic head 12 is moved. After the head is sent, it is energized by the charge motor drive circuit 16 to the charge motor 17 as indicated in FIG. 2 (h) and the shutter 6 is initially set (hereinafter referred to as a charge). The conference shooting operation is terminated. In the continuous shooting mode, after the end of the charge, the magnet is again energized to the release magnet (not shown), the front curtain magnet, and the rear curtain magnet, and the above-described operation is repeated to perform continuous shooting.

In the above example, since the charging is performed after the end of the head movement, there is a problem that the time required for one shooting operation becomes long and the continuous shooting speed cannot be increased. In addition, in order to increase the continuous shooting speed, it is conceivable to simultaneously perform head movement and charge, but since the current required for head driving and charge is large, the current required is too large to simultaneously perform a large power supply. If it is not used, current cannot be supplied, which is a great obstacle for miniaturization of equipment.

The present invention improves such a conventional drawback. When the current flowing in the charge motor is lowered to a predetermined value or less, the head movement is started, and the battery can be driven by a small capacity battery, and the continuous shooting speed is increased. To provide an electronic still camera that can be.

The electronic still camera according to the present invention comprises imaging means for imaging an object image on an imaging surface of a solid-state imaging device having a photoelectric conversion function and a charge transfer function by an optical system to generate an image signal corresponding to each pixel on the imaging surface, Exposure control means for controlling the exposure amount of the light, recording means for recording the video signal on a recording medium via a recording head, and a head movement for moving the recording head to have a plurality of recording tracks on the recording medium. Means and an initial setting means for initial setting of the exposure control means, and the recording head is operated when the initial setting means is operated after the end of recording and the current flowing to the initial setting means drops below a predetermined value. In the configuration in which the moving means is operated, the current flowing through the charge motor is lowered below a predetermined value, Since the head movement is started, no large current flows at one time, battery driving is possible, and the head movement is performed in the middle of the charging operation, so that the time required for one shooting operation can be shortened, and the continuous shooting speed Can be faster.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 3 is a block diagram showing the configuration of an electronic still camera according to an embodiment of the present invention. 4 is a timing diagram showing signals of each part, (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, and (e) ) Is the thick film magnet drive signal, (f) is the recording gate signal, (g) is the recording head drive signal, (h) is the charge motor drive signal (i) is the current waveform of the charge motor, and (j) is current detection. It is a signal. The same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. On completion of recording of the video signal, the charge motor 17 is energized from the charge motor drive circuit 16 via the current detection circuit 18 to the charge motor 17 as shown in FIG. The charge is disclosed. The current detection circuit 18 detects the current flowing through the charge motor 17 from the voltage at both ends of the current detection resistor inserted in series with the coil of the charge motor 17, and compares it with a predetermined voltage using a comparator. It is a well-known structure which detects that the electric current which flows through the charge electric motor 17 reduced below a predetermined value. When the charge is started, the voltages at both ends of the current detection resistor generate a voltage proportional to the current flowing in the charge motor 17 as shown in FIG. In comparison, when the voltage is lower than the predetermined voltage, the output of the comparator becomes " L " as shown in Fig. 4 (j), and is output from the current detection circuit 18 as the current detection signal j. When the current detection signal j is detected, (2) sends the head drive signal to the head drive circuit 15 as shown in Fig. 4 (g) to move the magnetic head 12. Continuous shooting mode In the city, after the type of charge, the magnet is again supplied with a release magnet (not shown), a front curtain magnet (not shown), and a thick film magnet (not shown), and the above-described operation is repeated for continuous shooting.

Thus, the present embodiment focuses on the fact that the current flowing through the charge motor 17 becomes a large current at the start, but then the current flowing through the charge motor 17 is greatly reduced when the number of revolutions of the charge motor 17 increases. In the case of conventional head movement, when attempting to start the charge, the current to be supplied becomes so large that the battery cannot be driven. After the end of the head movement, the charge is started first. 17) When the current flowing through the head moves simultaneously, the head movement is detected by detecting that the head current is lowered below a predetermined value that can be driven by the battery, and the magnetic head 12 is sent during the charging operation. The time required for the queen can be shortened, and the continuous shooting speed can be increased. In the above embodiment, the head current is started by detecting that the current flowing through the charge motor 17 has fallen below a predetermined value, but it is generally required for the current flowing through the charge motor 17 to decrease below a predetermined value. Since the time is approximately the same, the current detection circuit 18 of the above embodiment is replaced with a known timer that counts a predetermined time required for the current flowing in the charge motor 17 to be below a predetermined value after starting the charge. The timer may be operated after the start of idle time to count a predetermined time, and the head movement may be started after the predetermined time has elapsed after the start of the charge.

In the above example, the head movement is started when the current flowing through the charge motor 17 becomes less than or equal to a predetermined value. However, the current detection circuit 18 of the embodiment detects the rotation speed of the charge motor 17. It is also possible to change the cycle speed detection circuit to start the head movement when the rotation speed of the charge motor 17 is detected and the rotation speed becomes more than a predetermined value.

As described above, the present invention is to start the charge operation first after the end of recording, and to start the head movement when the current flowing in the charge motor 17 is lowered below a predetermined value capable of driving the battery, Since head movement is performed during the charging operation, the time required for one-sequence shooting can be shortened, which is very advantageous for speeding up the continuous shooting speed.

Claims (4)

Imaging means for imaging an object image on the imaging surface of the solid-state imaging device 8 having a photoelectric change function and a charge transfer function by an optical system to generate an image signal corresponding to each pixel on the imaging surface, and controlling the exposure amount of the imaging surface Exposure control means for recording, recording means 10 for recording the video signal on a recording medium 11 via a recording head 12, and a plurality of tracks on the recording medium 11; A head moving means 15 for moving the recording head 12, and a charge means 17 for performing an initial set of the exposure control means, and the charge means 17 are operated after the end of the recording, An electronic still camera characterized by operating the head moving means (15) after a predetermined time has elapsed since the start of the aji operation. The electronic still camera according to claim 1, wherein the predetermined time is a time until the current flowing through the motor has a motor at the driving source of the charge means (17) and falls below a predetermined value. An electronic still camera according to claim 1, further comprising means (18) for detecting that a current flowing through said charge means (17) is equal to or less than a predetermined value. 2. The rotational speed of the motor according to claim 1, further comprising a motor as a driving source of the charge means 17, and means for detecting the rotational speed of the electric motor, wherein the predetermined time is rotated by the rotational speed detection means to the electric motor. The electronic still camera, characterized in that it is a time until it detects that the value becomes more than a predetermined value.

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