JPS61208374A - Electronic still camera - Google Patents

Abstract

PURPOSE:To provide immediate confirmation whether or not the recording signal is normally recorded in a magnetic disc at the site of image-picking up and to elimi nate missrecording of the recording signal by providing a detecting-displaying means which detects and displays the state of the recording in a magnetic medium of such as the magnetic disc based on a reproduction signal. CONSTITUTION:The magnetic disc 7 is driven in revolution by a motor 8 whose revolu tion is controlled by a phase control signal from a phase control circuit 9. A magnetic head 13 is controlled of it motion on the magnetic disc 7 by a stepping motor 11 that responds to and is controlled by a movement control signal from a movement control circuit 12. Depending on the said control, the magnetic head 13 moves toward an inner circular track of the magnetic disc 7 in its radial direction at the end of every run of recording made by one turn of rotation of the disc 7. A reproducing means B is provided, which executes the reproduction processing of the recording signal recorded in the disc 7 as well as outputs the resulting signal of the said processing as a reproduction signal. Also, the detecting-displaying means C is provided, which detects and displays the state of recording in the disc 7 based on the said repro duction signal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an electronic still camera that images a subject and records its video signal, and particularly relates to a recording detection circuit that detects the quality of recording operation.

(Prior Art) Electronic still cameras that have been used in the past are configured so that a large number of video signals obtained through a solid-state imaging device such as a COD can be recorded on a small magnetic disk. In order to take an image of a subject, a user carries an electronic still camera, goes to a place where the subject is located, and records the image. When the image capturing is completed in this manner, the user takes the electronic still camera home, removes the magnetic disk from the electronic still camera, and sets it on an output device such as a television monitor or printer. As a result, the video signal recorded on the magnetic disk is displayed on a television monitor or by a printer. Therefore, based on such a display, it can be determined whether or not a recording signal has been recorded on the magnetic disk.

However, in the case of the conventional example having such a configuration, since a reproducing circuit is not provided, it is not possible to confirm whether or not a recording signal has been recorded on the magnetic disk at the location where the image is taken. Therefore, even if there is a recording error in the recording signal on the magnetic disk, it cannot be known until it is confirmed by the output device.

This recording error is caused by continuous contact between the magnetic head and magnetic disk during recording, temperature changes, etc.
The magnetic layer of the magnetic disk adheres to the gap of the magnetic head, causing the magnetic head to become clogged, and when the magnetic head is operated in such a clogged state, the magnetic flux generated from it does not reach the magnetic disk. , as a result, it may not be possible to record a recording signal on it,
Alternatively, there may be a case where the magnetic layer of the magnetic disk has peeled off due to physical or chemical causes, making it impossible to record a recording signal.

(Objective of the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic still camera that can confirm whether a recording signal has been recorded at the imaging location.

(Structure of the Invention) In order to achieve such an object, the present invention provides a reproducing means for reproducing a recorded signal recorded on a magnetic medium and outputting a signal resulting from this processing as a reproduced signal;
and a detection/display means for detecting and displaying the recording state of the recording signal on the magnetic medium based on the reproduction signal, the detection/display means detecting and displaying the recording state of the recording signal on the magnetic medium in a predetermined recording state. When the recording signal is being recorded,
A different display is displayed when no data is being recorded.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings. FIG. 1 is a block circuit diagram of an electronic still camera according to an embodiment of the present invention.

The electronic still camera according to the present invention includes a recording means A that processes signals related to an imaged object and records the processed signals on a magnetic medium such as the magnetic disk 7 as a recording signal. This recording means A includes an imaging lens 1 that captures an image of a subject (not shown), an imaging device 2 such as a CCD that stores and outputs an optical signal from the imaging lens 1 as an electrical quantity, and an imaging signal from the imaging device 2. An imaging circuit 3 that converts into an electrical signal, a recording signal processing circuit 4 that performs processing to create a video signal as a recording signal to be recorded based on the signal from the imaging circuit 3, and the recording signal processing circuit 4. a frequency modulation circuit 5 that frequency modulates the video signal from the frequency modulation circuit 5, a recording amplifier 6 that amplifies the video signal modulated by the frequency modulation circuit 5, and a magnetic head 13 that outputs the video signal amplified by the recording amplifier 6. ,
a magnetic disk 7 on which the output of the magnetic head 13 is recorded;
It is equipped with

The magnetic disk 7 is rotationally driven by a motor 8 whose rotation is controlled by a phase control signal from a phase control circuit 9 . That is, the magnetic disk 7 is controlled to rotate at, for example, 3600 revolutions per minute in order to synchronize with the video signal. The magnetic head 13 is in contact with the magnetic disk 7. The magnetic head 13 is also controlled to move over the magnetic disk 7 by a stepping motor 11 that is driven in response to a movement control signal from a movement control circuit 12 . By this control, the magnetic head 13 is moved to the inner circumference of the magnetic disk 7 in the radial direction every time the magnetic disk 7 rotates once and one recording is completed. One track (corresponding to one revolution of the magnetic disk) of the magnetic disk 7 records one field's worth of frequency-modulated FM video signals.

A feature of the present invention is that the following components are added to the components described above.

That is, the present invention provides a reproducing means B that reproduces a recorded signal recorded on the magnetic disk 7 and outputs a signal resulting from this processing as a reproduced signal;
and a detection/display means C for detecting and displaying the recording state on the basis of the reproduction signal.

The reproduction means B includes a reproduction amplifier 14 that amplifies the reproduction signal received via the changeover switch 10.

The detection/display means C includes a detection circuit 15 that performs envelope detection of the reproduced amplified signal from the reproduced amplifier 14, and detects when a recording signal is recorded on the magnetic disk 7 in a predetermined recording state and when it is not recorded. A comparison circuit 16 that displays a different display depending on the time, and compares the level of a preset reference signal and the detected signal; and a recording display circuit 17 that displays a display in response to the comparison output from the comparison circuit 16. It consists of The changeover switch 10 sets the movable contact C to the recording side individual contact a during recording, and switches to the reproducing side individual contact A during playback.

FIG. 2 shows the detection circuit 15 and comparison circuit 16 shown in FIG.
, is an electrical circuit diagram including a recording/displaying circuit 17. Further, FIG. 3 is a waveform diagram for explaining the operation of this electric circuit diagram. In FIG. 2, the detection circuit 15 includes a diode 18 for envelope detection. The recording display circuit 17 is
It has a light emitting diode 19 for displaying recording status.

The operation of this circuit will be explained below. The movable contact C of the changeover switch 10 shown in FIG.
A video signal is recorded. When detecting whether the FM video signal is normally recorded on the magnetic disk 7, the movable contact C of the changeover switch IO is switched to the playback side individual contact.

Thereby, the reproduction output of the magnetic head 13 is given to the reproduction amplifier 14. The reproduction amplifier 14 outputs a reproduction signal p1 as shown in FIG. 2(1), which is an amplified reproduction output. The reproduced signal p1 is provided to the detection circuit 15 via the coupling capacitor 20. The reproduced signal p1 is generated by this detection circuit 15.
Envelope detection is performed by a detection diode 18 and a capacitor 21 inside. The detected reproduced signal pl is output from the emitter of the impedance conversion transistor 22 as a detected signal p2 as shown in FIG. 2(2).

The comparison circuit 16 receives the detected signal p2 given to its inverting input terminal (-) and the reference level setting circuit 18 given to its non-inverting input terminal (+) as shown in FIG. 2 (3).
A level comparison is made with a reference signal level p3 as shown in FIG. That is, the comparison circuit 16 outputs a low level signal when the level of the detected signal p2 is higher than the reference signal level 93, and outputs a high level signal when the level of the detected signal p2 is less than the reference signal level 93.

In order to prevent the comparator circuit 16 from malfunctioning due to its DC offset voltage, noise, etc., the reference level signal p3 is set to a predetermined DC level. When the level of the detection signal p2 is equal to or higher than the reference signal level 93, it is a case where the FM video and image signals are normally recorded on the magnetic disk 7. Further, when the level of the detection signal p2 becomes less than the reference level 93, it is a case where the FM video signal is not recorded on the magnetic disk 7 due to the aforementioned clogging of the magnetic head 13 or the like.

level, the light emitting diode 1 of the display circuit 17 becomes high level, and the light emitting diode 31 lights up.This lighting can notify the user of a recording error in the FM video signal, that is, the recording signal.

In this embodiment, the light emitting diode 19 is turned on when there is a recording error, but the light emitting diode 19 may be turned on when recording is made. The comparator circuit 16 is not limited to the configuration shown in the second diagram, but may also include other circuits,
That is, any circuit that outputs a reproduction output at a predetermined level during normal operation may be used. Further, although the recording signal was recorded by frequency modulation, it may be recorded by other modulation. Further, in this embodiment, a magnetic disk is used as a medium for recording recording signals, but the present invention is not limited to this, and a configuration may be adopted in which a medium such as a magnetic tape is used.

(Effects of the Invention) As described above, according to the present invention, by providing a detection/display means for detecting and displaying the recording state on a magnetic medium such as a magnetic disk based on a reproduction signal, the magnetic disk You can immediately know whether the recording signal was recorded correctly at the location where the image was taken. Therefore, recording errors in recording signals are eliminated, and effects such as being extremely useful in practice for the user are exhibited.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an electronic still camera according to an embodiment of the present invention, Fig. 2 is an electric circuit diagram of the reproduction means and detection/display means included in this embodiment, and Fig. 3 is an operational diagram of the electric circuit. FIG. 3 is a signal waveform diagram for explanation. A is a recording means, B is a reproduction means, C is a detection/display means, 7
1 is a magnetic disk, 15 is a detection circuit, 16 is a comparison circuit, 1
7 is a recording display circuit, and 18 is a reference level setting circuit. Figure 2 3a

Claims (2)

[Claims] (1) Processing the signals related to the imaged subject,
In an electronic still camera equipped with a recording means for recording a signal resulting from this processing as a recording signal on a magnetic medium, the recorded signal recorded on the magnetic medium is subjected to reproduction processing, and the signal resulting from this processing is output as a reproduction signal. and a detection/display means for detecting and displaying the recording state of the recording signal on the magnetic medium based on the reproduction signal, and the detection/display means detects and displays the recording state of the recording signal on the magnetic medium in a predetermined recording state. An electronic still camera characterized in that a recording signal displays differently when it is being recorded and when it is not being recorded. (2) The detection/display means includes a detection circuit that detects the reproduced signal, a comparison circuit that sends out different outputs depending on whether the level of the output of the detection circuit is above or below a reference level, and a detection circuit that responds to the output of the comparison circuit. The electronic still camera according to claim 1, further comprising a display circuit that performs the display.