JPH0444671A - Recording/playback device - Google Patents

Abstract

PURPOSE:To discriminate whether a recordable area of a recording medium under reproducing is in the nonrecorded state or not by setting a criterion level based on a reference signal corresponding to a reproducing output level of other than a recording area in the recording medium. CONSTITUTION:A nonrecording signal corresponding to a noise level at the time of nonrecording, comprising noise at the time of driving a spindle motor 20 and noise of a reproducing system and an amplifier, etc., is detected by performing the reproducing under the noncontact state of a magnetic head 6 with a VH 19. Thus, calculation for deciding recorded tracks and nonrecorded tracks is performed from a nonrecording signal data corresponding to the detected and stored noise level at the time of nonrecording.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to electronic still cameras, etc., which detect recorded tracks by detecting carriers on video floppies, and record on unrecorded tracks. -Regarding playback devices.

[Prior Art] <Conventional Example 1> An example of a conventional recorded track detection circuit in an electronic still camera will be described with reference to FIG. In such an electronic still camera, recording is performed by FM modulating carriers in Y and C (color difference). First, the output of the magnetic head 6 is passed through a bandpass filter (BPF) or a bypass filter (HPF) 10 to limit the band, and then amplified by an amplifier 11. Next, the signal detected by a detector 12 is sent to a voltage comparator 16. The presence or absence of carriers is detected by comparing it with the reference voltage 17. In this comparison, when the detection output is higher than the reference voltage 17, the carrier is present, that is, the recorded track and the system controller 15 determines that, and when the detection pressure is lower than the determination voltage, there is no carrier.
In other words, it is determined that the track is an unrecorded track.

<Conventional Example 2> In another conventional example shown in FIG. After being amplified and then detected by the detector 12, the signal is inputted to the system controller 15 as digital data by the AD converter 13, and compared with a fixed value in the controller 15 to determine whether the track has been recorded or not.

[Problems to be Solved by the Invention] As explained in the above-mentioned conventional example, conventional electronic still cameras detect unrecorded tracks on a thio floppy and detect the presence or absence of a carrier on a video floppy. It is determined whether the data has not been recorded by comparing it with a standard comparison value. However, even when the magnetic head 6 is tracing an unrecorded track, noise is generated on the disk and within the head circuit, and a detection signal of a certain level is output. For this reason, the detection output generated when tracing an unrecorded track and the detection output from the carrier of a recorded track are collected, including the variations, and a certain value between these values is set as the judgment level. was used to determine whether the information was unrecorded or recorded.

In this case, noise is naturally superimposed on the detected signal of the recorded track. Furthermore, there are variations in the recording level and the like depending on the model, and this variation becomes larger when the models are different or when a video signal recorded on another machine is played back. As a result, it may be difficult to distinguish between unrecorded tracks with a high noise level and recorded tracks with a high noise level (low recording level).

In particular, when the characteristics of circuit elements change from lot to lot and the gain or noise of the amplifier changes, it becomes necessary to reset this determination level. Furthermore, it is difficult to set a determination level that takes into account all changes in the characteristics of these circuit elements.

The present invention has been made in view of the above-mentioned conventional example, and a value corresponding to the output of the magnetic head of the unrecorded track is obtained from the magnetic head reproducing system, and this value is used as a basis for comparing the recorded track/unrecorded track. The purpose is to provide a recording/playback device that performs judgment.

[Means for Solving the Problems] In order to achieve the above object, the recording/reproducing apparatus of the present invention has the following configuration. That is, a reference signal generating means for generating a reference signal corresponding to an output level when reproducing an area other than the recording area in a recording medium, and a level setting means for setting a determination level based on the reference signal generated by the reference signal generating means. and determining means for determining whether the recordable area of the recording medium being reproduced is in an unrecorded state by comparing the output level obtained by reproducing the recordable area in the recording medium with the determination level. has.

[Operation] With this configuration, the determination level is set based on the reference signal corresponding to the output level when reproducing an area other than the recording area in the recording medium. Then, the output level obtained by reproducing the recordable area on the recording medium is compared with the determination level, and depending on the comparison result, it is determined whether the recordable area of the recording medium being reproduced is in an unrecorded state. It operates to determine.

[Embodiment] FIG. 1 is a block diagram showing a schematic configuration of a still video recording apparatus according to an embodiment of the present invention.

In the figure, 1 is an image sensor such as a CCD, and 2 is a still video (hereinafter referred to as S
This is a signal processing circuit that converts into luminance signals and color difference signals that conform to the recording format of 3 is a modulator that FM-modulates the luminance signal and chrominance signal output from the signal processing circuit 2 onto a carrier wave that matches the SV recording format; 4 is a signal FM-modulated with the luminance signal and a signal FM-modulated with the chrominance signal; This is a mixer that mixes the files and creates a format for recording on an Sv floppy. 5 is a preamplifier that amplifies the output of the mixer 4 in order to supply it to the recording/reproducing head 6, and 6 is a recording/reproducing head.

7.8 is a switch for switching recording/playback, 9 is an initial stage amplifier during playback, and IO is a filter for limiting the band of the signal to be detected, such as a bandpass filter (BPF) or a high-pass filter ( HPF). 11 is an amplifier (
AMP). 12 is a wave detector, 13 is an A/D converter, and 14 is a synchronization signal generator that generates synchronization signals necessary for the image sensor 1, the signal processing circuit 2, and the modulator 3.

21 system controller, which is an arithmetic control section that controls the synchronizing signal generator 14, the recording/reproduction changeover switch 7.8, and the head drive section 18, and calculates the output of the A/D converter 13. 19 is a video floppy; 20 is a spindle morph for rotating the video floppy 19;

In addition, in the structure of each part mentioned above, the same parts as the conventional example shown in FIG. 6 and FIG. 7 are shown by the same number.

FIG. 2 is a schematic flow chart showing the processing of the still video recording apparatus shown in FIG. A control program for executing this process is stored in the control program area of the system controller 21.

When the device is powered on in step S1, step S2
Then, the presence or absence of a video floppy (hereinafter referred to as VF) 19 is determined. If VF19 is loaded, step S
In step 3, an unrecorded track is detected and the magnetic head 6 is moved to the detected unrecorded track.

After moving the magnetic head 6 to the unrecorded track, preparations for photographing are made in step S4, and it is determined whether the photographing start switch 22 has been pressed. When the switch 22 is pressed, the process advances to step S6, and the circuit elements of the first system that perform image recording,
Image sensor 1. Signal processing circuit 2. Modulator 3. Mixer 4. An FM-modulated video signal is output to a magnetic head 6 through a preamplifier 5. Here, the switch SW7 enables only the off-state recording system circuit, and the magnetic head 6
Image recording on the SV floppy disk 19 is then performed.

After imaging, it is checked in step S7 whether or not there is an unrecorded track based on the data at the time of unrecorded track detection. If there is an unrecorded track, the process advances to step S9 and the magnetic head 6 is moved to the next unrecorded track on the floppy disk 19. send it to the truck,
In step S4, the process returns to preparation for photographing. On the other hand, if there is no unrecorded track in step S7, it is determined that the jacket is finished, and the process proceeds to step S8, where it waits for the floppy (VF) 19 to be ejected. When the VF 19 is ejected, the process returns to step S2 and waits for the video floppy 19 to be inserted again.

FIG. 3 is a flowchart illustrating details of detecting an unrecorded track and moving the head to the detected unrecorded track performed in control step S3 of FIG. 2.

If video floppy 19 is loaded, step SI
The spindle motor 20 of the disk drive is started at O, and the floppy disk 19 is rotated at a predetermined speed by a known servo mechanism.

Thereafter, the position of the recording/reproducing head 19 is reset in step Sll. That is, the position of the magnetic head 6 is moved to the 50th track. Next, in step S12, switch SW7 is turned on and switch SW8 is turned off.

In this manner, in step S13, the output of the magnetic head 6 is detected by the detector 12 in the reproduction state, and the A/D converter 13 detects the output of the magnetic head 6.
performs A/D conversion and stores the value. In this reproducing state, the reproducing magnetic head 6 does not come into contact with the floppy disk 19. In this way, by performing reproduction with the magnetic head 6 not in contact with the VH 19, unrecorded signals equivalent to the noise level during unrecording, including noise from driving the spindle motor 20 and noise from the reproduction system and amplifier, are detected. Ru. In this way, calculations are performed to determine recorded tracks and unrecorded tracks from the detected and stored unrecorded signal data corresponding to the noise level when unrecorded.

There are the following two types of calculations for determining the determination level for determining recorded tracks and unrecorded tracks.

(2) The determination level is the level obtained by adding a predetermined noise margin to the detected noise level corresponding to the time of non-recording.

■A preset maximum noise level is set in addition to the detected noise level equivalent to the unrecorded state plus a predetermined noise margin, and the smaller one is set as the judgment level. do.

Next, the process proceeds to step S14, where the recording/reproducing head 6 is brought into contact with the floppy disk 19. In step S15, the A/D-converted detection output of the signal taken out from the recording/reproducing head 6 in this state is obtained, and in step S16, the control step S1
Compare with the judgment level obtained in step 3. If it is determined that the track is a recorded track, the process advances to step S17, and it is determined whether it is the 500th track. If it is the 50th track, the process returns to step S8 of the main flowchart of FIG. 2 and waits for an eject instruction. On the other hand, in step S17, 5
If it is not the 0th track, the process advances to step 818, and V
The magnetic head 6 is moved by one track toward the inner station of F19, and the process returns to the main flowchart of FIG. 2 again to proceed to step S4, preparation for photographing.

On the other hand, if it is determined in step S16 that it is an unrecorded track, the process advances to step S19, and it is then determined whether it is the first track (track 1). If it is the first track, the process advances to step S20, the magnetic head 6 is moved one track toward the outer circumference of the VF 19, and the process returns to step S15.

In this operation example, the innermost track of the recorded VF 19 is detected, and then the magnetic head 6 moves to the innermost track.
It is used to move and record.

[Other Examples] FIGS. 4 and 5 show the second embodiment of the present invention. 12 is a flowchart for explaining unrecorded track detection processing in the third embodiment.

In the embodiment shown in FIG. 3 described above, the spindle motor 20 is rotated without bringing the video floppy 19 into contact with the recording/reproducing head 6 to detect the playback output, but in this second embodiment, the playback output is detected in step S19. Then, the recording/reproducing head 6 is brought into contact with the video floppy 19, and without rotating the spindle motor 20,
- The playback output is detected in step S32.533.

Even in this case, an unrecorded signal equivalent to the noise level at the time of unrecording, including noise from the reproduction system, amplifier, etc., can be detected, and the determination level can be calculated based on this. Note that in this embodiment, since the spindle motor 20 is not driven, the determination level does not include noise when the motor is driven.

FIG. 4 is a control flowchart for detecting an unrecorded track of the electronic still camera and moving the magnetic head 6 to the detected track according to the second embodiment described above.

The control starts by bringing the magnetic head 6 into contact with the VF 19 in step S31, and after calculating the determination level in step S32, the steps other than detaching the magnetic head 6 from the disk 19 in step S34 will be explained using the flowchart in FIG. Avoid repeating explanations, as this has already been done.

<Embodiment 3> The flow chart of FIG. 5 shows the unrecorded track detection process of the third embodiment. In this embodiment, as in the first embodiment, the spindle motors 2G and ''J are started to rotate in step S51, and the recording/reproducing head 6 is brought into contact with the video floppy 19 in step S53, but the switch S is turned in step S54.
By turning on W7 and SW8, the magnetic head 6
The playback output is detected by shorting the output to ground level.

In this way, it is possible to detect the noise level during reproduction of an unrecorded track, including noise during driving of the spindle motor 20, noise from the reproduction system, amplifier, etc. When the calculation of the signal level for determining an unrecorded track is completed in step S55, the switch SW7 is turned on and the switch SW8 is turned off in step S56 so that only the playback system circuit part is utilized. do. Other than this, the second embodiment is the same as the first embodiment described above, so a description thereof will be omitted.

As shown in the embodiments of the above three aspects, as a method of obtaining a reference signal without reproducing outside the recording area, which is a feature of the present invention, there is a method in which the magnetic head 6- is not brought into contact with the VF 19, and a method in which the magnetic head 6 is not brought into contact with the VF 19; How to contact V F 1.9 but not rotate the spindle motor 20, spindle motor 2
0 is rotated to bring the recording medium into contact with the magnetic head 6 using wind pressure, but there is a method of short-circuiting the output of the magnetic head 6 to prevent the signal from being output.

As described above, according to this embodiment, a reference signal equivalent to an unrecorded signal outside the recording area of the VF can be generated by the own reproduction system without reproducing the area outside the recording area of the VFI 9.

Therefore, it is possible to provide a recording device or a reproducing device that can absorb circuit-specific errors, noise, etc., is not affected by noise or characteristics of circuit elements, and can be applied to, for example, an electronic still camera.

[Effects of the Invention] As explained above, according to the present invention, a value corresponding to the output of the magnetic head of an unrecorded track is obtained from the magnetic head reproducing system, and this value is used as a basis for the comparison value to determine the recorded track/unrecorded track. Since the track can be determined, it is possible to prevent erroneous determination of whether or not the track is a recorded track due to variations in characteristics of circuit elements, changes in characteristics, etc.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a still video recording/playback apparatus according to an embodiment of the present invention, FIG. Figures 3, 4, and 5 are respectively 1. A flowchart illustrating detection of an unrecorded track and movement of the magnetic head to the detected unrecorded track in the second and third embodiments, FIG. 6 is a block diagram showing the first conventional example, and FIG. 7 FIG. 2 is a block diagram showing a second conventional example. In the figure, 1... image carrier element, 2... signal processing section, 3...
・FM modulator, 4...mixer, 5...amplifier, 6.
...Recording/reproduction head (magnetic head), 7.8... Switch for switching recording/reproduction, 9... First stage amplifier, 10...
・Filter, 11...Amplifier, 12...Detector, 1
3... A/D converter, 14... Synchronization signal generator, 16... Comparator, 17... Judgment voltage source, 1
8... Head drive unit, 19... Floppy disk (VF), 20... Spindle motor, 21... System controller. Patent applicant Canon Co., Ltd.

Claims (4)

[Claims] (1) A reference signal generating means for generating a reference signal corresponding to an output level when reproducing an area other than a recording area in a recording medium, and a level setting for setting a judgment level based on the reference signal generated by the reference signal generating means. and determining means for determining whether the recordable area of the recording medium being reproduced is in an unrecorded state by comparing the output level obtained by reproducing the recordable area in the recording medium with the determination level. A recording/reproducing device characterized by having the following. (2) The reference signal generating means obtains the reference signal by rotating a motor that rotationally drives the recording medium without bringing a reading head into contact with the recording medium. The recording/reproducing device according to item 1. (3) The reference signal generating means brings a reading head into contact with the recording medium and obtains the reference signal based on the signal from the reading head without rotating the recording medium. The recording/reproducing apparatus according to claim 1, characterized in that: (4) The reference signal generating means rotates the recording medium by bringing a reading head of the recording medium into contact with the recording medium, and grounding an output signal level from the reading head to obtain the reference signal. Claim 1 characterized in that
Recording/playback device described in section.