JPS62125582A - Track discriminating method - Google Patents

Abstract

PURPOSE:To discriminate many tracks in a short time by deciding the head position by a mechanical means to perform the discrimination of tracks between sound and video signals and carrying out tracking servo control only when said track discrimination is impossible. CONSTITUTION:Both reproduction heads 2a and 2b are first shifted mechanically to the 1st track. Then a switch 4 is controlled for selection of the head 2a and the presence or absence of the envelope is decided for a reproduction signal. If the absence of the envelope is confirmed, a fact that the detected track has no signal is written on a memory 17. While the presence or absence of the horizontal synchronizing signal is decided when is decided when the presence of said horizontal signal is confirmed. If the absence of the data is confirmed, a fact that the detected track contains the video signals is written on the memory 17. While a fact that the detected track contains the sound signals is written on the memory 17 in case the absence of the horizontal signal and the presence of the data are confirmed respectively. Then the tracking servo control is carried out when the discrimination is impossible between the video and sound signals.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for distinguishing tracks between sound, voice signals, and video signals when, for example, an electronic still camera device is used to record audio signals as well. [Summary of the Invention] The present invention relates to a method for distinguishing tracks between an audio signal and a video signal.
By performing tracking servo only on the undiscernible cuts, it is possible to discriminate a large number of tracks in a short time. [Prior Art] An electronic still camera device that has an imaging device such as a CCD and records the signal of one arbitrary field or frame on a magnetic disk has been proposed (Utility Model No.
No. 197021, etc.). In other words, in such a device, one field or one frame of the video signal from the imaging device is gated and extracted at the time of arbitrary shutter operation, and one field of this signal becomes one annular track. recorded on a magnetic disk. Note that one frame of signal is recorded using two trunks. Therefore, in this device, a still image consideration signal can be formed by repeatedly reproducing one track or alternately button-repeatedly reproducing two tracks. It has been proposed to provide such devices with the additional possibility of recording audio signals. To do this, for example, the time axis of the audio signal is compressed using digital signal processing technology, the frequency band of the audio signal is increased to the band of the video signal, and the audio signal is recorded using the same distribution system as the video signal. There are possible ways. In this case, K, for example, by compressing the time axis of an audio signal up to 5 kHz by a factor of 600, it is possible to convert it into a signal with a video band of 3 MHz. And in this case,
Approximately 1 of 600 times that amount in one field period (1/60 second)
It is possible to record an audio signal for 0 seconds. That is, FIG. 4 shows a block diagram of an example of a recording device for this purpose. In this figure, the video signal is input terminal +41
). Recording circuit +4' from this video signal! J
1 field or 1 frame is taken out to form a predetermined recording signal, and this signal is sent to a pre-emphasis circuit with non-linear characteristics! 431, the video/audio changeover switch (44) is supplied to the FM modulation circuit (4!19).Then, the modulated FM signal is sent to the magnetic head (48a) (48b) through the head changeover switch H61, the recording amplifier (47a) (47b) ), and the disc is recorded on the disc.Also, the synchronization signal from the recording circuit (42) is supplied to the system control circuit (5G), and the iR pulse generator (49) associated with the rotational phase of the disc (49) is supplied to the system control circuit (5G). PG) 511 is supplied to the system control circuit 61. Then, in this system control circuit 6α, the signal from PG51 is supplied to the system control circuit 61.
A servo signal is formed so that the pulses from ) have a predetermined phase relationship with the vertical synchronization signal of the video signal, and this signal is supplied to the dry circuit of the motor for rotating the disk (c). . Furthermore, an audio signal is supplied to input terminal t54)K. This audio signal is supplied to an AD conversion circuit (to) through a noise reduction encoder circuit 69, and this digitally converted signal is supplied to a memory device 6η. In addition, the memory control signal from the system control circuit
757) The above-mentioned audio signal for about 10 seconds is compressed in time by 600 times, and the compressed signal is extracted in 2.5 second increments, for example, in accordance with the rotational phase of the disk (Tsukuda). The extracted signal is supplied to the DAAD conversion circuit, and this analog-converted signal is supplied to the changeover switch (441) through the pre-emphasis circuit 15 with linear characteristics and the mixing circuit. It is recorded on the disc (491) by the HDD (48a) (48b). Data such as continuity when the audio signal from the system control circuit 6G spans multiple tracks is also supplied to the data signal generation circuit. , CFLC code, and other redundant data are added and modulated with NRZ, for example, to generate a data signal.Then, this data signal API and start/end identification signals SID/EID, etc. are supplied to the mixing circuit f601, and the fifth It is added to the compressed audio signal AS as shown in the figure.The figure shows the 2.5 seconds mentioned above, which corresponds to one field of the video signal.Therefore, on the f isk decoy, As shown in FIG. 7, recording is performed so that four of these signals consecutively form one track.Furthermore, as shown in FIG. 7, this track includes a video signal track TV and an audio signal track TA. By the way, when a disk (4!lll) is inserted into the above-mentioned device, the device first records all 50 tracks. It is necessary to detect the presence or absence of recording.In other words, in the above-mentioned device, there is a possibility that the disk (41) is temporarily removed from the device before all tracks are recorded, and in that case, the disk (41) may be temporarily removed from the device before all tracks are recorded. In order to perform additional recording on a disc that is already loaded, it is necessary to detect the presence or absence of recording on all trunks immediately after inserting the disc, select the unrecorded track, and perform recording.Also, when playing back However, if the disc (original disc) is inserted immediately after, it is possible to distinguish between the video track and the audio track, detect the data signal API of the audio track, etc., and store it in memory etc., so that subsequent playback will be extremely smooth. However, when using the above-mentioned device, l/!:, for example, when detecting recording on one track, conventionally the head was first placed on the track with a so-called tracking sensor, and when the server was completed, The method used was to reproduce the signal and detect the recording.For this reason, it takes at least the time required for this tracking servo to detect one track, and for example, this is divided into 3 field periods and 50 minutes. In the case of a track, 150 fields = 2.5 seconds of time were required just for the servo. Therefore, in reality, in addition to this, the travel time of the head between tracks is added, so for example, it takes a considerable amount of time from inserting a disc to being able to take pictures, which is extremely inconvenient for use. Ta. [Problems to be Solved by the Invention] In the conventional method described above, tracking servo is performed every time each track is detected, so time is required for this servo, and it takes a long time from inserting the disc to shooting, etc. There were problems such as a large amount of waiting time being required. [Means for resolving gaps and spots] The present invention mechanically moves the playback head (2a) (2b) to a predicted track position, and detects the presence or absence of an envelope of the playback signal from the playback head. (Envelope detection circuit +181)L, when the envelope is absent, the track is determined to have no signal (system control circuit), and when the envelope is present, the video signal in the playback signal (horizontal synchronization detection circuit (2G) ) or audio signal (data signal detection circuit 0) (circuit mark), and when it is impossible to distinguish the video signal or audio signal, performs tracking servo for the position of the playback head (motor field) (circuit (161). [Operation] According to this method, since tracking servo is not performed in normal times, most of the time required for conventional tracking servo can be reduced, and the disc The waiting time from insertion to operation can be shortened. [Example] Fig. 1 shows a line of equipment for realizing the method of the present application. In this figure, (1) is a disk, (2a )(2
b) is a playback head, where head (2a) (2
(b) are provided in parallel with a track interval apart so that two tracks on the disk (1) can be reproduced at the same time. The playback signals from these navel) I (2a) (2b) are supplied through playback amplifiers (3a) <3b) to a head changeover switch (4) controlled by a system control circuit (161), which will be described later. The signal from (4) is FM demodulated Mr (6)
and the signal is demodulated. This signal is the f
A de-emphasis circuit (6) corresponding to the IJ emphasis circuit (4, 1), a reproducing circuit (7) corresponding to the recording circuit (4)
), and the reproduced video signal is taken out to the output terminal (8). In addition, the signal from the demodulation circuit 1 @ (5) is supplied to the AD conversion circuit (lO) through the de-emphasis circuit (9) corresponding to the above-mentioned pre-emphasis circuit and reception circuit, and this digitally converted No. 15 is sent to the memory device. supplied to e0υ. Then, the memory control signal from the system control circuit a (il) is supplied to the memory IJ (Ill), and time axis expansion corresponding to the above-mentioned time axis compression is performed. This expanded signal is supplied to the DAAD conversion circuit z, This analog-converted good signal (audio signal) is taken out from the output terminal (14) K through the noise reduction decoder circuit Q3 corresponding to the encoder circuit 6 mentioned above.Furthermore, the signal from the demodulation circuit (5) is outputted as the above-mentioned data. Data corresponding to the signal generation circuit 69 is supplied to the signal detection circuit (151), and data such as detected track continuity is stored in the memory (In) via the system control circuit Q61. Digital data corresponding to the level of the converted reproduction signal is supplied to the AD conversion circuit σ9 through the envelope detection circuit α&, and is supplied to the system control circuit aυ.The signal from the de-emphasis circuit (6) is also supplied to the horizontal synchronization signal detection circuit. The detection signal is supplied to the system control circuit (1G). Furthermore, the signal from the pulse generator (PG) Gυ related to the rotational phase of the disk (1) and the key voltage (2'2)
An operation signal from the system control circuit α is supplied to the system control circuit α. And these memo IJ (171, AD conversion circuit a9,
Each part is controlled by the system control circuit αυ according to the detection circuit fm, PG (211, #-&-rt23, etc.), No. 18. That is, this gus is A control signal is formed at a predetermined interval, and this signal is supplied to the rotation motor @ of the disk (1) through the dry no ζ circuit (to).The head ( A control signal for moving 2a) (2b) to the next track to be played is formed, and this signal is passed through the dry 9 circuit to the head (2b).
a) When the envelope of the reproduced signal is supplied to the moving motor (a) in (2b), the envelope of the reproduced signal is supplied to the conversion circuit (19).
tracking servo is performed to maximize this detection. Furthermore, head (2a) according to data from memo IJ (171 and key date (22) etc.)
A switching signal (2b) is formed, and this signal is supplied to the head switching switch (4). As a result, the video signal and audio signal recorded on the disk (1) are arbitrarily reproduced and taken out to the output terminal +81f141. Furthermore, when a new disk (1) is inserted into this device, track discrimination is performed in the system control circuit (I61) using the method described below. That is, FIG. 2 is a flowchart showing the procedure of the method. In this figure, when the operation is started, the heads (2a) (2b) are first moved to the first track in step [1]. Next, the switch (4) is controlled in step [2]. Then, in step [3], it is determined whether or not there is an envelope in the reproduced signal, and if there is no envelope, it is determined in step [4] that the detected track is in a no-signal state, and the corresponding address in the memory aη is If there is an envelope in step [3], the presence or absence of a horizontal synchronization signal is determined in step [5].If there is horizontal synchronization, the period corresponding to the data signal is determined in step [6]. Its presence or absence is determined by CR and C checks of Also, if there is no horizontal synchronization in step [5], step [
8], the presence or absence of data is determined in the same way as described above, and if the number of errors is less than the allowable value and it is determined that data exists, step

In step [9], the fact that the detected track is an audio signal is written to the corresponding address in the memory C171, and in step [10], the data contents are written in a predetermined address in the memo 'Jf171. Furthermore, if there is data in step [6], or if there is data in step [6],
If there is no data in step [8], the tracking servo is started in step [11], and the end of tracking is detected in step [12].
The tracking servo is stopped at step 3] and then step 5
will be returned to. When the loading of each data is completed in steps (4) and [71[10] at -tL, the head (
It is determined whether or not 2a) has been selected to I, and the head (
In case of 2a), the head (2b) is selected in step [15] and the process returns to step [3]. If the head (2b) was selected in step [14], it is determined in step [16] whether or not the last track is detected, and if it is not the last track, the head (2b) is selected in step [17]. Head (2a)
(2b) is moved and returned to step [2]. Further, if it is the last trunk in step [16], the operation is ended. Tracks are determined in this way, but in the above-mentioned electronic still camera device, for example, the mechanical precision of tracking is extremely high, and it is extremely likely that the head and track will match based solely on mechanical precision. So,
In the above flowchart, the case where step [11] is entered rarely occurs. In other words, the operation after inserting the disk is as shown in the time chart of Fig. 3. In response to the PG (21) output (corresponding to one field interval) shown in A, the hend feed remote (26)
As shown in FIG. 2B, it moves by two pitches in two field periods, and is stopped for the next two field periods. Then, in one field in the first half of this stop period, the signal of the head (2al) is extracted as shown in C in the same figure, and in one field in the latter half, the signal of the head (2b) is extracted, and then as shown in E in the same figure. Horizontal synchronization and data signals are detected in the latter half of each field. Furthermore, after the detection, similar detection is performed on the person's two tracks. Therefore, in the past, the ℃・
Most of the tracking period for the three fields can be omitted, and the waiting time from insertion of the disc to operation can be shortened. Although the above example is applied to a two-head device that performs frame recording, this method can also be applied to a one-head device. In that case, steps [2], C14], and [15) in the above flowchart are deleted, and step [17] is moved by one pitch. [Effects of the Invention] According to the present invention, since tracking servo is not performed during normal times, most of the time required for conventional tracking servo can be reduced, and the waiting time from insertion of the disk to operation can be reduced. Now it can be shortened.

[Brief explanation of drawings]

1 to 3 are diagrams for explaining the present invention, and FIGS. 4 to 7 are diagrams for explaining the conventional technology. (1) is a disk, (2a) (2b) is a playback head,
(15) is a data signal detection circuit, (161 is a system control circuit, Oa is an envelope detection circuit, (20
Reference numeral 1 indicates a horizontal synchronization detection circuit, and reference numeral 1 indicates a head movement motor.

Claims (1)

[Scope of Claims] A playback head is mechanically moved to a predicted track position, the presence or absence of an envelope of a playback signal from the playback head is detected, and when the envelope is absent, there is no signal on the track. In addition, when the envelope is present, the video signal or audio signal in the playback signal is determined, and when the video signal or audio signal cannot be determined, tracking servo is performed for the position of the playback head. A method for determining the track.