JPH0461053A - Rotary magnetic head device - Google Patents

Abstract

PURPOSE:To prevent generation of phase disturbance due to the conversion error of an A/D conversion by successively executing an A/D conversion when an adjustment mode is designated to obtain a delay amount data, and obtaining the delay amount data by reading out a memory when a normal mode is desig nated. CONSTITUTION:When the adjustment mode is set by a mode discrimination circuit 28, memories 22a and 22b become a writable state, and just the amount which corresponds to the A/D conversion data of A/D convertors 20a and 20b are delayed from delay circuits 16a and 16b for every PG pulse from a PG 12 and is outputted as a head switch signal. In the case of the normal mode, the data of the A/D convertors 20a and 20b are not used, the A/D conversion data stored in the memory 22a and 20b are read, and they are set as the delay amount data of the delay circuits 16a and 16b. Thus, the phase disturbance due to the A/D conversion error can be eliminated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotating magnetic head device, and particularly to a rotating magnetic head device that generates a head switching signal with a certain amount of delay by analog/digital conversion using a pulse signal from a pulse signal generator as a starting point. The present invention relates to a rotating magnetic hend device.

[Prior art]

When a pair of pulse generators (hereinafter referred to simply as rpcJ) are attached to the rotating magnetic head and are provided facing each other by 18 degrees, the rising and falling edges of the PC pulse shown in Fig. 6(a) are , as shown in Fig. 6(b), by delaying a certain amount by mono-multi-by-break, Fig. 6(b)
Generate the head switching pulse shown in c).

In addition, when there is one PG, an even number (2n) frequency generators (hereinafter simply rFGJ) are provided, and the PC pulse shown in FIG. 7(d) is used as a reference, and the frequency generator shown in FIG. n0
By delaying the rising or falling edges of the FC pulses of the th and no+nth FC pulses by a certain amount using the mono multivibrator as shown in FIG. 7(b), the head switching pulse shown in FIG. 7(C) is generated. create.

[Problem to be solved by the invention] Recently, software-based control methods have become mainstream, but in this case, analog/digital (A, /D) conversion is used instead of the mono-multivibrator described above to Often determines the amount. In this way, when delaying by A/D conversion, if A/D conversion is performed for every PC pulse or every predetermined FC pulse, conversion errors will always occur, resulting in phase disturbances such as jitter.

Therefore, the main object of the present invention is to provide a rotating magnetic head device that does not cause phase disturbance due to conversion errors in A/D conversion.

[Means for Solving the Problems] Simply put, the present invention provides an analog/
A rotary magnetic head device that generates a head switching signal with a certain amount of delay due to digital conversion includes a memory for storing the result of analog/digital conversion, and mode designation means for designating an adjustment mode or a normal mode. When the adjustment mode is specified, analog/digital conversion is performed sequentially using the pulse signal as a starting point to obtain delay amount data, and when the normal mode is specified by the mode specifying means, the memory is read out to obtain the delay amount data. This is a rotating magnetic head device characterized by the following.

[Effect]

The data of the A/D conversion performed once is stored in the memory, and when the normal mode is specified by the mode specifying means, the delay amount data is obtained by reading the memory for each PC pulse or every predetermined FC pulse. .

Also, adjustment work is performed to correct mechanical installation errors between the PC and the magnetic head, but in such an adjustment mode, if the delay amount data stored in memory is used, the delay amount will be fixed. , adjustment becomes impossible. For this purpose, when the adjustment mode is set by the mode setting means, A/D conversion is performed sequentially for each PC, pulse, or predetermined FC pulse to obtain delay amount data.

〔Effect of the invention〕

According to the present invention, since the delay amount data stored in the memory in advance is used in the normal mode, phase disturbances (jitter) due to A/D conversion errors are eliminated, and in the adjustment mode, sequential A/D conversion is performed. Since the delay amount data is obtained by using the method, adjustment work is also possible.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

〔Example〕

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the rotary magnetic head device 10 of this embodiment, 18
A pair of PCl3 facing each other at 0° is provided, and this PCl3
The PC pulse from the toggle flip-flop (T, FF
)14 toggle inputs. And this T-F
The output of F14 is given to delay circuits 16a and 16b such as presettable counters (timers). Also, a clock for A/D conversion is input to the clock terminal 18, and this clock is applied to the A/D converter 20a. and 20b, respectively.

The outputs of A/D converters 20a and 20b are
22a and 22b, respectively, and
One contact of each of switches 24a and 24b is provided. The other contacts of switches 24a and 24b are connected to the outputs of memories 22a and 22b. Outputs from the A/D terminals of the A/D converters 20a and 20b are also provided to a mode discrimination circuit 28 that receives signals from the operation button group 26.

In the mode discrimination circuit 28, the A/D converters 20a and 2
When the output of 0b is r256J, for example, the adjustment mode is set. When the adjustment mode is set, the output from the mode discrimination circuit 28 makes the memories 22a and 22b writable, and the switch 24
a and 24b are in the state shown in FIG.
converter 20a and 2Ob side). In addition, at other times, the mode discrimination circuit 28 is in the normal mode (
(non-adjustment mode). When the normal mode is set, the output from the mode discrimination circuit 28 enables the memories 22a and 22b to be read, and the switches 24a and 24b are set in the opposite direction (as shown in FIG. 1).
In other words, it is switched to the memory 22a and 22b side). Through these switches 24a and 24b, the A/
Delay amount data from D converters 20a and 20b or memories 22a and 22b is set in the aforementioned delay circuits 16a and 16b.

In the normal mode, the mode discrimination circuit 28 outputs mode signals such as playback, stop, etc. in response to operation signals from the operation button group 26.

In operation, when the mode discrimination circuit 28 sets the adjustment mode, the memories 22a and 22b are enabled for writing, and the switches 24a and 24b are set to the A/D converters 20a and 2Ob side. Therefore, in response to the clock from the clock terminal 18, the A/D converter 20
a and 20b perform an A/D conversion operation, and the data is stored in memories 22a and 22b each time, and is also sent to delay circuit 16 through switches 24a and 24b.
a and 16b. Therefore, for each PC pulse from the FC 12, from the delay circuits 16a and 16b,
The signal is delayed by an amount corresponding to the A/D converted data of the A/D converters 20a and 20b and output as a head switching signal.

When the mode discrimination circuit 28 designates the normal mode, the memories 22a and 22b become readable, and the switches 24a and 24b are switched to the memories 22a and 22b. Therefore, in the normal mode, the data of the A/D converters 20a and 20b is not used, and the data of the A/D converters 20a and 20b are not used.
The D conversion data is read and set as delay amount data of delay circuits 16a and 16b. Therefore, in the normal mode, delay circuits 16a and 16b
From then on, the PC pulse is delayed by the data stored in the memories 22a and 22b and output as a head switching signal.

In the embodiment of FIG. 1, the delay circuits 16a and 1
6b may be configured as one delay circuit.

FIG. 2 is a block diagram showing another embodiment of the invention. In this embodiment, one PC 12 and an FC 30 are provided, and the FG pulse from the FC 30 is applied to the counter 32. This counter 32 is reset by a PC pulse. Then, the A/D converter 20 performs A/D conversion according to the clock from the clock terminal 18, and the output thereof is given to the memory 22 and switch 24 as in the embodiment shown in FIG. The output is given to mode discrimination circuit 28.

In the rotary magnetic head device 1o° of this embodiment, the first
Since it operates in the same way as the embodiment shown in the figure, duplicate explanation will be omitted here.

In addition, when the embodiment of FIG. 1 or 2 is configured by one microcomputer, it operates according to the flowcharts shown in FIGS. 3 to 5. That is, when an interrupt by a PC, pulse or FC, pulse occurs, it is determined in step SI whether the PC pulse or FC pulse is a predetermined one. If not, return without doing anything.

And if it is a PG pulse or a predetermined FC pulse,
In step S2, it is determined whether the adjustment flag, which is set as shown in FIG. 4 or cleared as shown in FIG. 5, is in the set state. That is, if the corresponding A/D terminal is initially at a high level, an adjustment flag is set, and the adjustment flag is reset in the normal mode.

Then, in the normal mode, that is, when the adjustment flag is reset, data is read from the memory and used as delay amount data in step S3. Further, when the adjustment flag is set, steps S4 and S5 are executed to store the A/D conversion data in the memory and use the A/D conversion data as delay amount data.

Then, in step S6, step S3 or S
The PC pulse or a predetermined FC pulse is delayed according to the delay amount data set in step S5, and output as a head switching pulse in step S7.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a block diagram showing another embodiment of the invention. 3 to 5 are flowcharts showing the operation of other embodiments of the present invention. In the figure, 12 is a PC (pulse generator), 20a, 2
0b, 20 are A/D converters, 22a, 22b, 22 are memories, 24a, 24b, 24 are switches, 28 is a mode discrimination circuit, 30 is an FC (frequency generator), and 32 is a counter. Figure procedure amendment (method) % formula % Name of the invention Relationship to the case of person who corrects a rotating magnetic head device Patent applicant address 2-18 Keihan Hondori, Moriguchi City, Osaka Prefecture Name
(188) Sanyo Electric Co., Ltd. Representative Satoshi Iue 541e Osaka (06) 229-0531
Address: 2-6-6 Fushimicho, Chuo-ku, Osaka City, September 1990
25th of May (all sending dates) 7. Add the following sentence between lines 13 and 14 of page 11 of the statement of contents of the amendment. 6 and 7 are timing diagrams showing the operation of the prior art, respectively. FIG. 6 shows a case where a pair of PCs are provided, and FIG. 7 shows a case where one PC is provided. Indicates when that's all

Claims (1)

[Scope of Claims] A rotating magnetic head device that generates a head switching signal after a certain amount of delay by analog/digital conversion using a pulse signal from a pulse generator attached to the rotating magnetic head as a starting point, comprising: A memory for storing results, and a mode specifying means for specifying an adjustment mode or a normal mode, and when the adjustment mode is specified by the mode specifying means, the analog/digital conversion is sequentially executed using the pulse signal as a starting point, and the conversion is delayed. 1. A rotary magnetic head device, characterized in that the delay amount data is obtained by reading the memory when the normal mode is specified by the mode specifying means.