WO1985005213A1

WO1985005213A1 - Digital tape recorder

Info

Publication number: WO1985005213A1
Application number: PCT/JP1985/000243
Authority: WO
Inventors: Nobuya Sano
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 1984-05-07
Filing date: 1985-04-30
Publication date: 1985-11-21
Also published as: KR900004748B1; KR850008735A; JPS60234278A

Abstract

A rotary head digital tape recorder which enables a high speed search to be effected by utilizing address data recorded on the tape and the number of revolutions. An address detector (11) is provided to calculate the address data relying upon a reel (5) detected by a revolution detector means (10) or relying upon the number of revolutions of a roller. The thus calculated address data is corrected by address data that is read from a tape (2) via a rotary head (1) and that is reproduced by an address reproducing means (6).

Description

Specification

Title of invention

Digital Lute Blur Coder

Technical field

The present invention relates to a rotary head type digital tape recorder capable of performing a high-speed search using a time code recorded on a table and a reel rotation speed detection. It is about. Background art

In recent years, the digitization of audio sources has been rapidly progressing, as seen in compact disk II satellite broadcasting, and the development of digital tape recorders has been progressing accordingly.

Fig. 1 shows a configuration diagram of an example of a rotary head system among the digital tape recorders currently proposed.

In FIG. 1, 1 is a rotating head including a rotating drum and two recording / reproducing heads, 2 is a table, 3 is a capstan, ⁴ is a force set, and 5 is a reel. Reference numeral 6 denotes address reproducing means for reproducing the address information recorded on the table, reference numeral 7 denotes reel driving means, reference numeral 8 denotes capstan driving means, and reference numeral 9 denotes control means.

Fig. 2 shows an example of a recording track pattern of the digital tape recorder configured as described above. Table 2 is wound diagonally around the drum of rotating head 1, and when the tape runs in the direction of the arrow in FIG. 2, the two heads (A head) having different azimuth angles And the B head) move in the direction of the arrow with respect to the table, and as shown in Fig. 2, the A head has the A track force and the B head has the B track. Are alternately recorded. Consider a method of searching for an arbitrary address at high speed with the digital tape recorder configured as described above.

During the high-speed search, the address reproducing means 6 reads the address information recorded on the table 2 via the rotary head 1 and supplies the information to the control means 9. The control means 9 compares the target address with the reproduced address information, and controls the running systems such as the reel driving means 7 and the capstan driving means 8 so as to stop at the position where they coincide with each other. Do

However, when running the tape at high speeds, the head should not jump back and forth on the recording track. Fig. 3 shows an example of the relationship between the head trajectory and the recording track at the time of 15x fast-forward D. In this example, heads pass through ^{one in} ^every fifteen tracks. However, for example, when the A head passes through the track on the track where the address is recorded, if the track is an A track, it can be read but if it is a B track Cannot be read because the azimuth angle is different, and its probability is about. Therefore, on average, an address can be read only once per 3 O tracks, and the address information is coarse J), and it is difficult to search accurately.

The currently proposed rotary head type digital tape recorder — the tape traveling speed of the taper is ² «WZ seconds, so the fast-forward speed of the conventional compact cassette is about 1 If sent in ⁴ seconds, it will be 200 times faster. Since the proposed head rotation speed is 66.7 rotations Z seconds, the head passes once every 3 seconds in terms of tape recording time at ² OOx speed, If the address could be read in half of them, it would be very coarse once every 6 seconds. • I was only able to read dress information, and it was difficult to search accurately.

Disclosure of the invention

An object of the present invention is to solve the above-mentioned conventional problems, and to provide a digital tape recorder capable of obtaining detailed address information even during a high-speed search 5 and performing an accurate search. . The present invention relates to a tape recorder provided with address information reproducing means, reel rotation detecting means, and tape traveling system control means. The tape recorder converts the reel rotation speed into address information, and converts it into address information. With a configuration that corrects with the reproduced address information, accurate and detailed address information can be obtained and an accurate search can be performed.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram of a conventional digital table recorder, FIGS. 2 and 3 are operation explanatory diagrams of FIG. 1, and FIG. 4 is a digital tape recorder according to one embodiment of the present invention. Fig. 5 is an explanatory diagram of the calculation procedure of the address change amount, and Fig. 6 is a configuration diagram of the data area on the table.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 4 shows a configuration diagram of a digital record recorder 0 'in the embodiment of the present invention.

In FIG. 4, 1 to 9 are the same as those of the same number shown in FIG. 1, and 1 O is the rotation speed of the reel 5 by the pulse generated from the reel 5 with the pulse generator. For example, a ring-shaped magnet 5 with SN poles alternately magnetized 5 is mounted on a reel base, and a Hall element is mounted facing the magnet. • A calculation means that performs the calculation described below based on the output of the Hall element and the one attached to the fixed side. Reference numeral 11 denotes address detecting means for detecting address information using the output of the rotation detecting means ¹ O and the output of the address reproducing means 6. The address reproducing means 6 includes a sub-code extracting means 61 and a time code extracting means 62.

The digital table recorder of the embodiment configured as described above will be described below.

First, while stopped, the rotating head 1 traces almost along the recording track, so the address information recorded there can be read. You.

Next, when moving to the high-speed search, the number of revolutions of the reel 5 is detected by the rotation detecting means 1O, the detected pulse is multiplied by a coefficient, and added to the current address to obtain an address.

This coefficient is based on the detection hole provided in cassette ⁴ ! 5) Obtained value is obtained from the tape thickness information, the hub diameter of the reel, the number of rotation detection pulses per revolution of the reel, and the tape running speed.

More specifically, referring to Fig. 5, when winding the tape 2 of the reel S1 onto the empty reel 52 of the hub diameter Γ〇, t seconds have elapsed since the beginning of the winding. Assuming that the tape is wound by the rear length H and the half diameter of the tape is reduced to 1, the tape thickness information

Since T is known,

twenty two

7Γ r--7Γ r _0- = — ― = v _t V: Table speed

T

In addition, it detected pulse generator ^{1 2]?} When Li Lumpur ^{5 2} is the detected number of pulses that occur in your city for ^one rotation is P, the number N of detection pulses generated in 1 Byoto is

V

2 π r

The required coefficient K is

2 π 2 π-VT +

Κ =-= π Ο

The address t required for ゆえ V P V P is t = + K · N with the current address.

However, there is an error in the address at the time of high-speed traveling only by the detection by the reel rotation detecting means ¹ , and the error is accumulated as the traveling distance increases. Therefore, with the address information that can be read intermittently by the address reproducing means 6 during high-speed traveling, the address obtained from the above-described reel rotation detection is used by the address detection means 11. Correction ensures that the error is not cumulative and always gives an almost accurate address. The current address information of the output of the address detecting means 11 obtained in this way and the target address of the search destination are referenced, and the table is stopped when they match, and Or, by controlling the control means 7 and the capacitor driving means 8 so as to be in the reproducing state, an accurate search operation can be performed. In the above embodiment, the tape running amount during the high-speed search is calculated by detecting the rotation speed of the reel 5. Instead, the rotation speed of the rollers such as the post of the tape running system is calculated. I will detect Even so, the present invention is erect.

Next, a description will be given of a specific example in which the address obtained from the reel rotation detection is corrected using the address information extracted by the address reproducing means 6.

First, the recording format of the currently proposed rotating head digital recorder is described with reference to FIG.

Fig. 6a shows the configuration of one recording track, a PCM area for recording main data such as music signals, a sub-code area for recording time code and still image data, etc. It consists of an ATF area for recording a tracking signal, a PCM area, and a PLL area for reproduction clock provided before the subcode area.The subcode area is divided into the first half and the second half. Each of them has a PLL area in front of it.

As shown in Fig. 6b, the first half subcode area and the second half subcode area are each composed of ^eight blocks, for a total of 16 blocks. Each block is used for synchronization as shown in Fig. 6c.

S Y N C area, P & Q area for address information, block address area, wrong I? It consists of a detection CRC area and a data area, and the P & Q area is composed of one word.

Due to rotating head 1! The data on the tape ² that has been imported is first sent to the subcode extraction means 61 of the address reproduction means 6! ) The subcode area in Fig. 6b is extracted.

Thus, for example, as shown in Fig. 6d, the hour, minute, second, and track information of the addresses composed of time codes in the 1st O block to the 13th block If the address is stored, the address reproduction means 6 • According to the time code extraction means 62! ) As shown in Fig. 6d, the time code put in the P & Q area of each block can be taken out. Here, the mode consists of ² bits and is used to identify that address information is recorded in each of the following blocks.

In order to completely read the address information recorded in this way, it is necessary to read at least 5 blocks in a row. However, as can be inferred from Fig. 3, the higher the speed, the shorter the continuous reading section is. For example, at 2 OO double speed, only ¹ to 2 blocks can be read, so that Cannot be read. Σ-However, even during high-speed search, it is possible to read only ^one block. Therefore, as shown in Fig. 6e, the second information is recorded in the P & Q area of the ninth block immediately after the PLL, and is read at the time of a high-speed search, and the second information of the address is read. Should be corrected. Since the P & Q area of the ^ninth block has ⁶ bits outside the mode, the second information can be entered using a 6-bit binary code.

The address second information is corrected by the address detecting means 11 and the current address second information calculated by detecting the rotation speed of the reel is read into the second information read from the tape. To correct. At this time, if the second information before and after the correction is close to O seconds (or 59 seconds), the minute information may need to be corrected.

So, for example, if the value of the second before the correction is 45 to 59 seconds and the value of the second 5 read is O to 14 seconds, the value of the minute is increased by 1. If the value of the second before correction is between O seconds and 14 seconds, and the value of the read second is between 45 seconds and 59 seconds, the minute value should be reduced by 1 to reduce the probability of incorrect correction. The least.

In Fig. 6, the address information is entered from the ninth block. However, even if the address information is entered from the first block, since the second information comes immediately after the PLL area, it is read. ¾ D, it goes without saying that the same effect can be obtained. Further, in the embodiment of FIG. 6, an example is shown in which address information is stored in the P & Q area, but there is no problem if the address information is stored in the data area.

Industrial applicability

As described above, the present invention provides a means for reading address information on a tape and a means for detecting the number of revolutions of a reel or a mouthpiece, thereby achieving accurate addressing even during a high-speed search. Information can be obtained, and furthermore, by putting a part of the address information on the table into the block immediately after the PLL area of the subcode, it is possible to read the second information during high-speed search. It is possible to realize a digital recorder that is excellent if it can be performed reliably.

Claims

• The scope of the claims

1. Rotating head, address reproducing means for reproducing the address information recorded on the tape through the rotating head, and rotation for detecting the number of rotations of the reel or roller. The address change amount is calculated based on the output of the rotation detection means and the detection means, and the calculated change amount is added to the current address, and the current address is obtained based on the address information reproduced by the address reproduction means. And a control means for controlling the tape running system while referring to the current address information output from the address detection means.

.

2. Rotating head, address reproducing means for reproducing the address information recorded on the tape via the rotating head, and rotation detection for detecting the number of reel or roller rotations. Means, tape thickness information detecting means for knowing the tape thickness, and the above-mentioned tape thickness information and the current address.]? The obtained reel rotation detection output calculates the amount of change in address ^per pulse, and calculates it. The address is added to the current address, and the address detecting means for correcting the current address with the address information reproduced by the above address reproducing means and the current address information output from the address detecting means are referred to. A digital breaker consisting of a control means for controlling the tape running system.

3. a rotating head, address reproducing means for reproducing address information recorded on the tape via the rotating head, and rotation detecting means for detecting the number of reel or roller rotations. The address change amount is calculated based on the output of the rotation detection means, and is added to the current address, and the address reproduced by the address reproducing means is calculated. • An address detecting means for correcting the current address with the information, and a control means for controlling the tape running system while referring to the current address information output from the address detecting means, and The tracks recorded on the table by the pads consist of a PCM area for recording main data, one or more sub-code areas for recording other digital information, and each of the above sub-codes. It consists of a PLL area for clock synchronization provided immediately before the area, the subcode area consists of blocks of multiple values, and each of the above blocks consists of an address word and an address word. It is composed of multiple words including data, and the address word of the block immediately after the PLL area in each of the above blocks contains part of the address information. A digital tape recorder, which is characterized by o

4. A digital tape recorder according to claim 3, wherein the address is constituted by a time code, and a part of the address information is second information.

5. The seconds of the current in your in claim 4 § de Re scan is 5 9 seconds approximately ⁴ 5 seconds, when the seconds of § de-less information reproduced is O s -to-pot 1 4 sec Increases the minute of the current address by one, the second information of the current address is approximately 14 seconds from O seconds, and the second information of the reproduced address information is approximately 4 S seconds to 59. shake co one da - di Jitarute the case of a second to Toku徵that was due to decrease by ¹ minute of the current § de-less Unishi. Five