JPH0135355Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a high-speed search device for a rotating recording medium, and particularly for a disk-shaped rotating recording medium (hereinafter referred to as a "disk").
The present invention relates to a high-speed search device that searches for a desired track position in a short time.

PRIOR TECHNOLOGY In general, in a disc playback device, when performing a high-speed search to search for an arbitrary track position (information signal recording position) on the recorded tracks of a disc in a short time, an address value corresponding to a preset desired track position and a disc playback device are searched at high speed. The values of the address signals obtained during reproduction are compared with each other, and the pick-up reproduction element starts reproduction in a desired mode from the point where the two match. The above address signals include, for example, a chapter address signal that mainly indicates the order of recording programs, a time address signal that indicates the total time from the recording program start position, and a track address signal that indicates the order of recording tracks. The address signal is chronologically inserted into a specific period within the vertical blanking period of the recorded video signal and transmitted. These address signals are also recorded in the lead-in portion on the outer circumference side and the lead-out portion on the inner circumference side outside the program recording range.

Problems to be Solved by the Invention However, the value of the address signal has conventionally been selected in the lead-in portion so that the value gradually decreases from the start position of the lead-in to the final position of the lead-in. On the other hand, the values of the address signals recorded in the program recording range and the lead-out portion are selected so that the values gradually increase toward the inner circumference of the disk. Therefore, it is not possible to tell which side the pick-up playback element should be moved to just by the polarity of the output of the difference between the target address value and the playback address value, and when the playback address signal is obtained from the lead-in part, the program recording range The pick-up reproducing element must be moved in the opposite direction from when the reproducing address signal for the lead-out portion is obtained. For this reason, when the microcomputer performs the subtraction process between the target address value and the reproduced address value, the judgment as to whether the feed motor should be rotated forward or backward, etc., the computer program becomes complicated.

Therefore, the present invention adds predetermined values to the target address value and the playback address value, respectively, so that the address value on the disk increases toward the end of the lead-out section. It is an object of the present invention to provide a high-speed search device that simplifies processing during high-speed search.

Means to Solve the Problem The present invention is such that the maximum added address value of the lead-in portion of a certain number of bits of the added output with the address signal is smaller than the added address value of the first position of the program recording range. means for adding a constant value to a target address value and a reproduction address value, respectively; a comparison means for comparing the target address value to which the constant value is added and the reproduction address value to which the constant value is added; The device comprises means for controlling a transfer mechanism to transfer the pick-up reproduction element toward the final position of the lead-out portion or toward the start position of the lead-in portion in accordance with the polarity of the comparison output of the comparison means. An example will be described with reference to the drawings.

Embodiment FIG. 1 is a schematic diagram showing an example of a track pattern of a disc to be reproduced by the apparatus of the present invention. Disc 1 has a spiral track T, and the main information signal consisting of a video signal and an audio signal is a frequency modulated wave. It is recorded as a signal with pits formed according to the information content. Among one continuous spiral track T shown by a solid line in FIG. 1, the tracks corresponding to each rotation of the disk 1 are shown as t ₁ , t ₂ , t ₃ , . . . . Each track has a pit for the main information signal formed on a flat surface, and no needle guide groove is formed. For one track, pits for the first reference signal fp ₁ and pits for the second reference signal fp ₂ are formed on both sides in the longitudinal direction at positions corresponding to the horizontal blanking period every 1 horizontal scanning period 1H. ing.

Only one of the pits of the reference signals fp ₁ and fp ₂ is formed at an intermediate position between the center lines of adjacent tracks, and moreover, only one of the pits of the reference signals fp ₁ and fp ₂ is formed for one track. The side on which is recorded changes for each track. In other words, in Fig. 1, the reference signal
The track of fp ₁ is shown by a broken line, and the track of reference signal fp ₂ is shown by a dashed line. v ₁ , v ₂ , v ₃ , ... indicate the position of the vertical synchronization signal of each field. Further, a third reference signal fp ₃ is provided at the starting end position of each track t ₁ , _{t 2} , t ₃ , . _. . , that is, at a position v ₁ , v ₅ , v ₉ , . is recorded for a 3H period, for example.

Further, the disk 1 has one rotation period equal to, for example, four field periods of the video signal, and a vertical blanking period of tracks t ₁ , t ₂ , t ₃ within the ranges a, b, c, and d in FIG. , . . . various address signals to be described later are also recorded within this vertical blanking period.

In addition, white square marks are shown in the four vertical blanking period recording portions a to d of each of the four vertical blanking period recording portions of each track t ₁ , t ₂ , t ₃ , . . . on the disk 1. As shown, the chapter address signal Ac, the time address signal _AT , and the track address signal are each recorded in time series.

Figure 2A schematically shows the structure of a total of 29-bit chapter address signal Ac, which mainly indicates the order of recording programs on the same recording surface of a disk.
It consists of a line identification code 3 of bits, a voice identification code 4 of 2 bits, a chapter number identification code 5 of 8 bits, a time identification code 6 of 12 bits, and a parity bit 7 of 1 bit. When the recorded video signal is in the NTSC format, this chapter address signal Ac is used for each horizontal scanning period of horizontal scanning line numbers 17 and 280 (that is, for each horizontal scanning period of horizontal scanning line numbers 17 and 280 (that is, the equalization pulse after the vertical synchronization pulse for both even and even fields). Then, from the time when the eighth horizontal synchronizing signal is received, the signals are superimposed and transmitted in one horizontal scanning period).

Synchronization code 2 is a binary number "1100" that indicates the value of "C" in hexadecimal notation, line identification code 3 is a code that identifies the transmission line of the chapter address signal Ac, and audio identification code 4 is a code that identifies the transmission line of the chapter address signal Ac. This is a code indicating the type of audio signal (for example, stereo, monaural, bilingual, etc.). Further, the chapter number identification code 5 is a code indicating the order of the recording program, and can indicate chapter numbers up to 99, for example. Also, the time identification code 6 is a code that indicates the track position from the initial position of each head of the recording program of each chapter number indicated by the chapter number identification code 5 in seconds, and is called a local address, and is a code that indicates the track position from the initial position of each chapter number indicated by the chapter number identification code 5. It can be expressed up to (=2 ¹² -1) seconds.

On the other hand, FIG. 2B schematically shows the structure of a total 29-bit time address signal A _T that mainly indicates the track position in terms of time from the initial position of the first recorded program in the program recording section of the disk.
4-bit synchronization code 8, 2-bit line identification code 9, 2-bit audio identification code 10, 16-bit time identification code 11, 4-bit track identification code 12, and 1-bit parity bit 1.
It consists of 3. This time address signal A _T is
It is transmitted in one horizontal scanning period (horizontal scanning line number 18, 281) following the transmission period of the chapter address signal Ac. Line identification code 9 indicates this transmission period, and synchronization code 8 and voice identification code 10 have the same contents as synchronization code 2 and voice identification code 4, respectively. Also time identification code 11
indicates the time during normal playback from the first recording position of all recorded programs, from 0 minutes 0 seconds to a maximum of 59 minutes.
Can be shown for up to 59 seconds. The track identification code 12 is a code for identifying the number of the track played in one second. For example, in a disk that is supposed to play back a video signal with a field frequency of 60Hz along with an audio signal, the disk rotates 15 times per second, so this means how many tracks out of 15 tracks are played in the same second. This is because it is necessary to identify whether the

Furthermore, although not shown, a time address signal
In the 1H period following _AT , the tracks t ₁ ,
A total of 29-bit track address signals indicating the order of t ₂ , t ₃ , . . . are recorded. As can be seen from Figure 2 A and B, these address signals are
Address data is placed in a total of 20 bits from the 9th bit to the 28th bit, and as mentioned above, the address value is shown in Figure 3 from the beginning of the recording program recording range indicated by PA to the lead-out part.
The value gradually increases as you go to the final position of LO,
And in the lead-in part LI, the lead-out part
An address value that changes by a value greater than the address value of the final position of LO is selected and recorded on disk 1. This is to enable the lead-in portion LI, program recording range PA, and lead-out portion LO to be distinguished from each other. In addition, the first
In the figure and Figure 3, disk 1 has a radius of 13 cm, for example.
A lead-in portion LI is provided in a radius of about 3 mm from 12.5 cm to 12.2 cm, and the diameter of the center hole 14 is about 38.2 mm.

Figure 4 shows an example of the relationship between the 20-bit address data value (chapter address value) of the chapter address signal Ac of the address signals Ac and _AT and the recorded portion in the radial direction of the disk. show. As is clear from the figure, the lead-in part LI
At the start position, the value of chapter number identification code 5 is
The value of local address 6 is "FF" in hexadecimal notation.
Since it is "000" in hexadecimal notation, it becomes "FF000" in 20 bits, and the value of local address 6 gradually decreases as it reaches the final position of the lead-in portion LI. Also, the chapter address value at the start position of the recording range PA of the recording program is "00000" in hexadecimal notation, and the value at the beginning position of the second recording program is "01000", up to number 99. Therefore, if the 100th recording program is recorded, the chapter address value at the beginning position will be "99000".
Further, the chapter address value at the start position of the lead-out portion LO is "EE000", and only the value of the local address 6 gradually increases toward the inner circumference of the disk. The chapter address value of the final position of the lead-out part LO is the lead-in part LI
is smaller than that of the final position. The target address is any address within the recording range PA of the recording program.

Next, the apparatus of the present invention for reproducing the above-mentioned disc 1 will be explained. FIG. 5 shows a block system diagram of one embodiment of the apparatus of the present invention. In the figure, a disk 1 is placed on a turntable 15 and synchronously rotated by a motor 16 at, for example, 900 rpm. At the start of playback, the playback needle 17, which is an example of a pick-up playback element, is started to be moved together with the pick-up device 18 toward the inner circumferential direction of the disk by a transfer mechanism including a feed motor 19, etc., and when it reaches the lead-in portion LI shown in FIG. It is automatically lowered onto disk 1. Furthermore, the playback needle 17 continues to be moved toward the inner circumference of the disk while sliding on the disk 1 at the normal playback speed until it reaches the starting position of the recording program on the disk 1 (the boundary between LI and PA in FIG. 3). Arrive.

The playback needle 17 has an electrode fixed by vapor deposition on the rear end surface of its main body, and a sliding surface having a width larger than the width of the recording track of the disk 1 slides on the disk 1. Signals are recorded on the disk 1 in the form of intermittent pits, and the disk 1 also has an electrode function. Therefore, when the disk 1 is rotated by the motor 16 at, for example, 900 rpm clockwise in FIG. This change is converted into an electrical signal by the pickup device 18 using a known method, and the recorded information signal, address data, etc. are picked up and reproduced.

The reproduced signal taken out from the pickup device 18 is supplied to a demodulation circuit 21 through a preamplifier 20 shown in FIG. 5, and is also supplied to a tracking servo circuit 22. As shown in FIG. 1, on the disk 1, two types of tracking control reference signals having different frequencies are recorded between the track center lines of adjacent information signal recording tracks, and the tracking servo circuit 22 These two types of reference signals are differentially reproduced from the reproduced signal, envelope detection is performed, and both detection outputs are differentially amplified to generate a tracking error signal, which is returned to the pickup device 18 to constantly track the reproduction needle 17. To perform follow-up scanning on an information signal recording track without deviation.

The demodulation circuit 21 demodulates the reproduced signal and outputs the demodulated signal from an output terminal 23 to an information signal processing circuit (not shown).
While outputting to the address data acquisition circuit 24
The address data in the reproduced signal is detected and taken in here. During operations other than search, the search controller 25 is inactive, and pulses of a constant period are taken out from the feed motor control circuit 26 to control the rotational speed and direction of the feed motor 19 in accordance with its reproduction mode.

The operation at the time of search in the reproducing apparatus that performs the above operation will be described next. During the search, the search controller 25 performs operations according to the flowchart shown in FIG. That is, first, as shown in step 31 in FIG. 6, the 20-bit target address data input to the input terminal 27 indicating the track position desired to be searched is fetched, and then in step 32.
The hexadecimal value "10000" is added to the target address data as shown in (that is, the hexadecimal value "1" is added to the upper 4 bits of the 20-bit target address value). If the target address data value (target address value) input to the input terminal 27 is a chapter address value, the program recording range recorded on the disk 1 as shown in FIG.
Any value from the first value of PA "00000" to the last value (this varies depending on the recorded contents of disk 1, but the maximum value is "99000"), and if you add the above "10000" to this value, it will be added. Target address value after
As shown in FIG. 7, Ao takes any one value within the range from "10000" to the maximum "A9000".

Next, the search controller 25 sends the address data acquisition circuit 24 as shown in step 33 in FIG.
A reproduction address signal indicating the current position of the reproduction needle 17 is taken in, and a hexadecimal value "1" is added to the upper four bits of the taken-in reproduction address value (step 34). Therefore, the chapter address value "FF000" reproduced at the start position of the lead-in portion LI becomes "0F000" by adding "10000", and the chapter address value reproduced at the start position of the program recording range PA. The value "00000" becomes "10000" by the above addition, and the lead-out part
The chapter address value "EE000" reproduced at the start position of LO becomes "FE000" by the above addition.
Therefore, the reproduction address value A _P obtained by the above addition changes as shown in FIG. 7 in the case of a chapter address value.

As can be seen from FIG. 7, the chapter address value increases gradually and discontinuously toward the inner diameter of the disk. In other words, the constant value to be added to the target address value and the reproduction address value, respectively, is such that the maximum addition address value of the lead-in portion LI obtained by adding this constant value is the address value of the first position of the program recording range PA. Any value may be used as long as it is smaller than the sum of the value and the above-mentioned constant value, and in the embodiment, it is set to "10000". The upper 4 bits of the time identification code 11 of the time address signal A _T are "F" in the lead-in part LI, "E" in the lead-out part LO, and start from "0" in the program recording range PA. . On the other hand, the upper 4 bits of the 20 bits of address data of the track address signal also have a value of "F" in the lead-in part LI, "E" in the lead-out part LO, and a value of "0" to "0" in the program recording range PA. It begins. Therefore, by adding the constant value "10000" to both the time address signal _AT and the track address signal, the 20-bit added address value changes in the same way as the chapter address value shown in FIG.

The search controller 25 then proceeds to the operation shown in step 35 in FIG. 6, and compares the target address value Ao after the addition with the reproduced address value Ap after the addition, and determines that Ao is larger than Ap. Time is Ao
- The feed motor 19 is rotated forward at a speed corresponding to the value of Ap (step 36), and a signal is generated to move the pick-up device 18 and playback needle 17 toward the inner circumference of the disk 1. In some cases, the feed motor 19 is reversely rotated at a speed corresponding to the value of Ao-Ap (step 37), and a signal for moving the pick-up device 18 and playback needle 17 toward the outer circumference of the disk 1 is generated.

That is, the search controller 25 always uniquely calculates the difference Ao−Ap between the target address value Ao and the reproduction address value Ap, regardless of the reproduction address value Ap, and when the value of the difference is positive, The feed motor 19 is rotated forward to move the regeneration needle 17 etc. toward the inner circumference of the disk 1. On the other hand, when the value of the difference is negative, the feed motor 19 is rotated in the reverse direction to move the regeneration needle 17 etc. toward the outer circumference of the disk 1. This eliminates the need to determine the position of the regeneration needle 17 on the disk 1 and to perform different calculation processes accordingly. Note that, depending on the absolute value of the difference Ao-Ap, the search controller 25 transports the regeneration needle 17 etc. at a high transport speed when it is larger than a predetermined value, and when it is smaller than the predetermined value. When this happens, a signal is generated to move the regeneration needle 17 and the like at a slow speed.

By repeating the above operation, the reproducing needle 17 is moved to the track position of the target address while sliding on the disk 1 (at this time, the tracking servo circuit 22 is moved to the track position of the target address).
). In this way, a desired track position can be searched for quickly and accurately. After the reproduction needle 17 is moved to the desired track position, the tracking servo circuit 22 is deactivated and reproduction is started in a desired mode such as normal reproduction.

Note that the present invention is applicable to a disc reproducing apparatus that does not have a track pattern as shown in FIG. (However, the condition is that the address signal is recorded on the disk with the change in value as shown in FIG. 4).

Effects As described above, according to the present invention, the value of the address signal is changed to a value that gradually increases from the lead-in portion to the lead-out portion of the disk, and then compared with the target address value. Therefore, it is completely unnecessary to detect whether the pick-up playback element is in the lead-in area of the disc or other areas, and to change calculation processing accordingly. This system has features such as easy calculation and transfer control of the pick-up playback element, and easy programming of the search controller.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a schematic track pattern of a disc to be reproduced by the apparatus of the present invention, FIGS. 2A and B are diagrams showing an example of signal formats of a chapter address signal and a time address signal, respectively. The figure is a sectional view showing an example of a disc to be played by the device of the present invention, and FIG. 4 shows an example of the relationship between the chapter address value recorded on the disk to be played by the device of the present invention and the recording position of the disk. Figure, 5th
The figure is a block system diagram showing one embodiment of the device of the present invention, Figure 6 is a flowchart showing an example of the operation of the main parts of the device of the present invention, and Figure 7 is the addition of a constant value after playback by the device of the present invention. FIG. 3 is a diagram showing an example of the relationship between the chapter address value obtained by the above method and its disc playback position. 1...Disc-shaped rotating recording medium (disk), 5...
...Chapter number identification code, 6...Time identification code (local address), 11...Time identification code, 17...Regeneration hand, 19...Feed motor,
21... Demodulation circuit, 24... Address data acquisition circuit, 25... Search controller, 26...
Feed motor control circuit, 27...Target address data input terminal, Ac...Chapter address signal,
A _T ...Time address signal, LI...Lead-in part, LO...Lead-out part, PA...Program recording range.

Claims (1)

[Scope of utility model registration request] An address signal with a fixed number of bits indicating the recording position together with the information signal gradually increases in address value from the beginning of the recording range of the recording program to the final position of the lead-out part, and in the lead-in part, the address signal has a fixed number of bits indicating the recording position. A reproduction address value obtained by reproducing a rotating recording medium recorded with an address value that changes by a value greater than the address value of the final position, and a target address value indicating a desired search position of the rotating recording medium. In a device that transports a pick-up reproducing element at a high speed by a transport mechanism while reproducing the recorded signal of the rotary recording medium until both address values match, the above address value is compared with the address signal. A constant value is added to each of the target address value and the playback address value such that the maximum addition address value of the lead-in portion with a constant number of bits is smaller than the addition address value of the first position of the program recording range. means for comparing the target address value to which the constant value has been added and the reproduction address value to which the constant value has been added; 1. A high-speed search device for a rotating recording medium, comprising means for controlling the transport mechanism so as to transport the information toward the final position of the lead-out portion or toward the start position of the lead-in portion.