JPS5845677A - Reproducer for information recording medium - Google Patents

Abstract

PURPOSE:To shift a stylus type of information reading section to a desired address in a disc shaped information recording medium in high speed, by comparing the desired address with an address of a position of the information reading section detected at an operation processing section. CONSTITUTION:A control section 7 outputs an instruction disconnecting an information reading section 2 from an information recording medium to the section 2. A comparison section 5 compares a set desired address with an address of actual position of the section 2 inputted from an operation processing section 11, and outputs a signal corresponding to the difference of the addresses to the control section 7. The control section 7 generates a control signal shifting the reading section 2 in high speed in response to the signal and shifts the reading section 2 to a position corresponding to the set desired address at a desired address set section 6 via a shifting motor driving circuit 8 and a shifting motor 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for reproducing information recorded on a disc-shaped or cylindrical information recording medium, and particularly relates to a device for reproducing information recorded on a disk-shaped or cylindrical information recording medium, and in particular, a device for reproducing information recorded on a disk-shaped or cylindrical information recording medium, and in particular, a device for reproducing information recorded on a disk-shaped or cylindrical information recording medium. The information reading unit contacts the information recording medium and reads the information,
An object of the present invention is to provide a reproducing apparatus for an information recording medium that is capable of high-speed random access in which an information reading section is moved at high speed to a desired address in the information recording medium.

FIG. 1 shows a block diagram when performing conventional random access. In FIG. 1, (1) is an information recording medium, and information signals and address signals are recorded in advance on information recording tracks on this medium. Both signals are read through an information reading section (2) and FM demodulated by an FM demodulation circuit (3).

Of the synthesized reproduced signal of the information signal and address signal obtained in this way, the address signal is sent to the next stage address separation circuit (
4). Here, for the sake of explanation, the address signal will be referred to as a first address signal. The separated first address signal is sent to the next stage comparison section (5). On the other hand, in the desired address setting section (6), a desired address is set by external input, etc., and a second address signal is sent to the control section (7) as a signal for specifying the desired address to the comparison section (5). Said comparison section (5)
A control signal corresponding to the difference between the first and second address signals read at It begins to move in a direction perpendicular to the information recording track toward the position corresponding to the desired address input in the address setting section (6). The above-mentioned series of operations is performed in the first and second comparison section (5).
The process continues until the difference between the address signals becomes zero, that is, until the information reading section (2) reaches the position corresponding to the desired address.

We have previously described conventional random access, but when using this random access, the information reading section (2) records information while moving in a direction perpendicular to the direction of the °-4 multi-information recording track. In a playback device that has a needle-like structure in which it is necessary to read the address signal from the recording medium (1), the information reading section (2) should read the address signal from the recording medium (1). There is naturally a limit to the speed at which the information recording medium (1) K can be moved at right angles to the direction of the information recording track while in contact with it, and it may be impossible to move it at a sufficiently high speed.

Conversely, if the needle is moved away from the surface of the information recording medium (1), the moving speed can be increased, but it becomes impossible to read the address signal from the information recording medium (1), and the conventional random Access becomes impossible.

The present invention has been made to solve the problems of the conventional random access. The present invention will be described below with reference to the drawings, and parts having the same functions as those of the conventional example will be given the same drawing numbers. FIG. 2(a) is a block diagram showing the configuration of an embodiment of the present invention. (10) is a pulse generation section, and fall is an arithmetic processing section. Here, the structure of the information recording medium will be explained for convenience of explanation later. There are usually three areas on an information recording medium. Here, they will be referred to as a pre-program area, a program M area, and a post-program M area, respectively.

The program area is an area where information signals and address signals are recorded, and the other two areas have no information signals recorded, only code signals to indicate that they are post-program areas. This is the recorded area. Note that the pre-program area and the post-program area exist sandwiching the program area.

The operation of the playback device according to the present invention will be explained with reference to the above-mentioned information, and it is assumed that the playback device automatically shifts to the playback state when the information recording medium is placed in a predetermined position. . Now, once the information recording medium has been placed in the predetermined position, the information reading section (2) moves from the rest position and starts reproducing the preprogrammed area on the information recording medium. Eventually, the information reading section (2) enters the program area (Which of the three areas is being reproduced by the information reading section (2) is detected by an address signal pre-recorded in each area. ) In Fig. 2, the pulse generator (1) generates pulses in accordance with the rotation speed of the feed motor (9) when the information reading unit (2) starts reproducing the program area.The arithmetic processing unit (1υ is , the position of the information reading section is detected by counting the pulses. (At this time, since the information reading section (2) is reproducing the signal on the information recording medium, the address signal on the information recording medium is detected. Detection of the address of the information reading section (2) is also being performed at the same time by reproducing the information.) Now,
When the reproducing apparatus is in the above-mentioned reproducing state, that is, when the information reading section (2) is reproducing the program area in the information recording medium, a high-speed random access command is input to the control section (7). 1), it is assumed that a desired address is set in the desired address setting section (6). The high-speed random access command is valid only while the information reading section (2) is reproducing the program area. The control section (7) outputs a command to the information reading section (2) to move the information reading section (2) away from the information recording medium. The comparison unit (5) compares the set desired address with the address of the actual position of the information reading unit (2) input from the arithmetic processing unit αJ, and controls a signal corresponding to the difference between the two addresses. output to section (7). The control unit (7) generates a control signal to move the information reading unit (2) at high speed in response to the signal, and moves the information reading unit (2) via the feed motor drive circuit (8) and the feed motor (9). ) to the position corresponding to the desired address set in the desired address setting section (6). Even in this state, the pulse generator (1r1
Pulses are generated according to the rotational speed of the feed motor (9), and the arithmetic processing unit αD counts the pulses and detects the address of the position of the information reading unit (2). The above-mentioned series of operations continues until the difference between the desired address according to the signal from the desired address setting section (6) and the address according to the signal from the arithmetic processing section (1υ) becomes zero in the comparator (5), that is, the information is read. The operation is continued until the part (2) reaches the position corresponding to the desired address. FIG. 3 is a time chart for explaining the above-mentioned series of operations according to the present invention. (b) shows a command to move the information reading section (2) in a direction perpendicular to the direction of the information recording rack.Information reading section (2) is a high-speed random access command.
starts reproducing the information recording medium from time O, and thereafter plays the preprogram area until time T1, and from time T1 to time 12, uses the program area from time T2 onwards. Assume that the gram area is being played. Time when the information reading section (2) is reproducing the program area
When a high-speed random access command is issued at 3 ((a)
(Figure) At the same time, a command to move the information reading section away from the information recording medium is issued (Figure (b)), while a command to move the information reading section in a direction perpendicular to the direction of the information recording track is issued.

(Fig. (C)) After that, at time T4, when the information reading section (2) reaches the desired address, each of the above-mentioned commands is canceled and the normal reproduction state resumes.

Next, another embodiment of the present invention will be described with reference to FIG. 2(b). In Fig. 2(b), parts with the same functions as those in Fig. 2(a) are given the same number, but (9) is a feed motor that is driven in one step by one pulse. This is a stepping pulse motor. By employing the stepping pulse motor, the pulse generator (1α) receives a signal from the control unit (7), generates a pulse, and drives the feed motor (9) via the feed motor drive circuit (8). Further, the control unit (7) provides a signal to the arithmetic processing unit (Ill), and the arithmetic processing unit αυ performs counting processing on the signal to detect the address of the position of the information reading unit (2). Comparing the embodiments shown in FIG. 2(a) and FIG. 2(b), the difference lies in whether the pulse generating section 0 is driven by the feed motor (9) or by the control section (7). There is no difference in that the processing unit 01) counts pulses and detects the address of the information reading unit (2).

Furthermore, when accuracy is required when performing high-speed random access, random access is performed by detecting the address of the position of the information reading section by pulse counting according to the present invention, and recording on a conventional information recording medium is possible. Random access may be used in combination with random access, which is performed by reading the received address signal and detecting the address at the position of the information reading section. A block diagram of an embodiment of high-speed random access using both of the above-mentioned random accesses is shown in FIG. 4, and will be explained.

When a high-speed random access command is issued and a desired address is set in the desired address setting section (6), the comparison section (5) compares the actual address (7) of the information reading section (2).
The address of position ff and the set desired address are compared. If the difference between the two addresses is greater than a preset value, high-speed random access according to the present invention is performed according to the loop shown by the solid line in FIG. (In other words, the information reading unit (2) is moved away from the information recording medium, and the information reading unit (2) detected by the set desired address and the arithmetic processing unit (11) is
The device is moved at high speed in a direction perpendicular to the direction of the information recording track until the difference between the addresses of the actual positions in 2) becomes smaller than the specified value. ) After this operation is completed, the information reading section (2) is already in the vicinity of the desired address. Here, the information reading section (2) is brought into contact with the information recording medium (a1). After this, the information reading section (
2) is in contact with the information recording medium (1), so the speed at which the information reading section (2) is moved in the direction perpendicular to the information recording track is slightly reduced to read the information recorded on the information recording medium. The current address signal is read and compared with the desired address in the comparator (5), and conventional random access is performed according to the loop shown by the dotted line in FIG. 4 until the difference between the two addresses becomes zero. As described above, according to the present invention, the address at the position of the information reading section can be detected without reading the address signal recorded on the information recording medium. In a playback device that has an information reading section with:
Also, information l-1- is distributed in a direction perpendicular to the information recording track.
' It is possible to perform high-speed random access by moving the reading section at high speed, stopping at a desired address, and then switching to the playback state. Furthermore, when accuracy is required, accurate and high-speed random access can be performed by combining the conventional method with the present invention.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing conventional random access, FIGS. 2(a) and (b) are block diagrams showing high-speed random access according to the present invention, and FIG. 3 is a block diagram showing conventional random access.
4 is a time chart diagram for explaining the operation of the embodiment.
The figure is a block diagram showing an embodiment in which conventional random access and high-speed random access of the present invention are used in combination. Explanation of main figure numbers (1)...Information recording medium, (2)...Information reading section, (10)...Pulse generation section, (11)...Arithmetic processing section, (6)... ... Desired adrene setting section. t"T"+ rm Toichi 〇

Claims (1)

[Claims] 1. In an information recording medium reproducing apparatus that automatically starts reproducing the recorded information when a disc-shaped or cylindrical information recording medium is placed in a predetermined position, the reproducing apparatus contacts the information recording medium. an information reading section; a pulse generating section that generates pulses according to the number of rotations of a feed motor that drives the information reading section; and a pulse generating section that counts the pulses and determines the position of the information reading section. and a desired address setting section that can specify and input a desired address in the information recording medium, and the input desired address and the address detected by the arithmetic processing section are provided. 1. A reproducing apparatus for an information recording medium, characterized in that the information reading section is moved at high speed to a desired address in the information recording medium by comparing addresses of positions of the information reading section.