JPH04353678A - Reference synchronous signal generator - Google Patents

Abstract

PURPOSE:To provide a reference synchronous signal generator with excellent characteristic in shifting time to a stable state by allowing the determining of a reproduction synchronous signal and a reference synchronous signal to restart the reference synchronous signal at an interval corresponding to a value set at initial value using the reproduction synchronous signal immediately after a jumping. CONSTITUTION:Outputs of a window control signal generating section 14 for controlling a window section and a reproduction synchronous signal input terminal 11 are applied to a start signal generating section to generate a start signal from a reproduction synchronous signal obtained in the window section. The start signal is applied to a reference synchronous signal generating section 2 while being applied to an initial value setting section 13 to input an initial value to the reference synchronous signal generating section 2. The reference synchronous signal generating section 2 uses the start signal generating section 12. the initial value setting section 13 for determining a starting point of a reference synchronous signal and a reference signal from a reference signal generating section 1 to obtain the reference synchronous signal from a reference synchronous signal output terminal 3. This enables the obtaining of the reference synchronous signal which allows the setting of a relationship between the reference synchronous signal and the reproduction synchronous signal primarily at a restarting timing.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a reference synchronization signal generation device which is a reference synchronization signal necessary when reproducing signals on a video disc, and which is useful when performing special playback such as track search, track jump, and trick play. It is related to.

0002

2. Description of the Related Art In recent years, there has been an increasing demand for high performance for special playback functions on video discs.

A conventional reference synchronization signal generating device will be explained below. FIG. 5 shows a block diagram of a conventional reference synchronization signal generator. In FIG. 5, 1 is a reference signal generation section, 2 is a reference synchronization signal generation section, 3 is a reference synchronization signal output terminal, and 4 is a reset signal input terminal.

The operation of the reference synchronization signal generator constructed as described above will be explained below. The reference signal obtained by the reference signal generation section 1 is applied to the reference synchronization signal generation section 2, frequency-divided by the reference signal generation section 2 to become a reference synchronization signal, and outputted from the reference synchronization signal output terminal 3. Furthermore, when a reset signal is input from the reset signal input terminal 4, the reference synchronization signal is generated again from that point onwards.

[0005] In general, video discs have a constant rotational speed (hereinafter abbreviated as CAV), and
In order to increase the recording density, the linear velocity during recording and reproduction is constant (
Discs such as CLV (hereinafter abbreviated as CLV) are also used. The spindle servo that rotates the CAV and CLV disks in this manner is configured to generate a drive signal using a reproduction synchronization signal and a reference synchronization signal.

In particular, when playing a CLA disc, when jumping from one playback location to another, the reset signal input terminal 4 is activated when it is determined that another playback track has been tracked.
A reset signal is input to , and a new reference synchronization signal is generated. Normally, when a reset signal is input, the first pulse of the reference synchronization signal is generated after a time corresponding to 1/2 the period of the reference synchronization signal, and after that, pulses are generated sequentially at the period of the reference synchronization signal. I will do it.

[0007]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional configuration, the relationship between the reproduction synchronization signal immediately after jumping (immediately after reset) and the reference synchronization signal on a CLV disk is not uniquely determined. There has been a problem in that changes in the spindle servo drive signal caused by the precision of the disk or mechanism exceed the dynamic range of the drive signal, resulting in a longer time required to shift to a stable state.

[0008] The present invention solves the above-mentioned conventional problems by restarting the reference synchronization signal using the reproduction synchronization signal input immediately after a jump, thereby uniquely establishing the relationship between the reproduction synchronization signal and the reference synchronization signal. To provide a reference synchronization signal generating device which can realize a high-performance special regeneration function by making effective use of the dynamic range of a spindle servo drive signal and shortening the transition time to a stable state. With the goal.

[0009]

Means for Solving the Problems In order to achieve this object, the reference synchronization signal generation device of the present invention includes a reference signal generation section that generates a reference signal, and a reference synchronization signal generator that generates a reference synchronization signal using the reference signal. A signal generation section, a window control signal generation section that controls the window section, a start signal generation section that generates a start signal from a reproduction synchronization signal obtained in the window section of the reproduction signal by the window control signal, and an output from the start signal generation section. The signal to be generated is input to the reference signal generation section and the initial value setting section, and when the start signal is output from the start signal generation section, the reference synchronization signal is generated from the starting point specified by the initial value setting section from the reference synchronization signal section. It has a configuration that generates.

0010

[Operation] With this configuration, the reference synchronization signal can be restarted at intervals corresponding to the initial value set using the reproduction synchronization signal that is reproduced immediately after the jump operation (when the track can be followed). Therefore, the relationship between the reproduction synchronization signal and the reference synchronization signal at the time of restart can be uniquely determined.

[0011]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 11 is a reproduction synchronization signal input terminal, 12 is a start signal generation section, 13 is an initial value setting section,
14 is a window control signal generation section, 1 is a reference signal generation section,
2 is a reference synchronization signal generating section, and 3 is a reference synchronization signal output terminal.

The operation of the reference synchronization signal generator constructed as described above will be explained with reference to FIG. First, the reference synchronization signal generation section 2 can obtain a reference synchronization signal by dividing the reference signal outputted from the reference signal generation section 1 at a predetermined frequency division ratio, and can start the reference signal from the start signal generation section 12. When a signal is input, the reference synchronization signal is generated at a different phase from the previous one based on the start signal.

FIG. 2 shows the operation of the reference synchronization signal generator in a jump operation. During the jump operation, signals cannot be correctly reproduced from the recording medium, resulting in an undefined interval in which a correct reproduction synchronization signal cannot be obtained. However, the reference synchronization signal continues to be in the state before the jump operation, and continues to be generated during the jump. When the target track can be reproduced by the jump operation (the jump operation is completed), a signal is applied from the window control signal generator 14 to the start signal generator 12. At this time, the start signal generation section 12 generates a start signal in response to the reproduction synchronization signal inputted from the reproduction synchronization signal input terminal 11 and applies it to the reference synchronization signal generation section 2 and the initial value setting section 13. The start signal generator 12 no longer responds to the reproduction synchronization signal from the reproduction synchronization signal input terminal 11. When a start signal is input from the start signal generation section 12 to the initial value setting section 13, an initial value for setting the first time at which the reference synchronization signal restarts is transferred to the reference synchronization signal generation section 2. When the reference synchronization signal generation section 2 receives the start signal from the start signal generation section 12, it stops the reference synchronization signal that has been generated so far, and transfers the reference synchronization signal from the initial value setting section 13 again based on the start signal. After a time corresponding to the initial value, the first reference signal is generated, and thereafter, reference signals are continuously generated,
A reference signal is generated from the reference synchronization signal output terminal 3. Therefore, the initial value of the phase difference between the reproduction synchronization signal and the reference synchronization signal after the end of the jump operation is a phase difference corresponding to the setting value set by the initial value setting section 13. For example, in the case of a CLV disk, if the rotational speed required for reproduction differs before and after a jump, the phase difference between the reproduction synchronization signal and the reference synchronization signal changes depending on the characteristics of the spindle servo.

As described above, according to this embodiment, based on the reproduction synchronization signal obtained after the end of the jump operation (in a state in which it is possible to follow the target track), the generation of the reference synchronization signal is performed again with the initial value determined. By configuring it so that, for example, in a state where the rotational speed is different before and after a jump, such as with a CLV disc, the phase difference between the playback synchronization signal and the reference synchronization signal starts from a constant value immediately after the jump.
Since it changes sequentially, the dynamic range of the phase difference can be used effectively, and the spindle servo can be pulled in in a short time, resulting in an excellent effect in that performance can be improved.

(Embodiment 2) A second embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a block diagram of a reference synchronization signal generating device showing a second embodiment of the present invention. In FIG. 3, 11 is a reproduction synchronization signal input terminal;
2 is a start signal generation section, 13 is an initial value setting section, 14 is a window control signal generation section, 1 is a reference signal generation section, 2 is a reference synchronization signal generation section, and 3 is a reference synchronization signal output terminal. 21 is a reset signal input terminal, and 22 is a signal addition section. The difference from the configuration in FIG. 1 is that a signal adder 22 is provided, and the start signal generator 1
Start signal and reset signal input terminal 21 generated in step 2
By performing signal addition with the reset signal inputted from the input terminal and applying the obtained signal to the initial value setting section 13 and the reference synchronization signal generation section 2, the reference synchronization signal can be set not only with the reproduction synchronization signal but also with the reset signal. This is because we have made it possible to do so.

As described above, by providing the reset signal input terminal 21 and the signal adder 22 so that the reference synchronization signal can be generated by either the reset signal input or the start signal, the reproduction synchronization signal is generated when the power is turned on, etc. Even when the reference synchronization signal is not generated, the reference synchronization signal can be appropriately generated by applying the reset signal.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a block diagram of a reference synchronization signal generator showing a third embodiment of the present invention. In FIG. 4, 11 is a reproduction synchronization signal input terminal;
2 is a start signal generation section, 13 is an initial value setting section, 14 is a window control signal generation section, 1 is a reference signal generation section, 2 is a reference synchronization signal generation section, and 3 is a reference synchronization signal output terminal. The configuration is similar to that of , and 23 is an initial value control section. The difference from the configuration in FIG. 1 is that an initial value control section 23 is provided so that the set value of the initial value setting section 13 can be reset as appropriate.

As described above, by providing the initial value control section 23, the initial value can be reset during playback, and the relationship between the playback synchronization signal and the reference synchronization signal can be appropriately set after jumping, so optimal settings can be made. becomes.

[0020]

As described above, the present invention provides a reference signal generation section that generates a reference signal, a reference synchronization signal generation section that generates a reference synchronization signal using the reference signal, and a window control signal that controls a window section. a start signal generation section that generates a start signal from a reproduction synchronization signal obtained during a window section of a reproduction synchronization signal reproduced from a recording medium using a window control signal; and a signal output from the start signal generation section is a reference synchronization signal. It is applied to the generator and also applied to the initial value setting section that determines the starting point of the reference synchronization signal.When the start signal is output from the start signal generation section, the reference synchronization starts from the starting point specified by the initial value setting section. By configuring the signal section to generate a reference synchronization signal, the reproduction synchronization signal that is reproduced immediately after the jump operation (when the track can be followed) is used to generate the reference synchronization signal, which corresponds to the initial value set. Because the restart can be performed at intervals of This realizes a signal generator.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a reference synchronization signal generator in a first embodiment of the present invention.

[Fig. 2] An operation explanatory diagram for explaining the operation of the reference synchronization signal generating device in the first embodiment.

FIG. 3 is a block diagram of a reference synchronization signal generator according to a second embodiment of the present invention.

FIG. 4 is a block diagram of a reference synchronization signal generator according to a third embodiment of the present invention.

[Figure 5] Block diagram of a conventional reference synchronization signal generator

[Explanation of symbols]

11 Playback synchronization signal input terminal 12 Start signal generation section 13 Initial value setting section 14 Window control signal generation section

Claims (3)

[Claims] 1. A reference signal generation section that generates a reference signal; a reference synchronization signal generation section that generates a reference synchronization signal using the reference signal; a window control signal generation section that controls a window section; a start signal generation section that generates a start signal from a reproduction synchronization signal obtained during a window section of a reproduction synchronization signal reproduced from a recording medium according to the signal; and a signal output from the start signal generation section is input to the reference synchronization signal generation section. At the same time, it is also input to an initial value setting section that determines the starting point of the reference synchronization signal, and when a start signal is output from the start signal generation section, the reference synchronization signal is started from the starting point specified by the initial value setting section. A reference synchronization signal generating device, characterized in that a reference synchronization signal is generated from a signal section. 2. The reference synchronization signal generating device according to claim 1, wherein the start signal generating section generates the start signal even when a reset signal is input from the outside. 3. The reference synchronization signal generating device according to claim 1, wherein the initial value setting section resets the initial value.