JPH02116288A - Disk performance instrument - Google Patents

Abstract

PURPOSE:To satisfactorily expand the band of a chrominance signal even when jump action is executed by providing a controlling means to change the time base of the output of a delaying means by time corresponding to the change. CONSTITUTION:A 262H delaying circuit 24 is formed so that a signal delaying time may come to (262H-140ns), its output, after being delayed by 140ns through a delaying circuit 31, is further delayed by 140ns through a delaying circuit 32, and supplied to either input terminal of a change-over switch 33. The change- over switch 33, when a change-over control signal (a) comes to a higher level for instance, selectively selects the output of the delaying circuit 32 and selectively selects the output of the 262H delaying circuit 24 when the change-over control signal (a) comes to a lower level. Thus, higher area component is correctly interpolated and the band expansion of the chrominance signal can be satisfactorily executed even when the jump action is executed.

Description

[Detailed description of the invention] Technical field The present invention relates to a disc playing device.

Background Art In the NTSC system, one of the two color signal components, the so-called I signal, has a bandwidth of 1.5 MHz, while the other of the two color signal components, the so-called Q signal, has a bandwidth of 1.5 MHz. Since the width is as narrow as 0.5 MHz, color resolution may be significantly degraded depending on the color. Therefore, in 1987, a transmission system was developed that made it possible to expand the bandwidth of the Q signal to 1.5 MHz by transmitting the 0.5 to 1.5 MHz components of the ■ signal and the Q signal in field sequence. This was proposed in a paper entitled "Characteristics of Color Signal Band Expansion in rEDTV" at the John Society National Conference.

A device as shown in FIG. 4 has been devised as a performance device for playing a disc on which a video signal based on this method is recorded.

In FIG. 4, a disk 1 is rotationally driven by a spindle motor 2. As shown in FIG. A video signal is recorded on the disk 1 using a method of transmitting 0.5 to 1.5 MH components of the l signal and the Q signal in field sequence. According to this method, for example, the bandwidth of the l signal is 1.5 for odd-numbered feeds.
MHz, the bandwidth of the Q signal is 0.5 MHz, and in the even field, the bandwidth of the l signal is 0.5 MHz, and the bandwidth of the Q signal is 1.5 MHz.

As the disk 1 rotates, signals recorded on the disk 1 are read by a pickup 3. The pickup 3 includes a laser diode, an objective lens, a focus actuator, a tracking actuator, a photodetector, and the like. The output of the photodetector in the pickup 3 is supplied to the RF amplifier 4 and at the same time to a focus servo circuit (not shown) and a tracking servo circuit (not shown). The focus actuator and tracking actuator in the pickup 3 are driven by these servo circuits (not shown), and the laser light emitted from the laser diode in the pickup 3 is focused on the recording surface of the disk 1 to form a light spot for information detection. At the same time, the position of the light spot is controlled so that it follows the recording track.

Further, an RF (high frequency) signal output from the RF amplifier 4 is supplied to an FM demodulation circuit 5 to reproduce a video signal. The reproduced video signal is made into a jitter-free signal by a time base correction circuit (not shown). This reproduced video signal is supplied to one input terminal of the changeover switch 6 and is delayed by 140 ns by the delay circuit 7 before being supplied to the other input terminal of the changeover switch 6. A burst continuity determination circuit 8 is connected to the control input terminal of the changeover switch 6.
A switching control signal a output from the switch is supplied. For example, the changeover switch 6 selectively outputs the playback video signal from the FM demodulation circuit 5 when the changeover control signal a is at a high level, and outputs the playback signal delayed by the delay circuit 7 when the changeover control signal a is at a low level. It is configured to selectively output video signals. Further, the burst continuity determination circuit 8 generates, for example, a PLL (Phase Locked
Loop) circuit and this PLL circuit, when the comparison output of the phase comparator that compares the phase of the reproduced video signal and the output of the PLL circuit exceeds a predetermined level, it is determined that the continuity of the burst signal of the reproduced video signal is impaired. It is configured to make a judgment and invert the polarity of the switching control signal a to the changeover switch 6. These selector switches 6 and delay circuits 7
The burst continuity determination circuit 8 forms a time axis control means 9 that performs time axis control so that the continuity of the burst signal in the reproduced video signal is maintained.

The reproduced video signal is further supplied to a separation circuit 10 to separate horizontal and vertical synchronization signals and control signals inserted into portions of the reproduced video signal corresponding to predetermined lines. These horizontal and vertical synchronization signals and control signals are supplied to the system controller 1. The system controller 1 is further supplied with various commands corresponding to key operations from the operation section 12.

The system controller 1 includes, for example, a processor, RO
A mode control signal g is supplied to each section when a still image reproduction command is issued from the operation section 12, for example, by a processor that is formed by a microcomputer consisting of M, RAM, etc., and operates according to a program stored in advance in the ROM. becomes low level, and a vertical synchronizing signal from the separation circuit 10 sends a jump command to the track jump drive circuit 13 every other frame period.

The track jump drive circuit 13 is configured to drive a tracking actuator in the pickup 3 in response to a jump command to move the information detection light spot by one track in the inner circumferential direction.

Further, the reproduced video signal output from the changeover switch 6 is supplied to a luminance signal and chrominance signal separation circuit (hereinafter referred to as Y/C separation circuit) 15, where the luminance signal and chrominance signal are separated. The color signal is supplied to an l signal demodulation circuit 16 and a Q signal demodulation circuit 17.

The l signal demodulation circuit 16 and the Q signal demodulation circuit 17 are composed of synchronous detection circuits, and receive two reference signals for demodulation of 3 and 58 MHz having a phase difference of 90 degrees from each other from a reference signal generator (not shown). The configuration is such that the L signal and the Q signal are demodulated in response to the supplied signal. The demodulated I signal and Q signal are supplied to the signal switching circuit 18. A control input terminal of the signal switching circuit 18 is supplied with a switching control signal outputted from a switching control circuit 19 and inverted every one field period. For example, the signal switching circuit 18 derives the l signal as the output signal C and the Q signal as the output signal d when the switching control signal S is at a high level, and outputs the l signal when the switching control signal S is at a low level. It is configured to derive the Q signal as the output signal C as well as the output signal d. The switching control circuit 19 is composed of a T-type flip-flop to which, for example, a vertical synchronization signal separated from the reproduced video signal by the separation circuit 10 is supplied as a trigger input, and switches the Q output of this T-type flip-flop. The configuration is such that it is output as a control signal.

The output signal C of the signal switching circuit 18 is supplied to the signal switching circuit 22 via an LPF (low pass filter) 21 with a cutoff frequency of 1.5 MHz, and at the same time is supplied to a BPF (low pass filter) with a pass band of 0.5 MHz to 1.5 MHz. 262 consisting of a delay line, etc. via a bandpass filter) 23
The signal is supplied to the H delay circuit 24 and delayed by 262H.

The output of this 262H delay circuit 24 is the IH delay circuit 25
After being further delayed by IH, the signal is supplied to the adder circuit 26. In the adder circuit 26, the IH delay circuit 25
The output of the 262H delay circuit 24 and the output of the 262H delay circuit 24 are added together. The output of this adder circuit 26 is supplied to an attenuator 27 to reduce the amplitude to 1/2. The output of this attenuator 27 is supplied to an adder circuit 28, which passes through an LPF 29 with a cutoff frequency of Q and 5 MHz, and is added and synthesized with the output signal d of the signal switching circuit 18. The output of the adder circuit 28 is supplied to the signal switching circuit 22. The signal switching circuit 18 is connected to the control input terminal of the signal switching circuit 22.
Similarly, a switching control signal is supplied. For example, when the switching control signal S is at a high level, the signal switching circuit 22 outputs an L signal.
The output of the PF 21 is derived as the 1 signal e, and the output of the adder circuit 28 is derived as the Q signal f, and when the switching control signal is at a low level, the output of the LPF 21 is derived as the Q signal f, and the output of the adder circuit 28 is derived as the Q signal f. It is configured to derive the signal e as the signal e.

The I signal e and Q signal f output from the signal switching circuit 22 are supplied to the matrix circuit 30 together with the Y signal output from the Y/C separation circuit 15, and three primary color signals of R, G, and B are generated. Ru.

In the above configuration, the bands of the l signal and the Q signal output from the l signal demodulation circuit 16 and the Q signal demodulation circuit 17 change for each field, and for example, in an odd feed, the bandwidth of the l signal is 1.5 MHz.

The bandwidth of the Q signal is 0.5 MHz, and in the even field, the bandwidth of the l signal is 0.5 MHz, and the bandwidth of the Q signal is 1.5 MHz. When these l and Q signals are supplied to the signal switching circuit 18, the signal switching circuit 18 gives the LPF 21 and the BPF 23 a bandwidth of 1.5 MH.
The l signal and Q signal of z are alternately supplied to every other field.

Then, the bandwidth is reduced to 1.5MHz by BPF23.
A high-frequency component of 0.5 MHz or more is extracted from the 1 signal and the Q signal, and the delay circuit 24 delays this high-frequency component by 263H, resulting in a signal obtained by delaying the high-frequency component by 263H. The signal obtained by delaying the signal by the amount of time is added and synthesized by the adder circuit 26. The output of this adder circuit 26 is attenuated by half by an attenuator 27. As a result, in a field where an I signal or Q signal that does not contain high-frequency components of 0.5 MHz or higher is transmitted, the correspondence between two adjacent scanning lines of the I signal or Q signal transmitted one field period ago is determined. 0.5M of the part
A signal corresponding to the average level of high-frequency components of Hz or higher is obtained.

On the other hand, the LPF 29 with a cutoff frequency of Q and 5 MHz is alternately supplied with an I signal and a Q signal with a bandwidth of 0.5 MHz every other field. The I signal or Q signal with a bandwidth of Q and 5 MHz is sent to the adder circuit 2 after passing through the LPF 29.
8 and the output of the attenuator 27, that is, the average level of the Q of the corresponding portions of two adjacent scanning lines of the I signal or Q signal transmitted one field period ago, and the high frequency components of 5 MHz or more. It is added and combined with the corresponding signal, Q, 5
Interpolation of high-frequency components of MHz or higher is performed.

The output of this adder circuit 28 is supplied to one input terminal of the signal switching circuit 22. The other input terminal of the signal switching circuit is alternately supplied with an I signal and a Q signal containing high frequency components of 0.5 MHz or more at every one field period. In the signal switching circuit 22, the signal is switched roughly every field by the switching control signal, and the Q, I signal containing the high frequency component of 5 MHz or more and the high frequency component are interpolated alternately every other field period. ■The signal is a matrix circuit 30
It is output as an I signal e, which is supplied to

At the same time, Q,
A Q signal including a high frequency component of 5 MHz or more and a Q signal with the high frequency component interpolated are supplied to the matrix circuit 30.
It is output as a signal f. As a result, the bands of the ■ signal and the Q signal are expanded to 1.5 MHz, and the color resolution is improved.

However, for example, when a still image reproduction is commanded, the track jump drive circuit 1 is sent from the system controller 11.
3, a jump command is sent every one frame period to drive the tracking actuator, and the pickup 3
For example, the information detection point jumps by one track in the inner circumferential direction. Then, the same frame is repeatedly reproduced as shown in FIG. 5(A). In addition, in this FIG. 5(A), two
The two fields are shown as a first field and a second field, respectively. At this time again! The signal bandwidth is, for example, 1.5 MHz in the first field and 0.5 MHz in the second field, as shown in FIG. 5(B).
becomes. Also, the bandwidth of the Q signal is, for example, as shown in Fig. 5(C).
As shown in the figure, the frequency is 0.5 MHz in the first field and 1.5 MHz in the second field.

As described above, a jump operation is performed during special reproduction such as still image reproduction, but the phase of the color subcarrier immediately before and after the jump operation changes by 180 degrees, and continuity is lost. Then, the burst continuity determination circuit 8 detects that the bursts have become discontinuous, and the polarity of the switching control signal a supplied to the changeover switch 6 is reversed.

As a result, the video signal selectively output from the changeover switch 6 is switched from a video signal delayed by 140 ns to an undelayed video signal by the delay circuit 7, or vice versa. The circuit 7 switches to a video signal delayed by 140 ns.

Then, as shown in FIG. 5(D), in the field immediately after the jump operation, the high frequency components of 0.5 MHz to 1.5 MHz delayed by the 262H delay circuit 24,
(2) A phase difference corresponding to 140 ns occurs between the signal and the Q signal. As a result, even though the high-frequency components of the ■ signal are interpolated well as shown in Figure 5 (E), the high-frequency components of the Q signal are not interpolated correctly as shown in Figure 5 (F), and therefore the color signal There was a problem in that band expansion was not performed well and color resolution deteriorated.

Summary of the Invention The present invention has been made in view of the above points, and includes:
It is an object of the present invention to provide a disk performance device capable of satisfactorily expanding the band of a color signal even when a jump operation is performed.

In the disc performance device according to the present invention, each time a track jump is performed, the time axis of the read video signal included in the read output of the pickup is changed to (2) of the wavelength of the color subcarrier.
(n-1)/2 times (n is a natural number) a first time axis control means for changing the I signal and the Q signal alternately at every one field period from the read video signal; a high frequency extraction means for extracting a high frequency component;
a delay means for delaying the time by a first predetermined time smaller than the predetermined time; and a time axis of the output of the delay means in one field period immediately after a change in the time axis by the first time axis control means. a second time axis control means for changing the time axis by a time corresponding to the above change;
An interpolated color signal component is obtained by the output of the time axis control means and the signal obtained by delaying the output of the second time axis control means by twice the second predetermined time.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3.

In FIG. 1, disk 1. Spindle motor 2. Pickup 3. RF amplifier 4. demodulation circuit 5, changeover switch 6, delay circuit 7. Burst continuity determination circuit 81 separation circuit 10. System controller 11. Operation unit 12.
Track jump drive circuit 1B, Y/C separation circuit 15.
■Signal demodulation circuit 16, Q signal demodulation circuit 17. Signal switching circuits 18, 22, switching control circuit 19. LPF21,29
．． BPF23, 262H delay circuit 24. IH delay circuit 2
5. Addition circuit 26. 28. The matrix circuit 30 is
The devices are connected in the same way as the device shown in FIG. however,
In this example, the 262H delay circuit 24 is formed so that the signal delay time is (262H-140ns). The output of the delay circuit 24 is delayed by 140 ns by the delay circuit 31 and further delayed by 140 ns by the delay circuit 32 before being supplied to one input terminal of the changeover switch 33. The output of the 262H delay circuit 24 is supplied to the other input terminal of the changeover switch 33. A control input terminal of the changeover switch 33 is supplied with a changeover control signal a outputted from the burst continuity determination circuit 8. For example, the changeover switch 33 switches the delay circuit 32 when the changeover control signal a becomes high level.
The output of the 262H delay circuit 24 is selectively output when the switching control signal a becomes low level.

The output of this changeover switch 33 is supplied to one input terminal of a changeover switch 34. The output of the delay circuit 31 is supplied to the other input terminal of the changeover switch 34. The output of an OR (logical sum) circuit 35 is supplied to a control input terminal of the changeover switch 34. The OR circuit 35 is supplied with a switching control signal g output from the switching control circuit 19 and a mode control signal g which becomes low level during special playback involving a jump operation from the system controller 11. For example, the changeover switcher 34 selectively outputs the output of the delay circuit 31 when the output of the OR circuit 35 is at a high level, and selectively outputs the output of the changeover switch 33 when the output of the OR circuit 35 is at a low level. is configured to print. The output of this switch 1 switch 34 is the IH delay circuit 25 and addition circuit 2.
6. Time axis control means 37 that controls the time axis of the output of the 262H delay circuit 24 by these delay circuits 31, 32, changeover switches 34, 35, and OR circuit 35.
is formed.

In the above configuration, in a normal play operation that does not involve a jump operation, the mode control signal g output from the system controller 11 is at a high level, so the changeover switch 34 outputs the output of the delay circuit 31, that is, the I signal and the Q signal.
A signal obtained by delaying the high frequency component of the signal by 262H is selectively outputted to the IH delay circuit 25 and the adder circuit 26.
supplied to Therefore, during normal play operation, high-frequency components of the I and Q signals can be interpolated favorably in the same manner as in the apparatus shown in FIG.

Next, when a still image is reproduced, the same frame is repeatedly reproduced as shown in FIG. 2(A). Furthermore, this figure 2 (A)
In , the two fields forming a frame that is played repeatedly are the first field and the second field, respectively.
Shown as a field.

When moving from the second field to the first field, a jump operation is performed, and the continuity of the burst is impaired, so that the polarity of the switching control signal a output from the burst continuity determination circuit 8 changes as shown in FIG. 2(B). Invert. Then, the reproduced video signal output from the changeover switch 6 becomes a signal delayed by 140 ns or advanced by 140 ns from the signal immediately before the polarity inversion of the changeover control signal a.

That is, for example, when the switching control signal a changes from a high level to a low level, the immediately reproduced video signal becomes a signal delayed by 140 ns compared to the immediately preceding reproduced video signal, and conversely, when the switching control signal a changes from a low level When changing from a level to a high level, the immediately following reproduced video signal is a signal that is advanced by 140 ns compared to the immediately preceding reproduced video signal.

Therefore, here, each field in FIG. No. F+2. F+3... If the F+7th field is used, for example, the F+2th field to the F+th field.
When transitioning to 3 fields, the reproduced video signal is 140
The signal is advanced by n s, and the delay time of the high frequency component of the color signal required for correct interpolation in the F+3 field is < IV + 140 ns as shown in Figure 2 (C).
(However, IV-262, 5H), No. F+374
- Since there is no change in the time axis of the reproduced video signal when transitioning from field to field F+4,
In the field, the delay time of the high frequency component of the color signal required for correct interpolation is 1V. Also, No. F+4
At the time of transition from the field to the F+5th field, the reproduced video signal becomes a signal delayed by 140 ns, and in the F+5th field, the delay time of the high frequency component of the color signal necessary for correct interpolation is IV-140 ns. . Since there is no change in the time axis of the reproduced video signal when transitioning from the F+5th field to the F+6th field, the delay time of the high frequency component of the color signal required for correct interpolation in the F+6th field is IV. Become. These steps are repeated in each subsequent field.

Now, the mode control signal g is at a low level, and the switching control signal g is inverted every other field, so the switching switch 3
4, the output of the delay circuit 31 and the output of the changeover switch 33 are alternately output for every other field. Furthermore, since the switching control signal a is inverted every other frame as shown in FIG. be done. Therefore, in the F+3rd field, the signal selectively output from the changeover switch 34 is a signal obtained by delaying the output of the delay circuit 32, that is, the high frequency component extracted by the BPF 23, by 262H+140ns, and in this case, the The interpolation signal supplied to the circuit 28 is a signal delayed by IV+140nii+ from the high frequency component extracted by the BPF 23, so that the high frequency component is correctly interpolated. In the F+4th field, the signal selectively output from the changeover switch 34 is a signal obtained by delaying the output of the delay circuit 31, that is, the high frequency component extracted by the BPF 23, by 262H, and at this time, the signal output from the adder circuit 28 is The supplied interpolation signal is delayed by 1v from the high frequency component extracted by the BPF 23, so that the high frequency component is correctly interpolated.

In the F+5th field, the signal selectively output from the changeover switch 34 is the output of the 262H delay circuit 24, that is, the high frequency component extracted by the BPF 23.
The signal is obtained with a delay of 2H-140ns,
At this time, the interpolation signal supplied to the adder circuit 28 is B
IV-140 from the high frequency components extracted by PF23
The signal is delayed by ns, and interpolation of high frequency components is performed correctly. Further, in the F+6th field, the signal selectively outputted from the changeover switch 34 becomes the output of the delay circuit 31 as in the F+4th field, so that interpolation of high frequency components is performed correctly.

In this way, the time axis of the high frequency component is changed by the time axis control means 37 by a time corresponding to the change in the time axis of the reproduced video signal by the time axis control means 9, and the high frequency component is correctly interpolated. .

FIG. 3 is a block diagram showing another embodiment of the present invention, in which only the time axis control means 37 is shown. The other blocks 1 to 30 are omitted because they are connected in the same way as in the device of FIG. Time axis control means 37 in this example
, the output of the 262H delay circuit 24 is converted into a digital signal by an A/D conversion circuit 41 and then supplied to a variable length register 42. The variable length shift register 42 includes, for example, n registers R1+ R2+ """ Rn-2+ Rn-1+ forming a shift register.
Rn, and a signal selection circuit 43 that selectively outputs one of the control data signals indicated by i among the outputs of the registers R6-2+Rn-1 and Rn.

The control data signal i is a signal corresponding to each bit of a 2-bit binary code, and is output from the logic circuit 44. The logic circuit 44 is supplied with switching control signals a, b and a mode control signal g. The logic circuit 44 is
For example, when the switching control signal S or the mode control signal g is at a high level, a control data signal corresponding to the binary code indicating the output of the register R is output, and when the switching control signal S or the mode control signal g is at a low level. The control data signal corresponding to the binary code indicating one of the registers Rn-2 and Rn is output according to the state of the switching control signal a.

The output of this variable length shift register 42 is converted into an analog signal by a D/A conversion circuit 45 and supplied to an IH delay circuit 25 and an addition circuit 26. Note that the A/D conversion circuit 41. Register R,,R2,...Rn-2+
Rn-+ + Rn clock input terminals and D/A
The conversion circuit 45 includes timing signal generation circuits 46 to 14.
A timing signal consisting of pulses generated every 0 ns is supplied.

The above configuration also operates in the same manner as the device shown in FIG. 1.

Furthermore, the variable length shift register 42 in the circuit of FIG.
A field memory is used instead of the switching control signal a,
It is also conceivable that the same effect as that of the device shown in FIG. 1 can be obtained by changing the address control using b and mode control signal g.

In the above embodiment, the changeover switch 6 and the delay circuit 7 are
Although the time axis control means 9 is formed by the burst continuity determination circuit 8, the time axis control means 9 may include a time axis servo loop such as a spindle servo loop, etc.
It is also possible to use a circuit that adds an error signal corresponding to ns.

Effects of the Invention As detailed above, in the disc playing device according to the present invention, each time a track jump is performed, the time axis of the read video signal included in the read output of the pickup is set to (2n-1)72 times the wavelength of the color subcarrier. (n is a natural number), and and a second predetermined time equal to (2m-1) 72 times one horizontal scanning period (m is a natural number), the output of the high frequency extraction means is further smaller than one field period by a second predetermined time equal to (2m-1) 72 times one horizontal scanning period (m is a natural number). a delay means for delaying the time by a small predetermined time; and a first time axis control means that changes the time axis of the output of the delay means by a time corresponding to the change in one field period immediately after the change in the time axis occurs. A second time axis control means is provided, and an interpolated color is generated by the output of the second time axis control means and a signal obtained by delaying the output of the second time axis control means by a time twice the second predetermined time. Since the signal components are obtained, the I and Q
It is possible to prevent a phase difference from occurring between the signal and the interpolated color signal component for interpolation of the high frequency component, and it is possible to satisfactorily expand the band of the color signal even when a jump operation is performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a timing chart showing the operation of each part of the device in FIG. 1, and FIG. 3 is a circuit showing another embodiment of the present invention. FIG. 4 is a block diagram showing a conventional disc playing device, and FIG. 5 is a timing diagram showing the operation of each part of the device shown in FIG. Explanation of symbols of main parts 3...Pickup 24...262H delay circuit 25...IH delay circuit 26.28...Addition circuit 31.32...・・・・Delay circuit 33.34・・・・・・Changing switch

Claims (1)

[Claims] A disc playing device that plays a disc on which a video signal is recorded by a method of alternately transmitting high-frequency components of two color signal components each having a predetermined frequency or higher every other field period, the disc playing device comprising: Every time the pickup that reads the video signal performs a track jump, the time axis of the read video signal changes to (2) the wavelength of the color subcarrier
a first time axis control means for changing the time axis by a first predetermined time corresponding to n-1)/2 times (n is a natural number); and alternately transmitting the two color signal components from the read video signal every one field period. a high frequency extraction means for extracting high frequency components, and a high frequency extraction means for extracting the high frequency components of the high frequency extraction means; a delay means for delaying the time by the first predetermined time smaller than the time smaller than the second predetermined time; a second time axis control means for changing the time axis of the output by a time corresponding to the change; and an output of the second time axis control means and the second time axis.
and interpolation means for obtaining an interpolated color signal component using a signal obtained by delaying the output of the time axis control means by a time twice the second predetermined time.