JPH01223663A - Rotary recording medium and its recording and reproducing device - Google Patents

Abstract

PURPOSE:To enable recording and reproduction for many hours by making rotational speed variable so that the recording density becomes uniform and recording an information signal where a compression processing is performed, together with a rotational speed signal. CONSTITUTION:A video signal is compressed by a compression processing circuit 2, and based on a signal quantity per unit time from a signal quantity detecting circuit 3, a rotational speed determining circuit 4 determines rotational speed so that the recording density becomes roughly constant. On the other hand, a clock frequency control data circuit 5 generates control data for determining rotational speed at the time of reproduction, mixes it with compression processing data and stores it temporarily in a buffer 8. Subsequently, the output of the circuit 5 supplies a clock pulse to a recording data driving circuit 9 through a clock pulse generating circuit 6, and controls timing which is read out of the buffer 8 and timing which is recorded in a disk 12. Accordingly, based on position data, reproduction can be executed at the same rotational speed as recording, and recording and reproduction can be executed for many hours.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a rotating recording medium and a recording/reproducing device thereof;
In particular, the present invention relates to a rotary recording medium capable of recording and reproducing over a long period of time, and a recording/reproducing apparatus thereof.

2. Description of the Related Art Conventionally, methods have been known in which video signals are subjected to compression processing in order to improve the recording density of video signals and to keep the rotational speed of a rotating recording medium low. For example, in a 24-bit video signal, this is done by taking the difference between the video signals of two frames to be MRCed, compressing this to the number of bits corresponding to the difference, and transmitting it. can be reduced. This allows for high correlation between consecutive frames of a video image (for example, less movement)
In the case of 1, the compression ratio is high and the number of signal points per unit time is small.On the other hand, when the correlation between consecutive frames is low (for example, at a scene change), the compression ratio is low and the number of signal points per unit time is small. The amount of signal is also large. According to such a method, the signal amount changes both between n and I, and the change 3 is also very large.

The compressed video signal is transferred to a disc-shaped or cylindrical rotating recording medium that rotates at a constant linear velocity or rotational angular velocity, as a magnetic or optical signal, or as a mechanical uneven signal, in concentric circles. Recording is performed on the upper recording portion or the spiral recording portion, and during reproduction, these rotating recording media are rotated at a constant linear velocity or rotational angular velocity.

Problems to be Solved by the Invention However, even if compression processing is applied to the video signal,
Conventionally, recording or reproduction was performed while keeping the rotational angular velocity or linear velocity of the rotating recording medium constant, so this rotational angular velocity or linear velocity is the part where the most signal G of the video signal is recorded or reproduced per unit time. In other words, it was not possible to make the speed lower than that at which recording or reproduction of the portion with the lowest compression ratio could be performed. For this reason, the specifications of the rotational angular velocity or linear velocity are determined by the part with the lowest compression ratio, including the recording density of the recording medium and the capability of the reproducing element.

Generally, as mentioned above, the compression ratio is lowest at scene changes, which are infrequent, and the compression ratio for other parts is high. Therefore, even though the compression rate has increased for most parts of the video, the recording or playback specifications had to be determined based on the least frequent part of the video, so the compression effect could not be fully obtained.
It was not possible to record for a long time.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a rotary recording medium and a recording/reproducing apparatus thereof that are capable of recording or reproducing over a long period of time.

Means for Solving the Problems In order to solve the above problems, a rotating recording medium according to the present invention records information signals by forming spiral or concentric tracks on a disc-shaped or cylindrical recording medium. An information signal that has been subjected to a compression process in which the compression ratio changes over time, in which the information signal has been subjected to the compression process such that the recording density on the recording surface is approximately uniform. The information signal is recorded with a variable rotational speed according to the signal m, and a rotational speed signal for changing the rotational speed during reproduction to the same rotational speed as during recording according to the compression ratio is recorded together with the information signal. Become.

Further, the rotating recording medium recording table C according to the present invention detects the signal amount per unit time of an information signal that has been subjected to compression processing such that the compression rate changes over time depending on the information signal.
a detection means, a motor whose rotational speed is variable, a rotational speed determination means for determining the rotational speed of the motor based on the output signal of the signal separation means and outputting a rotational speed signal corresponding to the rotational speed; and the information signal. A mixing storage means for mixing the rotational speed signal to a recording signal and temporarily storing the recording signal; and a mixing storage means for reading out the recording signal from the mixing recording means at a predetermined timing based on the rotational speed signal and driving the recording signal to rotate by a motor. The rotary recording medium according to claim 1 is obtained by recording a recording signal on an unrecorded recording medium such that the recording density of the information signal is substantially uniform.

A rotating recording medium reproducing device according to the present invention includes a motor whose rotational speed is variable, a signal reading means for reading a recorded signal,
a signal separating means for separating an information signal and a rotational speed signal from a recording signal; a rotational speed determining means for determining the rotational speed of the motor from the rotational speed signal separated by the signal separating means;
The timing of reading the recording signal from the rotational speed signal is v
2. The rotary recording medium according to claim 1, wherein the rotary recording medium is rotationally driven by a motor while changing the rotational speed of the motor by a rotational speed determining means.

Further, the rotating recording medium recording/reproducing apparatus according to the present invention includes a motor having a variable rotation speed, a signal separating means for detecting the signal amount per ψ time of the compressed information signal,
a first rotation speed determining means that determines the rotation speed of the motor based on the output signal of the signal amount detection means and outputs a rotation speed signal related to this rotation speed, and mixes the information signal and the rotation speed signal as a recording signal. A mixing storage means for temporarily storing a recorded signal; a recording means for reading out a recording signal from the mixing storage means at a predetermined timing based on a rotational speed signal and recording it on an unrecorded rotating recording medium; a signal reading means for reading recorded signals of a recorded rotating recording medium; a signal separating means for separating an information signal and a rotational speed signal from the recorded signal; and a signal separating means for separating an information signal and a rotational speed signal from the recorded signal; A second rotation speed determination means for determining the rotation speed, and a timing for reading the recorded signal from the rotation speed signal.
A reading control means for rotating an unrecorded rotating recording medium by a motor, and changing the rotational speed of the motor so that the recording density of the information signal on the unrecorded rotating recording medium is approximately uniform, reads the recording signal. The rotational recording medium according to claim 1 is obtained by recording, and during reproduction, the rotational speed of the motor is changed by the rotational speed signal separated by the separation means from the reproduction signal of the recorded rotational record at11 body. The apparatus is configured to reproduce information signals recorded on the rotary recording medium described in item 1.

Effect: When an information signal is recorded on the rotating recording medium using the rotating recording medium recording device or the rotating recording medium recording and reproducing device configured as described above, the compression ratio of the information signal is low and the signal is recorded per ψ time. If the amount is large, the rotational speed of the motor will increase due to the rotational speed signal, and conversely, if the compression rate of the information signal is high and the number of signals m recorded per unit time r1 is small, the rotational speed will be slowed down and recorded. Ru. As a result, the recording density of information signals recorded on the rotating recording medium is approximately -
, and it becomes possible to record for a long time on a rotating recording medium.

When a rotating recording medium recorded with a substantially uniform recording density as described above is reproduced using a rotating recording medium reproducing apparatus or a rotating recording medium recording and reproducing apparatus configured as described above, the rotating recording medium is rotationally driven. If the compression rate of the information signal is high and the number of signals reproduced per unit time is small, the motor's rotational speed will be slow; if the compression rate is low and the amount of signals reproduced per unit time is large, the rotational speed will be slow. It gets faster.

Example Next, embodiments will be described with reference to the drawings.

FIG. 1 shows a block 2 of an example of the recording apparatus of the present invention.

In the same figure, a video signal input from a terminal 1 is subjected to well-known compression processing in a compression processing circuit 2 to reduce the signal amount. For example, a difference calculation is performed between two consecutive frames in a 24-bit video signal, and this video signal is converted into the number of bits (for example, 2 bits) necessary to calculate the difference. Thereafter, the signal amount detection circuit 3 detects the signal amount per unit time of the video signal after compression processing.

The rotational speed determination circuit 4 determines the rotational speed of the rotating recording medium (hereinafter referred to as "disc 1") 12 according to the signal amount per unit time detected by the signal amount detection circuit 3, and supplies the determined rotational speed to the motor control circuit 10. The rotational speed of the motor 911 is controlled to change according to the change in the signal amount.In other words, when the compression ratio is high and the signal is 1 or relatively low, the rotational speed of the motor 11 is slowed down, and conversely, when the pressure ratio is When the signal amount is low and relatively large, the rotation speed of the motor 11 is increased.

In this case, in order to prevent the rotational speed from falling below the minimum rotational speed required for recording or playback and the recording/playback operation failing, the motor 11 changes the rotational speed as shown by the broken line in FIG. Determine the rotation speed so that In the figure, the solid line indicates the minimum rotational speed required to record the video signal of the signal amount at each time.

As can be seen from FIG. 2, when transitioning from high-speed rotation to low-speed rotation (for example, time 1+), after passing a period (period from jo to tl) that requires high speed for signal recording, that is, When the rotation speed is lowered after a predetermined period of delay from the change in the signal ω of the signal to be recorded, and conversely, when transitioning from low-speed rotation to high-speed rotation (for example, at time t2
), the rotational speed is increased before LJ enters a period (period from iz to t3) that requires a high speed, that is, prior to a change in the signal to be recorded before time t2. Such an operation is performed in the rotation speed determination circuit 4 based on the output of the signal amount detection circuit 3.

On the other hand, the clock frequency control data circuit 5 also uses a clock frequency of $111 to determine the rotation speed of the disc during playback based on the output signal of the rotation speed determination circuit 4! 1 data is generated and is time-division multiplexed with the compressed video signal in the mixing circuit 7 to form image data in a predetermined signal format and temporarily stored in the buffer 8.

This clock frequency control data is also supplied to a clock pulse generation circuit 6 to generate clock pulses, and this clock pulse is supplied to a recording data drive circuit 9 that records image data on a disk, thereby reading out image data from a buffer 8. The timing and the timing at which image data is recorded on the disk 12 are determined by itlIlwJ.

By changing the rotational speed of the motor 11 and recording in this way, the slowest rotational speed of the motor 11 can be set to about 1/20th of the fastest rotational speed. , it is possible to record for a long time on average 2 to 3 times longer than in the past. Also, in this case, the recording density of the video signal on the disk 12 is approximately uniform; density) is at the same level as a compact disc (CD) on which audio signals are recorded (for example, about 800 Mbpi2).

FIG. 3 shows the signals recorded on this disk 12!
This is a very conceptual illustration of the part where the rotational speed mainly changes. In the figure, the disk 12 rotates in the direction shown by arrow a, and signals are recorded along a spirally formed track, and during playback, signals are recorded along this track by a pickup (not shown) at a predetermined position. The signal is played.

In the figure, a portion 13 indicates the recording state of the signal when the disk 12 moves from a portion 13a where the rotational speed is slow to a portion 13b where the rotational speed is fast;
A portion 13c between 3b is a transitional portion where the rotational speed is increasing, and the recording density is lower than that in 13a and 13b. The rotation speed of the part 13a is slow, but the signal compression rate is high, so the amount of signal per unit time is small, and the part 13b has a low compression ratio, so the amount of signal per unit time is large, but the rotation speed is fast. Therefore, the signal amount (recording density) per unit length along the track becomes equal for both 13a and 13b.

In the same figure, the part indicated by 14, contrary to 13, shows the state of the signal when the rotation speed changes from a high state to a slow state, and the part 14a where the rotation speed is low and the compression ratio is high, and the part 14a where the rotation speed is high and the compression ratio is high. The signal densities of the portion 14b where the rotational speed is slow are equal. The part indicated by 14C is 1 from the rotation speed of 14a.
This is a transitional portion where the rotational speed decreases to the rotational speed of 4b, and the recording density is lower than that of 14a and 14b.

In FIG. 3, an address signal indicating a position on the disk 12 is recorded in a portion indicated by 15. This address signal is used during random access when searching for a desired portion of the video signal, etc. In this case, the disk 12 is rotated at a constant speed, making it possible to search at high speed.

In addition to this address signal, a signal indicating the rotational speed at the time of reproduction of the signal recorded at the position following this is also recorded at the portion 15 at the same time. For example, in the section 15a, in addition to the address signal, a signal indicating the rotational speed of a transitional section 16c when transitioning from a section 16a, which is an intermediate rotational speed, to a section 16b, which is a slow rotational speed, is recorded. .

Transient portions 13c, 1 where the rotational speed changes in this way
Since the signal density in the area other than 4c, 15c and the area 15 where the address signal is recorded is substantially uniform over the entire disk 12, recording/reproduction can be performed for a long time.

FIG. 4 shows a block diagram of an example of a reproducing apparatus for reproducing the disc 12 on which signals are recorded as shown in FIG. The video signal recorded on the disc 12 and the clock frequency control data regarding the rotational speed of the disc 12 are reproduced by a reproduction data acquisition circuit 20 including a pickup (not shown), and are reproduced by a data separation circuit 21 at a high frequency of tIII. The frequency control data is separated.

The zero clock pulse generation circuit 22 generates clock pulses based on this clock frequency control data and supplies them to the reproduction data acquisition circuit 20 to control the timing of image data acquisition from the disk 12. Further, the rotational speed determination circuit 23 determines the rotational speed of the disk 12 based on the cock frequency $11111 data and supplies it to the motor control circuit 24 to drive the motor 11 to rotate the disk 12.
control the rotation speed. Further, the rotational speed during reproduction is changed as shown in FIG. 2, similar to that during recording, to prevent failure of the reproduction operation. The image data reproduced by the reproduction data acquisition circuit 20 is supplied to a video signal separation circuit 25, where the video signal is separated, and then supplied to an expansion processing circuit 26, where it is subjected to expansion processing corresponding to the compression processing of the recording device. is returned to the normal video signal, and output to output terminal 2 as an output video signal.
7 to the next stage image display (not shown).

Needless to say, the recording device and the reproducing device described in this embodiment can be configured as one recording and reproducing device. By integrating the recording device and the reproducing device into one device in this way, functions common to recording and reproducing, such as the motor 11, can be shared, which is also economically advantageous.

Effects of the Invention As described above, in the rotating recording medium according to the present invention, information signals are recorded at a substantially uniform recording density, and there is no need to determine recording and reproduction specifications according to the portion with the lowest compression ratio as in the past. Since the information signal is recorded according to the same signal after E reduction, the area where the recording density becomes sparse is greatly reduced.
The number of signals that can be recorded can be substantially increased compared to the conventional method, and information signals between long IRs can be recorded.

The recording device, playback device, and recording/playback device of the present invention are capable of recording substantially uniform recording density on the above-mentioned recording medium or reproducing a rotating recording medium recorded in this way, and are capable of recording over a long period of time. / It has the feature of being reproducible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a recording device according to an embodiment of the present invention, FIG. 2 is a diagram showing changes in motor rotational speed during recording or reproduction, and FIG. 3 is a rotating recording medium according to an embodiment of the present invention. FIG. 4 is a schematic diagram showing information signals recorded on a disc. FIG. 4 is a block diagram of a reproducing apparatus according to an embodiment of the invention. 2... Compression processing circuit, 3... Signal 3 detection circuit, 4゜23... Rotation speed determining circuit, 5... Clock frequency control data generation circuit, 6.22... Clock pulse generation circuit, 10.24...Motor control circuit, 11...
Motor, 12... Disk, 20... Data acquisition circuit, 21... Clock frequency control data separation circuit,
25... Video signal separation circuit, 26... Decompression processing circuit. Patent applicant: Victor Japan Co., Ltd. Patent attorney: Kaneyuki Matsuura -1゜, "・- 4J:. ・C1 1000 1 Diagram 2 Figure 3 Weighing figure 3

Claims (4)

[Claims] (1) A rotary recording medium in which information signals are recorded by forming spiral or concentric tracks on a disc-shaped or cylindrical recording medium, which is subjected to compression processing in which the compression rate changes over time. The compressed information signal is recorded at a rotational speed that is varied according to the amount of the compressed information signal so that the recording density on the recording surface is approximately uniform, and the rotational speed during playback is adjusted according to the amount of the compressed information signal. A rotary recording medium characterized in that a rotational speed signal for changing the rotational speed to the same rotational speed as during recording according to a compression ratio is recorded together with the information signal. (2) a signal amount detection means for detecting the signal amount per unit time of the information signal that has been compressed so that the compression rate changes over time depending on the information signal; and a motor with a variable rotation speed. , a rotation speed determining means for determining the rotation speed of the motor based on the output signal of the signal amount detection means and outputting a rotation speed signal related to this rotation speed; and mixing the information signal and the rotation speed signal. a mixing storage means for temporarily storing the recording signal as a recording signal; and a mixing storage means for reading out the recording signal from the mixing storage means at a predetermined timing based on the rotational speed signal and driving an unrecorded recording signal to be rotated by the motor. 2. A rotary recording medium recording apparatus comprising recording means for obtaining the rotary recording medium according to claim 1 by recording said recording signal on a recording medium so that the recording density of said information signal is substantially uniform. (3) A motor with a variable rotational speed, a signal reading means for reading a recorded signal, a signal separating means for separating an information signal and a rotational speed signal from the recorded signal, and the rotational speed separated by the signal separating means. The apparatus includes a rotation speed determining means that determines the rotation speed of the motor from a signal, and a reading control means that controls the timing of reading the recording signal from the rotation speed signal, and the rotation speed of the motor is changed by the rotation speed determination means. 2. A rotary recording medium reproducing apparatus for reproducing the rotary recording medium according to claim 1, which is rotationally driven by said motor while rotating said rotary recording medium. (4) a motor whose rotational speed is variable; a signal amount detection means for detecting the signal amount per unit time of the compressed information signal; and an output signal of the signal amount detection means to detect the motor. a first rotational speed determining means for determining the rotational speed of the engine and outputting a rotational speed signal related to the rotational speed; mixing the information signal and the rotational speed signal to form a recording signal; a recording means for reading out the recording signal from the mixing storage means at a predetermined timing based on the rotational speed signal and recording it on an unrecorded rotating recording medium; Signal reading means for reading the recorded signal of a recorded rotating recording medium; Signal separating means for separating the information signal and the rotational speed signal from the recorded signal; and From the rotational speed signal separated by the signal separating means. A second rotational speed determining means for determining the rotational speed of the motor; and a read control signal for controlling the timing at which the recording signal is read from the rotational speed signal, and a second rotational speed determining means for determining the rotational speed of the motor; The rotary recording medium according to claim 1, wherein the rotary recording medium according to claim 1 is rotatably driven, and the rotational speed of the motor is changed so that the recording signal is recorded so that the recording density of the information signal is substantially uniform on the unrecorded rotary recording medium. 2. Recording is performed on the rotary recording medium according to claim 1 while changing the rotational speed of the motor according to the rotational speed signal separated by the separating means from the recorded reproduction signal of the rotary recording medium. A rotating recording medium recording/reproducing device for reproducing the information signal.