JP2681897B2 - Mini disc player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mini disc player.

[0002]

2. Description of the Related Art With the advent of the mini disk system, E
A technique has been introduced in which a semiconductor memory is inserted as a data buffer between the FM / ACIRC decoder and the audio compression decoder to improve vibration resistance during playback (for example, JAS Journal, August 1991, "Sony. Mini Disc System ", pages 37-4
2). However, the method of utilizing the semiconductor memory in such a system has been widely introduced mainly for improving the vibration resistance, but it is necessary to eliminate the waiting time from when the play key is pressed until the sound is output. There is no introduction about what can be used for.

[0003]

The above-described method of utilizing the semiconductor memory has been made possible by the progress of audio compression technology and is epoch-making. It is an object of the present invention to effectively utilize this semiconductor memory to eliminate the waiting time from when the play key is pressed until the sound signal is output.

Even if the mini disk is mounted on the mini disk player, the reproduction is started without increasing the reproduction standby time until the reproduction is started, and the selected song is reproduced even when the audio signal is output. Another object of the present invention is to provide a mini disc player capable of reproducing a selected song by eliminating the waiting time until sound is output by an instruction.

Further, even if the mini disc is mounted on the mini disc player and the reproduction is started without increasing the time of the reproduction standby until the reproduction is started and the audio signal is outputted, the selected song is reproduced. It is an object of the present invention to provide a method of utilizing a semiconductor memory for eliminating the waiting time until the sound is output by the reproduction instruction and reproducing the selected song.

Further, even if the mini disc is mounted on the mini disc player and the reproduction is started without increasing the time for waiting for the reproduction until the reproduction is started and the audio signal is output, the selected song is reproduced. It is an object of the present invention to provide a system control algorithm for eliminating the waiting time until the sound is output by the reproduction instruction of and enabling the selected music to be reproduced.

[0007]

In the mini disc player according to claim 1 of the present invention, in the mini disc player for reproducing the mini disc recorded by compressing the voice data, the compressed voice data recorded on the mini disc is recorded. Selecting means for selecting audio compressed data to be reproduced, operating means for instructing start of reproduction, search means for searching the audio compressed data, reproducing means for reading and reproducing the audio compressed data searched by the search means, The storage means for storing the compressed audio data reproduced by the reproducing means in the semiconductor memory, the expansion means for expanding the compressed audio data stored in the storage means into the original audio data, and the output signal from the expansion means are digitalized. D / A converter for analog-to-analog output of audio signal, standby means for waiting the reading operation of the reproducing means, and D / A When an audio signal is output from the converter and the standby means puts the reproduction means on standby, the beginning of the audio compression data corresponding to the time from the beginning of the audio compression data selected by the selection means to at least the reproduction means can continue reproduction The audio compression data selected from the beginning of the audio compression data stored in the storage device when the reproduction device reads the audio compression data and causes the storage device to store the copy. It is characterized in that it comprises a control means for outputting the leading part of the above to the expansion means. Further, in the mini-disc player according to claim 2, in the mini-disc player according to claim 1, the control means compresses the sound recorded on the mini-disc when the selection means does not select the sound compression data. At least from the head block of the data, the head part of the audio compression data corresponding to at least the time until the reproduction means can continue the reproduction is read by the reproduction means and stored in the storage means, and the audio compression stored in the storage means according to the reproduction instruction. It is characterized in that the head portion of the data is output to the expansion means.

[0008]

In the mini disk player, since the compressed audio data stored in the storage means is output while being expanded by the expansion means, the reproducing means can reproduce the audio recorded in the mini disk even during reproduction while outputting the audio signal. There is a standby state (apparently stopped state) waiting for the compressed data read operation. Utilizing this waiting time, the reproducing means reads the head portion of the audio compressed data corresponding to the time from the head of the audio compressed data selected by the selecting means until at least the searching means can search and stores it in the storage means. Then, when a reproduction instruction is given by the operation means, the head portion of the audio compression data stored in the storage means is output to the decompression means. Therefore, when a reproduction instruction is given, the head portion of the designated audio compressed data can be output to the decompression means, and the audio signal can be immediately output. Even if the audio compression data is not selected by the selection means, the control means controls the audio corresponding to the time from the head block of the audio compression data recorded on the mini disk until at least the reproduction means can continue the reproduction. The head portion of the compressed data is read by the reproducing means and stored in the storing means, and the head portion of the audio compressed data stored in the storing means is output to the decompressing means every time a reproducing command is issued. Therefore, the selecting means selects the audio compressed data. Even if the reproduction is not performed, the audio signal can be output immediately when the reproduction command is issued.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mini disc player according to the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of hardware, FIG. 2 is a conceptual diagram showing a usage state and a servo state of a semiconductor memory and its time chart, and FIG. 3 is a flowchart showing a flow of system control.
In the figure, 1 is a mini disk, 2 is an optical pickup, 3 is an RF amplifier that amplifies a signal captured by the pickup, 4
Is a servo circuit block for controlling the motor to make the pickup follow the signal of the disk, 5 is a slide motor for sending and returning the pickup in the radial direction of the disk, 6 is a spindle motor for controlling the rotation of the disk, 7 Is an address decoder for reading the address recorded on the disc before recording the voice, and 8 is an EFM / ACIR for decoding the address of the disc by decompressing the ACIRC of the EFM signal recorded on the disc.
C decoder, 9 is a semiconductor memory control circuit block for managing the address of the semiconductor memory, 10 is an audio decompression decoder for decompressing and expanding compressed data, and 11 is a D / A for converting a digital signal into an analog audio signal. A converter, 12 is a semiconductor memory, 13 is a display device, 14 is a key input section for an operator to input data,
Reference numeral 15 is a microcomputer that controls the entire system.

Next, an embodiment of the present invention will be described with reference to the flowchart shown in FIG. S1 Start the transition process to stop state. (Step 1) The moment when the TOC is read when the entire system is started up or when the stop key is pressed during the normal play, the moment when the system apparently shifts to the stop state is shown. At this time, FIG.
It is assumed that the display block 13 indicates that the content indicating the stop state is displayed. This operation shows the time axis 0 in FIG.

S2 Next, when the play key is pressed, the beginning of the music to be reproduced first is searched. (Step 2) When the play key is pressed next time, in order to output the sound without waiting for the disc to start up, the compressed data at the beginning of the song to be reproduced first is stored in the semiconductor memory 12 in advance. Must be remembered in. Therefore, the position of the disk where the compressed data is recorded is searched for here. The song that should be played first here is the normal mode that does not have an instruction to select a song in advance.
This is the track with the lowest address recorded in the TOC. In the program mode, it is the song input to the first song of the program if there is no indication of the song to be played next. Is the song to be played next. This operation is shown between time axes 0 and 2 in FIG.

S3: Read compressed data while tracing and write to semiconductor memory. (Step 3) When the search is completed, the trace is started from the beginning of the music to be reproduced first when the play key is next pressed, and the compressed data recorded there is written in the semiconductor memory. Here, the amount of data to be written is the time until the disc can be read from the stopped state by starting the disc and searching for an arbitrary disc position (time axis 8 in FIG. 2). ~ 1
The minimum amount of voice data is 6 minutes). This operation is shown between time axes 2 and 4 in FIG.

S4 All servos are off. (Step 4) After the data is captured, it is necessary to shift to the stopped state, which is an apparent operation. Therefore, the tracking servo, the spindle servo, and the focus servo are turned off to shift to the stopped state. Turn off all servos,
When it is confirmed that the operation has transited to the stop state, both the apparent operation and the actual operation have transited to the stop processing. This operation is shown between time axes 4 to 8 in FIG.

S5 Play key is pressed and detected. (Step 5) This shows that the play key in the key block 14 shown in FIG. 1 is pressed and the system control microcomputer 15 recognizes it. This operation is shown on the time axis 8 in FIG.

S6 Audio output is started, and disk startup processing is performed. (Step 6) When the play key is pressed, the compressed data of the beginning portion of the song to be played first is already taken into the semiconductor memory, so that the compression is started from the moment the play key is pressed. If the data is read and expanded, the voice output can be started without waiting from the moment the play key is pressed. However, since the amount of data stored in the semiconductor memory is limited, it is necessary to read the rest of the data from the disk. Therefore, the servo state must first be shifted to a state where data can be read.

Therefore, the voice output is started from the moment the play key is pressed, and at the same time, the focus search is started, the focus point is searched for, and the focus servo is turned on. After that, by controlling the servo circuit 4, the spindle motor 6 is rotated and the spindle servo is turned on. Then, the tracking servo is turned on to read the data recorded on the disk. The compressed data can be read from the disk when all of these access processes are completed. This operation is shown between time axes 8 to 13 in FIG.

S7: Search the disk position where the continuation of the compressed data already written in the semiconductor memory is recorded. (Step 7) The audio output is interrupted unless the subsequent compressed data is read before all the compressed data already written in the semiconductor memory is read, so the subsequent compressed data is recorded. Start searching the disc position. This operation is shown between time axes 13 to 16 in FIG.

S8: Read compressed data while tracing and read to semiconductor memory. (Step 8) When the search is completed, tracing is started to write the compressed data of the subsequent data from the address next to the address where the compressed data already written in the semiconductor memory is recorded. After that, the same algorithm as in normal play is used. This operation is shown after the time axis 16 in FIG.

[0019]

According to the present invention, since the head portion of the selected audio compressed data is stored in the storage means, the audio signal instructed to be reproduced can be immediately output when the reproduction instruction is issued. .

[Brief description of the drawings]

FIG. 1 is a hardware block diagram showing an embodiment of a mini disk player of the present invention.

FIG. 2 is a conceptual diagram and a time chart showing a usage state and a servo state of a semiconductor memory showing an embodiment of a mini disk player of the present invention.

FIG. 3 is a flowchart showing an embodiment of a mini disc player of the present invention.

[Explanation of symbols]

1 Mini Disc 2 Optical Pickup 3 RF Amplifier 4 Servo Circuit 5 Slide Motor 6, 7 Address Decoder 8 EFM / ACIRC Decoder 9 Semiconductor Memory Control Circuit 10 Voice Expansion Decoder 11 D / A Converter 12 Semiconductor Memory 13 Display Block 14 Key Block 15 System Control microcomputer

Claims (2)

(57) [Claims] 1. A mini-disc player for reproducing a mini-disc in which voice data is compressed and recorded, and a selecting means for selecting the voice-compressed data to be reproduced from the voice-compressed data recorded in the mini-disc, and a reproducing device. Operation means for instructing start, search means for searching audio compressed data, reproducing means for reading and reproducing audio compressed data searched by the searching means, and storing the audio compressed data reproduced by the reproducing means in a semiconductor memory. Storage means, decompression means for decompressing the compressed audio data stored in the storage means into original audio data, and digital-to-analog conversion of the output signal from the expansion means to output an audio signal. A D / A converter, a standby unit for waiting the reading operation of the reproducing unit, and an audio signal output from the D / A converter for the standby unit. When the stage puts the reproducing means on standby, the reproducing means reads the beginning of the audio compressed data corresponding to at least the time from the beginning of the audio compressed data selected by the selecting means until the reproducing means can continue reproduction. Stored in the storage means, and the head portion of the voice compression data selected from the head portion of the voice compression data stored in the storage means when there is an instruction to reproduce the voice compression data selected by the selection means. And a control means for outputting to the expansion means. 2. The mini disk player according to claim 1, wherein the control means starts from the first block of the audio compressed data recorded on the mini disk when the audio compressed data is not selected by the selecting means. In order, at least, the head portion of the audio compressed data corresponding to the time until the reproducing means can continue the reproduction is read by the reproducing means and stored in the storage means, and the audio compressed data stored in the storage means according to the reproduction instruction. A mini disk player characterized in that the head portion of the is output to the expansion means.