JPH04339382A - Reproducing device for on-vehicle recording carrier - Google Patents

Abstract

PURPOSE:To enable to perform reproducing operation in succession to the reproducing before interruption when the reproducing is operated thereafter even by the interruption of power supply performed frequently in a vehicle. CONSTITUTION:This device is constituted so that data concerning with the re-producing lapse step of a recording carrier 1 is stored to a semiconductor memory 18. Then, the above-mentioned data is stored to hold in the semiconductor memory 18 by receiving the power supply from a battery 17 even at the time of the power interruption of a direct current power source 20. At the time of the reopening the power supply, the reproducing operation is performed from the reproducing position before the interruption based on the data stored to the semiconductor memory 18 by a system controller 14.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus for a record carrier such as a compact disc player mounted on a vehicle.

0002

[Prior Art] A compact disc player has a diameter of 12 mm.
This is a player that plays audio signals recorded in PCM format on small discs (compact discs) with a thickness of about 1.2 mm and 1.2 mm, and in combination with the recording format of the audio signals on those discs, it is possible to play back with high fidelity. However, its features go beyond simply high-fidelity playback; it also features a variety of speedy functions such as cueing any song and repeat play.

[0003] The various functions described above are performed by using control and display signals recorded on the disk. The information recorded as control and display signals includes the start song number, end song number, performance time, and start time of each song in the inner peripheral area of the disc called the lead-in area.On the other hand, the program in which audio information is recorded The area includes the song number (song number), index (subdivision within the song),
There is elapsed time within the song and cumulative elapsed time. In this specification, these eight pieces of information will be referred to as "track number and time information."

By the way, the basic functions required to implement special playback functions such as arbitrary cueing and repeat play that are performed in conventional compact disc players (hereinafter referred to as "players") are: (i) control; , a function to read display signals, and (ii) a function to search for a target position. By performing these two basic functions in combination with advanced control means such as a CPU, the above special playback function is achieved. . Therefore, the operation of the conventional player will be explained below, focusing on the above two basic functions.

In FIG. 7, reference numeral 1 denotes a disk to which a spindle motor 2 applies rotational force. Reference numeral 3 denotes an optical pickup, which includes optical reading means, focus and tracking adjustment means, and the like. A preamplifier 4 shapes the waveform of data read from the disk 1 and generates focus error and tracking error signals. Reference numeral 5 denotes a clock regeneration circuit that generates a clock when demodulating read data.

[0006] 6 is a demodulator, and EFM (Eight
t-FourteenModulation) The modulated read data is demodulated into data in units of 8 bits, and the subcode signal included in the read data is extracted. 7 is a decoder which performs error correction, error correction,
Performs correction code decoding including deinterleaving and jitter absorption operations. A D/A converter 8 converts the PCM signal input from the decoder 7 into an analog audio signal. A focus servo circuit 9 controls the focus of the signal reading light beam based on a focus error signal obtained from the preamplifier 4.

10 is a tracking servo circuit,
The tracking error signal obtained from the preamplifier 4 controls the movement of the signal reading light beam in the radial direction with respect to the disk 1. Reference numeral 11 denotes a slider servo circuit, which controls the slider drive section 12 to compensate for the radial movement of the disk 1 that cannot be followed by the optical pickup 3 alone.

Reference numeral 13 is a spindle motor servo circuit, which rotates the disk 1 at a constant linear velocity (CLV: Con
The rotation of the spindle motor 2 is controlled so that the stand linear velocity (referred to as stand linear velocity) is achieved. 1
A system controller 4 has the role of monitoring the status of each part of the player, including the operation input section 15, and issuing commands to each part of the player, including the display section 16, to perform various operations.

The basic function of extracting the aforementioned control and display signals from disk read data will now be described in detail. Figure 8 shows a disk read signal with a repetition frequency of 7.35k.
This shows the format of a unit called a frame that appears in Hz, and is a synchronization signal (a) of 24 channel bits (a channel bit is a unit of information regarding a disc recording signal).
, 14 channel bit control, display signal (b), 33
6 channel bits of data (c), 112 channel bits of error correction bits (d), and 102 channel bits of connection and low frequency suppression bits (e), total 58
It contains 8 channel bits and appears in a fixed sequence.

The 14 channel bits of the control and display signals have an information amount of 8 data bits in terms of data bits which are information units before EFM modulation. Furthermore, the control and display signals are 98 frames or 75Hz (7.35kHz/
The recorded contents are updated in units of one block (sub-coding block) which is repeated at a frequency of 98=75Hz). The sub-coding block includes two frames worth of sub-coding synchronization patterns and eight types of information, and one type of information is assigned to a fixed digit, one bit per frame. The song number and time information are also in this 1
included in two digits. These eight types of information include, in addition to track number and time information, information indicating the presence or absence of pre-emphasis, and information indicating whether the song is between or within a song. Note that the bits containing the track number and time information are called a channel Q, and may be used for recording other information, and are distinguished by an identification signal included in the same channel Q.

FIG. 9 shows a recording format when channel Q indicates a track number and time information in a program area. The mode control signal in the figure is made up of information indicating whether pre-emphasis is used or not, and information indicating whether stereo 2 channels are used. ADR1 is information that distinguishes what the data after ADR represents. In the lead-in area of the disc, information is repeated three times, including the start time (cumulative elapsed time) of each song, the first song number of the program, the last song number of the program, and the total playing time, which are distinguished by flags called points. ing.

To extract the track number and time information, first, the disc readout signal is bit-synchronized using the clock obtained from the clock regeneration circuit 5 shown in FIG. Then, the subcode is separated and extracted from the EFM demodulated data using this synchronization signal. The system controller 14 inputs all 8-bit subcodes or specific bits for a subcoding block as necessary, performs code error detection, and inputs a new subcode if an error is found. After confirming with the identification signal that the bit string corresponding to channel Q is the song number and time information, the input of the song number and time information is completed.

FIG. 10 shows a flowchart of time reading centered on the operation of the system controller. In Figure 4 (
6) Data rearrangement refers to the operation of rearranging 96 bits (98-2) of serial data according to content so that it can be easily processed by the CPU. Now, the second basic function that is essential for realizing special playback, such as the arbitrary cueing function, is the function of searching for the desired position, as mentioned earlier, and it is also important that this is done quickly. be. song number,
In order to search for the target position specified in the form of time information, means for moving the trace position of the optical pickup 3 and means for determining the amount of movement are required.

[0014] There are two ways to move the trace position: one is to trace the spiral signal track as it is and move to the desired position without leaving the spiral signal track, and the other is to jump the track and move.However, although the former method is reliable, it is usually not possible. Since it takes the same amount of time as playback, it is used in combination with the latter. The jump operation is performed by applying a pulse (referred to as a jump pulse) to the tracking servo circuit 10 to forcibly move the trace position of the optical pickup 3. In order to achieve high-speed movement, a large jump pulse and a sudden stop pulse are applied to the tracking servo circuit 10. reverse polarity pulse (referred to as brake pulse)
is combined.

Track jumps are executed as many times as the forward jump (jump in the direction of the outer circumference of the disk) or reverse jump (jump in the direction of the inner circumference of the disk) command output from the system controller 14. however,
There is a limit to the amount of movement of the trace position in the radial direction within the optical pickup 3, and this is automatically compensated for by the slider servo circuit 11 and the slider drive section 12.

Next, the amount of movement to the destination position is determined.
The system controller 14 roughly calculates the distance between the current position given as time information and the target position, outputs a jump command based on the result, reads the track number and time information at the next position, and returns to the target position. A method is adopted in which the operation of calculating the distance and outputting a jump command is repeated. If it is very close to the target position,
Wait until the target position is reached by tracing without jumping.

FIG. 11 shows the target position search operation centered on the processing of the system controller 14.
Here, in the process of (1) and (2), the target position is set to 1 second before the start of the song so that the first note of the song is never deleted in the beginning operation of the song, and the target position is set as the cumulative time elapses. It is converted into time expression (referred to as absolute time in FIG. 11). In FIG. 11, tA2 represents the absolute time of the current position, tB0 represents the start absolute time of the target song, tB1 represents the time within the song of the target position, and tB2 represents the absolute time of the target position, and N1 < N2 <N3 <N4,
T1 <T2 <T3 <T4 <T5 <T6 <T
7.

The start time of the target song is stored in advance by reading lead-in data (not shown). (3) PLL lock detection is the process to confirm that the CLV control has followed the movement of the trace position, (4) is the time reading process shown in Figure 10, and (6) and (7) are the steps to determine the movement direction. This result is given to the graph P indicating the polarity of the jump pulse, and (8) to (11) are the processes that determine the number of jump pulses from the time difference |△T| between the current position and the target position, In particular, (6) and (8) determine whether the current position is the same as the target position or very close to it, that is, the search has ended;
Further, T2>|ΔT| in (10) is a process for determining a case where a jump would result in jumping over the target position, and (13) is a process for outputting the determined number of jump pulses N and direction P. (9) and (14) are processes related to audio muting, and when the search start position and the target position are the same or very close, neither jumping nor muting is performed.

A special reproduction operation is realized by combining the control signal reading function and target position searching function described above with the system controller 14. For example, in a function that plays back songs arranged on a disc in an arbitrary order (hereinafter referred to as program play), the play order is input from the operation input section 15 using a predetermined method, and the system controller 14 Information storage circuit (not shown)
Store in. Next, the system controller 14 executes the above-mentioned target position search (in this case, cueing) to start playback, and repeats the operation of fetching information for the next song from the storage circuit each time one song ends. Therefore, programmed performance can be realized.

Now, as mentioned above, compact disc players realize rich and speedy functions by using subcodes recorded on the disc, that is, control and display signals. has an advantage over

[0021]

[Problems to be Solved by the Invention] However, in cassette tape or open reel tape players,
Since the tape winding state saves the past playback end position, even if the power is turned on again or the tape is removed from the player and inserted into the player again,
It has the advantage of not having to listen to the same performance or perform any special operations, whereas with conventional compact disc players, once the power is turned off or a disc is inserted or removed, The information for the disc that was being played back before that time is volatile, and it is necessary to play back from the first track on the disc again or to perform the cueing operation. At this time, if the operator does not remember how many tracks have previously finished playing, it is necessary to sample the contents of several tracks in order to search for that position, which requires a considerable amount of time and effort. It takes time.

[0022] Furthermore, if the disc is taken out of the player to check the title of the song by looking at the title written on the disc surface, the same result as above will be obtained. Such problems with conventional compact disc players become even more pronounced in vehicle-mounted compact disc players. In other words, in-vehicle players use the car's DC power supply, but in most cars, when the engine is started, the power supply to everything other than the engine is stopped, and when the driver gets out of the car, the power supply is turned off as well as the engine. Conventional compact disc players can be said to have extremely poor operability, considering the fact that they are disconnected, and that they are often used in cars for only a short period of time most days, during which time they listen to music. Particularly for the driver, there is a problem in that it takes time and effort to operate the player, which is not desirable in terms of driving safety.

The present invention has been made in view of the above-mentioned conventional problems, and allows the regeneration operation restarted after the power supply is interrupted due to vehicle operation to be performed following the regeneration before the interruption. The purpose is to do so.

[0024]

[Means for Solving the Problems] A reproducing device for an in-vehicle record carrier according to the present invention includes a storage means for storing data regarding the progress stage of reproduction of a record carrier, and a reproducing operation restarted after interruption of reproduction in the storage means. and means for determining based on stored data.

[0025]

[Operation] The in-vehicle record carrier reproducing device according to the present invention has the following features:
Data at the time of interruption of power supply due to operation of the vehicle is stored in a storage means, and when playback is started after power supply is resumed, the determining means reproduces data based on the data stored in the storage means. It is designed to determine the operation.

[0026]

【Example】

Example 1. FIG. 1 is a schematic block diagram of a first embodiment of the present invention, and the same reference numerals as in FIG. 6 indicate the same parts. In FIG. 1, 17 is a battery, which backs up the semiconductor memory 18. A diode 19 constitutes an OR circuit that ORs the battery 17 and the DC power supply 20 generated from the power supplied through a power switch (not shown). Reference numeral 21 denotes a power drop detection circuit, which serves to completely store data. By incorporating the battery 17, the semiconductor memory 18 (volatile) can be used equivalently as a nonvolatile memory.

Although data may be saved to the semiconductor memory 18 only when the output of the DC power supply 20 decreases due to power cut, etc., in this embodiment, the data may be saved even when the original power is being supplied to the player. The semiconductor memory 18 is used as a data storage register, thereby eliminating the need for data saving operations. However, DC power supply 2
Since there is a risk that the system controller 14 composed of a CPU or the like may access the semiconductor memory 18 incorrectly, the power drop detection circuit 21 prohibits access to the semiconductor memory 18 by hardware. At the same time, it prevents power consumption due to current leakage to areas other than memory circuits.

A non-volatile semiconductor memory may be used as the semiconductor memory 18, and in this case there is an advantage that a backup battery is not required. On the other hand, the backup means may be a rechargeable battery, a large-capacity capacitor, or a structure in which it is always in a conductive state without using a power switch. Further, instead of backing up only the semiconductor memory 18, the CPU portion of the system controller 14 or other circuits may also be backed up.

Now, the data to be saved by the semiconductor memory 18 differs depending on the selection of the function to be performed continuously after the power is turned on again, but in this embodiment, the data is played again from the previously played position (hereinafter Considering the function (referred to as "sequential play") and the function in which the previously input program play (described above) is continued, the minimum required data is time information (referred to as "sequential play") indicating the previously played position. (hereinafter referred to as "last time information"), information on the procedure of program performance (hereinafter referred to as "program information"), and information indicating in which order the songs were played during program performance (hereinafter referred to as "pointer") Is required.

Since it is unknown when the power will be cut off for the last time and pointer depending on the operation of the vehicle, it is necessary to frequently read the latest information from the disk and transfer it to the semiconductor memory 18. It is assumed that the controller 14 is configured to perform this function.

When the power is turned off, the last time information and program information are saved by hardware means, so the system controller 14 does not perform any particular processing different from that shown in FIG. 7, but when the power is turned on again, performs special processing.

FIG. 2 is a flowchart of the sequential play operation centered on the operation of the system controller 14. Here, tmin is the absolute start time of the first song, tmax is the total playing time, Ap is the pointer, [Ai
] represents the contents of register Ai, and [[Ap]] represents the contents of the address indicated by the pointer.

It is assumed that the initialization of the system controller 14 itself and the initialization of each part of the player have been completed before this flowchart, and the processing for display is omitted in the flowchart. FIG. 3 shows a last time storage register A provided in the semiconductor memory 18.
o shows the configuration of the program information storage registers A1 to AN and the pointer storage register Ap, and the program is played in the order in which the song indicated by A1 is played, followed by the song indicated by A2.

The last time and program information each store a song number and an absolute time (cumulative elapsed time), and the absolute time in the program information means the absolute start time of each song. The pointer shows program performance A1 to A
The address stage of N is stored as addresses A1 to AN, and if the contents of this pointer and last time are 0 (reset), it indicates that the entire program performance has been completed previously. Note that if program play is not specified, this means that the entire disc has already been played.

In FIG. 2, (3) to (6) are registers A
The contents of 0 to AN are checked, and if A0 is reset or if the contents of A0 indicate a lead-in or lead-out position, sequential play is not performed. The content of A0, that is, the last time position, is searched in (7) and playback is started, and the playback is started in (11).
) until the end of the current song is detected (9), (10)
Read the latest track number and time information and store it in A0. When the end of the song is detected, it determines whether it is a program play or not (12)
If it is a program play, the content (address) of the pointer is incremented by 1 in (15), and (16
), it is determined whether there is a song to be played next and the performance is ended, or processing is performed to proceed to search for the next song.

On the other hand, if it is not a program performance, (1
In step 3), it is determined whether it is the last song on the disc, and if it is the last song, the performance ends, and if it is not the last song (8).
and then go back to play the next song. (14) is a process of saving the completion of all procedures in the case of program play, or the completion of the performance of the last song on the disc in the case of non-program play, by resetting A0. Note that (7) “
The processes of ``Search'' and (9) ``Time reading'' are shown in Figure 11.
and corresponds to FIG.

Now, the sequential play operation has been described above, and as mentioned above, the operability is improved by automatically executing the sequential play.
Since this operation is not always required, countermeasures will be shown in the following embodiment.

Example 2. It is convenient to provide input means for executing or not executing a sequential play operation so that a specific initial state or initial operation can be performed without performing a sequential play when the power is turned on again. A second embodiment in which sequential play can be selectively realized by such means includes (i) a mechanically lockable sequential play execution/non-execution switch; The last time register A0 in the above embodiment is reset, or conversely, a function is added to the system controller 14 to ignore the contents of A0. (ii) It has an unlocked sequential play execution/non-execution switch and a register for sequential play execution/non-execution instructions in the semiconductor memory 18, and when this switch is pressed, the contents of this register are logically inverted. There is a method of adding processing to the system controller 14 to determine execution/non-execution of a sequential play operation according to the contents of the memory. The former stores the sequential play execution/non-execution command mechanically, and the latter electrically (flow chart omitted).

Example 3. Next, as a third embodiment, sequential play is performed only when the power is cut off for a short time,
The following describes a function that performs the initialized operation without performing sequential play when the power is turned on again after being turned off for a long time. This is a function in a vehicle-mounted player that performs sequential play only when the power is turned off when starting the engine or when the vehicle is stopped for a short time. FIG. 4 is a block circuit diagram showing a main part of a third embodiment having such a function, and is the same as FIG. 1 except for the area around the system controller 14, and the same reference numerals have the same contents.

In FIG. 4, 21 is a resistor through which power is supplied to the semiconductor memory 18. 22 is a diode for backflow prevention, 23 is a large capacitor that serves as a short-time backup power supply, and 24 is a comparator that allows the power supply voltage of the semiconductor memory 18 to be set to 2.
When the voltage is higher than the reference voltage No. 5, a high level (indicated as "H") is output, and in the opposite case, a low level (indicated as "L") is output to the system controller 14.

When the power supply to the player is normal and the output of the DC power supply 20 is normal, current is supplied to the semiconductor memory 18 through the resistor 21 and the diode 22. However, if the power supply to the player is stopped or the supply voltage is When the voltage drops, the DC power supply 20 and the memory circuit are separated by the action of the diode 22. In this case, the power supply voltage of the semiconductor memory 18 gradually decreases due to the charging capacity of the capacitor 23, but the semiconductor memory 18 retains its contents even if the power supply decreases to a certain extent. The comparator 24 operates as a timer by comparing the drop in the power supply voltage of the semiconductor memory 18 with a reference voltage 25, and at the same time selects the reference voltage 25 to be higher than the content retention limit voltage of the semiconductor memory 18, so that the content of the memory is Provides compensation for retention. In this case, the timer (in other words, time detection means) may be configured with digital detection means such as a frequency count, without being limited to the illustrated embodiment.

The flowchart in FIG. 5 shows the processing of the system controller 14 in the third embodiment.
Immediately after initialization when the power is turned on again, the output of the comparator 24 is detected in (1), and if it is "H", sequential play is performed, while if it is "L", it is assumed that the power has been stopped for a certain period of time. All registers A0 in FIG.
AN and Ap are reset, and the initialized player operation is performed (as described above, sequential play is not performed when A0 is reset). The charging speed of the capacitor 23 by the resistor 21 after the power is turned on again is selected to be slow, and when the system controller 14 checks the output of the comparator 24, the voltage on the capacitor 23 is almost the same as the value immediately before the power was turned on again. I try not to.

Example 4. Next, FIG. 6 shows a flowchart of the fourth embodiment, in which a sequential play execution command is not given when the power is turned on again, so the performance operation that has been initialized (for example, playing in order from the first song) Even if this is done, if it is within a certain period of time, the system has a function to accept and execute sequential play execution commands input during that period. This function is effective as a function to compensate for the operator's carelessness or change of intention. In this case, it is assumed that the player of FIG. 1 is provided with a sequential play switch, which is a mechanical lock type switch, for inputting the execution/non-execution of the sequential play described in the second embodiment.

FIG. 6 shows the processing of the system controller that implements the above function, which is a modification of the processing shown in FIG. 2, and the same symbols indicate the same contents.

In FIG. 6, after the power is turned on again, the lead-in data is first read in (1), and the last time information (contents of A0) is reset in (2) to (5).
Alternatively, if it is determined that the time information is not valid, the performance will be performed from the first track on the disc in the processing after (10), while on the other hand, if the last time information is determined to be valid in (2) to (5), the last time information of A0 will be played. is saved in the register with the address AQ (AQ does not need to be non-volatile), and the state of the sequential play switch is checked in (8). If the sequential play switch is ON (sequential play execution command), the timer is reset and started in (12) to search for the playback position indicated by A0 and play, and conversely, the sequential switch is OFF (non-execution command). If so, playback starts from the first track on the disc via step (10). Here, flag S indicates the state of the sequential play switch, and when S = 0, the switch is OFF.
, the switch is ON when S=1.

[0046] In (13), the first track on the disc or A0
When you search for the song indicated by and start playing (14), (15)
While always writing new track number and time information to A0, (
In step 16), the elapsed time of the timer is checked, and if the timer time T is less than the time limit Tmax, the state of the sequential play switch is checked in step 17. (20) detects a change in the switch state by taking the exclusive OR of the previous switch state S and the current switch state S', and if the state has not changed (S + S' = 0), special processing is performed. Without,
On the other hand, if there is a change in the state of the switch, the next process is performed. If sequential play was executed previously (S = 1) and the switch is now turned OFF (S' = 0), the sequential play will be stopped, the data of the first track on the disc will be transferred to A0, and the performance will start from the first track. (21)～(2
3).

On the other hand, sequential play has not been executed before (S=0), and the switch is now turned on (S'=1).
), if there is regular last time information saved in AQ in (24), the contents of AQ are restored to A0 in (26) and sequential play is performed, while in (24) AQ is If it has been reset, it will continue playing. In (16), the timer time is the limited time Tma
If it is determined that x is exceeded, then the state of the sequential switch is ignored. (27) The subsequent processing is the same as in the case of FIG. 2, so the explanation will be omitted. Note that in FIG. 6, processes such as the operation input switch in FIG. 2 are omitted for the sake of explanation. In the embodiments described above, it is possible to memorize the operation command itself when the power is turned off as a response to the case where a single operation such as a cueing operation is given and the power is stopped before the operation is completed. . Please note that even if the compact disc standard changes, the time and
The present invention is applicable as long as information regarding song numbers and the like is recorded on the disc.

[0048]

As described above, according to the present invention, data regarding the progress stage of reproduction of the record carrier when the power supply is interrupted due to operation of a vehicle is stored in the storage means, and then the data on the reproduction progress stage is stored in the storage means when the power supply is restarted. Since the regeneration operation is determined based on the data stored in the vehicle, even if the power supply is frequently interrupted due to vehicle operation, the regeneration operation can continue from the regeneration before the interruption. Since the operability can be greatly improved and the number of steps and time required for operation can be omitted, the present invention has the effect of making the vehicle more suitable for driving safety.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a compact disc player showing one embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of FIG. 1;

FIG. 3 is a diagram for explaining the configuration of a part of FIG. 1;

FIG. 4 is a block diagram showing the configuration of main parts in another embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of FIG. 4;

FIG. 6 is a flowchart showing the operation of still another embodiment of the present invention.

FIG. 7 is a block diagram of a conventional compact disc player.

FIG. 8 is a diagram for explaining signals recorded on a compact disc.

FIG. 9 is a diagram for explaining signals recorded on a compact disc.

FIG. 10 is a flowchart diagram of time reading in a compact disc player.

FIG. 11 is a flowchart diagram of a search in a compact disc player.

[Explanation of symbols]

1 Compact disc player 3. Optical pickup 5 Clock regeneration circuit 6 Demodulator 14 System controller 17 Battery 18 Semiconductor memory 20 DC power supply 21 Power drop detection circuit

Claims (1)

[Claims] 1. A storage means for storing data regarding the progress stage of reproduction of a record carrier that is reproduced by receiving power supply from a DC power source of a vehicle, and data stored in the storage means for recording reproduction operation restarted after interruption of reproduction. 1. A reproducing apparatus for an in-vehicle record carrier, characterized in that the storage means stores and holds data when power supply is interrupted due to operation of the vehicle.