JP2638335B2 - In-vehicle record carrier playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A compact disk player has a diameter of 12c.
m, a player that reproduces audio signals recorded in PCM on a small disk (compact disk) with a thickness of about 1.2 mm. High fidelity reproduction is possible in conjunction with the recording format of audio signals on the disk. However, the feature is that it is not limited to high-fidelity reproduction, and that abundant functions such as searching for an arbitrary song and repeat performance are performed quickly.

The various functions described above are performed by using control and display signals recorded on a disk. The information recorded as control and display signals includes a start song number, an end song number, a play time, and a start time for each song in the inner peripheral portion of the disc called a lead-in area, while a program in which audio information is recorded. The track number (song number), index (small section in the song),
There are elapsed time within the song and cumulative elapsed time. In this specification, these eight pieces of information will be referred to as "music number and time information".

The basic functions required for performing a special reproduction function such as arbitrary cueing and repeat performance performed in a conventional compact disk player (hereinafter referred to as a "player") include (i) control. And (ii) a function of searching for a target position. The special reproduction function is achieved by performing these two basic functions in combination with advanced control means such as a CPU. . Therefore, the operation of the conventional player will be described below focusing on the two basic functions.

[0005] In FIG. 7, reference numeral 1 denotes a disk, which is given a rotational force by a spindle motor 2. Reference numeral 3 denotes an optical pickup having optical reading means, focus and tracking adjustment means, and the like. Reference numeral 4 denotes a preamplifier that shapes a waveform of data read from the disk 1 and generates a focus error signal and a tracking error signal. Reference numeral 5 denotes a clock recovery circuit, which generates a clock for demodulating read data.

Reference numeral 6 denotes a demodulator, which is an EFM (Eight-Four
teenModulation) The demodulated read data is demodulated into 8-bit data, and a subcode signal included in the read data is extracted. Reference numeral 7 denotes a decoder for performing error correction, error correction, decoding of a correction code including deinterleave, and jitter absorption. Reference numeral 8 denotes a D / A converter, which converts a PCM signal input from the decoder 7 into an analog audio signal. Reference numeral 9 denotes a focus servo circuit which controls the focus of the signal reading light beam based on a focus error signal obtained from the preamplifier 4.

A tracking servo circuit 10 controls the movement of the signal reading light beam in the radial direction with respect to the disk 1 by a tracking error signal obtained from the preamplifier 4. Reference numeral 11 denotes a slider servo circuit, which covers the movement of the disk 1 in the radial direction, which cannot be followed only by the optical pickup 3, by controlling the slider drive unit 12.

Reference numeral 13 denotes a spindle motor servo circuit which rotates the disk 1 at a constant linear velocity (CLV: Constant).
d Linear Velocity). Reference numeral 14 denotes a system controller, which has a role of monitoring the state of each unit of the player including the operation input unit 15 and issuing a command to each unit of the player including the display unit 16 to perform various operations.

Here, the basic function of extracting the above-described control and display signals from the disk read data will be described in detail. FIG. 8 shows a disc read signal with a repetition frequency of 7.35 kHz.
This indicates the format of the unit called the frame that appears in the above. Synchronization signal (a) of 24 channel bits (channel bits are information units related to disc recording signals), control of 14 channel bits, display signal (b), 336 channel bits Data (c), error correction bits of 112 channel bits (d), connection of 102 channel bits, low frequency suppression bit (e), totaling 588 channel bits,
Appears in a fixed array.

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

FIG. 9 shows a recording format when the channel Q indicates a song number and time information in the program area. The mode control signal in the figure is formed of information indicating the presence or absence of pre-emphasis and information indicating whether or not the stereo channel is used. ADR1 is information for distinguishing what the data after ADR represents. In the lead-in area of the disc, information on 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, are repeated three times. ing.

To extract the song number and time information, first, the disk read signal is bit-synchronized by the clock obtained from the clock recovery circuit 5 in FIG. 7, and the demodulator 6 detects the frame synchronization signal and the sub-coding synchronization pattern. Then, the subcode is separated and extracted from the EFM demodulated data by the synchronization signal. The system controller 14 inputs the entire 8-bit sub-code or specific bits for the sub-coding block as needed, detects a code error, and inputs a new sub-code if there is an error.
The identification signal confirms that the bit string corresponding to the channel Q is music number and time information, and the input of music number and time information is completed.

FIG. 10 is a flow chart of time reading focusing on the operation of the system controller. The data rearrangement of (6) in FIG. 4 refers to an operation of rearranging 96-bit (98-2) serial data for each content so that the CPU can easily process the serial data. The second basic function indispensable for realizing special reproduction such as an arbitrary cueing function is a function of searching for a target position as described above, and it is also important that this is performed quickly. is there. To search for the desired location specified in the form of track number and time information,
Means for moving the trace position of the optical pickup 3 and means for determining the amount of movement are required.

To move the trace position, there is a method of tracing to a target position without traversing a spiral signal track and a method of jumping and moving the track. Since it takes the same time as reproduction, 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 and forcibly moving the trace position of the optical pickup 3. Reverse polarity pulse (referred to as brake pulse)
Are combined.

A forward jump (disc outer direction jump) command or a reverse jump (disc inner direction jump) output from the system controller 14
Track jumps are executed for the number of instructions. However, the movable amount of the trace position in the radial direction in the optical pickup 3 is limited, and this is automatically compensated for by the slider servo circuit 11 and the slider drive unit 12.

Next, the movement amount to the target position is determined.
The distance between the current position and the target position given as time information is roughly calculated by the system controller 14, and a jump command is output based on the result, and at the next position, the track number and time information are read and the target position is read again. , And the operation of outputting the jump command and calculating the distance is repeated. If it is very close to the target position, it traces without jumping and waits for reaching the target position.

System search for target position search operation
FIG. 11 shows the processing of FIG. 14 as the center. Here, the processing of (1) and (2) is performed so that the sound at the beginning of the music is not cut off at the beginning of the music. Is set one second before the start of the music, and the target position is converted to an accumulated elapsed time expression (referred to as an absolute time in FIG. 11).
In FIG. 11, t _A2 is the absolute time of the current position, t A
_B0 represents the start absolute time of the target music, t _B1 represents the time within the music at the target position, t _B2 represents the absolute time of the target position, and N ₁ <N ₂ <N ₃ <N ₄ , T ₁ < T ₂ <T ₃ <
It is assumed that T ₄ <T ₅ <T ₆ <T ₇ .

The start time of the target music is read from the lead-in data and stored in advance (not shown). The PLL lock detection of (3) is a process for confirming that the CLV control follows the movement of the trace position, (4) is a time reading process shown in FIG. 10, and (6) and (7) determine a movement direction. This result is given to a graph P indicating the polarity of the jump pulse, and (8) to (11) are processes for determining the number of jump pulses from the time difference | △ T | between the current position and the target position. In particular, in (6) and (8), it is determined whether the current position is the same as the target position or very close, that is, the end of the search.
In (0), T ₂ > | △ T | determines whether a jump jumps over the target position, and (13) outputs the determined jump pulse number N and direction P. (9) and (14)
Is processing related to audio muting. When the search start position and the target position are the same or are very close, neither jump nor muting is performed.

By combining the control signal reading function and the target position searching function described above with the system controller 14, a special reproducing operation is realized. For example, in a function of reproducing songs arranged in order in a disc in an arbitrary order (hereinafter referred to as a program performance), a performance order is input from the operation input unit 15 in a predetermined manner, and the system controller 14
Stores these pieces of program information in a storage circuit (not shown). Next, the system controller 14 repeats the operation of executing the above-described target position search (in this case, searching for the beginning), starting reproduction, and taking in the information of the next music from the storage circuit every time one music ends. Therefore, program performance can be realized.

As described above, the compact disk player realizes abundant and speedy functions by using the subcodes recorded on the disk, that is, the control and display signals. Has an advantage over

[0021]

However, in a cassette tape or open reel tape player,
Even if the power is turned on again because the tape winding state preserves the past playback end position, or if the tape is taken out of the player and attached to the player again,
While having the advantage of not listening to the same performance content or having to perform any special operations, conventional compact disc players once turn off the power or execute the disc loading / unloading operation. The information on the disc that has been played back before that is volatilized, and it is necessary to play back from the first song on the disc again or to perform the cueing operation. At this time, if the operator has not memorized the number of songs that have been reproduced before, it is necessary to listen to the contents of some songs in a sampling manner in order to search for that position, which is quite troublesome. It takes time.

If the user removes the disc from the player in order to check the title of the music by looking at the title portion described on the disc surface, the same result as described above will be obtained. Such a problem of the conventional compact disk player becomes more remarkable in a compact disk player for a vehicle. In other words, the in-vehicle player uses the DC power supply of the car, but in most cars, the power supply to the parts other than the engine is stopped when the engine is started. Considering that the user is disconnected and uses the car for a very short period of time almost every day and listens to music at that time, the operability of the conventional compact disc player is extremely poor. In particular, there is a problem that if the operation of the player takes time and trouble for the driver, it is not preferable in terms of driving safety.

The present invention has been made in view of the above-mentioned conventional problems, and a reproducing operation resumed after a power supply interruption due to an operation of a vehicle can be performed following the reproduction before the interruption. It is intended to be.

[0024]

According to the present invention, there is provided a reproducing apparatus for a vehicle-mounted record carrier, wherein power is supplied from a DC power source of a vehicle.
Reproducing means for performing a reproducing operation of the record carrier;
When the power supply to the reproduction means is stopped during the operation of the stage
Data on the playback progress stage and data on the playback method
Storage means for storing data and power supply to the reproducing means.
When the power is again supplied to the playback unit after stopping,
Data on playback progress stage stored in storage means and playback
Reproduction of reproduction means, based on both data on the method
It is provided with determination means for determining an operation.

[0025]

According to the present invention, there is provided a reproducing apparatus for a vehicle-mounted record carrier.
Regeneration when the power supply from the vehicle's DC power supply is stopped
Data on the progress stage and data on the playback method
It is stored in the storage means, and thereafter, when the power supply is restarted.
Data on the playback progress stage stored in the storage means
And reproduction means based on both data relating to the reproduction method
Is determined .

[0026]

【Example】

Embodiment 1 FIG. FIG. 1 is a schematic block diagram of a first embodiment of the present invention, and the same reference numerals as those in FIG. 6 denote the same parts. In FIG. 1, reference numeral 17 denotes a battery for backing up the semiconductor memory 18. Reference numeral 19 denotes a diode, which constitutes an OR circuit for ORing the battery 17 with a DC power supply 20 generated from a power supply supplied through a power switch (not shown). Reference numeral 21 denotes a power drop detection circuit, which plays a role of completely saving data. By incorporating the battery 17, the semiconductor memory 18 (volatile) can be equivalently used as a nonvolatile memory.

Although the data may be saved in the semiconductor memory 18 only when the output of the DC power supply 20 is reduced due to power-off or the like, in this embodiment, even when the original power is supplied to the player, The semiconductor memory 18 is used as a data storage register, so that a data saving operation is not required. However, there is a risk that the system controller 14 including a CPU or the like may erroneously access the semiconductor memory 18 due to a decrease in the DC power supply 20. At the same time as the prohibition, power consumption due to current outflow to other than the memory circuit is prevented.

A non-volatile semiconductor memory may be used as the semiconductor memory 18, in which case there is an advantage that a backup battery is not required. On the other hand, rechargeable batteries or large-capacity capacitors
Alternatively, the configuration may be such that the conduction state is always established without the intervention of a power switch or the like. Further, the semiconductor memory 18 may be backed up not only by backing up but also by including the CPU portion of the system controller 14 or other circuits.

The data to be stored in the semiconductor memory 18 differs depending on the selection of the function to be performed continuously after the power is turned on again. In the present embodiment, the performance is resumed from the previously reproduced position (hereinafter referred to as "reproduction"). Considering the function called “sequential play”) and the function in which the program operation previously input and operated (described above) is continued, the minimum necessary data is the data related to the reproduction progress stage.
Time information indicating the position that was previously played
"Last time information") and program performance
Information indicating the order in which songs were being played ("Poi
Data), and the professional data
Gram performance procedure information (hereinafter referred to as “program information”)
Required) .

Since the last time and the pointer are not known when the power is cut off by operating the vehicle, it is necessary to frequently read the latest information from a record carrier such as a disk and transfer it to the semiconductor memory 18. And the system controller 14 is configured to perform this function.

When the power is turned off, the last time information and the program information are stored by hardware means, so that the system controller 14 does not perform any processing different from the case of FIG. Performs special processing.

FIG. 2 is a flowchart of a sequential play operation centering on the operation of the system controller 14. Where t _min is the absolute start time of the first song, t
_max represents the total playing time, Ap represents the pointer, [Ai] represents the contents of the 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 and the initialization operation 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 Ao provided in the semiconductor memory 18.
Shows the configuration of a storage register A ₁ to A _N and pointer storage register Ap program information, program play is the order of playing music indicated by A ₂ to the next song indicated by A _1.

The last time and the program information store the music number and the absolute time (accumulated elapsed time), respectively. The absolute time in the program information means the start absolute time of each music. Program performance is A _{1 to} A _{N at the} pointer.
Or at the stage of the address of the throat is stored in address A ₁ to A _N, the pointer and the last time if the contents of 0 (reset), indicating that all the program play is completed earlier. If the program performance is not specified, it means that the performance of the entire disc has been completed before.

In FIG. 2, (3) to (6) are registers A
₀ to A and conduct the contents check _N, if A ₀ is reset, or the contents of the A ₀ does not perform sequential play when indicating the position of the lead-in or lead-out. The position of the content i.e. the last time of A ₀ to start playback by searching in (7), (11) until the end of the current song is detected (9), the latest track number, time (10) and stores the information to read a _0. When the end of the song is detected, it is determined in step (12) whether or not the program is to be played. If the program is to be played, the content (address) of the pointer is incremented by 1 in step (15), and the next song to be played in step (16) The performance is terminated by determining the presence / absence of the song, or the process proceeds to the search for the next song.

On the other hand, if it is not a program performance, (13)
It is determined whether or not the song is the last song on the disc. If the song is the last song, the performance is ended. If the song is not the last song, the process returns to (8) to play the next song. (14) when the program finished playing the entire procedure, if it is not a program play, a process of storing the performance end of the last track of the disc by the reset of the A _0. The processing of (7) “search” and (9) “time reading” in FIG. 2 correspond to FIGS. 11 and 10, respectively.

The sequential play operation has been described above. As described 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 embodiments.

Embodiment 2 FIG. It is convenient to provide a means for inputting execution and non-execution operations of the sequential play operation so that a specific initial state or initial operation can be performed without performing the sequential play when the power is turned on again.
As a second embodiment in which sequential play can be selectively realized by such means, (i) a mechanical play lockable sequential play execution / non-execution switch is provided, and when this switch is non-execution, The function of resetting the last time register A ₀ in the above embodiment or ignoring the contents of A ₀ is added to the system controller 14. (ii) An unlock type sequential play execution / non-execution switch, and a register for a sequential play execution / non-execution instruction 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 a process to the system controller 14 to determine whether to execute or not execute the sequential play operation according to the contents of the memory. The former mechanically stores the sequential play execution / non-execution instruction mechanically (the flowchart is omitted).

Embodiment 3 FIG. Next, as a third embodiment, sequential play is performed only for a short-time power-off,
A function of performing an initialized operation without performing a sequential play when the power is turned on again after a long power-off will be described below. This is a function for the in-vehicle player to perform the sequential play only when the power is turned off when the engine is started or when the vehicle is stopped for a short time. FIG. 4 is a block circuit diagram showing a main part of the third embodiment having such a function, and is the same as FIG. 1 except for the periphery of the system controller 14, and the same reference numerals are the same.

In FIG. 4, reference numeral 21 denotes a resistor through which power is supplied to the semiconductor memory 18. 22 is a diode for preventing backflow, 23 is a large-capacity capacitor serving as a short-time backup power supply, 24 is a comparator, and when the power supply voltage of the semiconductor memory 18 is higher than the reference voltage of 25, A high level (shown as "H"), and a low level (shown as "L") in the opposite case,
Output to 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, but the power supply to the player is stopped or the power supply voltage is reduced. When dropped, diode 22
The operation separates the DC power supply 20 from the memory circuit. 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 drops to a certain extent. The comparator 24 detects a decrease in the power supply voltage of the semiconductor memory 18 as a reference voltage.
By performing the operation as a timer by comparing with 25, the reference voltage 25 is selected to be equal to or higher than the content retention limit voltage of the semiconductor memory 18, thereby compensating for the retention of the content of the memory. In this case, the timer (in other words, the time detecting means) may be constituted by digital detecting means such as frequency counting without being limited to the illustrated embodiment.

System Controller in Third Embodiment
FIG. 5 is a flow chart showing the process of FIG. 14, and immediately after the initialization at the time of turning on the power again, the comparator 24 is executed at (1).
Detecting the output of which is subjected to sequential play if "H", the other hand all the registers A if "L" power outage in FIG. 3 as exceeding the predetermined time ₀ to A _N,
And resetting the Ap, performs initialized player operation (when A ₀ is reset not to sequential play are as described above). 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 of the capacitor 23 is almost the same as the value immediately before the power is turned on again. I try not to.

Embodiment 4 FIG. 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 that the performance operation once initialized (for example, the performance is performed in order from the first music). Is performed, if it is within a certain period of time, a function to accept and execute a sequential play execution command input during that time is provided. Such a function is effective as a function for compensating the carelessness of the operator or a change in intention. Here, it is assumed that the player shown in FIG. 1 is provided with a sequential play switch of a mechanical lock type switch for inputting execution / non-execution of the sequential play described in the second embodiment.

FIG. 6 shows the processing of the system controller for realizing the above functions, which is a modification of the processing of FIG. 2, and the same symbols indicate the same contents.

[0045] In FIG. 6, after power is turned on again, (1) first reads the lead-in data, (2) to (5) or the last time information (the contents of A ₀₎ is reset, or effective period of time If it is determined that the information is not information, the process from (10) onwards will be performed from the first track of the disc, while
(2) to (5) When it is judged last time information and enable last time information of A ₀ is retreated in the register with A _Q becomes address (A _Q may not be non-volatile),
At (8), the state of the sequential play switch is checked.
Here, if a sequential play switch is ON (sequential play execution instruction), (12) resets the timer, is started to play by searching the reproduction position indicated by A _0, sequential switch conversely OFF (non-execution instruction ), The performance starts from the first song on the disc via (10). Here, the flag S indicates the state of the sequential play switch. When S = 0, the switch is OFF, and when S = 1, the switch is ON.

The disk first track or the play start by searching the music indicated by A ₀ (13) (14), always new track numbers (15), while the writing time information A _0, (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 (17). (20) detects the change in the state of the switch by taking the exclusive OR of the state S of the previous switch and the state S 'of the current switch, and if the state has not changed (S + S' =
0) No special processing is performed. On the other hand, if there is a change in the state of the switch, the following processing is performed. Previously sequential play execution (S = 1), to stop the sequential play when the switch is turned OFF (S '= 0) This time, the play from the first track to transfer the data of the disk the first track to the A ₀ Perform (21)-(23).

On the other hand, the sequential play has not been executed before (S = 0), and the switch is now turned ON (S ′ =
If a 1), if there is legitimate last time information saved in the A _Q in (24), performs a sequential play to return the contents of the A _Q to A ₀ in (26), whereas, (24 ) At A
_{If Q} is reset, continue playing. (16)
When it is determined that the timer time exceeds the time limit Tmax,
Thereafter, the state of the sequential switch is ignored. (27)
Subsequent processing is the same as in FIG.
In FIG. 6, the processing such as the operation input switch in FIG. 2 is omitted for the sake of explanation. In the embodiment described above, it is also conceivable to store the operation command itself when the power is stopped, in order to cope with a case where a single operation such as a cueing operation is given and the power is stopped before the operation is completed. .
Even if the compact disc standard is changed, time,
The present invention can be applied as long as information on a song number or the like is recorded on the disc.

[0048]

As described above, according to the present invention , the vehicle
Regeneration stage when power supply from DC power supply is stopped
Stores data on floors and data on playback methods
And then store it by restarting the power supply.
The data relating to the reproduction progress stage stored in the
Reproduction of reproduction means based on both raw method data
Since the operation can be determined, frequent playback
Even if the power supply is interrupted, playback continues after playback before interruption
Since the operation is performed, operability is extremely improved, it is possible to omit the labor and time of the operation, there is an effect to be those suitable for safety drive of the vehicle.

[Brief description of the 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 a part of the configuration of FIG. 1;

FIG. 4 is a block diagram showing a configuration of a main part 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 of time reading in a compact disc player.

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

[Explanation of symbols]

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

Claims (1)

(57) [Claims] Power is supplied from a DC power supply of a vehicle , and
Reproducing means for reproducing the record carrier, operation of the reproducing means
Sometimes, when the power supply to the regenerating means is stopped,
Data on the life stage and data on the reproduction method
Storage means for storing the power supply to the reproducing means.
After the stop, the power supply is performed again to the reproducing unit.
At this time, the reproduction progress stage stored in the storage means
Based on both data and playback method data,
<br><br><br><br><br><br><br><br><br><br><br> According to an embodiment, a playback device for a vehicle-mounted record carrier including a determination unit that can determine a playback operation of the playback unit.