JP4373362B2 - Optical disc reproducing method and optical disc reproducing apparatus - Google Patents

Description

  The present invention relates to an optical disc reproducing apparatus such as a CD player.

  In recent years, CD (Compact Disc) players have storage means for temporarily storing the read data in addition to the specification of reading at 1 × speed and outputting at 1 × speed during normal CD-DA (Compact Disc Digital Audio) playback. There is a specification that reads at a speed of 1 × speed or higher, writes it to a storage means, and outputs it at a 1 × speed.

  In this specification, using the fact that the speed of accumulation in the storage means is faster than the reading speed, the following control for suppressing current consumption is performed.

  Reading is stopped when the amount of data stored in the storage means approaches the storage capacity. After reading is stopped, the data accumulated in the storage means is output. Thereafter, when the remaining amount of data stored in the storage means is reduced, reading of data from the disk is resumed. By performing such data reading control, current consumption during a period in which reading is stopped can be suppressed.

  In recent years, there is a CD player having a function of reproducing compressed audio such as MP3 (MPEG Audio Layer-3) as well as CD-DA. Even when compressed audio is played back, data reading and storage and reading stop are repeated as in the case of CD-DA playback.

  FIG. 9 is a diagram showing an outline of the change over time in the amount of data stored in the storage means of a conventional CD player. In the graph shown in FIG. 9, the vertical axis represents the amount of data stored in the storage means, and the horizontal axis represents time.

  The period A is a period during which data is read from the disk and stored in the storage means, and simultaneously read from the storage means and output of sound. The period B is a period in which reading of data from the disk is stopped and data accumulated in the storage unit is consumed for reproduction. In period B, data is only output from the storage means, and the amount of accumulated data gradually decreases. When the accumulated data reaches a predetermined reference value, data reading is started again. In this way, the operation in which the period A and the period B are one cycle is repeated.

  Note that the amount of data output after decoding is the same during compressed audio playback, but the size of the data before decoding is smaller than the data size after decoding, so if the amount of data stored in the storage means is the same The consumption speed of data stored in the storage means is slower than that of CD-DA.

  As a result, the storage speed in the storage means during compressed audio playback is faster than during CD-DA playback. As a result, when the compressed audio is reproduced, the period during which the CD player stops reading data is longer than when the CD-DA is reproduced.

  FIG. 10 is a flowchart showing a read control procedure of a conventional CD player. With reference to FIG. 10, a description will be given of an optical disk read control method during compressed audio playback of a conventional CD player.

  The CD player starts reproduction upon receiving a predetermined user operation (S50). After the start, the rotation of the disk is accelerated (S51), data is read from the disk at a high speed, and accumulation in the memory as the storage means is started (S52). When the data read out is CD-DA when it is stored in the memory, it is encoded as it is or encoded into ADPCM (Adaptive Differential Pulse Code Modulation) or the like, and the read data is compressed audio such as MP3. Is once decoded into PCM (Pulse Code Modulation), encoded as it is or into ADPCM, etc., and stored in the memory.

  After starting storage in the memory, output is started while reading data stored in the memory (S53). After starting output, check if the memory is full. If it is full (y in S54), reading of data from the disk and accumulation in the memory are stopped while the output continues (S55). At this time, the disk rotation is also forcibly stopped. Or it slows down by leaving it as inertial. If it is not full (n in S54), the memory storage capacity is continuously checked until it becomes full.

  After stopping reading and storing data, the remaining amount of data stored in the memory is checked. If the remaining amount is less than the predetermined reference value (y in S56), the rotation of the disk is started again and accelerated (S51). If the remaining amount is equal to or greater than the predetermined reference value (n in S56), the remaining amount check is continued until it falls below the reference value.

  The above operation ends during an arbitrary operation due to the end of reproduction of all data on the disc or a stop command from the user. If there is another command, it operates according to it.

A technique relating to the above-described reproduction accompanied by intermittent reading of data from the disc (hereinafter referred to as “intermittent reproduction”) is also disclosed (see, for example, Patent Document 1).
JP 2000-90449 A

  However, in the conventional method, for example, when data recorded on a disc is reproduced, reading and stopping of data are always repeated alternately. That is, the acceleration of the disk rotation is always repeated, and the current consumption increases. This is because the current required to accelerate the rotation is much larger than when the disk is rotated at a constant speed. Thereby, for example, when power is supplied to the CD player by a battery, there is a problem that the operable time is shortened.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an optical disc reproducing method and an optical disc reproducing apparatus for reducing useless current consumption when reproducing data recorded on an optical disc. And

  In order to achieve the above object, an optical disc reproducing method of the present invention is an optical disc reproducing method for rotating an optical disc and reading and reproducing data recorded on the optical disc, wherein the data recorded on the optical disc is reproduced. Data is read from the optical disk while rotating the optical disk at a rotational speed less than the rotational speed at the 1 × speed according to the output speed.

  The optical disk reproduction apparatus of the present invention is an optical disk reproduction apparatus that rotates an optical disk, reads out data recorded on the optical disk, and reproduces the data, depending on the output speed of the data recorded on the optical disk. Rotation control means for rotating the optical disc at a rotational speed less than the rotational speed at double speed, and reproduction means for reading out and reproducing data from the optical disk rotating at the rotational speed.

  Thus, according to the optical disc playback method and optical disc playback apparatus of the present invention, data can be played back while rotating the optical disc at a reduced rotational speed in accordance with the output speed of the data recorded on the optical disc. . That is, acceleration is not repeated and wasteful current consumption can be reduced. Here, since the rotation speed is a speed according to the data output speed, the sound is not interrupted.

  The optical disc reproducing method of the present invention further has a first consumption current value that is a value of a consumption current in a first reproduction mode in which data is reproduced while reading data from the optical disc at a reading speed of 1 × speed or less, and is faster than 1 × speed. A second consumption current value that is a value of the consumption current in the second reproduction mode in which reproduction is performed while reading from the optical disc at a predetermined double speed is compared, and the first consumption current value is smaller than the second consumption current value. In this case, data may be read from the optical disc while the optical disc is rotated at a rotational speed less than the rotational speed at 1 × speed according to the output speed.

  The optical disc playback apparatus of the present invention further has a first consumption current value that is a current consumption value in a first playback mode in which data is played back while reading data from the optical disc at a reading speed of 1 × or less, and is faster than 1 × speed. Current measuring means for measuring a second consumption current value which is a value of a consumption current in a second reproduction mode for reproduction while reading from the optical disc at a predetermined double speed; the first consumption current value and the second consumption current value; And comparing means for determining that the first regeneration mode is executed when the first consumption current value is smaller than the second consumption current value as a result of comparison by the comparison means. The rotation control means, when it is determined by the determination means that the first reproduction mode is to be executed, at a rotation speed less than the rotation speed at 1 × speed according to the output speed. It may rotate the optical disc.

  As described above, according to the optical disc reproducing method and the optical disc reproducing apparatus of the present invention, it is possible to determine the execution of the reproducing mode with a small current consumption.

  The present invention can also be realized as a program that causes a computer to execute the optical disc reproducing method of the present invention. The program can be distributed via a recording medium such as a CD-ROM or a transmission medium such as a communication network.

  The present invention can provide an optical disc reproducing method and an optical disc reproducing apparatus for reducing useless current consumption when reproducing data recorded on an optical disc.

  According to the optical disc reproducing method and the optical disc reproducing apparatus of the present invention, when compressed audio is reproduced, reading and stopping of the disc are alternately performed, and when the current consumption is increased by repeating acceleration, 1 is set in accordance with the output rate. By reading at a constant speed of a speed less than double speed, useless current consumption can be reduced. Accordingly, for example, when power is supplied using a battery, a long operation time can be secured.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  First, a functional configuration of the CD player 30 according to the embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a functional block diagram showing a functional configuration of a CD player 30 according to an embodiment of the present invention. A CD player 30 is an example of an optical disk reproducing apparatus according to the present invention. As shown in FIG. 1, a disk rotating unit 1, a pickup 2, a focus actuator 3, a tracking actuator 4, an amplifying unit 5, an arithmetic unit 6, and a drive signal generator are prepared. Unit 7, control unit 8, data storage unit 9, and optical disk 20. The control unit 8 includes a determination unit 81 and a current measurement unit 82.

  The CD player also includes an input unit that receives commands from the user, an output unit that outputs reproduced sound, and the like. However, for clarity of the characteristics of the present invention, their illustration and description are omitted.

  The central portion of the optical disk 20 is fixed to the disk rotating unit 1. At the time of reproduction, focus servo is performed by the pickup 2, the amplification unit 5, the calculation unit 6, and the drive signal creation unit 7. Further, tracking servo is performed by the pickup 2, the amplification unit 5, the calculation unit 6, and the drive signal creation unit 7. Further, rotation servo is performed by the disk rotation unit 1, the pickup 2, the amplification unit 5, the calculation unit 6, and the drive signal creation unit 7. In the rotation servo, the calculation unit 6 reads the current rotation speed from the RF signal generated by the amplification unit 5 by adding and amplifying the signal read from the pickup 2. The drive signal is instructed to the drive signal creation unit 7 so that the rotation number becomes an assumed rotation number.

  The data storage unit 9 is a storage device for temporarily storing data read from the optical disc 20. The data storage unit 9 is realized by, for example, an SDRAM (Synchronous Dynamic Random Access Memory).

  The functions and operations of the above components are the same as those of a conventional CD player. However, the CD player 30 can reduce useless current consumption by the operations of the determination unit 81 and the current measurement unit 82 included in the control unit 8. The data storage unit 9 is an example of the first storage means in the optical disc playback method and optical disc playback apparatus of the present invention.

  The control unit 8 is a processing unit that controls the operation of each component of the CD player 30, and includes a determination unit 81 and a current measurement unit 82. The current measuring unit 82 is a processing unit that measures the current consumed by the CD player 30. Although not shown, the current measuring unit 82 is connected to the power supply unit of the CD player 30 in order to measure the consumed current. In addition, the control unit 8 has a function of controlling the operation of each component of the CD player 30, and each component operates under the control of the controller 8.

  The determination unit 81 is a processing unit that determines the reproduction mode based on the result measured by the current measurement unit 82. The reproduction mode will be described later with reference to FIG. The determination unit 81 realizes a function for determining a reproduction mode, which is included in the comparison unit and the determination unit in the optical disc reproduction apparatus of the present invention.

  Next, the operation of the CD player 30 according to the embodiment of the present invention will be described with reference to FIGS.

  FIG. 2 is a flowchart showing a procedure related to data read control of the CD player 30 according to the embodiment of the present invention.

  When receiving an instruction to reproduce the data recorded on the optical disc 20 by a predetermined operation by the user, the CD player 30 starts examining the reproduction mode (S10).

  Here, the reproduction mode is a method and procedure for reproducing data. The CD player 30 selects and executes one of the two playback modes. The two modes are an intermittent reproduction mode and a continuous reproduction mode. As described above, the intermittent reproduction mode is to perform data reproduction while intermittently reading data from the optical disk. Continuous reproduction is to reproduce data while rotating the optical disc 20 at a rotational speed of 1 × speed or less and continuously reading data. Note that “rotational speed at n-times speed” (n is an integer equal to or greater than 1) refers to a rotational speed corresponding to an n-times speed reading speed.

  The continuous playback mode is an example of the first playback mode in the optical disc playback method and optical disc playback device of the present invention, and the intermittent playback mode is an example of the second playback mode in the optical disc playback method and optical disc playback device of the present invention.

  The selection of the reproduction mode described above is executed by the current measuring unit 82 and the determining unit 81. Hereinafter, the function and operation of the current measurement unit 82 and the determination unit 81 will be mainly described.

  After the examination of the reproduction mode is started, the rotation of the optical disc 20 is accelerated from the state where the optical disc 20 is stationary (S11). When it is accelerated to the normal rotational speed, which is the normal rotational speed, the reading and outputting of data from the optical disk is started while rotating at the normal speed (S12). The current measuring unit 82 measures the current consumption of the entire CD player 30 in the 1 × speed playback state (S13), and notifies the determination unit 81 of the measurement result. The 1 × speed reproduction state is a state where data is being reproduced while continuously reading data at 1 × speed. That is, it is a continuous reproduction state.

  After the notification, the CD player 30 starts acceleration of the rotation of the optical disc 20 again (S14). The current measurement unit 82 measures the current consumption of the entire CD player 30 during acceleration (S15), and notifies the determination unit 81 of the measurement result.

  After the acceleration, data is read from the disk with the rotation speed of the optical disk 20 at a predetermined high speed. The read data is written in the data storage unit 9 (S16). That is, data accumulation is started.

  Here, when data is accumulated in the data storage unit 9, the following processing is performed. When the read data is a CD-DA, it is encoded as it is or in ADPCM and stored in the data storage unit 9. When the read data is compressed audio such as MP3, it is once decoded into PCM, and directly or encoded into ADPCM or the like and stored in the data storage unit 9. Simultaneously with the accumulation, the data accumulated in the data storage unit 9 is output for data reproduction.

  The current measurement unit 82 measures the current consumption of the entire CD player 30 in the above state, that is, the reproduction state at high speed (S17), and notifies the determination unit 81 of the measurement result.

  After the notification, it is checked whether the data storage unit 9 is full. That is, it is checked whether or not the data read from the optical disk 20 can be further stored in the data storage unit 9. If not full (n in S18), the check is repeated. When the data storage unit 9 is full (y in S18), reading from the disk and accumulation in the data storage unit 9 are stopped (S19). At this time, the rotation of the optical disk 20 is also forcibly stopped. Alternatively, the rotation speed is decelerated while being left rotating with inertia. Note that the output of data from the data storage unit 9 is continued. The state in which the motor shaft rotates due to inertia is also referred to as “axial loss”, and “intermittent regeneration” is also referred to as “axial loss regeneration”.

  The current measurement unit 82 measures the current consumption of the entire CD player 30 in a state where reading from the optical disc 20 is stopped (S20), and notifies the determination unit 81 of the measurement result. Here, after the CD player 30 starts accelerating the rotation speed to the high speed (S14), the data reading is continued until the next data reading is resumed while the reading from the optical disc 20 is stopped (S19). The operation of continuing to output data from the storage unit 9 is one cycle in intermittent reproduction.

  With the operation so far, the power consumption in each state of the CD player 30 is measured and held in the determination unit 81. Each state of the CD player 30 includes reproduction at 1 × speed (S12), acceleration to high speed (S14), reproduction at high speed (S16), and stop of reading from the disc (S19). State.

  FIG. 3 is a diagram illustrating an example of measurement results of current consumption in each state of the CD player 30. In the graph shown in FIG. 3, the vertical axis represents current consumption and the horizontal axis represents time.

  In the graph shown in FIG. 3, T4 is a period during reproduction at 1 × speed, T1 is a period during acceleration to high speed, T2 is a period during reproduction at high speed, and T3 is This is a period during which reading from the disk is stopped. The current value in each period is I44, I41, I42, and I43. As shown in the graph of FIG. 3, it can be seen that the current consumption is the highest during acceleration to high speed.

  The determination unit 81 calculates the average current consumption during the three periods T1, T2, and T3 according to (Equation 1) shown below (S21). Here, the three periods are periods in which one cycle of intermittent reproduction is performed. That is, the determination unit 81 calculates Ia as the average current consumption in the intermittent playback mode of the CD player 30.

  Ia = (I41 × T1 + I42 × T2 + I43 × T3) / (T1 + T2 + T3) (Formula 1)

  Further, the period T4 is a state in which data is reproduced while continuously reading data at 1 × speed. That is, I44 is the current consumption in the continuous playback mode.

  The determination unit 81 compares the average consumption current Ia in the intermittent reproduction mode with the consumption current I44 in the continuous reproduction mode, and determines whether the reproduction mode of the continuous reproduction mode or the intermittent reproduction mode should be executed.

  Specifically, it is determined that the playback mode with the smaller value should be executed. Thereby, for example, when the CD player 30 is driven by battery power, the battery life is extended.

  When I44 is smaller than Ia, that is, when the current consumption during continuous playback is smaller than the average current consumption during intermittent playback (y in S22), the CD player 30 enters the continuous playback mode (S30). Transition. Further, when Ia is smaller than I44, that is, when the average consumption current during intermittent reproduction is smaller than the consumption current during continuous reproduction (n in S22), the CD player 30 uses the intermittent reproduction mode (S30). )

  Note that the processing shown in the operation flow shown in FIG. 2 ends during an arbitrary operation due to the end of reproduction of all data on the optical disc 20 or a stop command from the user. If there is another command, it operates according to it.

  FIG. 4 is a flowchart showing the operation of the CD player 30 in the continuous playback mode. The operation when the CD player 30 performs continuous playback will be described with reference to FIG. In addition, the operation | movement at the time of performing intermittent reproduction | regeneration is later mentioned using FIG.

  The CD player 30 starts continuous reproduction according to the determination of the determination unit 81 (S30). After the start, the determination unit 81 determines whether the data being reproduced is compressed audio such as MP3. If it is not compressed audio (n in S31), that is, if it is a CD-DA, the CD player 30 reads and reproduces data while rotating the optical disc 20 at a single-speed rotation speed.

  If it is compressed audio (y in S31), the determining unit 81 detects the bit rate of the compressed audio (S32). Further, based on the detected bit rate, the rotation speed is determined (S33). Specifically, the ratio between the bit rate of the detected compressed audio and the bit rate of the CD-DA is obtained, and the rotation speed is determined according to the ratio.

  For example, it is assumed that the bit rate of compressed audio is 128 Kbps. The bit rate of CD-DA is 1.411 Mbps, and this value is the output speed of 1 × speed. Therefore, the ratio between the output speed of compressed audio and the output speed of 1 × speed is 1: 11.0234375.

  Therefore, ideally, the rotational speed should be set to be 1 / 11.0234375 of 1 × speed. In this case, the data recorded on the optical disc 20 can be reproduced without interruption, and the data storage unit 9 stores the data at the same speed and consumes the data.

  However, the above rotation speed may be set to a speed slower than the ideal rotation speed, for example, 1/12 of the 1 × speed. In this case, when the remaining amount of data stored in the data storage unit 9 is reduced to a predetermined value, control is performed to increase the rotational speed to 1/11 of 1 × speed.

  Further, the rotation speed may be set to 1/11 of the 1 × speed. In this case, the data storage unit 9 stores data at a speed slightly higher than the data consumption speed, so that the data storage amount gradually increases and overflow occurs. Therefore, when an overflow occurs, the reading and storage of data from the disk are temporarily stopped (set to PAUSE state) while maintaining the rotation speed at 1/11 of the 1 × speed, or the rotation speed is temporarily set to 1 × speed. When the remaining amount of accumulated data is reduced to a predetermined value, the rotational speed is controlled to return to 1/11 of the 1 × speed again.

  As described above, the rotation speed is reduced (S34). At the reduced rotational speed, reading, decoding of the compressed audio, and output of the decoded data are executed simultaneously (S35).

  In practice, data is stored in the data storage unit 9. However, since the data amount per unit time of data output from the data storage unit 9 for data reproduction and data reproduction for the data reproduction is the same, apparently the amount of data stored in the data storage unit 9 Is constant.

  Note that the processing shown in the operation flow shown in FIG. 4 ends during an arbitrary operation due to the end of reproduction of all data on the optical disc 20 or a stop command from the user. If there is another command, it operates according to it.

  FIG. 5 is a diagram illustrating an outline of a temporal change in the amount of data stored in the data storage unit 9 in the continuous reproduction mode. In the graph shown in FIG. 5, the vertical axis represents the amount of accumulated data, and the horizontal axis represents time.

  The period A is a period during which data is read from the disk and stored in the data storage unit 9. The period B is a period in which reading of data from the disk is stopped and data is not accumulated in the data storage unit 9 and only the accumulated data is output.

  Note that data accumulated in the data storage unit 9 continues to be output even after the period B has elapsed. However, the amount of data stored in the data storage unit 9 per unit time is equal to the amount of consumed data. Therefore, as shown in the graph of FIG. 5, the amount of data accumulated in the data storage unit 9 is constant.

  As described above, in the CD player 30, the determination unit 81 calculates the average current consumption during intermittent reproduction based on the result measured by the current measurement unit 82. The determination unit 81 further compares the current consumption during continuous reproduction with the average current consumption during intermittent reproduction. As a result of the comparison, when the current consumption during continuous reproduction is smaller than the average current consumption during intermittent reproduction, it is determined that the continuous reproduction mode is to be entered.

  In addition, the determination unit 81 determines whether or not the data to be reproduced is compressed audio in the continuous reproduction mode. In the case of compressed audio, the bit rate is detected, and the rotational speed corresponding to the detection result is calculated and determined. As a result, a rotational speed lower than 1 × speed is determined.

  When the average consumption current during intermittent reproduction is smaller than the consumption current during continuous reproduction, it is determined that the intermittent reproduction mode is to be entered.

  FIG. 6 is a flowchart showing the operation of the CD player 30 in the intermittent playback mode. The operation when the CD player 30 performs intermittent reproduction will be described with reference to FIG.

  The CD player 30 checks the remaining amount of data in the data storage unit 9 (S41). If the remaining amount is equal to or less than the predetermined reference value (y in S41), acceleration of rotation of the optical disk 20 that has been left forcibly stopped or rotated due to inertia is started (S42). If the remaining amount is greater than the predetermined reference value (y in S41), the check is repeated until the remaining amount is equal to or less than the reference value.

  After the acceleration, data is read from the disk with the rotation speed of the optical disk 20 at a predetermined high speed. The read data is written in the data storage unit 9 (S43). That is, data accumulation is started.

  Here, when data is accumulated in the data storage unit 9, processing such as encoding is performed as described above. That is, when the read data is CD-DA, it is encoded as it is or ADPCM and is stored in the data storage unit 9. When the read data is compressed audio such as MP3, it is once decoded into PCM, and directly or encoded into ADPCM or the like and stored in the data storage unit 9. Simultaneously with the accumulation, the data accumulated in the data storage unit 9 is output for data reproduction.

  After accumulation of data in the data storage unit 9 and output of data from the data storage unit 9 are started, it is checked whether the data storage unit 9 is full. If not full (n in S44), repeated checks are performed. When the data storage unit 9 is full (y in S44), reading from the disk and accumulation in the data storage unit 9 are stopped. At this time, the rotation of the optical disk 20 is also forcibly stopped. Alternatively, the rotation speed is decelerated by being left rotating with inertia. The output of data from the data storage unit 9 is continued (S45).

  Thereafter, the process from checking the remaining amount of data in the data storage unit 9 (S41) to reading data (S45) is repeated.

  Note that the processing shown in the operation flow shown in FIG. 6 ends during an arbitrary operation due to the end of reproduction of all data on the optical disc 20 or a stop command from the user. If there is another command, it operates according to it.

  As described above, when the average consumption current during intermittent reproduction is smaller than the consumption current during continuous reproduction, the CD player 30 shifts to the intermittent reproduction mode and performs the above operation.

  As described with reference to FIGS. 4 and 6, the CD player 30 can reproduce data recorded on the optical disc 20 in two reproduction modes, a continuous reproduction mode and an intermittent reproduction mode. Measure current consumption. Furthermore, based on the measurement result, a playback mode with less current consumption is selected and executed.

  When the continuous playback mode is executed, if the data recorded on the optical disc 20 is compressed audio such as MP3, the bit rate of the compressed audio is detected. Further, based on the detection result, the rotational speed of the optical disc 20 is reduced to 1 × speed or less. By decelerating to 1x speed or less, current consumption can be reduced at least as compared with the state of rotating at 1x speed.

  With the above operation, the CD player 30 can suppress useless current consumption when reproducing data recorded on the optical disc 20.

  In the above-described embodiment, when the CD player 30 performs continuous reproduction, data is output from the data storage unit 9 while accumulating data in the data storage unit 9. However, data need not be stored in the data storage unit 9 after shifting to the continuous playback mode.

  That is, the data read from the optical disk 20 may be output as it is without being stored in the data storage unit 9 after performing necessary processing such as encoding and decoding.

  FIG. 7 is a diagram showing an outline of a temporal change in the amount of accumulated data in the storage unit 9 when data is not accumulated in the data storage unit 9 after transition to the continuous reproduction mode.

  In the graph of FIG. 7, period A and period B are periods in which data reading and accumulation at the time of studying the reproduction mode, data reading stop, and output from the data storage unit 9 are performed.

  The CD player shifts to the continuous playback mode after the lapse of the period A and before the lapse of the period B, but the accumulated data amount becomes zero unlike the time change of the accumulated data amount shown in FIG. This is because data is not accumulated in the data storage unit 9. By doing so, it is possible to reduce current consumption required to write data to the data storage unit 9.

  In addition, when the playback mode to be executed is determined, the determination unit 81 determines based on the measurement value of the current measurement unit 82. However, the playback mode to be executed may be determined based on the past results of current consumption.

  For example, when playing back compressed audio in the continuous playback mode, the bit rate of the compressed audio and the current consumption during playback are stored in association with each other as performance data. Further, after that, when determining the playback mode to be executed, the playback mode to be executed may be determined using the stored record data.

  FIG. 8 is a functional block diagram showing a functional configuration of the CD player 30 including a result storage unit for storing result data.

  The result storage unit 10 illustrated in FIG. 8 is a storage device that stores the results measured by the current measurement unit 82. The performance storage unit 10 is realized by a non-volatile memory such as a flash memory, for example. Note that the components other than the performance storage unit 10 are the same as those of the CD player 30 shown in FIG.

  The record storage unit 10 is an example of the second storage means in the optical disc playback method and optical disc playback apparatus of the present invention. In addition, the function of extracting information from the second storage means included in the extraction means in the optical disc playback apparatus of the present invention is realized by the determination unit 81.

  In the CD player 30 shown in FIG. 8, the playback mode can be determined by executing the following operations.

  When reproducing the data recorded on the optical disc 20, it is determined whether or not the data read from the optical disc 20 is compressed audio.

  In the case of compressed audio, the determination unit 81 detects the bit rate. After the detection, the past consumption current associated with the detected bit rate is extracted from the record storage unit 10.

  In addition, an operation for calculating the average consumption current in the intermittent reproduction mode, a current measurement, and an average consumption current calculation (corresponding to S14 to S21 in FIG. 2) are performed.

  The determination unit 81 compares the actual value of the current consumption in the continuous reproduction mode extracted from the result storage unit 10 with the calculated average current consumption in the intermittent reproduction mode, and executes the reproduction mode with a small current consumption. It is determined that the playback mode should be used.

  In this way, for example, when playing back compressed audio, there is no need to measure current consumption in the continuous playback mode and perform an operation for measurement.

  When there are a plurality of pieces of record data having the same bit rate in the record storage unit 10, the average of the plurality of record data may be calculated and used as the current consumption in the continuous playback mode of the compressed audio having the bit rate. Further, the latest result data may be adopted as the current consumption in the continuous playback mode of the compressed audio having the bit rate.

  Further, the actual value of the current consumption may be stored in the actual result storage unit 10 in association with the rotation speed instead of the bit rate. In this case, the rotational speed may be calculated after the bit rate is detected, and the determination unit 81 may extract the actual value of the current consumption corresponding to the calculated rotational speed from the actual storage unit 10.

  As described above, when the bit rate detection and the rotation speed calculation are performed at the start of data reproduction, the bit rate detection and the rotation speed calculation are performed in the operation in the continuous reproduction mode shown in FIG. There is no need to do it.

  As described above, the CD player 30 may determine the playback mode to be executed based on the actual value as well as the actual value of the current consumption. Thereby, for example, when designing the CD player 30, it is possible to design the CD player 30 by selecting an optimum reproduction mode determination method for reducing useless current consumption.

  In the calculation of the rotation speed, the ratio between the bit rate of the compressed audio and the output speed of 1 × speed was calculated, and the calculated ratio was used as it was for the calculation of the rotation speed. However, the calculated ratio may not be used as it is for calculating the rotation speed.

  For example, the data may be reproduced while being stored in the data storage unit 9 by setting the rotation speed higher than the value when the calculated ratio is used.

  The data stored in the data storage unit 9 is consumed during so-called “sound skipping” when the pickup 2 cannot read data normally due to, for example, an impact given to the CD player. That is, storing a large amount of data in the data storage unit 9 is one of effective means for preventing sound skipping.

  Therefore, as described above, by reducing the rotation speed within a range where data can be accumulated in the data storage unit 9, it is possible to reduce current consumption while preventing sound skipping.

  The read control procedure of the CD player according to the present invention is such that, when compressed audio is reproduced, reading and stopping of the disc are alternately performed, and when the current consumption increases by repeating acceleration, the speed is less than 1 × in accordance with the output rate. Reading at a constant speed rotation reduces the wasteful current consumption. For example, when power is supplied using a battery, it is useful because a long operation time can be secured. Therefore, it is particularly useful for a portable CD player driven by a battery.

It is a functional block diagram which shows the functional structure of the CD player of embodiment of this invention. It is a flowchart which shows the procedure regarding the read-out control of the data of a CD player. It is a figure which shows the example of the measurement result of the consumption current in each state of CD player. It is a flowchart which shows operation | movement of CD player in continuous reproduction mode. It is a figure which shows the outline | summary of the time change of the accumulation | storage data amount of a data storage part in continuous reproduction mode. It is a flowchart which shows operation | movement of the CD player in intermittent reproduction mode. It is a figure which shows the outline | summary of the time change of the accumulation | storage data amount of the memory | storage part 9 when not accumulating data in the data memory | storage part 9 after transfer to continuous reproduction mode. It is a functional block diagram which shows the functional structure of CD player provided with the performance memory | storage part for memorize | stores performance data. It is a figure which shows the outline | summary of the time change of the data amount accumulate | stored in the memory | storage means of the conventional CD player. It is a flowchart which shows the read-out control procedure of the conventional CD player.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Disc rotation part 2 Pickup 3 Focus actuator 4 Tracking actuator 5 Amplification part 6 Calculation part 7 Drive signal preparation part 8 Control part 9 Data storage part 10 Results storage part 20 Optical disk 30 CD player 81 Judgment part 82 Current measurement part

Claims (11)

An optical disc playback method performed by an optical disc playback apparatus that rotates an optical disc and reads and plays back data recorded on the optical disc,
(A) a first consumption current value that is an average value of consumption current in a continuous reproduction mode in which data is reproduced while reading data from the optical disc at a rotation speed less than the rotation speed at 1 × speed; and (b) a predetermined speed that is higher than the 1 × speed. A second consumption current value that is an average value of the consumption current in the intermittent reproduction mode for reproducing the accumulated data while repeating the reading and accumulation of the data from the optical disc at the double speed and the stop of the reading and accumulation. Compare and
As a result of the comparison, when the first consumption current value is smaller than the second consumption current value , the rotation speed is less than the rotation speed at 1 × speed according to the output speed of the data recorded on the optical disc. An optical disc reproducing method for reading data from the optical disc while rotating the optical disc. When the first current consumption value is smaller than the second current consumption value,
When the output speed of the data recorded on the optical disc is less than the 1 × read speed, the optical disc is rotated while rotating the optical disc at a rotational speed less than the 1 × rotational speed in accordance with the output speed. Read data
The optical disk reproducing method according to claim 1 . Further, (1) the value of the current consumption during acceleration from the rotational speed at the 1 × speed to the high double speed rotational speed that is the rotational speed at the predetermined double speed and reading and reproducing data from the optical disc;
(2) Consumption when reading data from the optical disk rotating at the high-speed rotation speed and storing it in the first storage means until there is no free space in the storage area, and reading and reproducing data from the first storage means Current value, and
(3) The first storage means until the free capacity of the storage area of the first storage means runs out, the drive of the rotation of the optical disk is stopped, and the free capacity of the storage area of the first storage means reaches a predetermined value. Measure the current consumption when reading and playing data from
The second consumption current is calculated by calculating an average value of the three measured current consumption values.
The optical disk reproducing method according to claim 1 . Further, an average value of current consumption when reading and reproducing data from the optical disk while rotating the optical disk at a rotational speed less than the rotational speed at 1 × speed according to the output speed, and the output speed or the rotational speed Are stored in the second storage means as performance information in association with each other,
When data is read from the optical disk after the record information is stored in the second storage means, the average of the current consumption corresponding to the output speed of the data read from the optical disk or the rotation speed corresponding to the output speed A value is extracted from the performance information stored in the second storage means;
In place of the first consumption current value, the average value of the consumption current extracted from the record information is compared with the second consumption current for the optical disc ,
When the average value of the consumption current extracted from the record information is smaller than the second consumption current value, the optical disc is rotated at a rotation speed less than the rotation speed at 1 × speed according to the output speed. While reading data from the optical disc
The optical disk reproducing method according to claim 1 . Further, as a result of the comparison, when the first consumption current value is smaller than the second consumption current value, the data read from the optical disc is stored in the first storage means, and the first storage at the time of reproduction is stored. Read data from the means,
After there is no more free space in the storage area of the first storage means,
The optical disk reproducing method according to claim 1, wherein data is read from the optical disk while the optical disk is rotated at a rotation speed less than a rotation speed at 1 × speed according to an output speed of data recorded on the optical disk. Data recorded on the optical disc is an audio data compressed, according to any one of the output speed of the compressed audio data according to claim 1 which is a rate of less than read 1x speed 5 Optical disc playback method. An optical disk playback device for rotating an optical disk and reading and playing back data recorded on the optical disk,
(A) a first consumption current value that is an average value of consumption current in a continuous reproduction mode in which data is reproduced while reading data from the optical disc at a rotation speed less than the rotation speed at 1 × speed; and (b) a predetermined speed that is higher than the 1 × speed. Measures a second consumption current value that is a current consumption value in an intermittent reproduction mode in which the accumulated data is reproduced while repeating reading and accumulation of data from the optical disc at a double speed and stopping the reading and accumulation. Current measuring means for
Comparing means for comparing the first consumption current value and the second consumption current value;
A determination unit that determines to execute the first regeneration mode when the first consumption current value is smaller than the second consumption current value as a result of the comparison by the comparison unit;
When the determination means determines that the first reproduction mode is to be executed, a rotation control means for rotating the optical disc at a rotation speed less than the rotation speed at 1 × speed according to the output speed of the data recorded on the optical disk. When,
An optical disc reproducing apparatus comprising: reproducing means for reading out and reproducing data from the optical disc rotating at the rotational speed. The rotation control means is judged by the judging means to execute the first reproduction mode, and further when the output speed of the data recorded on the optical disc is judged to be a speed less than the 1 × read speed. The optical disc is rotated at a rotational speed lower than the rotational speed at 1 × speed according to the output speed.
The optical disk reproducing apparatus according to claim 7 . The current measuring means (1) from a single-speed rotational speed that is a rotational speed corresponding to reading of data at 1 × speed to a high-speed rotational speed that is a rotational speed corresponding to reading of data at the predetermined double speed. Value of current consumption during acceleration of
(2) When reading data from the optical disk rotating at the high-speed rotation speed and storing it in the first storage means until there is no free space in the storage area, and when reading and reproducing data from the first storage means Current consumption, and
(3) The first storage until the free space in the storage area of the first storage means runs out, the rotation of the optical disk is stopped, and the free space in the storage area of the first storage means reaches a predetermined value. Measure the three current consumption values of the current consumption when reading and reproducing data from the means,
The comparison unit compares the average value of the three consumption currents, which is the second consumption current value, with the first consumption current value.
The optical disk reproducing apparatus according to claim 7 . Furthermore, the average value and the output speed or the rotational speed of the current consumption upon reading and reproducing data from the optical disk while rotating the optical disk at a rotational speed less than the rotational speed in the 1 × speed in response to the output speed And a second storage means for storing the result information in association with each other,
When the data is read from the optical disk after the record information is stored in the second storage unit, the current consumption corresponding to the output speed of the data read from the optical disk or the rotation speed corresponding to the output speed is Extraction means for extracting an average value from the performance information stored in the second storage means,
The comparison means, instead of the first consumption current value, compares the average value of the consumption current extracted from the performance information and the second consumption current,
The determination unit determines to execute the continuous reproduction mode when the average value of the consumption current extracted from the performance information is smaller than the second consumption current value.
The optical disk reproducing apparatus according to claim 7 . A first storage means for storing data read from the optical disc;
Free space detecting means for detecting the capacity of the free area of the storage area of the first storage means,
As a result of the comparison, when the first consumption current value is smaller than the second consumption current value,
The reproduction means reads out and reproduces data from the first storage means,
The rotation control unit rotates the optical disc at a rotation speed less than the rotation speed at 1 × speed according to the output speed after the capacity detected by the free space detection means reaches a predetermined value.
The optical disk reproducing apparatus according to claim 7 .

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