JP4054654B2 - Recording medium playback device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording medium playback apparatus for playing back information signals such as audio / music data recorded on a recording medium.
[0002]
[Prior art]
Hereinafter, a conventional recording medium playback device will be described by taking a mini-disc playback device (hereinafter referred to as “MD playback device”) as an example.
[0003]
The MD playback device is a digital audio device that plays back information signals such as voice / music data digitally recorded on a mini-disc (hereinafter referred to as “disc”).
[0004]
The information signal digitally recorded on the disc is subjected to time-axis compression for recording only the change in data between frames, and the MD playback device extends the information signal read from the disc after time-axis expansion, The original voice / music data is reproduced by digital / analog conversion.
[0005]
In recent MD reproducing apparatuses, after the information signal read from the disk is expanded in time, digital signal processing is performed in a digital signal processor circuit (hereinafter referred to as “DSP circuit”), and low frequency components of audio / music data are obtained. With a DSP function that can be used to boost the sound or divide the frequency band into several categories for each genre such as J-POP / JAZZ, and digitally process the information signal for each frequency to make the sound the user likes There is also a device.
[0006]
Such a conventional MD reproducing apparatus with a DSP circuit is simply shown in a block diagram as shown in FIG.
[0007]
The RF signal read from the disk 17 through the pickup 18 is amplified by the RF amplifier 19 and input to the decoder / servo LSI 20.
[0008]
The decoder / servo LSI 20 performs processing such as time-expanding the signal or generating a servo signal for controlling the pickup 18.
[0009]
The LSI (hereinafter referred to as “DSP LSI”) 21 having the DSP circuit is a circuit different from the decoder / servo LSI 20, and an LSI that performs digital signal processing is often used.
[0010]
The DSP LSI 21 receives four signals BCLK, LRCLK, DATA, and MCLK generated in the decoder / servo LSI 20. BCLK, LRCLK, and DATA are digital audio signals, and MCLK is a clock for operating the DSP LSI 21. BCLK is a clock for transmitting and receiving DATA, and LRCLK is a signal for indicating whether DATA is Lch or Rch, and is H output in the case of Lch DATA and L output in the case of Rch DATA.
[0011]
When the DSP LSI 21 receives these four signals, it synchronizes with the PLL circuit existing in the LSI. Then, the voice / music data is processed with a signal of the same time so as to produce an acoustic effect, the processed digital audio signal is returned to the decoder / servo LSI 20 again, and the D / A converter circuit in the LSI The analog signal is converted and output to the amplifier circuit 22. Finally, it is output to the headphones 25.
[0012]
In the MD reproduction apparatus with a DSP circuit, a switch 24 for determining whether or not to enable the DSP function is provided, and monitoring is performed by a system controller microcomputer (hereinafter referred to as “system controller”) 23. The system controller 23 also performs various controls on the decoder / servo LSI 20 and the DSP LSI 21.
[0013]
In such a recording medium reproducing apparatus with a DSP circuit, the DSP LSI supplies an operation clock from its own oscillation circuit to the digital-analog conversion circuit only while reproducing music data, Some have reduced power consumption without operating an analog conversion circuit (see Patent Document 1).
[0014]
[Patent Document 1]
JP2001-142474 (0127 stage)
[0015]
[Problems to be solved by the invention]
In the above-mentioned Patent Document 1, the power consumption is reduced by disabling the circuit during non-reproduction. However, as described below, the present invention reproduces not only non-reproduction but also a recording medium with a DSP circuit. Taking advantage of the characteristics of the device, the power corresponding to the playback mode is taken into consideration at the time of playback, and further power saving is attempted.
[0016]
In a conventional MD playback device with a DSP circuit, when the DSP function is turned ON during playback, the operation of the PLL circuit in the DSP LSI 21 is between the two LSIs of the decoder / servo LSI 20 and the DSP LSI 21 as described above. The digital audio signals are exchanged in accordance with the above, but even when the DSP function is turned off at the time of reproduction, the digital audio signals are sent to the DSP LSI 21 and are synchronized and input by the PLL circuit. The digital audio signal is output from the output terminal without being processed.
[0017]
This is because when a signal is transmitted directly from the audio expansion circuit to the D / A converter, both the audio expansion circuit and the power supply voltage from the DSP circuit are input, resulting in data collision and data error. This is because it may occur.
[0018]
Therefore, even when the DSP function is turned off, power is consumed by the DSP circuit or PLL circuit in the DSP LSI 21.
[0019]
A portable MD playback device that is easy to carry uses a rechargeable battery, a dry battery, or the like as its power source.
[0020]
In view of the above problems, the present invention is a recording medium reproducing apparatus, particularly a portable recording medium reproducing apparatus that is easy to carry, and is capable of reliably suppressing power consumption even when the DSP function is turned off. An object is to provide a medium reproducing apparatus.
[0021]
[Means for Solving the Problems]
In order to achieve the above object, a storage medium playback apparatus according to the present invention comprises the following arrangement.
[0022]
(1) Reading means for reading compressed information recorded on a recording medium, extension means for extending a signal read by the reading means, and processing so as to give an acoustic effect to the signal extended by the extension means Processing means, signal conversion means for converting a signal processed by the processing means or a direct signal extended by the extension means without going through the processing means into an analog signal, and whether or not processing is performed by the processing means A machining switching means for switching between them, and when the machining switching means is set so as not to perform machining by the machining means, the output portion of the machining means is set to high impedance and other than the output portion of the machining means It is characterized in that the operation of is made non-operation.
[0023]
In this configuration, in the case where the processing switching means is set so as not to perform processing by the processing means, power is saved by disabling operations other than the output unit of the processing means, and the processing Since the output part of the means has a high impedance, it is possible to prevent an abnormal current from being output.
[0024]
(2) In the recording medium reproducing apparatus according to claim 1, the processing means includes a PLL circuit that synchronizes a plurality of signals, and a digital signal processor circuit that performs digital signal processing on the signals synchronized by the PLL circuit And an output section constituted by a switching circuit for switching whether to output the processed signal or to completely cut off the current as high impedance.
[0025]
In this configuration, similarly to the first aspect, it is possible to save power by setting the output unit to high impedance and inactivating the PLL circuit and the digital analog processor circuit.
[0026]
(3) The recording medium reproducing apparatus according to claim 1 or 2, wherein the signal decompressed by the decompressing means is directly output to the signal converting means.
[0027]
In this configuration, since the output of an abnormal current or the like is prevented in the configuration of claim 1, when the processing switching unit is set so as not to perform processing by the processing unit, the expansion is performed. By directly outputting the signal expanded by the means to the signal conversion means, the circuits related to the processing means other than the expansion means and the signal conversion means are stopped, and the power can be saved.
[0028]
(4) The recording medium reproducing apparatus according to any one of claims 1 to 3, further comprising: an input / output switching unit that switches whether or not a signal is input from the processing unit to the signal conversion unit; When setting the machining switching means so as not to perform machining, the input port of the input / output switching means connected to the output part of the machining means is converted to an output port, and the output part of the machining means is set to high impedance. It is characterized by setting.
[0029]
In this configuration, when setting the processing switching means so as not to perform the processing by the processing means, the input port of the input / output switching means connected to the output portion of the processing means is converted to an output port, By setting the output part of the processing means to high impedance, it is possible to surely shift to the power saving mode.
[0030]
(5) In the recording medium reproducing apparatus according to any one of claims 1 to 4, when the processing switching means is set so as not to perform processing by the processing means, initial setting is performed so that processing is performed by the processing means. The recording medium reproducing apparatus is set so as not to be processed by the processing means after performing the above.
[0031]
In this configuration, when setting the processing switching means so as not to perform processing by the processing means, after performing an initial setting to perform processing by the processing means, the processing means does not perform processing. By performing the setting, it is possible to reliably shift to the power saving mode.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a storage medium playback apparatus according to the present invention will be described below with reference to FIG. 1, taking a portable MD playback apparatus with a DSP circuit as an example.
[0033]
FIG. 1 is a block diagram showing a schematic configuration of an MD playback apparatus with a DSP circuit.
[0034]
The MD playback apparatus according to the present embodiment is provided with a DSP function that enhances the sense of presence of sound, and is provided with a switch (hereinafter referred to as “DSP SW”) 15 for switching the DSP function ON and OFF so that the reproduced sound is full of presence. Or not.
[0035]
The disc 1 has concentric or spiral tracks, and information signals such as voice / music data are digitally recorded along the tracks.
[0036]
The information signal digitally recorded on the disc 1 is subjected to time axis compression. In addition to the main information such as voice / music data, the disc 1 also records U-TOC information including a disc title name, each track title name, address information of a memory storing the voice / music data, and the like. ing.
[0037]
When reproducing the information signal recorded on the disk 1, the disk 1 is rotated at a constant linear velocity or a constant angular velocity by the spindle motor 2, and at the same time, the pickup 3 is step-driven in the radial direction of the disk 1 by the feed motor 4. Then, the information signal is read by irradiating a laser beam from the pickup 3 positioned on a predetermined track toward the track, and detecting the intensity change of the reflected light again with the pickup 3.
[0038]
The drive control of the spindle motor 2, the pickup 3, and the feed motor 4 is performed by a driver circuit 5.
[0039]
The pickup 3 sends the information signal read from the disk 1 to the RF amplifier 6.
[0040]
The RF amplifier 6 amplifies the information signal and outputs the amplified information signal to an LSI (hereinafter referred to as “decoder LSI”) 7 having a decoder / signal processing circuit, and at the same time, a focus error signal based on the information signal. And a servo control signal such as a tracking servo signal are generated and sent to the decoder LSI 7.
[0041]
Here, the decoder LSI 7 includes a servo circuit 7a, a signal processing circuit 7b, a shock proof memory controller (hereinafter referred to as “memory controller”) 7c, an audio decompression circuit 7d, a digital audio interface circuit 7e, a D / A converter 7f, an input / output The switching circuit 7g is used.
[0042]
The servo control signal is received by the servo circuit 7a, and the servo circuit controls the driver circuit 5 according to the servo control signal, the address signal from the signal processing circuit 7b, and the control signal from the system controller 11, Servo control of various operations such as focusing, tracking, and disk spinning is performed.
[0043]
The information signal amplified by the RF amplifier 6 is received by a signal processing circuit 7b and subjected to processing such as extraction of an address signal, demodulation of a main signal, and error correction. Thereafter, the processed information signal is sent to the memory controller 7c.
[0044]
The memory controller 7c is means for controlling the writing and reading of information to and from the shock proof memory 8, and the information signal from the signal processing circuit 7b is once written into the shock proof memory 8.
[0045]
Here, the write rate when the memory controller 7c writes to the shock proof memory 8 is 1.4 Mbit / sec, and the read rate is 0.3 Mbit / sec. Here, a difference in processing speed of 1.1 Mbit / sec occurs, and the information signal before the time-axis compression is accumulated is stored in the shockproof memory 8 due to the difference in processing speed. As a result, even when the MD reproducing apparatus receives a shock from the outside and the reading position of the disc 1 by the pickup is shifted, the time until the pickup can read correctly can be absorbed.
[0046]
Further, the U-TOC information read from the disk 1 is also stored in the shock proof memory 8, and for example, the start position, end position or time information of each song recorded on the disk 1 is obtained. Can do.
[0047]
Then, the memory controller 7c sends the information signal read from the shock proof memory 8 to the audio decompression circuit 7d.
[0048]
The voice decompression circuit 7d decompresses the information signal input from the memory controller 7c by decompressing it in accordance with a predetermined format.
[0049]
Since the processing of the information signal after this differs depending on whether the DSP SW 15 is ON (DSP function ON) or OFF (DSP function OFF), a diagram showing various setting procedures when the DSP function is ON and OFF The description will be continued with reference to the flowchart of FIG.
[0050]
The DSP SW 15 is connected to the system controller 11, and the system controller 11 monitors the state of this switch. Here, whether the DSP SW 15 is ON or OFF is detected (step m1).
[0051]
When the DSP SW 15 is ON, the following setting is made by the system controller 11 to enable the DSP function.
[0052]
First, the output configuration from the audio decompression circuit 7d to the digital audio interface circuit 7e is set (step n1).
[0053]
Next, the output configuration is set based on the digital audio signal sent from the digital audio interface circuit 7e to the DSP LSI 9 (step n2).
[0054]
The DSP LSI 9 includes a DSP circuit 9a, a PLL circuit 9b, and an output / Hi-Z switching circuit 9c.
[0055]
The output / Hi-Z switching circuit 9c in the DSP LSI 9 is set to “output” (step n3), and the input / output switching circuit 7g in the decoder LSI 7 is switched to the “input” port (step n4).
[0056]
Also, the “processing conditions” of the digital audio signal in the DSP circuit 9a are set (step n5), and then the operation of the DSP LSI 9 is started to output the data of the digital audio output. Various settings for performing the DSP operation, such as the operation, are performed (step n6).
[0057]
Under the setting that each circuit has a DSP function as described above, the information signal is processed as follows.
[0058]
The information signal expanded by the audio expansion circuit 7d is input to the digital audio interface circuit 7e and converted into a digital audio signal.
[0059]
The four signals BCLK, LRCLK, DATA, and MCLK generated by the digital audio interface circuit 7e are input to the DSP circuit 9a and the PLL circuit 9b in the DSP LSI 9. In the PLL circuit 9b, the four input signals are synchronized, and the DSP circuit 9a processes the information signal at the same time based on the synchronization.
[0060]
The digital audio signal output from the DSP circuit 9a is returned to the decoder LSI 7 through the output / Hi-Z switching circuit 9c.
[0061]
The digital audio signal processed by the DSP LSI 9 passes through the input / output switching circuit 7g in the decoder LSI 7 and is then input to the D / A converter 7f to be an analog voice / music signal and output to the amplifier circuit 10.
[0062]
On the other hand, when the DSP SW 15 is OFF, the system controller 11 makes the following settings so that the DSP function does not work.
[0063]
First, the output configuration from the audio decompression circuit 7d to the digital audio interface circuit 7e is set (step m2).
[0064]
Next, the output configuration is set based on the digital audio signal sent from the digital audio interface circuit 7e to the DSP LSI 9 (step m3).
[0065]
Further, the output / Hi-Z switching circuit 9c of the DSP LSI 9 is set to “output” (step m4), and the input / output switching circuit 7d in the decoder LSI 7 is switched to the “input” port (step m5).
[0066]
The processing from step m2 to step m5 is the same as the processing from step n1 to step n4 when the DSP SW 15 is ON.
[0067]
In this way, after performing the same operation as when the DSP function is operated, the setting of the output configuration of the digital audio signal from the digital audio interface circuit 7e to the DSP LSI 9 is canceled (step m6).
[0068]
Next, the input / output switching circuit 7g of the decoder LSI 9 is switched from the “input” port to the “output” port (step m7).
[0069]
Further, the output / Hi-Z switching circuit 9c of the DSP LSI 9 is set to “Hi-Z” (step m8), and data collision occurs when the input / output switching circuit 7g of the decoder LSI 9 is switched to the “output” port. Respond so that there is no match.
[0070]
Then, the setting of the output configuration of the information signal from the audio expansion circuit 7d to the digital audio interface circuit 7e is canceled (step m9), and then the information signal is output from the audio expansion circuit 7d to the D / A converter circuit 7f. (Step m10).
[0071]
Finally, in order to perform normal reproduction without performing the DSP operation, the digital audio interface circuit 7e, the DSP circuit 9a, and the PLL circuit 9b are set to be stopped (step m11).
[0072]
Under the setting that the DSP function does not work as described above, the information signal is processed as follows.
[0073]
The information signal expanded from the audio expansion circuit 7d is not output to the digital audio interface circuit 7e, but directly output to the D / A converter 7f, and becomes an analog audio / music signal.
[0074]
At this time, if the input / output switching circuit 7g remains in the “input” port state, an erroneous signal is input to the D / A converter 7f, and therefore, the “output” state is set.
[0075]
When the input / output switching circuit 7g becomes an output port, the output / Hi-Z switching circuit 9c of the DSP LSI 9 is switched from “output” to the “Hi-Z” state with high impedance, the signals collide, and an abnormal current is generated. I try not to flow.
[0076]
Further, since no signal is output from the digital audio interface circuit 7e to the DSP circuit 9a or the PLL circuit 9b of the DSP LSI 9, the operation of the DSP circuit 9a or the PLL circuit 9b is stopped, and the DSP LSI 9 consumes as little power as possible. It is said that.
[0077]
Even when the DSP SW 15 is OFF, the reason why the opposite process is performed after performing the same process as the DSP SW 15 ON process (steps n1 to n4) is that the settings of the decoder LSI 7 and the DSP LSI 9 are surely omitted. This is to prevent the data from colliding with the fact that the input / output switching circuit 7d of the decoder LSI 7 is switched to the output port in the power mode.
[0078]
Regardless of whether the DSP SW 15 is turned on or off, the analog voice / music signal output from the D / A converter 7f is output to the amplifier circuit 10, and the volume of the voice / music data is passed through the circuit. The voice / music data is reproduced and output to the user through the headphones 16.
[0079]
The D / A converter 7f may be an external DA converter IC. If the DSP SW 15 is OFF at this time, the information signal is output from the audio expansion circuit 7d to the external DA converter IC through the input / output switching circuit 7g.
[0080]
The system controller 11 constantly checks the voltage value of the power supply 14 detected by the power supply voltage detection circuit 13 and confirms whether or not the voltage value of the power supply 14 is suitable for the reproducing operation of the disk 1. Power is supplied to the power supply circuit 12 from the power supply 14.
[0081]
The power supply circuit 12 is constituted by a DC-DC conversion circuit or the like, and supplies necessary voltages to each part of the MD reproducing apparatus.
[0082]
As the power source 14, a lithium ion rechargeable battery / Ni-MH rechargeable battery having good portability and a long life may be used.
[0083]
In the above-described embodiment, the portable MD playback device has been described as an example. However, the present invention is not limited to the MD playback device, and the information signal read from the recording medium is stored in the memory. Widely applied to a recording medium playback apparatus that reads the information from the memory at a speed slower than the writing speed to the memory, and that reproduces the information recorded on the recording medium while accumulating the information signal in the memory. To get.
[0084]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0085]
(1) In the case where the processing switching means is set so as not to perform processing by the processing means, power is saved by disabling operations other than the output unit of the processing means, and the processing means Since the output unit has a high impedance, it is possible to prevent an abnormal current from being output.
[0086]
(2) As in the first aspect, it is possible to save power by setting the output unit to high impedance and inactivating the PLL circuit and the digital analog processor circuit.
[0087]
(3) Since the construction according to claim 1 prevents the abnormal current from being output or the like, when the processing switching means is set so as not to perform processing by the processing means, By directly outputting the decompressed signal to the signal conversion means, the circuits related to the processing means other than the decompression means and the signal conversion means are stopped, and the power can be saved.
[0088]
(4) When setting the processing switching means so as not to perform processing by the processing means, the input port of the input / output switching means connected to the output portion of the processing means is converted into an output port, and the processing means By setting the output section of the power supply to high impedance, it is possible to surely shift to the power saving mode.
[0089]
(5) When setting the processing switching means so as not to perform processing by the processing means, after performing initial setting to perform processing by the processing means, setting not to perform processing by the processing means. This makes it possible to shift to the power saving mode with certainty.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an MD playback apparatus with a DSP function according to the present invention.
FIG. 2 is a flowchart showing the operation of the MD playback apparatus with a DSP function according to the present invention.
FIG. 3 is a block diagram showing a schematic configuration of a conventional MD playback apparatus with a DSP function.
[Explanation of symbols]
1, 17 Mini disk 2 Spindle motor 3, 18 Pickup 4 Feed motor 5 Driver circuit 6, 19 RF amplifier 7 Decoder LSI
8 Shockproof memory 9, 21 DSP LSI
10, 22 Amplifier circuit 11, 23 Microcomputer for system control 12 Power supply circuit 13 Power supply voltage detection circuit 14 Power supply 15, 24 DSP ON / OFF SW
16, 25 headphones 20 decoder / servo LSI

Claims (3)

Reading means for reading the compressed information recorded on the recording medium;
Decompression means for decompressing the signal read by the reading means;
Processing means for processing so as to give an acoustic effect to the signal extended by the extension means, a PLL circuit for synchronizing a plurality of signals, and digital signal processing for the signal synchronized by the PLL circuit Processing means comprising a digital signal processor circuit to be performed and an output section configured by a switching circuit for switching whether to output the processed signal or to completely cut off the current as high impedance;
Processing switching means for switching whether to perform processing by the processing means; and
And a signal converting means for converting the analog signal to direct signal expanded by the expansion means without passing through the processed signal or said processing means by said processing means,
In the case where the processing switching means is set so as not to perform processing by the processing means,
The output part of the processing means is set to high impedance,
An operation other than the output unit of the processing means is deactivated. The recording medium playback apparatus according to claim 1,
I / O switching means for switching whether or not a signal is input from the processing means to the signal conversion means,
When setting the processing switching means so as not to perform processing by the processing means, the input port of the input / output switching means connected to the output portion of the processing means is converted to an output port,
A recording medium reproducing apparatus, wherein an output section of the processing means is set to high impedance. The recording medium reproducing apparatus according to claim 1 or 2 ,
When setting the processing switching means so as not to perform processing by the processing means,
The recording medium reproducing apparatus according to claim 1, wherein after the setting for outputting the processed signal is performed by the switching circuit, the setting is changed to a setting for completely interrupting the current as high impedance .

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