JP2001142474A - Data reproducing device, clock supply control method and program storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a data a reproducing device to be used for longer time by extending the utilizing time of a driving battery. SOLUTION: The device is provided with a semiconductor flash memory 80 which stores digital music contents C1, a DSP 82 which reproduces musical data D1 read from the memory 80 and a digital analog converting circuit 108 which converts the data D1 reproduced by the DSP 82 into analog musical signals. Since the DSP 82 supplies operating clocks from its own oscillation circuit to the circuit 108 only during the data D1 is being reproduced. Thus, the DSP 82 does not operate the circuit 108 at the time other than reproducing to reduce the power consumption, thus a longer utilization time is realized by means of carefull power conservation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data reproducing apparatus, a clock supply control method, and a program storage medium, and is suitably applied to, for example, a data reproducing apparatus for reproducing content data stored in predetermined storage means.

[0002]

2. Description of the Related Art In recent years, a portable recording / reproducing apparatus using a semiconductor memory as a storage means has been proposed, and content data is reproduced from a semiconductor memory and enjoyed.

[0003]

The portable recording / reproducing apparatus having such a configuration uses a driving battery as a power supply, and there has been a demand to further extend a use time in which reproduction can be performed by the driving battery. .

The present invention has been made in view of the above points, and has as its object to propose a data reproducing apparatus, a clock supply control method, and a program storage medium that can be used for a long time.

[0005]

According to the present invention, there is provided a storage means for storing content data, a digital signal processing means for reproducing the content data read from the storage means, and a digital signal processing means. Digital-to-analog converting means for converting the reproduced data reproduced by the digital signal into an analog signal. The digital signal processing means transmits an operation clock to the digital-to-analog converting means from its own oscillation circuit only while reproducing the content data. Since the operation clock is not supplied to the digital-to-analog conversion means except during reproduction, the power consumption is reduced without operating the digital-to-analog conversion means, and thus the power consumption is reduced. Realizing long-term use by effective power saving Kill.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

(1) Use of Electronic Music Distribution Service Recently, EMD that distributes digital music contents using a computer network based on the Internet
(Electric Music Distribut
An electronic music distribution service called “ion) has been proposed.

As shown in FIG. 1, in this kind of electronic music distribution service, a personal computer (hereinafter referred to as a computer device) 3 at home from an EMD server 1 that supplies contents via the Internet 2. To distribute the digital music content C1 to

In the computer device 3, the EMD server 1
Is downloaded to an internal hard disk and reproduced according to the operation of the user, so that the user can enjoy the music at any time.

In such an electronic music distribution service, E
The digital music content C1 downloaded from the MD server 1 to the computer device 3 is as if a CD (Co)
While there is a purchase method called “purchase” that can be reproduced at any time and any number of times as in the case of “mpact disc), a“ reproduction ”service with a reduced price setting is provided with a reproduction period and a reproduction limit of the number of reproductions. There is a new purchase method called "limited".

Accordingly, when the user purchases the digital music content C1 from the EMD server 1 with "reproduction restriction", the computer device 3 reproduces the purchased digital music content C1 within the reproducible period or the reproducible number of times. can do.

The computer device 3 includes a portable digital reproduction device 4 having a built-in nonvolatile semiconductor flash memory as a storage means and a USB (Universal).
(Serial Bus) cable so that the digital music content C1 can be uploaded to the semiconductor flash memory of the digital playback device 4 as digital data.

Thus, the user can use the computer device 3
Not only the digital playback device 4 but also the digital playback device 4 can play back the digital music content C1 with "playback restriction" within a playable period or within the range of the number of playable times, so that high-quality music can be played outdoors via the headphones 5. It is made to be enjoyable casually.

In practice, as shown in FIG.
The digital music content C1 with "playback restriction" downloaded from the server 1 to the computer device 3 is configured by integrating a header H1 and music data D1.
The header H1 stores various information related to reproduction restrictions such as a reproducible period, a reproducible number of times, and a number of times of actual reproduction (hereinafter, referred to as an actual number of times of reproduction).

Next, as shown in FIG. 2B, the computer device 3 uploads the digital music content C1 to the semiconductor flash memory of the digital reproducing device 4 as digital data.

The digital reproduction device 4 always reproduces the music data D1 after reading the reproduction restriction information of the header H1 when executing the reproduction processing in response to the reproduction operation of the user. This effectively utilizes the playback restriction information managed by the, and prevents unauthorized playback processing.

The digital reproducing apparatus 4 according to the present embodiment does not include an RTC circuit,
Since the reproduction period cannot be managed by the clock function as it is, even if the reproduction restriction information of the header H1 is read, it cannot be determined whether or not the reproduction restriction period is within the range of the reproduction period. Unlimited playback is possible.

In order to prevent such a situation, even if the digital reproducing device 4 is in the range of the reproducible period,
The reproduction process is permitted only within the range of the "reproducible number of times (for example, two times)" defined by the reproduction restriction information of the header H1, and the "actual number of times of reproduction" updated at the time of actual reproduction is set to "reproduction". When the "possible number of times" is reached, protection for limiting the reproduction process is applied.

However, as shown in FIG. 2C, the digital reproduction device 4 can reproduce only twice, even though it is within the range of the reproducible period. And receives the current time information T1 from the RTC circuit 3A incorporated in the computer device 3 and determines whether or not the time is within the range of the reproducible period based on the time information T1, and makes the reproduction possible. When it is recognized that the number is within the range of the period, the “actual number of times of reproduction” of the header H1 is rewritten to “0”.

Thus, when the digital reproduction device 4 is within the range of the reproducible period, the digital reproducible device 4 sets the number of reproducible times (for example, 2
The above-mentioned reproduction process can be executed any number of times by repeatedly using the restriction of "times)".

Further, the digital reproducing apparatus 4 outputs the time information T
When it is recognized that the reproducible period has expired based on No. 1, the reproduction process is not executed without rewriting the “actual number of times of reproduction” in the header H1 to “0”.

As described above, the digital reproduction device 4 repeats the reproduction process up to the “reproducible number of times” and the check of the reproducible period due to the connection with the computer device 3 so that the digital reproduction device 4 If so, the reproduction process up to the “reproducible number of times (two times)” can be repeatedly executed, and the reproduction process can be restricted when the reproducible period ends.

On the other hand, in the case of the digital music content C1 to which only the reproduction limit of the number of reproducible times is added, the digital reproducing device 4 executes the reproducing process within the range of the number of reproducible times, When the minute is reproduced, the subsequent reproduction processing is not executed.

(2) Overall Configuration of Digital Reproducing Apparatus (2-1) Structure of Digital Reproducing Apparatus As shown in FIG.
The housing case 10 has a substantially cylindrical shape, and various operation switches, operation buttons, a display window 11 for a display unit, and the like are provided on a peripheral side surface of the housing case 10.

Here, the display window 1 of the digital reproduction device 4
4 (A) to 4 (D), description will be given of respective peripheral side surfaces when the housing case 10 is rotated by 45 degrees around the axis when the side where 1 is provided is the front.

As shown in FIG. 4A, the housing case 10
On the left side of the housing case 10 (hereinafter, referred to as a longitudinal direction).
A volume upper limit fixing switch 12 for fixing the upper limit of the volume is slidably provided at one end of the case (referred to as the longitudinal direction of the case), and a USB (Universal).
A plastic USB connector cover 13 is provided to open and close a hole (not shown) in which a Serial Bus (Serial Bus) connector is stored.

Actually, the USB connector cover 13 is
When the B connector is not used, the case is closed by closing the hole.
When the USB connector is used, the USB connector (not shown) is protected by opening the hole when the USB connector is used.
To be connected to the computer device 3 via the.

As shown in FIG. 4B, a volume up button 14, a volume down button 15, a fast-forward button 16, a fast-return button 17, and a display are provided on the front of the casing case 10 from substantially the center to one end thereof. A window 11 and a shift button 18 are sequentially provided. A play / stop button 19 for inputting a play command and a stop command is provided on one end surface of the housing case 10.

Then, on the front of the housing case 10,
A display unit (not shown) provided below the display window 11 performs a display according to various operations, so that the display content can be presented through the display window 11.

Incidentally, when the fast forward button 16 is depressed while the shift button 18 is being depressed,
Together with the fast forward button 16, the button functions as an operation button for switching the reproduction mode. Shift button 18
When the fast-return button 17 is pressed in a state where the button is pressed, the button also functions as an operation button for switching the sound quality mode together with the fast-return button 17.

Further, as shown in FIG. 4C, a hold switch 2 is provided on one end of the right side of the housing case 10.
0 is slidably provided, and the hold switch 2
For example, by sliding “0” to one end of the housing case 10, the input of various operation buttons is invalidated, and this state can be maintained.

In addition to this, as shown in FIG. 4 (D), on the back of the housing case 10, a dry cell storage section 22 is provided on the other end side, in which an AA size driving battery 21 can be loaded. , Lid part 23 for closing the dry cell storage part 22
Is detachably attached.

Thus, in the dry cell storage section 22,
When the lid 23 is removed, the driving battery 21 can be loaded inside or taken out of the inside, and the lid 23 can be attached with the driving battery 21 loaded inside. Then, the cover 23 prevents the driving dry battery 21 from falling off and holds it.

On the back surface of the housing case 10, a jack holding portion 25 for holding a headphone jack 24 at one end thereof and a clip portion 26 for attaching the housing case 10 to a chest pocket or the like of a jacket are provided. The digital playback device 4 is arranged side by side along the longitudinal direction of the case and adjacent to the jack holding portion 25 and the clip portion 26.
The annular strap fitting 27 is located at a predetermined position shifted from the center of gravity of
Is provided.

The strap fitting 27 is used for the housing case 1
0 can be freely rotated within a range of approximately 180 degrees from a position in contact with the jack holding portion 25 to a position in contact with the clip portion 26 with respect to the back surface of the backing member 0. The strap can be easily attached or detached.

Here, in the digital reproducing apparatus 4,
Unlike a recording / reproducing apparatus having a mechanical recording / reproducing mechanism, such as a hard disk drive, recording and reproducing the digital music content C1 with respect to the internal semiconductor flash memory as described above with reference to FIG. Even under such an environment, the music data D1 of the digital music content C1 can be reproduced without causing a skip or the like.

For this reason, in the digital reproducing apparatus 4, as shown in FIG. 5, a plug 29 provided on a headphone cord 28 is usually connected to a headphone jack 24.
, The music obtained by reproducing the music data D1 from the semiconductor flash memory can be listened to through the headphones 5. At this time, a strap-like neck strap is attached to the strap fitting 27. By attaching the base 31, it can be used while hanging from the neck.

The digital reproducing apparatus 4 has a weight of about 25 g except for the driving battery 21, and most of the various components constituting the digital reproducing apparatus 4 are provided at one end in the longitudinal direction of the case. ing. Also, in the digital reproducing device 4, for example, a driving dry battery 21 having a weight of about 23 [g] is loaded into a dry battery storage portion 22 provided on the other end side in the case longitudinal direction. When loaded, the center of gravity is substantially at the center in the longitudinal direction of the case.

In the digital reproducing device 4,
As shown in FIG. 6, when the strap 31 for neck hanging is used and is hung from the neck, the mounting position of the strap metal member 27 serving as a fulcrum is located at a predetermined position on one end side along the case longitudinal direction from the center of gravity. Therefore, the other end of the housing case 10 is oriented substantially vertically downward, and the housing case 10
Is maintained so that the play / stop button 19 provided on one end face is substantially vertically upward.

Thus, in the digital reproducing apparatus 4, when the user hangs his / her neck, the user
By simply grasping the peripheral side surface of the “0”, the thumb can be easily touched to the play / stop button 19 for operation.

Incidentally, in the digital reproducing apparatus 4,
As is apparent from FIG.
A predetermined cord holding portion 32 for holding the headphone cord 28 is provided on the
When used by hanging from the neck using the headphone cord, it is possible to prevent the headphone cord 28 from being complicated.

In the digital reproducing apparatus 4, as shown in FIG. 7, the jack holding portion 25 is formed in a wedge shape, and the headphone jack 24 inclines the axis of the cylindrical plug insertion hole with respect to the longitudinal direction of the case. Thus, it is held by the jack holding portion 25.

Therefore, in the digital reproducing device 4,
The plug 29 can be inserted into the headphone jack 24 from one end of the housing case 10 while being inclined with respect to the longitudinal direction of the case, so that the connection between the plug 29 and the headphone cord 28 can be relatively moved from the play / stop button 19. Thus, the operability of the play / stop button 19 can be prevented from being impaired by the connection between the plug 29 and the headphone cord 28.

In addition, in the digital reproducing apparatus 4, as shown in FIG.
Is pivotally supported by a support shaft (not shown) embedded in the jack holding portion 25, and the other end of the clip portion 26 is rotated within a predetermined angle range with respect to the rear surface of the housing case 10. Has been made.

Thus, in the digital playback device 4, the chest pocket 33 of the outerwear is attached to the chest pocket 33 from the other end of the housing case 10 so as to be sandwiched between the back surface and the clip portion 26. Can be.

In the digital reproducing device 4,
Even when attached to the breast pocket 33 in this way,
The play / stop button 19 is maintained in a posture of being out of the breast pocket 33, so that the operability of the play / stop button 19 can be prevented from being impaired.

Here, in the case 10, FIG.
As shown in FIG. 3, a front case 35 forming one end to the other end on the front side, a back case 36 forming one end of the back, a lid 23 forming the other end of the back, And a button holding unit 37 for holding the / stop button 19.

The front case 35, the rear case 36, the lid 23 and the button holding part 37 are respectively Polyca
rbonate) resin and ABS (Acrylonit)
and Rile Butadiene Styrene) resin at a predetermined ratio.

The front case 35 has the dry battery housing 22 described above with reference to FIG. The storage space formed between one end of the front case 35 and the rear case 36 includes a display unit protection member 40, a display unit 41, a sub circuit board 42, a main circuit board 43, Switch circuit board 4
4 are sequentially stacked and stored. Incidentally, the switch circuit board 44 includes switch circuit elements 44A and 44A for the volume upper limit fixing switch 12 and the hold switch 20.
B is a flexible board on which is mounted, and is fixed inside the rear case 36.

In practice, as shown in FIGS. 10A and 10B, the driving battery 21 is
A negative electrode terminal 45 formed in a coil shape by a conductive metal wire is disposed at one end along the case longitudinal direction, having a cylindrical storage space having an inner diameter corresponding to the outer diameter of the case.
At the other end along the longitudinal direction of the case, a positive electrode terminal 46 formed of a conductive metal material, for example, in a disk shape is arranged.

In this case, in the dry cell storage section 22,
One end of the negative electrode terminal 45 is directly electrically connected to the main circuit board 43, and the positive electrode terminal 46 is electrically connected to the main circuit board 43 via a plate-shaped conductive plate 47 formed integrally therewith. .

A groove 22A is formed at the bottom of the dry cell storage portion 22 from one end to the other end in the case longitudinal direction, and the conductive plate 47 is fitted into the groove 22A. At this time, the depth of the groove 22A is 0.2 [m
m], so that the conductive plate 47 is prevented from protruding into the storage space from the inner surface of the dry cell storage part 22.

On the bottom of the dry cell housing 22, from one end along the longitudinal direction of the case to the other end, 0.1 [mm]
A sheet-shaped serial label 48 having a moderate thickness is attached so as to cover the conductor plate 47.

As shown in FIGS. 11A and 11B, the serial label 48 includes, for example, an acrylic pressure-sensitive adhesive layer 49 having a relatively strong adhesive force and an aluminum layer 50.
And PET (polyethylene tereph)
an insulating printing resin layer 51 made of
The transparent film 52 is sequentially laminated and formed, and the thickness of the aluminum layer 50 is appropriately selected.
The serial label 48 has a certain degree of rigidity so that the serial label 48 itself can be prevented from being broken or broken.

In the serial label 48, a pattern 53 indicating the loading direction of the driving dry battery 21 on one side of the printing resin layer 51, and a character indicating the serial number of the digital reproducing apparatus 4 to which the serial label 48 is to be attached. 54 and 2
The three-dimensional barcode 55 is printed and the printing resin layer 5 is printed.
By laminating the transparent film 52 on one surface, the pattern 53, the character 54, and the like are protected.

Therefore, in the dry cell storage portion 22 (FIGS. 10A and 10B), the conductive plate 47 floats from the groove portion 22A due to the adhesive force and the rigidity of the serial label 48, and the peripheral surface of the driving dry battery 21 The serial label 48 can be prevented from being damaged by scratching or the like.
The insulation property of the drive battery 21 allows the peripheral side surface of the driving dry battery 21 to be insulated from the conductive plate 47.

In the dry cell housing 22, the conductive plate 47 is fitted into the groove 22A,
A serial label 4 having a thickness of about 0.1 [mm] is used for insulation between the conductive plate 47 and the peripheral side surface of the driving dry battery 21.
By using 8, the inner diameter of the dry battery storage section 22 can be selected to be substantially the same as the outer diameter of the drive dry battery 21 of about 14.5 [mm].

The thickness of the dry cell housing 22 is selected so as to protect it from damage, so that the outer diameter of the dry cell housing 22 can be adjusted according to the inner diameter and the wall thickness.
[Mm], so that the overall size can be reduced.

On the other hand, as shown in FIG. 12, the display portion protection member 40 is formed of a conductive metal plate having both ends in the width direction bent, and a diaphragm structure corresponding to the shift button 18 is provided at one end of the flat portion 40A. And a volume up button 14, a volume down button 15, a fast forward button 1 at the other end of the flat portion 40A.
6 and a switch element 58 to 61 having a diaphragm structure corresponding to the fast-return button 17, respectively.

An opening 40B corresponding to the display section 41 is provided between the switch element 57 at one end and the switch elements 58 to 61 at the other end in the flat portion 40A.

In the display section 41, as shown in FIG. 13, an LCD (Liquid Crystal Disp) is used.
layer) 63, a U-shaped light guide plate 64 is laminated,
When the end in the width direction of the light guide plate 64 is illuminated by a backlight (not shown), the entire back surface of the LCD 63 can be almost uniformly illuminated via the light guide plate 64.

The display section 41 has an anisotropic conductive member 65 in which a plurality of wires penetrate at a predetermined pitch into an insulating sheet made of a resin material such as silicon rubber. The anisotropic conductive member 65 is substantially parallel to the thickness direction of the light guide plate 64 and the arm portion 64A of the light guide plate 64.
And 64B, one end of each wire is electrically connected to a plurality of electrodes of the LCD 63.

In the sub circuit board 42, FIG.
As shown in (A), one end has a width of about 12.4 [mm] and the other end has a trapezoidal shape having a width of about 13.2 [mm]. 19, a switch circuit element 67 for I.
Various surface-mounted electronic components such as a C package 68I, a digital-to-analog conversion circuit, and a circuit element group 69 constituting an amplifier are mounted, and a plurality of LEDs (Light Emitt) for a backlight corresponding to the light guide plate 64.
ing Diodes) 70A to 70C are mounted.

On one surface of the sub-circuit board 42, an LCD
A plurality of LCD lands 71 made of a conductor pattern corresponding to each of the electrodes 63 are formed.
When housed inside, each LCD land 71 is electrically connected to a corresponding electrode of the LCD 63 via each wire of the anisotropic conductive member 65.

Further, as shown in FIG. 14B, an EEPROM (Electric
cally Erasable Programmab
I that make up the "leRead-Only Memory"
For example, a male of a pair of connectors (hereinafter, referred to as an inter-board connection connector) for directly connecting circuit boards to predetermined portions while mounting various surface mount electronic components such as the C package 72I. The board-to-board connector 73 is mounted.

Incidentally, the other surface of the sub-circuit board 42 is electrically connected to each of the switch elements 57 to 61 provided on the display section protection member 40 via a flexible board (not shown) by a conductor pattern. Switch land 74
A and 74B are formed, and the switch circuit board 4 is formed.
The circuit board lands 75 electrically connected to the circuit board 4 are formed.

In the main circuit board 43, FIG.
As shown in (A), the IC package 77I, which has a rectangular shape having a width of about 17.2 [mm] and forms a flash memory controller on one surface thereof, includes a CPU (Ce).
IC (Integrated Circuit) package 78I constituting a central processing unit and an IC constituting a USB controller
Various surface-mounting electronic components such as a package 79I are mounted, and a male board-to-board connector 73 (FIG. 1).
4 (B)), a female inter-board connection connector 80 is mounted at a predetermined position corresponding to (B).

As shown in FIG. 15B, on the other surface of the main circuit board 43, an IC package 81I and a DSP (Digital) constituting a semiconductor flash memory are provided.
Various surface-mounted electronic components such as an IC package 82I constituting a signal processor, a USB connector 83, a circuit element group 84 constituting a power supply circuit, and the like are mounted. Incidentally, the negative electrode terminal 45 and the conduction plate 47 of the dry cell housing 22 are electrically connected to the circuit element group 84 constituting the power supply circuit.

As shown in FIGS. 16 (A) and 16 (B), the main circuit board 43 and the sub circuit board 42 are connected to the female type board-to-board connector 80 in a state where they are substantially parallel to each other. The connector 73 for inter-substrate connection of the mold is inserted so that it can be directly connected mechanically and electrically.

Incidentally, a bus is formed by a conductor pattern on the main circuit board 43, and various digital surface-mounted electronic components connected to the bus are mounted. Various analog surface-mounted electronic components are mounted, so that various surface-mounted electronic components of the sub-circuit board 42 are not affected by noise generated by the operation of the various surface-mounted electronic components of the main circuit board 43. Has been made.

On one side of the main circuit board 43 and on the other side of the sub-circuit board 42, surface-mounted electronic components are mounted so as not to face each other. 73, the main circuit board 43 and the sub circuit board 4
The distance between the two can be made close to the thickness of the surface mount electronic component.

Incidentally, the main circuit board 43 (FIG. 15)
In (A)), after a female-type board-to-board connector 80 is positioned via solder on one surface thereof together with various surface-mounted electronic components, the solder is melted using, for example, a reflow furnace. And implemented
Due to errors in the amount of solder applied on one surface, positioning errors in the connector 80 for board-to-board connection, etc., the connector 80 for board-to-board mounting is rotated in parallel with one surface of the main circuit board 43 when the solder is melted. May be done.

Similarly, in the sub-circuit board 42 (FIG. 14B), after the male board-to-board connector 73 is positioned via solder together with various surface-mounted electronic components on the other surface. It is mounted in such a way that the solder is melted using a reflow furnace, and the board-to-board connection connector 73 is caused by an error in the amount of solder applied to the other surface, a positioning error of the board-to-board connection connector 73, and the like. When the solder is melted, the sub-circuit board 42 may be mounted while being rotated in parallel with the other surface.

For this reason, the sub circuit board 42 (FIG. 16)
(B)) is a case where, when connecting to the main circuit board 43, the connection is made in a state of being rotated up to about 5 degrees in parallel with the main circuit board 43 around the mounting position of the inter-board connector 73. There is.

Then, on one surface of the main circuit board 43,
The inter-board connection connector 80 is mounted at a predetermined portion on the other end, and the inter-board connection connector 73 is mounted on the other surface of the sub-circuit board 42 at a predetermined portion on the other end. When the sub circuit board 42 is connected in a state of being rotated in parallel with one surface of the main circuit board 43, the amount of deflection in the longitudinal direction of the main circuit board 43 becomes largest at one end of the sub circuit board 42.

However, since the sub-circuit board 42 is formed in a trapezoidal shape with one end narrower than the other end, both side surfaces of the sub-circuit board 42 correspond to the main circuit board 43. The main circuit board 43 is connected to the main circuit board 43 so as to fall within an angle range until it is substantially parallel to both side surfaces. Thus, even in the state of being connected to the main circuit board 43, it is easily inserted into the arc-shaped storage space inside the front side case 35. It is made so that it can be stored.

In practice, the front case 35 (FIG. 9) is provided with a positioning pin 86 for positioning the display unit protection member 40 at a predetermined position on the bottom on one end side. Further, around the display window 11, L-shaped columns 87A to 87D respectively corresponding to the four corners of the display unit 41 are provided, and a plate-like member 88 corresponding to the anisotropic conductive member 65 of the display unit 41. Is provided.

In addition to this, the display unit protection member 40 (FIG. 1)
In 2), the hole 40C corresponding to the positioning pin 86 of the front side case 35 is provided substantially at the center of the plane portion 40A.
In addition, holes 40D to 40H corresponding to the columns 87A to 87D and the plate member 88 of the front side case 35 are formed around the opening 40B.

As a result, in the front case 35,
As shown in FIG. 17, on one end side, columns 87A to 87A-8
7D and the plate-shaped member 88 are passed through the corresponding holes 40D to 40H of the display unit protection member 40, and the positioning pins 86 are passed through the corresponding holes 40C, so that the display unit protection member 40 is elongated in the case. Direction so that the display unit protection member 40
Can be attached with the opening 40B and the display window 11 facing each other.

Further, in the front case 35, FIG.
By fitting the four corners of the display unit 41 to the corresponding columns 87A to 87D, as shown in FIG.
Is held facing the opening 40B, and at this time,
By bringing the plate-shaped member 88 close to the anisotropic conductive member 65, it is possible to prevent the light guide plate 65 from falling off between the arm portions 64 </ b> A and 64 </ b> B.

In the front case 35, FIG.
As shown in FIG. 9, the main circuit board 43 and the sub circuit board 42 connected via the pair of board connectors 80 and 73 are connected to one surface of the sub circuit board 42 and the display unit protection member 40 (FIG. 18). The flat portion 40A is stored facing the flat portion 40A.

Next, in the front case 35, FIG.
As shown at 0, the rear case 36 is attached, and in this state, the main circuit board 43 (FIG. 19) is fixed together with the rear case 36 by the fixing screws 89A and 89B.

By the way, as the board-to-board connectors 80 and 73 mounted on the main circuit board 43 and the sub-circuit board 42, small ones having a relatively small outer shape and a relatively low height are selected. .

Therefore, connectors 80 and 73 for connection between boards are provided.
Can prevent the main circuit board 43 and the sub-circuit board 42 from being enlarged by reducing the mounting area thereof, and make the main circuit board 43 and the sub-circuit board 42 as close as possible to each other. The storage space in the inside can be made small.

However, since the inter-board connectors 80 and 73 are miniaturized, the connector pins provided on the inter-board connectors 80 and 73 are fine, and the connector pins themselves are not provided. Is significantly reduced in elasticity.

Therefore, in the inter-board connectors 80 and 73, when the main circuit board 43 and the sub-circuit board 42 are housed in the housing case 10, the sub-circuit board 42 If the addition is made in the direction of rotation in parallel with, it is considered that a connection failure occurs between the corresponding connector pins of the inter-board connection connectors 80 and 73.

Therefore, in the sub-circuit board 42, FIG.
As shown in FIG. 1, even when the main circuit board 43 (FIG. 19) fixed to the front case 35 is housed in a state of being rotated in parallel with one surface, inside the front case 35,
One end and the other end are formed in a trapezoidal shape so that the rotation is allowed, and are not particularly fixed to the front case 35.

Thus, in the digital reproducing apparatus 4, even if the sub-circuit board 42 housed together with the main circuit board 43 is rotated in parallel with one surface of the main circuit board 43, the connector for connecting boards can be used. 80 and 7
3 can prevent the occurrence of connection failure between corresponding connector pins.

Further, in the digital reproducing apparatus 4, an impact due to a drop or the like is applied to the digital reproducing apparatus 4 in a state where an external force is applied to the sub circuit board 42 in a direction rotating in parallel with one surface of the main circuit board 43. Although it is conceivable that the inter-board connectors 80 and 73 may be peeled off from the main circuit board 43 and the sub-circuit board 42, the sub-circuit board 42 is not particularly fixed, so that the inter-board connection connector 80 is not fixed. And 73 can be prevented from occurring.

Incidentally, in the front case 35, the movement regulating protrusions 90 are provided at one end and the other end of the inner surface, respectively.
A to 90D are provided, and the movement regulating projections 90A to 90D are provided on one end and the other end of both side surfaces of the sub-circuit board 42, respectively.
90D, and the movement restricting projections 90A to 90D.
Notch portions 91A to 91D wider than 90D are provided.

The sub-circuit board 42 engages at least the notch portions 91A and 91D on the other end side with the corresponding movement restricting projections 90A and 90D in accordance with the rotation angle with respect to the main circuit board 43, so that the Case 35
And is regulated so as not to move in the longitudinal direction of the case.

In the sub-circuit board 42 (FIG. 14A), the LCD lands 71 are formed to have a predetermined length along the width direction of the sub-circuit board 42, respectively. Thereby, even when the sub circuit board 42 is stored in a state of being rotated in parallel with the main circuit board 43, the wire of the anisotropic conductive member 65 can be reliably electrically connected to the LCD land 71. Has been made.

By the way, in the housing case 10, 17
Although formed on the basis of a cylindrical shape having an outer diameter of about [mm], in the main circuit board 43 (FIGS. 15A and 15B), an IC package 77I and a CPU which constitute a flash memory controller are provided. I which constitutes
Since each of the C packages 78I is formed in a square shape having sides of about 16 mm,
It is formed in a rectangular shape having a width of about 7.2 [mm].

Therefore, as shown in FIG. 22, L-shaped ribs 35A and 35B and L-shaped ribs 35A and 36A are provided at the joint portions of the front case 35 and the rear case 36, respectively.
B is provided so as to protrude to the outside along the longitudinal direction of the case.

The front case 35 has ribs 35.
Fitting portions 3 substantially parallel to the left and right side surfaces at A and 35B
Fitting portions 36AX and 36BX substantially parallel to the left and right side surfaces are fitted to 5AX and 35BX at the corresponding ribs 36A and 36B of the rear case 36, respectively.

As a result, in the housing case 10, the inside of the U-shaped protrusion formed by the fitted one of the ribs 35A and 36A is replaced by the inside of the U-shaped protrusion formed by the other ribs 35B and 36B. The main circuit board 43 is housed over the display case, and thus the display section protection member 40, the display section 41, the sub-circuit board 42, and the switch circuit board 44 are almost intact without substantially impairing the substantially cylindrical shape of the housing case 10. The main circuit board 43 can be easily housed.

Further, in the case 10, the corresponding ribs 35A and 35B of the front case 35 and the rear case 36 and a fitting portion 35AX between 36A and 36B are formed.
And 35BX and 36AX and 36BX are fitted so as to overlap each other, whereby the corresponding ribs 35A and 35B and 36A and 36B are integrated with each other, and thus the rigidity of the housing case 10 can be improved. .

By the way, on the other surface of the main circuit board 43 (FIG. 15 (B)), a conductor pattern for ground (hereinafter, referred to as a conductor pattern) is provided at both ends in the width direction from one end to the other end in the longitudinal direction. Are referred to as ground patterns) 92, and the ground patterns 92 at the both ends correspond to a pair of corresponding ribs 35A, 36A and 35B, respectively.
And 36B.

As a result, in the case 10, as shown in FIG. 23, the ribs 35A, 35B and 36
Even if static electricity jumps into the inside through the gap between A and 36B, the static electricity can be taken into the relatively large ground patterns 92 at both ends of the main circuit board 43 and flow therethrough, and thus the internal surface The mounting type electronic component can be prevented from being damaged by high voltage of static electricity.

The display section protection member 40 (FIG. 12) is made of a conductive metal plate as described above, and has protrusions 40K and 40L on one end and the other end of both feet 40I and 40J, respectively. Is provided.

In addition to this, the sub-circuit board 42 (FIG. 14)
(A) On one surface, the projection 40 of the display unit protection member 40 is provided.
Ground patterns 94 are formed at both ends in the width direction corresponding to K and 40L.

As shown in FIGS. 24 and 25, when the display unit protection member 40 is housed in the housing case 10, it is positioned in the front case 35 by the positioning pins 86, and When the sub-circuit board 42 is stored with its movement restricted in the longitudinal direction of the case, the projections 4 provided on the feet 40I and 40J are provided.
0K and 40L are electrically connected to the corresponding ground pattern 94 of the sub-circuit board 42.

Thus, when the housing case 10 is brought close to a charged metal member or the like, a gap 95A between the front case 35 and the display window 11 from outside, the volume up button 14, the volume down button 15, even if the static electricity jumps in through the gap 95B between the fast forward button 16, the fast reverse button 17, the shift button 18, and the hole formed in the front case 35 for holding them. The static electricity can be taken into the display part protection member 40 adjacent to these gaps and flow to the ground pattern 94 of the sub-circuit board 42, thus preventing the LCD 63 and the switch elements 57 to 61 from being damaged by the high voltage of the static electricity. Have been made to gain.

In addition, in the display section protection member 40, the switch elements 57 to 61 provided on the plane section 40A are each supported by the sub-circuit board 42 and formed by a metal plate. Even when pressed through the corresponding shift button 18, volume down button 15, volume up button 14, fast rewind button 17, and fast forward button 16, it has sufficient rigidity to be able to withstand without being deformed. The gap between the inner surface of the side case 35 and the plane portion 40A can be effectively used as a storage space for the switch elements 57 to 61.

Further, since the display section protection member 40 is formed of a metal plate as described above, even when the thickness is selected to be relatively small, each of the switch elements 57 to 6 is not required.
Sufficient rigidity can be ensured enough to cope with the pressing of the button 1, and the storage space occupied by the display unit protection member 40 inside the housing case 10 can be significantly reduced.

(2-2) Circuit Configuration of Digital Reproducing Apparatus Next, the circuit configuration of the digital reproducing apparatus 4 is shown in FIG.
This will be described with reference to FIG. The digital reproducing apparatus 4 is configured to drive the entire apparatus by converting a power supply voltage supplied from the driving dry cell 21 into internal power of a predetermined voltage by the power supply circuit 102 and supplying the internal power to the CPU 78 and various circuit blocks. I have.

When the digital playback device 4 is connected to the computer device 3 via the USB connector 83 via the USB cable 103, the digital music content C1 bulk-transferred from the computer device 3 is transmitted to the USB
CP via the internal bus 104 by the B controller 79
Supply to U78.

Here, the digital music content C1 is
The frame configuration is 64 [Byte] per packet.
e], and is transferred from the computer device 3 at a transfer rate of 12 [Mbit / sec].

The digital music content C1 is
As shown in FIG. 27, the header H1 is composed of a header H1 and music data D1, and the header H1 includes "file ID", "header size", "content key (for encryption)", "file size", "codec ID", "File name" and "File information" are stored, and "playback restriction data", "playback start date", "playback end date", "playable number" and “Actual number of times played” is stored.

Actually, in the header H1, as shown in FIG. 28, each of the stored information is displayed in hexadecimal notation, the "header size" indicates the data length of the header H1 (33 bytes in this case). "File size" is the data length of the file of the music data D1 (in this case, 3363
6138 bytes).

The "content key" is the music data D
1 (FIG. 27), which is used to decrypt the encryption of the digital music content C1 between the computer device 3 and the digital playback device 4 in practice. It is transferred in the state where it was done.

When the computer device 3 and the digital playback device 4 are actually connected, the digital playback device 4 needs to be authenticated by the computer device 3. Between them, for example, challenge-response authentication is performed. By the way, in the digital reproduction device 4, DS
P82 is responsible for decryption processing when performing challenge-response authentication.

Here, the challenge-response method refers to a value (response) generated by the digital reproduction device 4 using a secret key shared with the computer device 3 for a certain value (challenge) generated by the computer device 3. Since the challenge changes every time, even if the response is eavesdropped, there is no danger of being reused, and mutual authentication can be performed safely.

The “codec ID” is used by the digital reproduction device 4 to record the music data D1 of the digital music content C1.
Is an ID number corresponding to the decompression method when reproducing
For the ID number “1”, ATRAC (Adaptive
e Transform Acoustic Codi
ng) 3, an expansion method corresponding to the data compression method is assigned, and MP3 (MP3) is assigned to the ID number “0”.
An expansion method according to a data compression method called EG Audio Layer-3) is assigned.

The “file name” is, for example, the file name “ABCD.AAC” of the digital music content C1
SCII (American National St)
andrard Code for Information
The “file information” is data obtained by converting the music title, artist name, poet name, composer name, and the like of the digital music content C1 into ASCII code.

[0116] The "reproduction limit data" is data indicating whether or not the reproduction limit of the reproducible period or the number of reproducible times is added to the digital music content C1 reproduced by the digital reproducing device 4, and is limited to the reproducible number of times. "1" is assigned only when there is a limit, and "2" is assigned only when there is a limit on the reproducible period, and "0" is assigned when the digital music content C1 is purchased by "purchase". Have been assigned.

[0117] The "reproduction start date" and "reproduction end date"
When the “reproduction limit data” is “2”, this is data indicating the range of the reproducible period, and “Apr. 15, 2000” to “July, 2000” based on data “00040F” and “00070F”. 15 days "is within the range of the reproducible period.

Similarly, the “reproducible number of times” and “actual number of times of reproduction” indicate the maximum number of reproducible times specified in advance when the “reproduction restriction data” is “1” and “2”, and the reproduction process. This is data indicating the actual number of playbacks updated by the CPU 78 when executed, and is “02” and “01”.
Indicates that the “reproducible number of times” is “2” times and the “actual number of times of reproduction” at the present time is “1” times.

Therefore, according to the reproduction restriction information of the header H1, the digital reproduction device 4
Is "April 15, 2000"-"July 15, 2000"
The reproduction process can be repeated twice or more as long as it is within the range of "day".

Incidentally, the header H1 of the digital music content C1 to which the reproduction limit is added only to the number of reproducible times is added.
For example, as shown in FIG. 29, “reproduction restriction data” indicates “1”, “reproduction start date” and “reproduction end date” are “000000” and “000000”, The number of times of reproduction is “0a” and “05”. That is, there is no restriction on the reproducible period by the “reproduction start date” and the “reproduction end date”, and the “reproducible number” is “1”.
"0" times indicates that the current "actual number of times of reproduction" is "5" times.

By the way, the digital reproducing device 4 (FIG. 26)
Is transmitted from the computer device 3 together with the digital music content C1 and a write command for the digital music content C1.
When a write command is received by the m access memory (105), a read-only memory (ROM) is received.
y) The digital music content C1 is written in the semiconductor flash memory 80 by controlling the flash memory controller 77 according to the main program read from the RAM 106 into the RAM 105.

Incidentally, the semiconductor flash memory 80 has a storage capacity of about 64 [MByte], and has a CD (Comp
act Disc) It is possible to store music for one or more albums.

Further, in the semiconductor flash memory 80, a reproduction code for reproducing the music data D1 in a decompression method corresponding to the music data D1 of the digital music content C1 which has been compressed by a predetermined compression method is stored in advance. Have been.

Therefore, when a reproduction command corresponding to the user's pressing operation of the reproduction / stop button 19 is given to the CPU 78 via the operation key controller 107, the digital reproduction device 4 causes the reproduction code to be read from the semiconductor flash memory 80 by the CPU 78. And the music data D1 of the digital music content C1.
To a RAM (not shown).

The DSP 82 is a semiconductor flash memory 8
0 on the basis of the reproduction code transferred from the digital music content C1 based on the CRC (Cycle).
After an error is detected by the icRedundancy Check) method, the data is expanded and reproduced, and supplied to the digital-to-analog conversion circuit 108.

Here, the DSP 82 is an IC package 82I (FIG. 15B) integrally formed with an oscillation circuit (not shown) provided therein, and the DSP 82 receives a signal from an oscillator 82A made of an external crystal. The music data D1 is reproduced based on the master clock MCLK, and the master clock MCLK and a bit clock BC having a predetermined frequency generated by an internal oscillation circuit based on the master clock MCLK.
LK and L channel clock LCLK in frame units
And an R-channel clock RCLK to the digital-to-analog conversion circuit 108.

In this case, when the music data D1 is being reproduced, the DSP 82 sends the above-mentioned operation clock to the digital-to-analog conversion circuit 108 in accordance with the reproduction code. However, when the music data D1 is not reproduced, the DSP 82 follows the reproduction code. By stopping the supply of the operation clock and not operating the digital-to-analog conversion circuit 108, the power consumption of the entire digital reproduction apparatus 4 can be reduced.

Similarly, the CPU 78 and the USB controller 79 are also provided with external oscillators 78A and 79A made of crystal, and execute predetermined processing using the master clock MCLK supplied from the oscillators 78A and 79A. It has been made like that.

As a result, the digital reproducing device 4
A clock generation module for supplying a clock to each of the circuit blocks such as the U78, the DSP 82, the USB controller 79, and the like is not required, so that the circuit configuration can be simplified and the size can be reduced accordingly.

The digital-to-analog conversion circuit 108 converts the reproduced music data D1 into an analog audio signal.
This is sent to the amplifier 109. The amplifier 109 amplifies the audio signal to a predetermined level, and thereafter, the headphone jack 2
By outputting the music from the headphones 4 to the headphones 5, the music reproduced through the headphones 5 is provided to the user.

As described above, when the playback / stop button 19 is pressed down, the digital playback device 4 plays back the music data D1 of the digital music content C1 stored in the semiconductor flash memory 80 under the control of the CPU 78, and When the playback / stop button 19 is pressed during the playback, the playback is stopped.

When the playback / stop button 19 is pressed again after the digital playback device 4 is stopped, the CPU 7
When the reproduction of the music data D1 is resumed from the position where the reproduction was stopped based on the control of Step 8 and the reproduction was stopped by pressing the reproduction / stop button 19, and a few seconds or more have passed without any operation, the power is automatically turned off. To reduce power consumption.

By the way, even if the playback / stop button 19 is pressed after the power is turned off, the digital playback device 4 does not play back the music data D1 from the previous stop position, but plays the music data D1 from the first tune. Will do.

The digital playback device 4 is provided with a CPU 78
By controlling the LCD controller 68, the playback mode state, equalizer adjustment (sound quality mode),
The display unit 41 displays various information such as a song number, a playback time, processing states such as playback, stop, fast forward, and fast rewind, a volume, and a remaining battery level.
Is displayed.

Further, in the digital reproducing apparatus 4, the EEPR having a smaller storage capacity than the semiconductor flash memory 80 has
The OM 72 stores the number of music pieces of the entire digital music content C1 written in the semiconductor flash memory 80, the block position of the semiconductor flash memory 80 in which each digital music content C1 is stored, and the so-called FAT (FAT). File Al
location Table) is stored.

Incidentally, in the present embodiment, 64 [KB] of the digital music content C1 is treated as one block, and the block position corresponding to one piece of digital music content C1 is included in the FAT. Become.

When the FAT is stored in the semiconductor flash memory 80 as shown in FIG. 30, for example, when the first digital music content C1 is written under the control of the CPU 78, the block position in the first music digital music content C1 is changed. Is written as FAT, and the next digital music content C1
Is written, the block position in the digital music content C1 of the first music piece and the block position in the digital music content C1 of the current music piece are rewritten into the same area again as a new FAT.

As described above, the FAT is rewritten each time the digital music content C1 is written into the semiconductor flash memory 80. Therefore, the CPU 78 reads the FAT to recognize the block position as the storage location of the desired digital music content C1. Can be.

In addition, the FAT is designed so that the same data is double-written for reserve, so that the data is protected by the reserve FAT even if the driving dry battery 21 is removed during writing of the FAT. Has been made.

However, the semiconductor flash memory 80
Although the stored digital music content C1 can be freely rewritten by the computer device 3, the number of rewrites is currently defined.

Therefore, the semiconductor flash memory 80 has F
When the AT is stored, the FAT is rewritten and double rewritten each time the digital music content C1 is stored. Therefore, the number of rewriting of the FAT becomes very large, and the number of rewriting of the digital music content C1 is consumed. Resulting in.

That is, if the FAT is stored in the semiconductor flash memory 80, the CPU 78
The number of rewrites of T becomes enormous, the number of rewrites of the digital music content C1 decreases, and the specified number of rewrites cannot be satisfied.

On the other hand, the EEPROM 72 has the FAT
The CPU 78 may store the FAT of the stored digital music content C1 in the EEPROM 72 each time the digital music content C1 is stored in the semiconductor flash memory 80. It is not necessary to rewrite each time the music content C1 is stored.

As described above, the CPU 78 does not store the FAT with a large number of rewrites together with the digital music content C1 in the semiconductor flash memory 80, but writes the FAT in the EEPROM 72 separately from the digital music content C1. 80
Can be effectively used for rewriting the digital music content C1.

In practice, the CPU 78 stores the digital music content C1 in the semiconductor flash memory 80 and writes the FAT having a large number of rewrites into the EEPROM 72, so that both the FAT and the digital music content C1 are stored in the semiconductor flash memory 80. Compared with the case where the data is stored, the semiconductor flash memory 80
, The number of rewrites of the digital music content C1 can be increased by several tens of times or more.

The CPU 78 stores the FAT in the EEPROM.
By writing to add to 72,
E with a small storage capacity by minimizing the number of FAT rewrites
The EPROM 72 can be prevented from becoming unrewritable in a short period of time.

By the way, the digital reproducing device 4 is
When connected to the computer device 3 via the cable 103 (hereinafter referred to as USB connection), it is recognized that the USB connection has been made based on an interrupt signal supplied from the USB controller 79 to the CPU 78.

When the digital playback device 4 recognizes that the USB connection has been made, the computer device 3 sends a U
External power having a specified current value is supplied via the SB cable 103, and the power supply circuit 102 is controlled to stop the supply of internal power by the driving dry battery 21.

At this time, the CPU 78 receives the supply of external power from the computer device 3 via the USB cable 103, and at the same time, stops the reproduction of the music data D1 by the DSP. This allows CP
U78 prevents the external power supplied from the computer device 3 from exceeding the specified current value, and controls so that the external power of the specified current value can always be received.

As described above, when the CPU 78 is connected via USB, the CPU 78 switches from the internal power supplied by the driving dry cell 21 to the external power supplied by the computer device 3, so that the external power from the computer device 3 with a low unit price can be obtained. The electric power is used to reduce the power consumption of the driving battery 21 having a high power unit price, thereby extending the life of the driving battery 21.

The CPU 78 stops the reproduction process of the music data D1 by the DSP 82 when external power is supplied from the computer device 3 via the USB cable 103, thereby reducing the radiation caused by the operation of the DSP 82. As a result, the total radiation including the computer device 3 can be further reduced.

When the CPU 78 switches from the internal power supplied by the driving dry cell 21 to the external power supplied by the computer 3, the CPU 78 stops the music data D1 reproduction process by the DSP 82 and executes various operation buttons (volume). Upper limit fixing switch 12, hold switch 20, volume up button 14, volume down button 15,
The digital music content C1 is written into the semiconductor flash memory 80 under the control of the computer device 3 without performing various operations according to the operation of the play / stop button 19, the fast forward button 16, the fast forward button 17, and the like. Thus, even when various operation buttons are pressed during rewriting of the digital music content C1, the operation of the device itself is reliably prevented from becoming unstable, and the digital music content C1 can be protected. It has been done.

At the same time, the CPU 78 can reliably receive the external power from the computer device 3 at all times by switching from the internal power supplied by the driving battery 21 to the external power supplied by the computer device 3.

Thus, the digital playback device 4 controls the computer device 3 to write the digital music content C1 into the semiconductor flash memory 80 while
Even when the driving dry battery 21 is removed or the battery runs out, the process is prevented from being interrupted, and the data writing process can be reliably executed.

At this time, the CPU 78 controls the LCD controller 68 on the basis of the external power supplied by the computer device 3 to display “PC” on the display section 41. And notifies the user that the operation with the various operation buttons and switches cannot be performed.

(3) Operation and effect of the present embodiment In the above configuration, the DSP 8 of the digital reproduction device 4
Reference numeral 2 denotes an IC package 82I integrally formed with an oscillator 82A together with an oscillation circuit provided therein. When the music data D1 is not reproduced, the master clock MCL from the oscillator 82A and the master clock M
Bit clock BCLK generated by the oscillation circuit based on CL
And an L channel clock LCLK in frame units;
By stopping the operation by not supplying the operation clock composed of the R channel clock RCLK to the digital-to-analog conversion circuit 108, the power consumption can be reduced and the life of the driving dry battery 21 can be extended.

Since the DSP 82 knows best whether or not the reproduction of the music data D1 is being executed, the DSP 82 supplies or stops the operation clock to the digital-to-analog conversion circuit 108 in accordance with the reproduction code. Fine control can be performed, and thus power consumption can be efficiently reduced.

[0158] The digital reproducing apparatus 4 is provided with a DSP 82
Similarly to the above, the oscillators 78A and 79A made of crystal are also externally attached to the CPU 78 and the USB controller 79, and a predetermined process is executed using the master clock MCLK supplied from the oscillators 78A and 79A. CPU78, DSP82, US
A clock generation module for supplying a clock to each circuit block such as the B controller 79 is not required, so that the circuit configuration can be simplified and the size can be reduced.

According to the above configuration, when the digital reproduction device 4 does not reproduce the music data D1 according to the reproduction code, the digital clock 4 stops supplying the operation clock from the DSP 32 to the digital-to-analog conversion circuit 108.
Power consumption can be efficiently reduced, and thus long-time use can be realized.

(4) Other Embodiments In the above-described embodiment, a system for separately controlling the supply of the operation clock from the DSP 82 to the digital-to-analog conversion circuit 108 during reproduction or non-reproduction of the music data D1 is described. Although the case where the present invention is applied to the digital reproducing apparatus 4 has been described, the present invention is not limited to this.
As long as the digital data such as image data is converted into an analog signal using the P82 and the digital-to-analog conversion circuit 108, the present invention may be applied to various other data reproducing apparatuses.

In the above embodiment, the DSP
82 has been described in which the supply of the operation clock to the digital-to-analog conversion circuit 108 is controlled based on the reproduction code stored in the semiconductor flash memory 80, but the present invention is not limited to this. The clock supply may be controlled by installing the reproduction code from the computer device 3 into the digital reproduction device 4 using the program storage medium storing the program.

As described above, the program storage medium used to install the reproduction code for controlling the clock supply described above in the digital reproduction device 4 and to make it executable by the digital reproduction device 4 includes: For example, floppy disk, CD-ROM (C
ohmpact Disc-Read Only Mem
ory), DVD (Digital Video Di)
Not only package media such as sc) but also a semiconductor memory or a magneto-optical disk in which a program is temporarily or permanently stored may be realized. As a means for storing a program in these program storage media, the program may be stored via various communication interfaces such as a local area network, the Internet, and digital satellite broadcasting.

Further, in the above-described embodiment, the semiconductor flash memory 80 as storage means for storing music data D1 as content data, and the music data D1 read from the semiconductor flash memory 80
CPU 78 as digital signal processing means for reproducing
And a DSP 82, and a digital-to-analog conversion circuit 108 as digital-to-analog conversion means for converting reproduction data reproduced by the DSP 82 into an audio signal as an analog signal.
1 from the own oscillation circuit to the digital-to-analog conversion circuit 108 only during reproduction of the operation clock MCL.
Although a case has been described in which K, BCLK, LCLK, and RCLK are supplied, the present invention is not limited to this, and a data reproducing apparatus constituted by various other storage means, digital signal processing means, and digital / analog conversion means Thus, the operating clock may be supplied from its own oscillation circuit to the digital-to-analog conversion means only while the digital signal processing means is playing back the music data D1.

[0164]

As described above, according to the present invention, storage means for storing content data, digital signal processing means for reproducing content data read from the storage means, and reproduction data reproduced by the digital signal processing means. Digital-to-analog converting means for converting data into an analog signal, wherein the digital signal processing means supplies an operation clock to the digital-to-analog converting means from its own oscillation circuit only while the content data is being reproduced. As a result, the operation clock is not supplied to the digital-to-analog conversion means except during playback, so that the power consumption is reduced without operating the digital-to-analog conversion means by that much, and thus precise power saving is achieved. It can be used for a long time.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining a usage form of digital music content.

FIG. 2 is a schematic diagram used to explain the restriction on reproduction of digital music content.

FIG. 3 is a schematic perspective view showing the configuration of the digital playback device according to the present embodiment.

FIG. 4 is a left side view, a front view, a right side view, and a rear view showing a configuration of a peripheral side surface of the digital reproducing apparatus.

FIG. 5 is a schematic diagram for explaining a digital playback device to which a neck strap is attached.

FIG. 6 is a schematic diagram for explaining a digital playback device hanging from a neck by using a strap for hanging the neck;

FIG. 7 is a schematic perspective view for explaining insertion of a plug into a headphone jack.

FIG. 8 is a schematic diagram used for describing a digital playback device attached to a breast pocket.

FIG. 9 is a schematic exploded perspective view showing the internal configuration of the digital playback device.

FIG. 10 is a schematic cross-sectional view showing a configuration of a dry battery storage unit.

FIG. 11 is a schematic perspective view and a schematic exploded perspective view showing the configuration of a serial label.

FIG. 12 is a schematic perspective view illustrating a configuration of a display unit protection member.

FIG. 13 is a schematic perspective view illustrating a configuration of a display unit.

FIG. 14 is a schematic front view and a schematic rear view showing the configuration of a sub-circuit board.

FIG. 15 is a schematic front view and a schematic rear view showing the configuration of a main circuit board.

FIG. 16 is a schematic side view and a schematic top view for explaining connection between a sub circuit board and a main circuit board.

FIG. 17 is a schematic perspective view for explaining attachment of the display unit protection member to the front side case;

FIG. 18 is a schematic perspective view for explaining attachment of a display unit.

FIG. 19 is a schematic perspective view for explaining storage of a main circuit board and a sub circuit board in a housing case.

FIG. 20 is a schematic perspective view for explaining attachment of the rear case to the front case.

FIG. 21 is a schematic perspective view for explaining storage of a sub-circuit board in a front side case;

FIG. 22 is a schematic side view for explaining storage of a main circuit board in a housing case.

FIG. 23 is a schematic cross-sectional view with a part cut away for explaining the flow of static electricity to the main circuit board.

FIG. 24 is a schematic side view for explaining the assembly of the display unit protection member and the sub-circuit board;

FIG. 25 is a schematic side view partially cut away for explaining the flow of static electricity from the display unit protection member to the sub-circuit board;

FIG. 26 is a block diagram illustrating a circuit configuration of a digital playback device.

FIG. 27 is a schematic diagram illustrating a data structure of digital music content.

FIG. 28 is a schematic diagram showing a data structure (1) of a header.

FIG. 29 is a schematic diagram illustrating a data structure (2) of a header.

FIG. 30 is a schematic diagram for explaining a data structure of a semiconductor flash memory when an FAT is stored;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... EMD server, 2 ... Internet, 3 ... Computer device, 4 ... Digital reproduction device, 5 ... Headphones, 21 ... Dry batteries, 41 ... Display unit, 68 ...
LCD controller, 72 …… EEPROM, 77 ……
Flash memory controller 78 CPU 79
... USB controller, 80, semiconductor flash memory, 82, DSP, 83, USB connector, 10
2 Power supply circuit 103 USB cable 105
... ROM, 106 ... RAM, 108 ... Digital-to-analog conversion circuit, 109 ... Amplifier.

Continuing from the front page (72) Inventor Masayuki Chiba 254 Shimokomaba, Senmaya, Senmaya-cho, Higashiiwai-gun, Iwate Prefecture F-term (reference) 5B019 CA06 CA07 HF02 HF10 5B079 BA11 BB01 BC01 DD20 5D045 DB01 5D108 CA04 CA07 CA29 9A001 BB03 BB06 EE05 JZ25 JZ27 KZ43 KZ60 KZ62

Claims (6)

[Claims] 1. A storage means for storing content data, a digital signal processing means for reproducing the content data read from the storage means, and a digital signal for converting the reproduction data reproduced by the digital signal processing means into an analog signal. Analog conversion means, wherein the digital signal processing means supplies an operation clock to the digital-analog conversion means from its own oscillation circuit only while the content data is being reproduced. apparatus. 2. The digital signal processing unit according to claim 1, wherein when the content data is not being reproduced, the supply of the operation clock to the digital-to-analog conversion unit is stopped and the digital signal processing unit shifts to an idle state. A data reproducing apparatus according to claim 1. 3. The content data read from a predetermined storage means is reproduced by a digital signal processing means based on an operation clock, and the reproduced data is converted into an analog signal by a digital-to-analog conversion means based on the operation clock. In the clock supply control method of a data reproducing apparatus for converting and outputting, the digital signal processing means transmits the operation clock from its own oscillation circuit to the digital-to-analog converting means only while reproducing the content data. A clock supply control method, comprising a clock supply step of supplying. 4. A clock supply stopping step for stopping the supply of the operation clock to the digital-to-analog conversion means and shifting to an idle state when the digital signal processing means is not reproducing the content data. The clock supply control method according to claim 3, wherein: 5. A content signal read from a predetermined storage means is reproduced by a digital signal processing means based on an operation clock, and the reproduced data is converted into an analog signal by a digital-to-analog conversion means based on the operation clock. In a program storage medium for controlling the clock supply of a data reproducing device for converting and outputting, the digital signal processing means transmits the digital data to the digital-to-analog converting means from its own oscillation circuit only while reproducing the content data. A program storage medium comprising a clock supply step of supplying the operation clock, the program storage medium causing the data reproduction device to execute a program. 6. A clock supply stopping step for stopping the supply of the operation clock to the digital-to-analog conversion means and transitioning to an idle state when the digital signal processing means is not reproducing the content data. The program storage medium according to claim 5, wherein