JP4308116B2 - Data playback device - Google Patents

Description

  The present invention relates to a data reproducing device including a capacitance sensor and a hard disk device.

  In recent years, various portable data playback devices that can be driven by a battery, such as portable information terminals (for example, PDAs), portable music terminals, and portable video terminals, have been developed and widely spread. Some data reproducing apparatuses of this type have a built-in small hard disk device.

  Since this type of data reproducing apparatus is often carried by a user, there is a risk that the data reproducing apparatus may be inadvertently dropped. In particular, in a hard disk device built in a data reproducing apparatus, when an impact is applied during an access operation, the disk is damaged due to a collision between the head and the disk.

Therefore, in Patent Document 1, a weightless sensor for detecting that the device itself is in a falling state is provided, and when it is detected that the device is in a falling state, an impact countermeasure mechanism is activated (for example, the hard disk head is retracted). A data playback device is disclosed. Further, Patent Document 2 discloses a data reproducing device that includes an acceleration sensor for detecting that the device itself is in a fall state, and activates an impact countermeasure mechanism when it is detected that the device is in a fall state.
JP 2003-263240 A JP 2003-263853 A

  However, mounting the above-described weightless sensor or acceleration sensor in the data reproducing apparatus increases the size and cost of electronic equipment. SUMMARY OF THE INVENTION An object of the present invention is to provide a data reproducing apparatus having an impact countermeasure mechanism that does not increase the size and cost of the data reproducing apparatus.

  The data reproducing apparatus according to claim 1 is a data reproducing apparatus including a capacitance sensor and a hard disk device, and a controller that retracts a head of the hard disk device when an output of the capacitance sensor changes. It is provided with.

  According to the data reproducing apparatus of the first aspect, even if the user accidentally releases the hand and drops it, the head of the hard disk device is immediately retracted (for example, retracted to a shipyard provided on the outer periphery). Therefore, it is possible to prevent the hard disk from being damaged by the head. In addition, since the drop can be detected by the capacitance sensor, it is possible to provide a data reproducing apparatus having an impact countermeasure mechanism without increasing the size of the apparatus and increasing the cost.

  Among the above-described capacitance sensors, there is one in which the capacitance value decreases when a conductive object comes into contact or approaches.

  Accordingly, a data reproduction device according to claim 2 is the data reproduction device according to claim 1, wherein when the capacitance sensor and the output of the capacitance sensor are less than a predetermined value, the user reproduces the data reproduction device. A holding state determining unit that determines that the device is held and determines that the user does not hold the data reproducing device when the output of the capacitance sensor is equal to or greater than a predetermined value; . Further, the control unit is configured to retract the head of the hard disk device when the determination by the holding state determination unit changes from the held state to the non-holding state.

  Some data reproducing apparatuses of the present invention have a plurality of capacitance sensors.

  Accordingly, a data reproduction device according to claim 3 is the data reproduction device according to claim 1, wherein the outputs of the plurality of capacitance sensors and the plurality of capacitance sensors are less than a predetermined value. When it is determined that the user is holding the data reproducing device, and all the outputs of the capacitance sensor are equal to or greater than a predetermined value, it is determined that the user is not holding the data reproducing device. A holding state determination unit. Further, the control unit is configured to retract the head of the hard disk device when the determination by the holding state determination unit changes from the held state to the non-holding state.

  For example, when the user touches any one of the capacitance sensors, the data reproducing apparatus according to the third aspect determines that the holding state is present, and when the user does not touch any of the capacitance sensors, It is determined that the state is the holding state.

  By the way, it is assumed that the data reproducing apparatus of the present invention is used for music reproduction or the like while the user is stored in a pocket or the like. Even in such a case, the user may accidentally drop the data reproducing device from the pocket. Some of the above-described capacitance sensors can detect a change in capacitance even when a thin shirt is worn even when the pocket is put in the pocket.

  Accordingly, a data reproduction device according to a fourth aspect is the data reproduction device according to the second or third aspect, wherein the predetermined value is different between video reproduction and music reproduction.

  According to the data reproducing device of the fourth aspect, even when the user drops the user from the state of being stored in the pocket, it is possible to detect the drop more reliably.

  The data reproduction device according to claim 5 is the data reproduction device according to any one of claims 2 to 4, wherein the predetermined value is determined based on a history of output values of the capacitance sensor. Features.

  According to the data reproducing apparatus of claim 5 as well, it is possible to reliably detect the drop when the user drops the user from the state of being stored in the pocket.

  By the way, according to the data reproducing device of claims 1 to 5, not only when it is accidentally dropped, but also when the user simply changes the device or when the data reproducing device is placed on a desk or the like. Even so, the output of the capacitance sensor changes, and the head of the hard disk is retracted to the outer periphery of the disk. In such a case, it is desirable to return the hard disk head to the disk again so that data can be reproduced continuously.

  Accordingly, a data reproducing device according to claim 6 is the data reproducing device according to any one of claims 1 to 5, wherein the head control unit moves the head after a lapse of a predetermined time after the head is retracted. The hard disk is returned to the hard disk.

  The predetermined time refers to a time longer than the time from when the user of the data reproducing apparatus releases his / her hand from a certain height until it collides with the ground or the like. For example, when it is assumed that the data reproducing device collides with the floor 1 second after the hand is released from the data reproducing device at a height of 1 meter, the predetermined time is, for example, about 2 seconds. Is desirable.

  Further, as in the data reproducing apparatus of the sixth aspect, it is desirable that the output of data is not interrupted even while the head is temporarily retracted for a certain time. Here, the output of data means display of video data on the display unit if the data playback device is a video playback device, and if the data playback device is a music playback device, the output from the speaker or earphone output of music data. Means output. That is, it is desirable not to interrupt the display of video data and the output of music data even while the head is temporarily retracted for a certain time.

  Accordingly, a data reproduction device according to claim 7 is the data reproduction device according to claim 6, wherein the data reproduction device is generated based on a memory that temporarily stores data read from the hard disk device, and the data An output unit that outputs video data and / or music data, and the memory stores video data and / or data from the output unit while the head of the hard disk device is retracted to the outer periphery of the hard disk. Alternatively, the data read from the hard disk device is buffered so that the output of music data is not interrupted.

  For example, if it is assumed that the data reproducing apparatus according to claim 6 returns the head to the hard disk after 2 seconds have elapsed since the head of the hard disk apparatus has been retracted, the output to the memory is at least about 3 seconds. It is desirable to always accumulate data (video data, music data, etc.).

  According to the present invention, it is possible to provide a data reproducing apparatus having an impact countermeasure mechanism without enlarging the data reproducing apparatus and increasing the cost.

  With reference to FIG. 1, the external view of the portable video terminal 100 which is one Embodiment of the data reproducing device of this invention is demonstrated.

  FIG. 1A is a front view of the portable video terminal 100. The portable video terminal 100 is provided with capacitance sensors 1a and 1b on the left and right of the display unit 2 for displaying video. Further, a capacitive sensor 1 c is also provided on the side surface of the portable video terminal 100. FIG. 1B is a rear view of the portable video terminal 100, but the capacitive sensor 1 d is also provided on the rear surface of the portable video terminal 100. The capacitance sensors 1a to 1d have a capacitance value that decreases when a conductive object contacts or approaches. The conductive object includes, for example, a human body and a metal object. In the present embodiment, the conductive object particularly refers to a human finger. The configuration and operation of this capacitance sensor will be described in detail later. In the following, the reference numeral “1” is used to indicate individual capacitance sensors without specifying them.

  FIG. 2 shows the configuration of the portable video terminal 100.

  Analog signals output from the capacitance sensors 1a to 1d are amplified and A / D converted (binarized) by the sensor signal processing units 11a to 11d. The capacitance value of the capacitance sensor 1 decreases when a finger touches or approaches. Therefore, the sensor signal processing unit 11 outputs “1” when the finger is not in contact with the capacitance sensor 1, and outputs “0” when the finger is in contact with the capacitance sensor 1. Thus, the binarization level is set.

  The holding state determination unit 12 determines whether or not the portable video terminal 100 is held by the user based on the outputs from the sensor signal processing units 11a to 11d. Specifically, it is determined whether or not the portable video terminal 100 is held by the user by performing an AND operation of the sensor signal processing units 11a to 11d. That is, when the AND operation result is “0”, it is determined that the finger is in contact with any one of the capacitance sensors 1a to 1d, and the portable video terminal 100 is held by the user. to decide. When the AND operation results of the sensor signal processing units 11a to 11d are “1”, it is determined that the finger is not in contact with any of the capacitance sensors 1a to 1d, and the portable video terminal 100 is determined by the user. Judge that it is not held.

  The control unit 13 controls operations of the hard disk device 3 and the buffer 4 described later based on the output of the holding state determination unit 12. Details of the control by the control unit 13 and details of the hard disk device 3 will be described in detail later.

  The buffer 4 temporarily stores data read from the hard disk device 3. The decoder 15 decodes data temporarily stored in the buffer 4 (for example, data in Mpeg format) into stream data displayed on the display unit 2.

  The hard disk device 3 of this embodiment can reproduce data at several tens of MB (megabytes) per second, but the data processing capability of the decoder 15 is several hundred Kb (kilobits) per second. Therefore, the hard disk device 3 intermittently reproduces the data while monitoring the capacity of the data temporarily stored in the buffer 4, and if the data capacity temporarily stored in the buffer 4 becomes less than a certain value, the hard disk device 3 3 outputs the reproduction data to the buffer 4. The hard disk device 3 does not transfer the reproduction data to the buffer 4 while the data capacity temporarily stored in the buffer 4 is equal to or greater than the predetermined value.

  In the above description, the hard disk device 3 side is described as intermittently reproducing data while monitoring the data amount of the buffer 4. However, the buffer 4 side controls the hard disk device 3 while monitoring its own data amount. May be.

  FIG. 3 is a sectional view of the capacitance sensor 1. The capacitance sensor 1 includes a first electrode 31, a second electrode 32, and the like.

  FIG. 4 shows the operating principle of the capacitance sensor 1, and FIG. 5 shows an example of the user's holding state and the output of the capacitance sensor 1.

  With reference to FIG. 4A, a voltage is applied between the first electrode 31 and the second electrode 32 of the capacitance sensor 1, whereby the first electrode 31 and the second electrode 32 are There are electric lines of force between them. When a finger is brought close to the capacitance sensor 1 where such electric lines of force are generated, electric lines of force that wrap around from the first electrode 31 to the second electrode 32 as shown in FIG. A part of is absorbed to the finger side by the approach of the finger, and the capacitance value decreases. This absorption occurs due to the conductivity of the human body. Thus, the capacitance sensor 1 determines whether or not a finger is in proximity to the capacitance sensor 1 by sensing the changed capacitance.

  Referring to FIG. 5, when the user is in contact with capacitance sensor 1, the output of capacitance sensor 1 is Vh. When the user releases it from the capacitance sensor 1, the output of the capacitance sensor 1 rises to Vr. As described above, the sensor signal processing unit 11 converts the analog output of the capacitance sensor 1 into a digital signal (binary signal). The sensor signal processing unit 11 outputs a digital signal “1” when the output of the capacitance sensor 1 is equal to or higher than Vth, and outputs a digital signal “0” when the output of the capacitance sensor 1 is less than Vth. Is output.

  As described above, since the capacitance sensor 1 is arranged at any location on the front, back, and side of the portable video terminal 100, when the user holds the portable video terminal 100, the user's finger is always It contacts one of the capacitance sensors 1a to 1d. In other words, when the user releases his / her hand from the portable video terminal 100, the output of any one of the capacitance sensors 1a to 1d always changes, so that the AND from the sensor signal processing units 11a to 11d. If a change in output is detected, the holding state determination unit 12 estimates that the user has released his hand from the portable video terminal 100. If the user releases the hand from the portable video terminal 100, the portable video terminal 100 may be in a fall state. Therefore, the control unit 13 sends a command to the hard disk device 3 to retract the head to the outside of the hard disk in order to prevent damage to the hard disk device 3 due to dropping.

  6 and 7 are diagrams showing the configuration of the hard disk device 3.

  FIG. 6 is a diagram showing an internal configuration of the hard disk device 3. The disk 19 at the center is called a platter, is made of a metal disk, and is coated with a magnetic material. The magnetic state of the magnetic material on the platter is stored by changing the head 21 at the tip of the head arm actuator 20 or information is read from the head 21 by detecting the magnetic state. . The head arm actuator 20 is controlled to move by a voice coil motor driving movable coil 22 and the magnetic circuit 18. In the figure, the head arm actuator 20 indicated by a broken line is a case where the head arm actuator 20 is retracted to a ship yard 23 which is a non-operating area (this ship yard is also called a “ramp mechanism”). is there.

  When such a hard disk device 3 is dropped, the head does not collide with the platter 19 because the head is retracted to the shipyard 23 when reading / writing is not performed. However, when reading and writing, the head 21 collides with the platter 19 due to an impact on the hard disk device 3 due to dropping, and the magnetic layer on the surface of the platter 19 and the head 21 are destroyed. Furthermore, not only the collision location, but also the so-called head crash, in which the fragments generated at that time collide with other areas of the platter 19 rotating at high speed and repeatedly break down, making the entire area of the disk unusable. May cause.

  Therefore, when the holding state determination unit 12 detects an output change of the capacitance sensor 1, the control unit 13 predicts that the portable video terminal 100 may fall, and ships the head 21 of the hard disk device 3. A command signal is sent to the hard disk device 3 so as to retreat to the yard 23.

  It should be noted that the time required to retract the head 21 of the hard disk device 3 during data reproduction to the shipyard 23 is a case where the head 21 is at the innermost circumference of the disk, which requires the longest retract time. Even so, it is tens of milliseconds at most. Therefore, the time required for the head 21 of the hard disk device 3 to be retracted to the shipyard 23 after the holding state determination unit 12 detects the holding state of the portable video terminal 100 is determined so that the portable video terminal 100 leaves the user's hand. This is much shorter than the time it takes to hit the ground.

  FIG. 7 is a block diagram of an electric circuit configuration of the hard disk device 3. As shown in FIG. 7, the hard disk device 3 incorporates an interface circuit 201, a head arm actuator drive control circuit 203, a position control circuit 205, a disk rotation control circuit 207, a data processing circuit 209, and the like. .

  The head arm actuator drive control circuit 203 drives the head arm actuator 20 by supplying a drive signal to the movable coil 22 of the voice coil motor based on the position control signal from the position control circuit 205. A command signal from the control unit 13 is sent to the head arm actuator drive control circuit 203 via the interface circuit 201. Alternatively, the command signal from the control unit 13 may be directly sent to the head arm actuator drive control circuit 203.

  The data reproduced by the head 21 is amplified and demodulated by the data processing circuit 209 and sent to the buffer 4 via the interface circuit 201.

  FIG. 8 is a flowchart showing the operation of the portable video terminal 100. When the holding state determination unit 12 detects a change in the holding state while the portable video terminal 100 is playing back an image (Yes in step S1), the control unit 13 prevents damage to the hard disk device 3 due to dropping. Then, a command is sent to the hard disk device 3 to retract the head 21 to the shipyard 23 outside the hard disk (step S2). When a predetermined time has elapsed after the holding state determination unit 12 detects a change in the holding state (Yes in step S3), the control unit 13 returns the head of the hard disk device 3 and resumes data reproduction. Then, a command is sent to the hard disk device 3 (step S4). The fixed time in step S3 refers to a time longer than the time from when the user of the portable video terminal 100 releases his hand from a certain height until it collides with the ground or the like. For example, when it is assumed that the portable video terminal 100 collides with the floor 1 second after the hand is released from the portable video terminal 100 at a height of 1 meter, the predetermined time is about 2 seconds, for example. It is desirable to do.

  It should be noted that it is desirable not to interrupt the display of the video data on the display unit 2 even while the head is retracted to the shipyard 23 for a certain time as in step S2. Therefore, a certain amount of data (for example, 3 seconds) is stored in the buffer 4 so that the display of video data is not interrupted while the head 21 is retracted to the shipyard 23 for a certain time (for example, about 2 seconds). It is desirable to always buffer the video data).

(Modification 1)
In the above embodiment, the capacitance sensor 1 has been described as being provided on the front surface, the rear surface, and the side surface as in the portable video terminal 100 illustrated in FIG. 1, but the operation unit is also configured as illustrated in FIG. 9. The portable video terminal 200 realized by the capacitance sensor 1 ′ may be used. Outputs from the respective capacitance sensors 1 and 1 ′ provided in the portable video terminal 200 are input to the holding state determination unit 12. Similar to the portable video terminal 100, the holding state determination unit 12 performs an AND operation on the output from the capacitance sensor 1, and determines the holding state of the portable video terminal 200 based on the result.

(Modification 2)
In the above embodiment, when the user of the portable video terminal 100 releases his / her finger from the portable video terminal 100, the head of the built-in hard disk is retracted to the shipyard. On the other hand, in the case where the mobile video terminal 100 is placed on a table such as a desk, the user of the mobile video terminal 100 accidentally touches the mobile video terminal 100 with a finger. As a result, the case where the portable video terminal 100 falls down (the rear surface of the portable video terminal 100 collides with the desk surface) is also assumed. Even in such a case, it is desirable to retract the head of the built-in hard disk to the shipyard.

  The operation that the portable video terminal 100 should take at this time will be described below. First, when the mobile video terminal 100 is placed in a standing state on a table such as a desk, the holding state determination unit 12 determines that the mobile video terminal 100 is not held. Next, when the user accidentally touches the portable video terminal 100 with his / her finger, the holding state determination unit 12 determines that the portable video terminal 100 is held. At this time, since the portable video terminal 100 placed in a standing state falls from the rear side toward the desk surface, the finger naturally leaves the portable video terminal 100, so the holding state determination unit 12 Judge that it is not held. At this time, the control unit 13 sends a command to the hard disk device 3 to retract the head 21 to the shipyard 23.

(Modification 3)
In the above embodiment, the data reproducing apparatus is the portable video terminal 100, but the data reproducing apparatus of the present invention includes a portable music terminal. In the portable music terminal, it is assumed that the user uses the portable music terminal in a state of being stored in a pocket or the like. Even in such a case, the user may accidentally drop the data reproducing device from the pocket. Even if the capacitance sensor 1 is not in contact with the human body, the capacitance change is detected if it is in a pocket of thin clothes. Therefore, the data reproducing apparatus of the present invention may be able to detect the fall more reliably even when the user drops the user from the state of being stored in the pocket.

  Further, even when the portable video terminal 100 of the above-described embodiment can also play music, it is conceivable that the user uses the portable video terminal 100 in a state where the user is stored in a pocket. Therefore, a fall detection method in such a case will be described with reference to FIG.

  At the time of video reproduction, the user uses the portable video terminal 100 while holding it, and the output of the capacitance sensor 1 at that time is Vh. During video reproduction, when the output of the capacitance sensor 1 becomes equal to or higher than Vth, the digital output of the sensor signal processing unit 11 is “1” as in the case described with reference to FIG.

  Here, when the user changes to the music playback mode, the control unit 13 changes the binarization threshold of the sensor signal processing unit 11 from Vth to Vth2. Thereafter, when the user puts the portable video terminal 100 in the pocket, the output of the capacitance sensor 1 becomes Vp. In this case, if the output of the capacitance sensor 1 is equal to or higher than Vth2, the digital output of the sensor signal processing unit 11 is “1”.

  In the above description, when the user switches from the video playback mode to the music playback mode, the control unit 13 changes the binarization threshold value of the sensor signal processing unit 11. Based on this, the binarization threshold of the sensor signal processing unit 11 may be changed. For example, the binarization threshold may be changed based on the average output value of the capacitance sensor 1 over the past several seconds. Further, the binary threshold value is obtained by dividing the value obtained by adding the output value in the non-holding state (Vr in FIG. 10) by the average value of the output values of the capacitance sensor 1 over the past several seconds. It is good as a value.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, in the above description, the portable video terminal 100 has been described as an example of the data reproducing apparatus according to the present invention. However, instead of this, any portable music terminal or portable information terminal may be used as long as it includes at least a hard disk device. It may be.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capacitance sensor 2 Display part 3 Hard disk apparatus 4 Buffer 11 Sensor signal processing part 12 Holding state determination part 13 Control part 15 Decoder 21 Head 23 Shipyard 100 Portable video terminal

1 is an external view of a portable video terminal 100 which is an embodiment of a data reproducing device of the present invention. (A) is a front view of the portable video terminal 100, and (b) is a rear view of the portable video terminal 100. The structure of the portable video terminal 100 is shown. 1 is a cross-sectional view of a capacitance sensor 1. FIG. The principle of operation of the capacitance sensor 1 is shown. (A) shows the lines of electric force when the finger is not approaching the capacitance sensor 1, and (b) is the electric force when the finger is approaching the capacitance sensor 1. A line is shown. An example of a user's holding state and the output of the capacitance sensor 1 is shown. 2 is a diagram showing an internal configuration of a hard disk device 3. FIG. 3 is a block diagram of an electric circuit configuration of a hard disk device 3. FIG. 3 is a flowchart showing the operation of the portable video terminal 100. The operation unit also shows a portable video terminal 200 realized by a capacitance sensor. The other example of the relationship between a user's holding | maintenance state and the output of the electrostatic capacitance sensor 1 is shown.

Claims (1)

A data reproduction device including a capacitance sensor and a hard disk device,
When the output of the capacitance sensor is smaller than a predetermined value, it is determined that the user is holding the device, and when the output is larger than the predetermined value, a holding state determination unit that determines that the device is not holding;
A control unit that retracts the head of the hard disk device when the determination by the holding state determination unit changes from the held state to the non-holding state, and
The data playback apparatus according to claim 1, wherein the predetermined value is different between video playback and music playback .

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