JP4643488B2 - Disc recording / reproducing apparatus and recording / reproducing control method - Google Patents

Description

  The present invention relates to a disk recording / reproducing apparatus and a recording / reproducing control method for recording / reproducing a video signal on a disk medium such as an HDD, and more particularly to a technique for reducing power consumption.

  In a disk recording / reproducing apparatus such as an HDD, a pre-reading method is used to improve a reading speed for data continuously arranged on the disk. In the pre-reading method, not only the data block requested to be read but also the subsequent data block is read and stored in a cache memory or the like. When a read request for the previous data block is received, the read-ahead data stored in the cache memory is immediately transferred, so that the disk rotation time and read head seek time are not limited, and the data can be quickly read. Data transfer can be performed.

  As a technique related to the prefetching method, the disk memory device described in Patent Document 1 determines continuity detection means for detecting the prefetching direction of data based on a read command, and the position and size on the disk memory medium on which prefetching is performed. Prefetch area determination means and the like are provided. Thus, it is stated that special reproduction such as reverse reproduction and high-speed reproduction of data such as moving images and sounds can be handled.

  On the other hand, disk recording / playback devices such as HDDs are being used as portable video players because they can record large volumes. However, there are many mechanically operating parts such as a motor part for rotating the disk and a head movable part, and reduction of power consumption is required for mobile applications.

  As a technique related to power consumption reduction, in the magnetic disk device described in Patent Document 2, when there is no access for a certain period of time, power saving processing is performed to stop the motor of the device, and if it is in the power saving processing state, a dummy seek (magnetic head) It is stated that even if there is a request for a process of moving fine particles at regular intervals to blow out fine dust, this is ignored and the dummy seek process is not executed.

JP 2001-285805 A JP-A-7-121306

  In a disk recording / reproducing apparatus such as an HDD, the techniques disclosed in Patent Document 1 and Patent Document 2 described above are adopted, the transfer of read data is speeded up by a pre-read method, and power saving processing is performed to reduce power consumption. It is possible. That is, when the next read operation is not performed for a certain time after the pre-read read operation is finished, the motor is stopped and switched to the low power consumption mode.

  In this case, there is no problem if it is ensured that the low power consumption mode continues for a certain period of time, but it is generally uncertain when the next read operation is resumed. The switching time (transition time) from the normal mode to the low power consumption mode and the switching time (return time) from the low power consumption mode to the normal mode are not zero but have finite values (overhead time). Therefore, in order to surely switch to the low power consumption mode, it is necessary that the pause period of the read operation is longer than the time required for switching (transition time and return time). If a command for the next read operation is received in the middle of switching to the low power consumption mode, the next read operation may be delayed due to the return time, and the reproduced image may be disturbed or temporally discontinuous. . The read operation pause period depends on the data read-ahead condition, and there are multiple low-power consumption modes. Therefore, in order to facilitate device operation and reduce power consumption, consider the optimal combination of these. There is a need. However, Patent Document 1 and Patent Document 2 do not take into consideration the time required for switching to the low power consumption mode and the mode selection for low power consumption.

  An object of the present invention is to provide a disc recording / reproducing apparatus and a recording / reproducing control method capable of reliably switching to a data reading or writing process and a low power consumption mode and obtaining a good reproduced image or the like.

  An object of the present invention is to optimally select a mode with low power consumption and further reduce power consumption.

  The present invention relates to a disk recording / playback apparatus having a disk drive for reading or writing continuous data to / from a disk medium at a speed k times faster than the playback speed, and a buffer for storing data read or written by the disk drive A memory, a read / write amount determination unit that determines a time Tr for continuously reading or writing data, and a control unit that controls a read or write operation of the disk drive are provided. The control unit reads or writes data from / to the disk drive for the time Tr, and after the reading or writing is completed, compares the time Tr with a predetermined value Trm. If the time Tr is greater than the predetermined value Trm, Is switched to the low power consumption mode in which the operation of the unit is stopped (where Trm = To / (k−1), To is the switching time to the low power consumption mode).

  The present invention is a disk recording / reproducing apparatus having a disk drive that reads or writes continuous data on a disk medium at a speed Br that is k times faster than the reproduction speed. A buffer memory for storing, a read / write amount determining unit for determining a data amount Fr for continuously reading or writing data, and a control unit for controlling a read or write operation of the disk drive are provided. The control unit reads or writes data to or from the disk drive by the data amount Fr. After the reading or writing is completed, the control unit compares the data amount Fr with a predetermined value Frm, and if the data amount Fr is greater than the predetermined value Frm, Is switched to a low power consumption mode where a part of the operation is stopped (where Frm = To · Br / (k−1), To is a switching time to the low power consumption mode).

  Here, when a plurality of modes having different switching times and power consumptions can be selected as the low power consumption mode in the disk drive, the control unit further calculates the average power consumption in each mode from the time Tr or the data amount Fr. It has a power consumption calculation unit to calculate and a mode selection unit to select a mode that minimizes the calculated average power consumption.

  The present invention also relates to a recording / playback control method for a disk drive that reads or writes continuous data to / from a disk medium at a speed k times faster than the playback speed, and is a time Tr for continuously reading or writing data. The data is read from or written to the disk medium for the time Tr. After reading or writing, the time Tr is compared with a predetermined value Trm, and if the time Tr is larger than the predetermined value Trm, the disk drive is switched to a low power consumption mode in which a part of the operation is stopped.

  The present invention is a recording / playback control method for a disk drive that reads or writes continuous data to / from a disk medium at a speed Br that is k times faster than the playback speed, and continuously reads or writes data. A data amount Fr is determined, and data is read from or written to the disk medium by the data amount Fr. After the reading or writing is completed, the data amount Fr is compared with a predetermined value Frm. If the data amount Fr is larger than the predetermined value Trm, the disk drive is switched to a low power consumption mode in which a part of the operation is stopped.

  Here, when a plurality of modes having different switching time and power consumption can be selected as the low power consumption mode, the average power consumption in each mode is calculated from the time Tr or the data amount Fr, and the average power consumption is minimized. Select a mode.

  According to the present invention, it is possible to suitably perform data reading or writing processing in a disk recording / reproducing apparatus and reduce power consumption.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a block configuration of a mobile video player using an HDD as a recording medium as an embodiment of a disc recording / reproducing apparatus according to the present invention.

  The HDD (Hard Disk Drive) 1 stores video content data such as moving images and audio, and can read (read) or write (write) the content data at a higher speed than the reproduction speed (display speed) as required. it can. The HDD includes a hard disk as a medium, a disk motor that rotates the hard disk, a read / write head, a servo mechanism, and the like, and can be switched to a low power consumption mode by stopping some of the operations as will be described later. . The CPU 2 controls each device in the apparatus via the bus 3 and executes a program for reproducing content from the HDD 1. The memory 4 stores various programs and data executed by the CPU 2. The input device (key / remote controller) 5 inputs a user operation and transmits it to the CPU 2. The decoder / display IF 6 decodes the reproduced content file and performs a GUI display process according to an instruction from the CPU 2. The display 7 performs display output such as moving images and sounds output from the decoder / display IF 6 and GUI display.

  The memory 4 stores the following programs. The application (program) 8 receives a user operation from the key / remote controller 5, and performs a process of displaying a GUI and reproducing the content stored in the HDD 1 and displaying it on the display 7. At that time, the following programs 9 to 14 are used. The reproduction processing unit (program) 9 performs content reproduction processing to read content data from the HDD 1 and pass the read data to the decoder / display IF 6.

  The HDD access scheduling unit (program) 10 receives the HDD read request from the reproduction processing unit 9 and manages the read operation and pre-read operation from the HDD 1 and the timing of switching the HDD 1 to the low power consumption mode. For this purpose, the prefetching amount determination unit 15 determines the range and data amount to be prefetched from the HDD 1 in accordance with the reproduction conditions acquired from the application 8. The power consumption calculator 16 calculates the average power consumption when switching to the low power consumption mode. The mode selection unit 17 selects an optimum low power consumption mode based on the calculation result of the power consumption calculation unit 16. The prefetch buffer 11 is a memory area for storing the data read by the reproduction processing unit 9 (the area requested to be read and the prefetched data).

  The decoder access scheduling unit (program) 12 receives a decoding request from the reproduction processing unit 9 and manages the timing for transferring data in units of video display frames to the decoder / display IF 6.

  The HDD driver 13 manages an interface for passing a data read request from the HDD access scheduling unit 10 and a request for switching to the low power consumption mode to the HDD 1. The decoder driver 14 receives the decoded data from the decoder access scheduling unit 12 and causes the decoder / display IF 6 to decode the content data.

  Here, the order of the video playback operation of the video player will be described. When the user inputs an operation for starting playback or the like via the key / remote controller 5, the application 8 receives this, and instructs the playback processing unit 9 to start video playback or to specify a playback mode. The reproduction processing unit 9 issues a read request to the HDD access scheduling unit 10. The HDD access scheduling unit 10 reads data from a predetermined area of the HDD 1 via the HDD driver 13 (including prefetching) and receives read data. The prefetched data is stored in the prefetch buffer 11. Then, the reproduction processing unit 9 passes the received read data to the decoder access scheduling unit 12 for decoding and reproduction. The decoder access scheduling unit 12 passes the read data to the decoder 6 / display IF via the decoder driver 14. At this time, the delivery timing is adjusted so that the decoder 6 / display IF can perform decoding at a predetermined timing. The decoder / display IF 6 decodes the received data and displays an image on the display 7.

  In this video player, the HDD access scheduling unit 10 determines the prefetch data range (data amount) when the prefetch operation from the HDD 1 is performed by the prefetch amount determination unit 15, and stops the disk rotation in the HDD 1. Control to switch to the power mode. Further, when a plurality of modes are provided as the low power consumption mode, the power consumption calculation unit 16 calculates the total power consumption (average power consumption), and the mode selection unit 17 selects the mode that minimizes the mode. select.

  The video player performs effective HDD data prefetching and switching to a low power consumption mode in accordance with various playback modes. Since the playback operation of the video player is not only forward playback but also backward playback, the prefetch direction is switched according to the playback direction. At the time of forward reproduction, prefetching is performed in the end direction of the data file including the data requested to be read, and at the time of backward reproduction, prefetching is performed in the head direction of the data file including the data requested to be read.

  There are also cases of high-speed playback (fast forward and fast reverse). In this case, data used for reproduction is not continuous but discrete. When the video content is in the MPEG format, the data is composed of data of three types of pictures (I, B, P), and only I picture data is used for high-speed playback. Therefore, the prefetch range is limited to only I pictures that are discretely stored in the content data.

  Although the example of FIG. 1 shows a portion of a playback function necessary as a video player, a video recorder / player is realized by adding a video content data recording function. In that case, the HDD access scheduling unit not only data in the range specified in response to the write request but also data that changes in time at high speed can be “summarized” or “pre-written” to increase the efficiency of data transfer. Can be improved. Then, the power consumption can be reduced by switching the HDD to the low power consumption mode during the write operation suspension period. In the following embodiments, the case of reproduction will be described, but the same applies to the case of recording.

  FIG. 2 is a diagram showing a time change of power consumption in the video player of the present embodiment. The horizontal axis represents time t, and the vertical axis represents power consumption P. Here, it is shown how the power consumption of the HDD unit changes due to the data prefetching operation and the low power consumption mode switching.

  As the operation state of the HDD, there are a period Tr for prefetching in the normal mode, a transition period Tot for switching from the normal mode to the low power consumption mode, a period Tlp for the low power consumption mode, and a return period Tor for switching from the low power consumption mode to the normal mode. . Data prefetched at high speed during the period Tr is reproduced over the period T on the display. These operations are repeated with a period T. Here, the normal mode is a state in which the HDD drive is operated and data can be read. The low power consumption mode is, for example, a state where the disk rotation of the HDD is stopped and the head is retracted. The power consumption in the prefetch period Tr is Pr, the power consumption in the low power consumption mode period Tlp is Plp, and the power consumption in the mode switching transition period Tot and the return period Tor is Po. As described above, a finite period (overhead time) Tot, Tor is required for mode switching, and power Po is consumed for that purpose. The switching period (Tot + Tor) is several seconds, and the switching power Po may reach ½ or more of the power in the normal mode, and cannot be ignored for power reduction.

  The length of the low power consumption mode period Tlp depends on the length of the prefetch period Tr. When the prefetch period Tr is short, the low power consumption mode period Tlp is also short. However, since the switching period (Tot + Tor) is constant, the low power consumption mode period Tlp cannot be secured if the prefetch period Tr is too short. Therefore, the length (lower limit value) of the look-ahead period in which the low power consumption mode can be ensured is obtained. In this way, it is possible to avoid a situation where the normal mode is restored in the middle of switching to the low power consumption mode, and a stable reproduction operation can be maintained.

Next, a lower limit value Trm of the prefetch period Tr for stably switching to the low power consumption mode is derived. Assume that the read bit rate (read throughput) at the time of pre-reading is Br, and the bit rate at the time of data reproduction (image display) is Bc. Here, Br> Bc, and this ratio Br / Bc = k. Since the amount of data to process is equal,
Tr · Br = T · Bc
It becomes. In order to secure the low power consumption mode period Tlp,
Tlp = T-Tr-Tot-Tor> 0
If it becomes. From these, when the condition of Tr is obtained,
Tr> To / (k-1) (where To = Tot + Tor)
Therefore, the lower limit value Trm of the prefetch period Tr is
Trm = To / (k−1) (1)
It becomes.

Alternatively, as a condition for securing the low power consumption mode period Tlp, it can be expressed by a prefetch data amount Fr. In that case, if the lower limit value of the prefetched data amount is Frm,
Frm = Trm · Br = To · Br / (k−1) (2)
It is expressed. Therefore, the prefetch data amount Fr> Frm may be set.

  The HDD access scheduling unit 10 (prefetching amount determination unit 15) in this embodiment prefetches data so as to be larger than the lower limit values Trm and Frm of the formula (1) or (2), and switches to the low power consumption mode. . If this cannot be satisfied, switching to the low power consumption mode is not executed.

  Specifically, it can be determined by the capacity of the prefetch buffer 11. That is, when the capacity Fb that can be stored in the buffer 11 satisfies Fb> Frm, switching to the low power consumption mode is executed. In other words, a buffer memory having a capacity equal to or larger than the capacity determined by Expression (2) is adopted as the prefetch buffer 11. However, if data that cannot be erased remains in the buffer 11, it is needless to say that the determination is based on the remaining usable capacity, not the capacity of the entire memory.

  In the above calculation, it is assumed that switching to the low power consumption mode is performed immediately after the prefetching operation is completed. If it is desired to wait for a predetermined time To ′ before switching is performed, the time To ′ may be added to the To.

  As described above, in this embodiment, in consideration of the switching time (overhead time) of the HDD to the low power consumption mode, the read-ahead is performed in accordance with the content reproduction conditions (HDD read speed, display bit rate, reproduction direction and speed, etc.). Determine the time (the amount of prefetched data). Thus, the HDD can be reliably shifted to the low power consumption mode, and the power consumption of the HDD can be reduced.

  FIG. 3 is a flowchart showing an example of the reproduction control method in the present embodiment. Here, the pre-reading operation performed by the HDD access scheduling unit 10 and the switching operation to the low power consumption mode will be mainly described.

  The HDD access scheduling unit 10 acquires playback conditions from the application 8 (step S301). The reproduction conditions include a reproduction direction (forward direction, reverse direction), reproduction mode information (standard reproduction, high-speed reproduction), a reproduction bit rate, and the like. Then, the data amount Fr to be prefetched and the data range are determined according to the reproduction condition (S302). At that time, the capacity of the prefetch buffer 11 and the condition of the lower limit value Frm in the above equation (2) are considered.

  When a read request is received from the reproduction processing unit 9 (S303), it is determined whether data in the read requested range is stored in the prefetch buffer 11 (S304). When there is requested data in the prefetch buffer 11 (Yes in S304), the requested data is taken out from the prefetch buffer 11 and returned to the reproduction processing unit 9 (S305), and the process proceeds to S313. If there is no requested data in the prefetch buffer 11 (No in S304), the process proceeds to S306 and prefetching of the requested data is executed.

  In S306, the HDD is set to a normal mode in which read operation is possible. If the current mode is the low power consumption mode, the normal mode is restored. It is determined which direction the reproduction direction of the reproduction condition acquired in S301 is (S307). If the reproduction direction is the forward direction (Yes in S307), prefetching is performed in the end direction of the data file including the requested data range, and the prefetch buffer 11 is stored (S308). The amount of prefetched data is the amount determined in S302. If the reproduction direction is the reverse direction (No in S307), prefetching is performed in the head direction of the data file including the requested data range and stored in the prefetch buffer 11 (S309).

  In S310, it is determined whether the prefetched data amount Fr is larger than the lower limit value Frm shown in the above equation (2). If Fr> Frm (Yes in S310), a command for changing the HDD to the low power consumption mode is issued, and the HDD is changed to the low power consumption mode (S311). If Fr <Frm (No in S310), the process proceeds to the next S312 without executing the transition to the low power consumption mode.

In step S312, the data in the range requested by the reproduction processing unit 9 is taken out from the prefetch buffer and returned to the reproduction processing unit 9. Thereafter, the process is repeated until the reproduction operation is completed (S313).
As described above, in the flowchart (S310) of this embodiment, the prefetched data amount Fr is compared with the lower limit value Frm, and it is determined whether or not to shift to the low power consumption mode. Therefore, switching to the low power consumption mode is performed. There is no failure and stable data reproduction can be realized.

  Note that, in the determination (S310), it is possible to determine based on the prefetch period Tr instead of the prefetched data amount Fr. In this case, it is determined whether the prefetch period Tr is longer than the lower limit value Trm shown in the above equation (1), and the transition to the low power consumption mode is determined.

  The HDD in the video player of the present embodiment has a plurality of low power consumption modes such as active idle, low power idle, and standby as low power consumption modes. In these modes, the operation state inside the HDD is different, so the power consumption is different, and the switching time (overhead time) when switching from the normal mode to these modes is also different. In this embodiment, when switching to the low power consumption mode, the mode with the smallest total power consumption is selected.

FIG. 4 is a diagram for explaining an example of a plurality of low power consumption modes of the HDD. (A) In the active idle mode, only the head arm servo control is turned off, the power consumption Pa is slightly large, but the switching time Toa with the normal mode (read) is short. (B) In the low power idle mode, the power consumption Pl decreases while the head is retracted, but the switching time Tol becomes longer. (C) In the standby mode, the drive (disk rotation) is further stopped, and the power consumption Ps is the smallest. However, since many parts are stopped, the switching time Pos becomes the longest. That is, in these modes, regarding power consumption P and switching time To,
Pa>Pl> Ps and Toa <Tol <Tos
There is a relationship. FIG. 4 shows specific values of power consumption and switching time in each mode.

FIG. 5 is a diagram showing temporal changes in power consumption when each of the low power consumption modes shown in FIG. 4 is selected. (A) is an active idle mode, (b) is a low power idle mode, and (c) is a standby mode. When each mode is compared in order, the power consumption decreases as Pa>Pl> Ps, but the switching time increases as Toa <Tol <Tos (in the figure, the switching time Toa is divided into a transition time Toat and a return time Toar. The same applies to the other switching times displayed). As a result, let Ta, Tl, and Ts be the periods during which the low power consumption state can be maintained in each mode.
Ta>Tl> Ts
It becomes a relationship.

  In order to reduce the total power consumption, it is needless to say that the power consumption is small and the holding time is long, but as a result of the switching time being different depending on the mode, the power consumption and the holding time tend to conflict. . Therefore, in selecting the low power consumption mode of the HDD, the standby mode (c) with the lowest power consumption is not necessarily the optimum mode. That is, to determine which mode is optimal, it is necessary to calculate the total power consumption in each mode and compare them to select the mode that minimizes the total power consumption.

Hereinafter, the total power consumption in each mode is calculated. In the calculation, an average power consumption Pav for one period T in each mode is obtained (this includes power consumption in the look-ahead period).
When the average power consumption in the active idle mode is Pav (A),
Pav (A) = (Pr · Tr + Po · Toa + Pa · Ta) / T
= (Po-Pa) · Toa / (k · Tr)
+ Pa · (1-1 / k) + Pr / k (3)
When the average power consumption in the low power idle mode is Pav (L),
Pav (L) = (Pr · Tr + Po · Tol + Pl · Tl) / T
= (Po-Pl) · Tol / (k · Tr)
+ Pl · (1-1 / k) + Pr / k (4)
When the average power consumption in the standby mode is Pav (S),
Pav (S) = (Pr · Tr + Po · Tos + Ps · Ts) / T
= (Po-Ps) · Tos / (k · Tr)
+ Ps · (1-1 / k) + Pr / k (5)
It becomes. Here, k is the aforementioned bit rate ratio Br / Bc.

  FIG. 6 is a diagram illustrating an example of a calculation result of average power consumption in each mode obtained by the equations (3), (4), and (5). The horizontal axis is the look-ahead time Tr, the vertical axis is the average power consumption Pav, the curve A is the active idle mode Pav (A), the curve L is the low power idle mode Pav (L), and the curve S is the standby mode Pav (S). Is the case. In addition, the numerical values of the power consumption and the switching time shown in FIG. 4 are used for each constant in the calculation formula. The average power consumption Pav decreases as the read-ahead time Tr increases, but the gradient varies depending on the mode. As a result, the curves intersect, and the curve (mode) in which the average power consumption Pav is minimized is switched.

  When selecting the optimum mode, the pre-reading time Tr is given to the above equations (3), (4), and (5), and the respective average power consumption Pav (A), Pav (L), and Pav (S) are calculated. Then, the calculated average power consumption Pav is compared, and a mode in which the average power consumption Pav is minimized is determined.

  Alternatively, the optimum mode can be selected by comparing the look-ahead time Tr with a threshold value. The prefetch time at the intersection of the curve A and the curve L is Tr1, and the prefetch time at the intersection of the curve L and the curve S is Tr2 (where Tr1 <Tr2). These threshold values Tr1 and Tr2 are fixed values depending on the apparatus conditions, and can be obtained from the conditions in which the values of the expressions (3), (4), and (5) are equal.

  First, if the look-ahead time Tr is shorter than Tr1 (Tr <Tr1), the average power consumption Pav is minimized in the active idle mode (curve A). If the look-ahead time Tr is larger than Tr1 and smaller than Tr2 (Tr1 <Tr <Tr2), the average power consumption Pav is minimized in the low power idle mode (curve L). If the prefetch time Tr is longer than Tr2 (Tr> Tr2), the average power consumption Pav is minimized in the standby mode (curve C). Thus, by determining which section the look-ahead time Tr is in, it is not necessary to calculate the average power consumption each time, and the optimum mode can be determined quickly.

In the above description, the optimum mode is selected by paying attention to the size of the prefetch time Tr. However, the determination can also be made by paying attention to the prefetch data amount Fr. In this case, the above equations (3), (4), and (5) are as follows when Tr = Fr / Br = Fr / (k · Bc).
Pav (A) = (Po−Pa) · Toa · Bc / Fr
+ Pa · (1-1 / k) + Pr / k (6)
Pav (L) = (Po−Pl) · Tol · Bc / Fr
+ Pl · (1-1 / k) + Pr / k (7)
Pav (S) = (Po−Ps) · Tos · Bc / Fr
+ Ps · (1-1 / k) + Pr / k (8)
The prefetch data amount Fr is given to the equations (6), (7), and (8), the average power consumption Pav in each mode is compared, and the mode that minimizes the average power consumption is selected.

  It is also possible to select the optimum mode by comparing the prefetch data amount Fr with a threshold value. In this case, the threshold values are set such that Fr1 = Tr1 · Br and Fr2 = Tr2 · Br corresponding to the Tr1 and Tr2. When Fr <Fr1, the active idle mode is selected. When Fr1 <Fr <Fr2, the low power idle mode is selected. When Fr> Fr2, the standby mode is selected.

  As is clear from the above results, the guidelines for mode selection are as follows. When the prefetch time Tr or the prefetch data amount Fr is small, a mode with a shorter switching time To is selected (for example, the active idle mode), and when the prefetch time Tr or the prefetch data amount Fr is large, the power consumption P is smaller. (For example, standby mode) is selected.

  Thus, according to the present embodiment, mode selection with low power consumption can be performed optimally, and power consumption can be further reduced. Therefore, it greatly contributes to reduction of power consumption in a video player for mobile use that strongly demands power saving.

  FIG. 7 is a flowchart showing an example of the regeneration control method in the present embodiment, and here, shows a step of selecting and switching an optimum mode from a plurality of low power consumption modes. This step can be executed in step S311 in the overall flowchart of FIG.

  First, the prefetch time Tr is acquired (S701), and the average power consumption Pav when switching to each low power consumption mode is calculated. In S702, the average power consumption Pav (A) in the active idle mode is calculated using equation (3). In S703, the average power consumption Pav (L) in the low power idle mode is calculated using equation (4). In S704, the average power consumption Pav (S) in the standby mode is calculated using equation (5).

  Next, the calculated average power consumption Pav of each mode is compared. If Pav (A) is minimum (Yes in S705), the HDD is shifted to the active idle mode (S706). If Pav (L) is minimum (Yes in S707), the HDD is shifted to the low power idle mode (S708). If Pav (S) is minimum (Yes in S709), the HDD is shifted to the standby mode (S710).

  In this way, the optimum low power consumption mode can be switched according to the prefetch time Tr. Note that, when calculating the average power consumption Pav, it is also possible to calculate using the above formulas (6), (7), and (8) based on the prefetch data amount Fr instead of the prefetch time Tr.

  Further, if the prefetch time threshold values Tr1 and Tr2 or the prefetch data amount threshold values Fr1 and Fr2 are obtained in advance, the prefetch time Tr or the prefetch data amount Fr is compared with these threshold values to obtain an optimum low power consumption mode. Can be switched to. In that case, the steps (S702 to S704) of calculating the average power consumption Pav can be omitted.

  In the above-described embodiment, three types of specific low power consumption modes have been described. However, these are merely examples, and can be applied to other types of modes. In addition, the calculation formula, threshold value, and the like used when selecting the optimum mode from them may be appropriately changed and set.

  The present invention can be applied not only to a video player using an HDD but also to a video recorder using an HDD. In that case, it is only necessary to write the data in the HDD at a high speed so that the HDD is switched to the low power consumption mode during the period when the writing is not performed.

  Further, the present invention is applicable to a disk device that reads / writes data at high speed using not only an HDD but also a disk medium including an optical disk. In that case, the data stored in the disk is not limited to video data, but improves the efficiency of reading / writing for temporally continuous data, and contributes to the reduction of power consumption required for disk rotation and the like.

The figure which shows the block structure of a video player as one Example of the disc recording / reproducing apparatus by this invention. The figure which shows the time change of the power consumption in a video player. 6 is a flowchart illustrating an example of a reproduction control method. The figure explaining the example of several low power consumption mode. The figure which shows the time change of the power consumption at the time of selecting each mode. The figure which shows the example of the calculation result of the average power consumption in each mode. The flowchart which selects and switches the optimal low power consumption mode.

Explanation of symbols

1 ... HDD
2 ... CPU
4 ... Memory 5 ... Key / Remote control 6 ... Decoder / Display IF
DESCRIPTION OF SYMBOLS 7 ... Display 8 ... Application 9 ... Playback processing part 10 ... HDD access scheduling part 11 ... Prefetch buffer memory 12 ... Decoder access scheduling part 13 ... HDD driver 14 ... Decoder driver 15 ... Prefetch amount determination part 16 ... Power consumption calculation part 17 ... Mode selection part Tr ... Lead time (read-ahead time)
To, Toa, Tol, Tos ... Mode switching time Tlp, Ta, Tl, Ts ... Low power consumption mode time T ... Content data read cycle Pr ... Power consumption at reading (pre-reading) Po ... Power consumption at mode switching Plp, Pa, Pl, Ps: power consumption in the low power consumption mode Pav: average power consumption.

Claims (9)

A disk recording / playback apparatus having a disk drive for reading or writing continuous data to / from a disk medium at a speed k times faster than the playback speed,
A buffer memory for storing data read or written by the disk drive;
A read / write amount determination unit for determining a time Tr for continuously reading or writing data;
A control unit for controlling the reading or writing operation of the disk drive;
The controller reads or writes data to the disk drive for the time Tr,
After the reading or writing, the time Tr is compared with a predetermined value Trm,
When the time Tr is larger than the predetermined value Trm, the disk drive is switched to a low power consumption mode in which the disk drive is partially stopped. (However, Trm = To / (k−1), To is the switching time to the low power consumption mode) A disk recording / reproducing apparatus having a disk drive for reading or writing continuous data with respect to a disk medium at a speed Br that is k times faster than the reproduction speed thereof,
A buffer memory for storing data read or written by the disk drive;
A read / write amount determination unit for determining a data amount Fr for continuously reading or writing data;
A control unit for controlling the reading or writing operation of the disk drive;
The controller reads or writes data to the disk drive by the data amount Fr,
After the reading or writing, the data amount Fr is compared with a predetermined value Frm,
When the data amount Fr is larger than the predetermined value Frm, the disk drive is switched to a low power consumption mode in which a part of the disk drive is stopped. (However, Frm = To · Br / (k−1), To is the switching time to the low power consumption mode) The disc recording / reproducing apparatus according to claim 1 or 2,
The read / write amount determination unit, when reading data from the disk medium, determines data in a requested range and data in a range continuous in a playback direction as a pre-read range. The disc recording / reproducing apparatus according to claim 1 or 2,
When the plurality of modes having different switching time and power consumption can be selected as the low power consumption mode in the disk drive,
The control unit is further configured to calculate an average power consumption in each mode from the time Tr or the data amount Fr; and
A disc recording / reproducing apparatus comprising: a mode selection unit that selects a mode in which the calculated average power consumption is minimized. A recording / playback control method for a disk drive that reads or writes continuous data to / from a disk medium at a speed k times faster than the playback speed,
A time Tr for continuously reading or writing data is determined,
Read or write data to the disk medium for the time Tr,
After the reading or writing, the time Tr is compared with a predetermined value Trm,
When the time Tr is greater than the predetermined value Trm, the disk drive is switched to a low power consumption mode in which a part of its operation is stopped. (However, Trm = To / (k−1), To is the switching time to the low power consumption mode) A recording / playback control method for a disk drive that reads or writes continuous data to / from a disk medium at a speed Br that is k times faster than the playback speed,
A data amount Fr for continuously reading or writing data is determined,
Read or write data to the disk medium by the data amount Fr,
After the reading or writing, the data amount Fr is compared with a predetermined value Frm,
When the data amount Fr is larger than the predetermined value Trm, the disk drive is switched to a low power consumption mode in which a part of its operation is stopped. (However, Frm = To · Br / (k−1), To is the switching time to the low power consumption mode) The recording / reproducing control method according to claim 5 or 6,
A recording / reproduction control method, wherein when reading data from the disk medium, the data in a requested range and data in a range continuous in the reproduction direction are prefetched. The recording / reproducing control method according to claim 5 or 6,
When it is possible to select a plurality of modes with different switching time and power consumption as the low power consumption mode,
The average power consumption in each mode is calculated from the time Tr or the data amount Fr,
A recording / reproducing control method, wherein a mode that minimizes the average power consumption is selected. The recording / reproducing control method according to claim 5 or 6,
When it is possible to select a plurality of modes with different switching time and power consumption as the low power consumption mode,
The time Tr or the data amount Fr is compared with a threshold value,
If smaller than the threshold, select a mode with a short switching time,
A recording / reproducing control method, wherein a mode with low power consumption is selected when the threshold value is larger than the threshold value.

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