JP2003173611A - Recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the speed of information transmission to be automatically changed over in accordance with the capacity of a power source in a recording and reproducing device capable of being connected to an external information processor. <P>SOLUTION: In this recording and reproducing device, whether a second power source such as an AC adaptor, a battery is connected to this device or not is detected and when a second power source is connected to this device, the speed of information transmission between the device and the external information processor is increased and when the second power source is not connected to the device, the speed of the information transmission is made to be lowered or a recording operation is made to be prohibited. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing device which receives power from an external information processing device such as a host computer.

[0002]

2. Description of the Related Art The miniaturization and speeding up of computer systems is remarkable, and even portable computers such as notebook PCs can handle large-capacity data such as still image data and moving image data in addition to text data and voice data. It was A portable computer system may be driven by a commercial AC power source, but it is often driven by a built-in battery at a destination, and reduction of power consumption is a big problem. Therefore, in data recording / reproducing devices such as optical disk devices and hard disk devices used in portable computer systems, it is important to reduce power consumption in addition to downsizing, speeding up, and increasing capacity.
Conventionally, as a technique for reducing the power consumption of a data recording / reproducing apparatus, for example, Japanese Patent Application Laid-Open No. 2000-228053, Japanese Patent Application Laid-Open No. 2001-202690, and Japanese Patent Application Laid-Open No.
There is one described in Japanese Patent No. 308055. JP 2
Japanese Patent Application Laid-Open No. 000-228053 describes a technique for detecting the load on a spindle motor of a hard disk drive and switching the spin motor to a low speed rotation to reduce power consumption when the load on the spindle motor is large at low temperatures. In Japanese Patent Laid-Open No. 2001-202690, when a notebook PC is driven by a commercial AC power source, the hard disk drive is driven in a quick mode of high-speed transfer / high-speed access, and when it is driven by an internal battery, the hard disk drive is driven at a low speed. A technique of driving in a silent mode of transfer / slow-speed access is described. The hard disk drives in the techniques described in both the publications do not have a power source for the drive itself, but are configured to receive drive power from a notebook PC or the like. In addition, JP-A-10
According to Japanese Laid-Open Patent Publication No. -308055, in an optical disk reproducing apparatus, a necessary processing circuit differs depending on the type of data to be reproduced, so that only the necessary processing circuit is supplied with power to be in an operating state, and an unnecessary circuit is in a standby state. Techniques for saving power consumption are described.

On the other hand, a method suitable for a portable environment has also been proposed as a method for connecting a computer and peripheral devices.
For example, one of them is USB (Universal Serial Bu
s) There is a connection. USB connection is Universal
Serial Bus Specification
As described in (Rev.1.0), a pair of signal lines (D +, D) for transmitting serial data as differential signals.
-) And a pair of power lines (Vcc, GND) are connected to the computer and peripheral devices with a single cable that combines the four lines. The power supplied from the host computer to the peripheral device through the USB cable has a power supply voltage of 5 V ± 5% and a maximum supply current of 500 mA.

An example of a conventional peripheral device compatible with USB connection will be described with reference to FIGS. 4 and 5. FIG. 4 shows a configuration example in which the power supply capacity used in the optical data reproducing device 22 is equal to or less than the capacity that the host computer 17 can supply.
The drive power of the optical data reproducing device 22 is supplied from the host computer 17 to the power supply circuit 13 via the USB cable 20 and the USB connector 16. Power supply circuit 13
The spindle motor 3 rotates the optical disk 1, the traverse motor 5 moves the optical pickup 4, the laser drive circuit 6 turns on the laser light source, and the servo circuit 8 performs automatic focus control and tracking control. Then, the front circuit 7 and the interface circuit 12 reproduce information. The power supplied to the power supply circuit 13 is also used as drive power for the system control circuit 14 for controlling these operations. The system control circuit 14 comprises a microcomputer. In order to realize high-speed data transfer, the optical disc 1 needs to rotate at high speed, which requires a large amount of electric power. However, the electric power supplied from the host computer 17 via the USB cable 20 has a maximum supply current. Is 500
Since there is a limit of mA, the data transfer rate of the optical data reproducing device 22 is set low.

FIG. 5 shows an example of a configuration in which the power supply capacity used in the optical data recording / reproducing apparatus 23 exceeds the power supply capacity that can be supplied by the host computer 17. The power of the data recording / reproducing device 23 is supplied to the power supply circuit 13 from the AC adapter or the battery 19. The electric power supplied to the power supply circuit 13 causes the spindle motor 3 to rotate the optical disc 1, the traverse motor 5 to move the optical pickup 4, the laser drive circuit 6 to turn on the laser light source, and the servo circuit 8 to perform automatic focus control and Tracking control is performed, the interface circuit 12 and the laser drive circuit 6 perform information recording, and the front circuit 7 and the interface circuit 1
2 reproduces information. The power supplied to the power supply circuit 13 is also used to drive the system control circuit 14 for controlling these operations. The power supplied from the AC adapter or battery 19 is generally
Since there is a sufficient margin, the optical data recording / reproducing device 23
Information is recorded by making the laser light source emit light at a high output, and the optical disc 1 is rotated at a high speed to transfer data at a high speed. In the conventional data recording / reproducing apparatus shown in FIGS. 4 and 5, the transfer rate of read data or write data is set by the capability of the data recording / reproducing apparatus or a command from the host computer 17.

[0006]

When a data recording / reproducing apparatus is attached to a movable host computer and used, in the above-mentioned prior art, data recording is impossible with the configuration of FIG. 4 which does not use an AC adapter or a battery. Moreover, in the configuration of FIG. 5, data can be recorded by using the AC adapter or the battery, and the AC adapter or the battery is indispensable for recording the data. However, it is heavy and inconvenient to carry an AC adapter or battery with a host computer. An object of the present invention is to enable recording and reproducing of data not only when an AC adapter or a battery is used as a second power source but also when it is not used and automatically First, it is possible to switch the speed of information transmission such as a data transfer speed performed with an external information processing device. An object of the present invention is to provide a technique capable of solving such a problem.

[0007]

In order to solve the above problems, according to the present invention, in a recording / reproducing apparatus, (1) a power source for an external information processing apparatus (corresponding embodiment: reference numeral 17) such as a host computer is provided. Is provided with a power supply detecting means (corresponding embodiment: reference numeral 18) for detecting whether or not a second power supply (corresponding embodiment: reference numerals 24, 26) such as an AC adapter or a battery is connected, and based on the detection result. The speed of information transmission with the external information processing device is switched. (2) When the connection of the second power supply is detected, at least the power is supplied from the second power supply to increase the speed of information transmission. (3)
When the connection of the second power source is not detected, the recording or reproducing speed is reduced and the information transmission speed is reduced. (4)
When the connection of the second power source is not detected, the recording operation is stopped and the reproducing operation at a slower speed is performed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are explanatory diagrams of a first embodiment of the present invention. FIG. 1 shows the configuration of a recording / reproducing apparatus according to the present invention, and FIG. 2 is an example of a flowchart of its operation. In FIG. 1, 21 is a recording / reproducing device, 17 is a host computer as an external information processing device, and 20 is a USB.
(Universal Serial Bus) cable, 16 is a USB connector. Recording / playback device 21 and host computer 1
7 is connected to the USB cable 20 via the USB connector 16. 24 is an AC adapter as a second power source, 26 is also a battery, 28 is a USB cable 20
, And 29 is a power line. In addition, the recording / reproducing device 2
1 is configured to be connected to an AC adapter 24 or a 5V battery 26, which supplies a 5V power source from the outside, via an AC adapter connector 25 or a battery holder 27, respectively. The AC adapter 24 or the battery 26 can be attached and detached. Reference numeral 18 denotes a power supply detection circuit as a power supply detection means, which is connected to the AC via the AC adapter connector 25.
Whether or not the adapter 24 is connected or the battery 26 is attached to the battery holder 27 is detected by comparing with a predetermined voltage, and the detection result is output as a voltage signal. Power for driving the power detection circuit 18 is supplied from the power line 29 of the USB cable 20. Reference numeral 15 is a power supply switching circuit, which is operated by the power supplied from the power line 29 of the USB cable 20 to supply power from the USB cable 20 and the power supply from the AC adapter 24 or the battery 26.
It is switched by the detection signal of the power supply detection circuit 18. That is, the power supply switching circuit 15 controls the recording / reproducing apparatus 21 to
If the power can be supplied from the C adapter 24 or the battery 26, the power supply from the AC adapter 24 or the battery 26 is selected. If the power cannot be supplied from the AC adapter 24 or the battery 26, the power is supplied from the USB cable 20. Select the power supply. The electric power selected by the power supply switching circuit 15 is sent to the power supply circuit 13 and used to drive the recording / reproducing device 21. Furthermore, 1 is an optical disc, 3
Is a spindle motor, 4 is an optical pickup, 5 is a traverse motor, 6 is a laser drive circuit, 7 is a front circuit,
8 is a servo circuit, 9 is a traverse motor drive circuit, 10
Is a spindle motor drive circuit, 11 is a signal processing circuit, 1
Reference numeral 2 is an interface circuit, and 14 is a system control circuit as a control means. The system control circuit 14 is composed of a microcomputer. When the optical disc 1 is mounted on the spindle motor 3, the spindle motor drive circuit 10 drives the spindle motor 3 to rotate the optical disc 1. The rotation speed information of the optical disk 1 is sent to the servo circuit 8 via the spindle motor drive circuit 10, and the servo circuit 8 rotates the rotation speed information of the optical disk 1 and the system control circuit 1 as a control means.
4 is compared with the designated rotation speed set by 4 and the difference signal is returned to the spindle motor drive circuit 10. The spindle motor drive circuit 10 changes the drive voltage of the spindle motor 3 according to the difference signal from the servo circuit 8. As described above, the rotation speed of the optical disc 1 is maintained at the designated rotation speed set by the system control circuit 14. The optical pickup 4 is moved in the radial direction of the optical disc 1 by a traverse motor 5. The spindle motor 3, the optical pickup 4, and the traverse motor 5 are incorporated in the unit mechanism 2 and are integrated structural parts. The laser drive circuit 6 causes a laser light source (not shown) in the optical pickup 4 to emit light, and irradiates the optical disc 1 with a laser beam 30. The laser beam 30 reflected by the optical disc 1 is received by a photodetector (not shown) in the optical pickup 4 and converted into a current signal. The converted current signal is converted into a voltage signal by the front circuit 7. The servo circuit 8 is
Various calculations are performed based on the detection signal of the photodetector converted into voltage to generate a focus shift detection signal and a track shift detection signal, and a two-dimensional lens actuator (not shown) in the optical pickup 4 is driven to automatically Focus control and tracking control are performed. When the automatic focus control and the tracking control are achieved, the signal processing circuit 11 demodulates the information signal recorded on the optical disc from the output signal of the front circuit 7. The demodulated information signal is transferred to the interface circuit 12
Via the USB cable 20 and the host computer 17
Sent to. As a result, the information is reproduced. Further, an information signal to be recorded sent from the host computer 17 via the USB cable 20 is modulated into a code suitable for optical recording by the signal processing circuit 11 via the interface circuit 12, and is optically converted by the laser drive circuit 6. The amount of light emitted from the laser light source in the pickup 4 is modulated. Thereby, the information is recorded. The rotation control of the optical disc, the traverse control of the optical pickup, the automatic focus control, the tracking control, and the information recording / reproducing operation are
It is performed by the power supplied from the power supply circuit 13. In addition, a system control circuit 1 that controls these operations
4 is also driven by the electric power supplied from the power supply circuit 13.

USB is Universal Seri
al Bus Specification (Re
v. 1.0), four cables of a pair of signal lines (D +, D-) for transmitting serial data as a differential signal and a pair of power lines (Vcc, GND) It is connected with a (decoding cable), and the power supply voltage is 5V ± 5 from the host computer 17 through the USB cable 20.
%, A maximum supply current of 500 mA can be supplied to one peripheral device. However, in order to maintain high-speed data transfer, the recording / reproducing device 21 connected to the host computer 17 increases the number of rotations of the spindle motor 3 in order to increase the speed of reading / writing from the disk 1, and also the data to be read. In order to perform the signal processing at high speed, it is necessary to increase the processing speed of the signal processing and further increase the output of the laser beam irradiated at the time of high speed writing. As a result, the required current consumption exceeds 500 mA. Therefore, to drive the recording / reproducing apparatus 21, it is necessary to connect the AC adapter 24 or the battery 26 to the outside. On the other hand, AC adapter 24
Since the mass of the battery and the battery 26 is heavy, in the case of the recording / reproducing device 21 connected to the movable host computer, the recording operation can be performed by using the power source of the host computer 17 together without using the AC adapter 24 and the battery 26. It is convenient to do so.

FIG. 2 is an example of a flowchart of the operation of the recording / reproducing apparatus of FIG. In FIG. 2, first, (1)
It is determined whether or not there is a power supply connection other than the USB cord (step 41). AC adapter 24 or battery 26
If is connected, the determination result is “Yes”, and if not connected, is “No”. (2) If the determination result is “Yes”, the read / write data transfer rate is set to the maximum speed mode (spindle motor 3) according to the control signal from the system control circuit 14.
Rotation speed, the signal processing speed in the signal processing circuit 11, the laser light output of the laser light driving circuit 6, etc.) (step 42). (3) On the other hand, the determination result is "N
In the case of “o”, the transfer rate of the read / write data is set to the low speed mode (rotation speed of the spindle motor 3, signal processing speed, laser light output) by the control signal from the system control circuit 14 due to the current limit of 500 mA or less. Etc.) (step 43) Specifically, in the above (1), the power supply detection is performed to detect whether the AC adapter 24 or the battery 26 is connected to the AC adapter connector 25 or the battery holder 27, respectively. Done in circuit 18,
When it is determined that the power supply is connected, the power supply detection circuit 18 transmits the information “connected” to the power supply switching circuit 15. On the other hand, when it is determined that the power supply is not connected, the power supply detection circuit 18 transmits detection information “no connection” to the power supply switching circuit 15. Above (2)
Then, when the power supply switching circuit 15 receives the information “connected” from the power supply detection circuit 18, the power supply switching circuit 15 switches the power supply circuit 13 so that power is supplied from the AC adapter 24 or the battery 26 side. Then, the power from the AC adapter 24 or the power from the battery 26 is supplied. In addition, the detection information of the power supply detection circuit 18 is also transmitted to the system control circuit 14 and "connected"
When the information is transmitted, the system control circuit 14 sets the laser drive circuit 6, the front circuit 7, and the laser drive circuit 6 so that the read and write data transfer rates are maximized.
It controls the servo circuit 8, the signal processing circuit 11, and the interface circuit 12. Further, in the above (3), when the power supply switching circuit 15 receives the detection information “no connection” from the power supply detection circuit 18, power is supplied to the power supply circuit 13 from the host computer 17 side through the switch section. Switch from the power supply of the host computer 17 to US
Power is supplied to the power supply circuit 13 via the power line 29 of the B cable 20. The detection information "no connection" is output from the power supply detection circuit 18 to the system control circuit 1
4, and the system control circuit 14 controls the laser drive circuit 6, the front circuit 7, the servo circuit 8 and the signal processing so that the transfer rate of the read / write data becomes low based on the detection information. Circuit 1
1. Control the interface circuit 12. When the data is read from the disk 1, the system control circuit 14 uses the USB standard 5 which is known in advance as a data read speed for the front circuit 7, the servo circuit 8, the signal processing circuit 11, and the interface circuit 12.
The low-speed operation mode is set so that it will be 00 mA or less. Further, at the time of data writing, the system control circuit 14 sets the low speed operation mode so that the data writing speed may be 500 mA or less, which is known in advance, to the laser driving circuit 6 in addition to the above. To do. After the setting, a data reading command is transmitted from the host computer 17, the spindle motor 3 rotates at a low speed according to the set low speed mode, the control of the optical pickup 4 also becomes low, and the data of the disk 1 is read at a low speed. The read data passes through the signal processing circuit 11 and the interface circuit 12, and is transmitted to the host computer 17 via the USB cable 20. Further, in the case of writing data to the disc 1, the host computer 17 issues a data write command, and the recording / reproducing device 21 writes the data to the disc 1 in the low speed mode.

According to the first embodiment, the data recording operation and the data reproducing operation can be performed not only when the AC adapter or the battery is used as the second power source but also when it is not used. Further, the speed of data transfer performed with the host computer 17 can be automatically switched according to the power capacity, and the recording or reproducing operation can be always performed in the speed mode according to the power capacity. Power can be efficiently supplied from the host computer within the range regulated by the interface cable such as USB.

FIG. 3 is an explanatory diagram of a second embodiment of the recording / reproducing apparatus of the present invention. In the second embodiment, the system controller circuit 14 in the configuration of FIG.
4 is an example of a configuration in which the data write operation is prohibited and stopped when the battery 4 or the battery 26 is not connected. The configuration of the other parts is the same as in the case of FIG. In the present embodiment as well, when sufficient power is supplied, it is assumed that data can be recorded at high speed by using power with a current exceeding 500 mA.

In the flowchart of FIG. 3, first,
(1) It is determined whether "there is a power supply connection other than the USB cord" (step 41). When the AC adapter 24 or the battery 26 is connected, the determination result is "Yes
s ”, and“ No ”if not connected.
(2) If the determination result is “Yes”, the read / write data transfer speed is set to the maximum speed mode (the rotation speed of the spindle motor 3, the signal processing in the signal processing circuit 11 by the control signal from the system control circuit 14). The speed and the laser light output of the laser light drive circuit 6) are set (step 42). (3) On the other hand, if the determination result is “No”, the write operation is prohibited and the write operation is stopped, and the power supply current is 500 mA.
If the value exceeds the limit of 500 mA of the USB standard, the control signal from the system control circuit 14 controls the read data transfer rate to a low speed mode (rotation speed of the spindle motor 3, signal processing speed, laser light output). Etc.) (step 44). In particular,
In the above (1), similarly to the case of FIG. 2, the power supply detection circuit 18 detects whether or not the AC adapter 24 or the battery 26 is connected to the AC adapter connector 25 and the battery holder 27, respectively. As a result, when it is determined that the power supply is connected, the power supply detection circuit 18
The information “connected” is transmitted to the power supply switching circuit 15.
On the other hand, when it is determined that the power supply is not connected, the power supply detection circuit 18 transmits detection information “no connection” to the power supply switching circuit 15. Also in the above (2), as in the case of FIG.
When the information "connection is present" is received from 8, the switch unit is switched so that power is supplied from the AC adapter 24 or the battery 26 side, and the power supply circuit 13 receives the power from the AC adapter 24 or the battery 26. Power is supplied. Further, the detection information of the power supply detection circuit 18 is
When the information indicating “connected” is transmitted to the system control circuit 14 as well, the system control circuit 14 controls the laser drive circuit 6 so that the read / write data transfer rate is maximized. The front circuit 7, the servo circuit 8, the signal processing circuit 11, and the interface circuit 12 are controlled. Further, in the above (3), when the power supply switching circuit 15 receives the detection information “no connection” from the power supply detection circuit 18, power is supplied to the power supply circuit 13 from the host computer 17 side through the switch section. The power supply circuit 1 from the power supply of the host computer 17 through the power line 29 of the USB cable 20.
So that the power is supplied to 3. The power supply detection circuit 18
The detection information "no connection" is transmitted from the system control circuit 14 to the system control circuit 14
Then, the laser drive circuit 6, the front circuit 7, the servo circuit 8, the signal processing circuit 11, and the interface circuit 12 are prohibited so that the write operation is prohibited based on the detection information and the transfer rate of the read data becomes low. Control. Even if a write command is issued from the host computer 17, the system control circuit 14 requires electric power exceeding the upper limit current 500 mA that can be supplied from the USB cable 20 to follow the write command. An error code is returned to the host computer 17 to prohibit writing. Further, the system control circuit 14 has a known USB standard as a data read speed for the front circuit 7, the servo circuit 8, the signal processing circuit 11, and the interface circuit 12 when reading data from the disk 1. 5
The low-speed operation mode is set so that it will be 00 mA or less. After the setting, a data read command is transmitted from the host computer 17, the spindle motor 3 rotates at a low speed according to the set low speed mode, the control of the optical pickup 4 also becomes slow, and the data of the disk 1 is read at a low speed. . The read data is sent to the signal processing circuit 11,
USB cable 20 through the interface circuit 12
Is transmitted to the host computer 17 via.

According to the second embodiment, as in the case of the first embodiment, it is possible to automatically switch the speed of data transfer with the host computer 17 in accordance with the power source capacity, and always. The recording or reproducing operation can be performed in the speed mode according to the power capacity. Power can be efficiently supplied from the host computer within the range regulated by an interface cable such as USB.

In the first and second embodiments described above, when the AC adapter 24 or the battery 26 is connected, the power source switching circuit 15 switches the switch section so that the power to the power source circuit 13 is supplied to the AC adapter 24. Alternatively, the configuration is such that the power is supplied from the battery 26, but the present invention is not limited to this, and the power to the power supply circuit 13 is supplied from the power source of the host computer 17 at the same time as being supplied from the AC adapter 24 or the battery 26. Good. In some cases, the third power source may be used together with the AC adapter 24 or the battery 26.

[0016]

According to the present invention, the speed of data transfer performed with an external information processing device such as a host computer can be automatically switched according to the capacity of the connected power source,
It is possible to always perform the recording or reproducing operation in the speed mode according to the power capacity.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the recording / reproducing apparatus of FIG.

FIG. 3 is an operation explanatory diagram of the second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration example of a conventional recording / reproducing apparatus.

FIG. 5 is a diagram showing a configuration example of another conventional recording / reproducing apparatus.

[Explanation of symbols]

1 ... Disc, 2 ... Unit mechanism, 3 ... Spindle motor, 4 ... Optical pickup, 5 ... Traverse motor, 6 ... Laser drive circuit, 7 ... Front circuit, 8
… Servo circuit, 9… Traverse motor drive circuit, 1
0 ... Spindle motor drive circuit, 11 ... Signal processing circuit, 12 ... Interface circuit, 13 ... Power supply circuit, 14 ... System control circuit, 15 ... Power supply switching circuit, 16 ... USB connector, 17 ... Host computer, 18 ... Power supply detection circuit , 20 ... USB cable, 21 ... Recording / reproducing device, 24 ... AC adapter, 26 ... Battery.

Claims (7)

[Claims] 1. A recording / reproducing apparatus which is connected to an external information processing apparatus and records or reproduces information, or both, and whether a second power source other than the power source of the external information processing apparatus is connected. A recording / reproducing apparatus having a configuration for detecting whether or not there is detected, and switching a speed mode in a recording or reproducing operation based on the detection result. 2. A recording / reproducing apparatus which is connected to an external information processing apparatus and records or reproduces information, or both, and whether a second power source other than the power source of the external information processing apparatus is connected. A power source detecting unit for detecting whether or not the second power source is connected, and a control unit for controlling the speed of information transmission to and from the external information processing apparatus based on the detection result. In this case, the recording / reproducing apparatus is characterized in that at least electric power is supplied from the second power source so that the speed of information transmission can be increased. 3. A recording / reproducing apparatus which is connected to an external information processing apparatus and records or reproduces information, or both, and whether a second power source other than the power source of the external information processing apparatus is connected. And a control means for controlling the speed of information transmission to and from the external information processing apparatus based on the detection result, wherein the connection of the second power supply is not detected. The recording / reproducing apparatus is characterized in that the recording or reproducing speed is reduced to decrease the information transmitting speed. 4. A recording / reproducing apparatus which is connected to an external information processing apparatus and records or reproduces information, or both, and whether a second power source is connected to the external information processing apparatus. And a control means for controlling the speed of information transmission to and from the external information processing apparatus based on the detection result, wherein the connection of the second power supply is not detected. The recording / reproducing apparatus is characterized in that the recording operation is stopped and the reproducing operation is performed at a reduced speed. 5. The recording / reproducing apparatus according to claim 2, wherein the power supply detecting means is configured to be supplied with power from a power supply of an external information processing apparatus. 6. The recording / reproducing apparatus according to claim 1, wherein the recording / reproducing apparatus has a structure in which power is simultaneously supplied from a power source of an external information processing apparatus and the second power source. 7. The recording / reproducing apparatus according to claim 1 or 2, wherein a USB connector is provided at a connection portion with the external information processing apparatus, and power is supplied from the external information processing apparatus via a USB cable.