JP3911457B2 - Portable electronic device and charging method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a portable electronic device, for example, a portable electronic device having a rechargeable internal battery (hereinafter referred to as a rechargeable battery) and a method for charging the rechargeable battery.
[0002]
[Prior art]
As a recording medium for music information and the like of recent audio devices, a CD (Compact Disc) or an MD (Mini Disc) is often used instead of a conventional magnetic tape. Music information or the like is digitally recorded in advance on these recording media such as CD or MD, and the recorded music information or the like is reproduced by rotating the CD or MD with a drive motor and reading with an optical pickup.
[0003]
Such an audio device has been developed and put into practical use, for example, various portable audio devices that have a built-in rechargeable battery and can operate with the rechargeable battery for a certain period of time without receiving external power supply. However, since portable audio devices are preferably small and light, the operation time with a rechargeable battery is generally relatively short. Therefore, during times other than when going out (moving), such portable audio devices are equipped with a charging circuit that receives power from an external power source (commercial power supply) to charge the rechargeable battery, and are operated with the rechargeable battery only when going out. Is normal.
[0004]
FIG. 4 is a block diagram showing a schematic configuration of an MD player which is a typical portable audio device. This portable audio device 10 includes an MD playback unit 20, a charging circuit 30 including a rechargeable battery, a system microcomputer (microcomputer) 41, a memory (DRAM: Dynamic Random Access Memory) 42, an ATRAC (Adaptive Transform Acoustic Coding) decoder 43, a D / A converter (digital / analog converter) 44 and a speaker 45. The MD reproducing unit 20 includes an MD mechanical unit 21 including an optical pickup, a thread motor, a spindle motor, and the like, a servo control circuit 22, and a signal demodulation circuit 23.
[0005]
In the MD player 10 that is this portable audio device, the MD playback unit 20 is a part that reads and plays back music data recorded on an MD that is a digital recording medium. In particular, the MD mechanical unit 21 rotates the MD and moves the optical pickup along the MD track at a constant speed. The servo control circuit 22 is a control unit that controls the rotation or movement of the motor of the MD mechanical unit 21 to a constant value. The signal demodulating circuit 23 demodulates the music data read by the MD mechanical unit 21. On the other hand, the charging circuit 30 has a built-in rechargeable battery, supplies operating power to each part of the MD player 10, and charges the rechargeable battery when an external power source is supplied as will be described later. The MD reproducing unit 20 and the charging circuit 30 are circuit parts that consume the largest current in the MD player 10.
[0006]
The system microcomputer 41 includes a microprocessor (MPU) and is a control unit that controls the operation of each unit of the MD player 10. The DRAM 42 is a memory that temporarily stores music data or music information reproduced by the MD reproducing unit 20. The ATRAC decoder 43 is a decoder that decodes music data compressed and recorded in the MD in a predetermined format. D / A converter 44, the music data outputted from ATRAC decoders 43 (digital) is a converter that converts an analog signal. The speaker 45 is an electro-acoustic converter that converts the music signal converted into analog by the D / A converter 44 into an acoustic output.
[0007]
Here, when the MD player 10 is connected to an external power source, the charging circuit 30 charges the rechargeable battery. Thereby, the rechargeable battery is always charged, and the MD player 10 can be operated for a predetermined time by the rechargeable battery when going out. The MD reproducing unit 20 intermittently reproduces music data recorded on the MD, and charges the rechargeable battery by the charging circuit 30 during the reproduction suspension period. The MD music data read at a high speed during the reproduction period is temporarily recorded in the DRAM 42 as described above and read at a constant speed. Therefore, regardless of the intermittent reproduction operation of the MD reproduction unit 20, the speaker 45. Will play back continuous music. Thereby, the reproducing operation of the MD reproducing unit 20 and the charging operation of the rechargeable battery by the charging circuit 30 can be apparently performed in parallel.
[0008]
Next, the charging operation of the rechargeable battery by the charging circuit 30 will be described. This charging operation is performed by two types of charging currents, for example, a small charging current A of 200 mA and a large charging current B of, for example, 800 mA. That is, before the rechargeable battery is rapidly charged with the large charge current B, the rechargeable battery is checked by charging with a small charge current A only for a certain time (for example, 10 seconds). That is, by charging the rechargeable battery with a small charge current A, the terminal voltage change is checked (hereinafter referred to as rechargeable battery check), and it is not in an abnormal state such as deterioration or built-in batteries other than the specified battery. After confirmation, safety is ensured by performing rapid charging with a large charging current B.
[0009]
FIG. 5 is a flowchart for explaining a charging operation of a rechargeable battery of a conventional portable audio device. First, the charging current A (small current) is turned on to start a rechargeable battery check (step S1), and a timer for this rechargeable battery check time is started (step S2). Next, it is determined whether or not the terminal voltage of the rechargeable battery is normal (step S3). When the terminal voltage of the rechargeable battery is not normal (step S3: No), the charging or rechargeable battery check is stopped with the charging current A turned off (step S8). On the other hand, when the terminal voltage of the rechargeable battery is normal (step S3: Yes), it is determined whether or not the MD reproducing unit 20 has started the reproducing operation (step S4). When the reproduction is started (step S4: Yes), the charging current A is turned off, and the rechargeable battery check is interrupted (step S5). If it is not the reproduction | regeneration operation | movement of MD reproduction | regeneration part 20 (step S4: No), it will be judged whether the timer for rechargeable battery timed out (step S6). When the timer times out (step S6: Yes), the charging current B is turned on to perform quick charging (step S7). On the other hand, when the timer does not time out (step S6: No), the process returns to the above-described step S3 and waits for the timer to time out.
[0010]
[Problems to be solved by the invention]
However, if the playback operation of the MD playback unit 20 starts during the above-described rechargeable battery check with the small charging current A, the MD playback unit 20, particularly the MD mechanical unit 21 consumes a large current. Impossible. For this reason, when the MD reproducing unit 20 starts the reproducing operation, it is necessary to interrupt the rechargeable battery check operation by turning off the small charging current A, and there is a problem that accurate determination with little variation cannot be made. This problem also occurs in general portable electronic devices.
[0011]
OBJECT OF THE INVENTION
The present invention has been made in view of the above-described problems of the prior art, and provides a portable electronic device and a charging method thereof that enable accurate determination even when an MD playback operation is started during a rechargeable battery check. Objective.
[0012]
[Means for Solving the Problems]
In order to solve the above-described problems, the portable electronic device and the charging method thereof according to the present invention employ the following characteristic configuration.
[0013]
(1) In a portable electronic device driven by a rechargeable battery that can be charged by a charging circuit, including a mechanical unit that causes a large load current to flow during operation .
A timer for measuring elapsed time and a detecting means for detecting the end of operation of the mechanical unit;
The charging circuit uses the timer and the detection means to charge the rechargeable battery with a first charging current with a second charging current after a first predetermined time check with a first charging current in a normal state. In some cases, the rechargeable battery check is interrupted, and after the second predetermined time has elapsed, when the operation of the mechanical unit is detected, the portable electronic device performs the rechargeable battery check again .
[0014]
(2) The portable electronic device according to (1), wherein the mechanical unit rotates and reproduces a recording medium on which video and / or audio data is recorded .
[0015]
(3) The portable electronic device according to (1), wherein the mechanical unit performs an opening and closing operation of a tray or the like for taking in or out a recording medium on which video and / or audio data is recorded .
[0016]
(4) In a charging method for a portable electronic device including a rechargeable battery that is charged by a charging circuit and supplies operating power to each unit, a recording unit that drives a recording medium on which music information or the like is recorded,
When a rechargeable battery check is performed with a relatively small charging current and the mechanical unit operates during the rechargeable battery check, the rechargeable battery check is interrupted, and after a certain period of time, and after the operation of the mechanical unit is completed, A method for charging a portable electronic device, in which a battery check is performed again, and rapid charging is performed with a relatively large charging current based on the result of the rechargeable battery check.
[0017]
(5) The method for charging a portable electronic device according to (4), wherein the operation of the mechanical unit that interrupts the rechargeable battery check is a reproduction operation of rotating the storage medium and reading the music information and the like.
[0018]
(6) The method for charging a portable electronic device according to (4), wherein the operation of the mechanical unit that interrupts the rechargeable battery check is an opening / closing operation of a tray or the like that holds the recording medium.
[0019]
(7) The method for charging a portable electronic device according to (4), (5), or (6), wherein the predetermined time is preset by a timer.
[0020]
(8) The method for charging a portable electronic device according to any one of (4) to (7), wherein when the rechargeable battery check is interrupted and rechecked, the fact is displayed on a display device.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a configuration and an operation of a preferred embodiment of a portable electronic device and a charging method thereof according to the present invention will be described in detail with reference to the accompanying drawings.
[0022]
FIG. 1 is a flowchart illustrating a charging operation of a rechargeable battery according to a preferred embodiment using a portable audio device as a portable electronic device according to the present invention. In addition to the conventional timer (timer A) for checking the rechargeable battery, the portable audio device (for example, MD player) of this embodiment has another timer (timer B) for checking the elapsed time after the rechargeable battery check is interrupted. Is provided. This avoids a rechargeable battery check during an unstable period immediately after interruption of the rechargeable battery check, and enables an accurate rechargeable battery check.
[0023]
Next, the operation of the portable audio device of this embodiment will be described based on the flowchart of FIG. The charging current A is turned on to start the rechargeable battery check (step A1), and at the same time, the first timer (timer A) is started (step A2). Next, it is checked whether or not the terminal voltage of the rechargeable battery is normal (step A3). When the terminal voltage of the rechargeable battery is not normal (step A3: No), the charging current A is turned off and charging is stopped (step A11). On the other hand, when the terminal voltage of the rechargeable battery is normal (step A3: Yes), it is checked whether or not the regenerating operation is started (step A4). When the reproduction operation is not started (step A4: No), the process proceeds to step A9 described later. When the regenerating operation is started (step A4: Yes), the charging current A is turned off, the rechargeable battery check is interrupted, and the second timer (timer B) is started (step A5).
[0024]
Next, it is checked whether or not the timer B has timed out (step A6). If the timer B has not timed out (step A6: No), the process returns to step A6, waits for the time-out, and if the timer B has timed out (step A6: Yes), check whether the playback operation has ended. (Step A7). If the playback operation has not ended (step A7: No), the process returns to step A7 and waits for the end of the playback operation. On the other hand, when the regenerating operation is finished (step A7: Yes), the charging current A is turned on, the timer A is started again, and the rechargeable battery check is restarted (step A8).
[0025]
Thereafter, it is checked whether or not the timer A has timed out (step A9). If the timer A has not timed out (step A9: No), the process returns to step A3 described above. On the other hand, when the timer A times out (step A9: Yes), the charging current B is turned on, and quick charging of the rechargeable battery is started (step A10). Note that the time of the timer B is set in advance according to the recovery characteristic of the terminal voltage that has risen due to the rechargeable battery check.
[0026]
Next, the charging operation of the rechargeable battery of the portable electronic device (portable audio device as an example) 10 according to the present invention will be described with reference to FIG. In FIG. 2, the horizontal axis represents time (seconds) and the vertical axis represents the charging characteristic curve of the terminal voltage (V) of the rechargeable battery. First, in FIG. 2A, a charging characteristic curve A1 shows a charging characteristic of a normal rechargeable battery, and a charging characteristic curve B1 shows a charging characteristic of an abnormal battery. It is assumed that the terminal voltages of both charging characteristics A1 and B1 are both V1 at time 0 second. At this time, when the charging current A is turned on, the charging characteristic A1 of a normal rechargeable battery is gradually charged with a relatively low slope, and the terminal voltage becomes V2 after 10 seconds, for example. At this time, the charging current B is turned on, and thereafter, rapid charging is performed with a steep slope as illustrated. However, in the case of an abnormal battery charging characteristic B1, the terminal voltage rapidly increases due to the charging current A and exceeds the threshold voltage Vr. Therefore, an abnormality is detected in the terminal voltage check (step A3) of the rechargeable battery in the flowchart of FIG. 1, and charging is stopped with the charging current A turned off. As a result, the terminal voltage of the battery rapidly decreases (note that this battery is not charged with the charging current B).
[0027]
On the other hand, in the case of FIG. 2B, the charging characteristic curve is a normal battery charging characteristic, which is the same as the charging characteristic curve A1 of FIG. However, in the case of an abnormal battery charging characteristic curve B2, the charging current A is turned off in the conventional technique when the regenerating operation starts 1 second after the charging current A is turned on and the charging is started. , the terminal voltage of the battery is elevated in V3 or less than the threshold voltage Vr. Accordingly, there is a possibility that the battery current is not detected and the charging current B is turned on after 10 seconds and the battery is charged with a large current. In that case, the terminal voltage may rise abnormally, which is dangerous. However, according to the portable audio device 10 according to the present embodiment, as shown in step A8 in the flowchart of FIG. 1, the charging current A is turned on after the end of the reproduction operation, and as described above with reference to FIG. Abnormal battery check omissions can be reliably avoided.
[0028]
In the above-described preferred embodiment of the present invention, the case of a combination of a reproduction operation and a charging operation with large power consumption has been described. However, a portable audio device that electrically operates an MD or CD tray or lid has the same problem when the tray or lid is opened and closed. Therefore, in another embodiment of the present invention, as shown in the flowchart of FIG. That is, among Steps B1 to B11, Steps B4 and B7 set the “reproducing operation” to “open / close tray”, and other steps are the same as those in FIG. The time of the timer B is set according to the time necessary for the terminal voltage of the rechargeable battery to stabilize after the tray is opened and closed. Further, the order of steps A6 and A7 in FIG. 1 (and steps B6 and B7 in FIG. 3) may be reversed.
[0029]
The configuration and operation of the preferred embodiment of the portable electronic device and the charging method thereof according to the present invention have been described above in detail. However, it should be noted that such embodiments are merely examples of the present invention and do not limit the present invention in any way. Those skilled in the art will readily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention. For example, the portable electronic device of the present invention may be provided with a display device or a display to display re-execution of a rechargeable battery check, quick charge, and the like.
[0030]
【The invention's effect】
As understood from the above description, according to the portable electronic device and the charging method thereof of the present invention, the following remarkable effects in practical use can be obtained. That is, when the regenerating operation is started during the rechargeable battery check, the rechargeable battery check is interrupted, but after that, after a predetermined time interval and the regenerating operation ends, the rechargeable battery check is executed again. And since it judges whether quick charge is performed based on the rechargeable battery check result, exact judgment is possible. That is, since the charging operation is not performed based on the uncertain rechargeable battery check result, trouble can be reliably prevented.
[Brief description of the drawings]
FIG. 1 is a flowchart illustrating a charging operation of a preferred embodiment of a portable electronic device according to the present invention.
FIG. 2 is a charging characteristic diagram illustrating a charging operation of the portable electronic device.
FIG. 3 is a flowchart illustrating a charging operation of another embodiment of the portable electronic device according to the present invention.
FIG. 4 is a block diagram showing a configuration of a typical MD player.
FIG. 5 is a flowchart for explaining a charging operation of a conventional MD player.
[Explanation of symbols]
10 Portable electronic devices (portable audio devices, MD players)
20 MD playback unit 21 mechanical unit 30 charging circuit 41 system microcomputer (control unit)
42 memory

Claims (8)

In a portable electronic device that is driven by a rechargeable battery that can be charged by a charging circuit, including a mechanical part that flows a large load current during operation ,
A timer for measuring elapsed time and a detecting means for detecting the end of operation of the mechanical unit;
The charging circuit uses the timer and the detection means to charge the rechargeable battery with a first charging current with a second charging current after a first predetermined time check with a first charging current in a normal state. In some cases, the rechargeable battery check is interrupted, and the rechargeable battery check is performed again when the operation end of the mechanical unit is detected after a second predetermined time has elapsed . The portable electronic device according to claim 1, wherein the mechanical unit rotates and reproduces a recording medium on which video and / or audio data is recorded . The portable electronic device according to claim 1, wherein the mechanical unit performs an opening / closing operation of a tray or the like for taking in or out a recording medium on which video and / or audio data is recorded . In a charging method for a portable electronic device including a rechargeable battery that is charged by a charging circuit and supplies operating power to each unit, a recording unit that drives a recording medium on which music information or the like is recorded,
When a rechargeable battery check is performed with a relatively small charging current and the mechanical unit operates during the rechargeable battery check, the rechargeable battery check is interrupted, and after a certain period of time, and after the operation of the mechanical unit is completed, A method for charging a portable electronic device, wherein the battery check is performed again and rapid charging is performed with a relatively large charging current based on the result of the rechargeable battery check.   The method of charging a portable electronic device according to claim 4, wherein the operation of the mechanical unit that interrupts the rechargeable battery check is a reproduction operation of rotating the storage medium and reading the music information and the like.   The method of charging a portable electronic device according to claim 4, wherein the operation of the mechanical unit that interrupts the rechargeable battery check is an opening / closing operation of a tray or the like that holds the recording medium.   7. The method for charging a portable electronic device according to claim 4, wherein the predetermined time is preset by a timer.   The method for charging a portable electronic device according to any one of claims 4 to 7, wherein when the rechargeable battery check is interrupted and rechecked, the fact is displayed on a display device.

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