JP3721081B2 - Mobile telephone device and its AC adapter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile phone device and an AC adapter thereof, and more particularly, when a mobile phone device and a charging AC adapter are connected, the charging control circuit of the mobile phone device can be experienced through a housing even if an illumination circuit or a radio unit operates. The present invention relates to a mobile telephone device and an AC adapter for the mobile phone device that prevent generation of heat.
[0002]
[Prior art]
In mobile phone devices such as mobile phones and PHS (Personal Handyphone System), when using indoors or charging a built-in battery (secondary battery) whose capacity is insufficient, a charging AC adapter (hereinafter referred to as AC adapter) is used. It can be connected). In addition, most mobile telephone devices include a backlight for illuminating the display unit and operation unit (keys), and an illumination circuit for driving the backlight. There is also a model that can be set so that the lighting of the operation unit and the display unit is always turned on by the user during charging by the AC adapter.
[0003]
FIG. 3 shows an example of a mobile phone device provided with a backlight and an illumination circuit.
The cellular phone device 300 includes an antenna 301 that is telescopically attached to the device main body, a radio unit 302 connected to the antenna 301, a modem unit 303 connected to the radio unit 302, and a voice connected to the modem unit 303. A processing unit 304, a speaker 305 connected to the audio processing unit 304, a microphone 306 connected to the audio processing unit 304, a control unit 307 for controlling the radio unit 302 to the audio processing unit 304, and connected to the control unit 307 Display unit 308, operation unit 309 connected to control unit 307, control unit 307, backlights 310a and 310b installed in the vicinity of display unit 308 and operation unit 309, illumination circuit 310 for driving these backlights, and each circuit A battery 311 (secondary battery such as a lithium ion battery) for supplying power to the unit and an AC adapter (not shown) It is configured to include a charge control circuit 312 to charge the battery 311 when it is continued.
[0004]
The operation in the configuration of FIG. 3 will be described. A radio wave received by the antenna 301 is amplified and frequency-converted by the radio unit 302 and then demodulated by the modem unit 303. Further, the demodulated output is decoded as an audio signal by the audio processing unit 304 and then output from the speaker 305 as audio. On the other hand, during transmission, the voice of the speaker (user) is converted into an electrical signal by the microphone 306, processed by the voice processing unit 304, then modulated by the modulation / demodulation unit 303, and converted by the radio unit 302. After power amplification, the signal is transmitted from the antenna 301 as a radio wave.
[0005]
The control unit 307 performs radio channel control, received data processing, audio processing unit 304 control, display information output control to the display unit 308, lighting circuit 310 on / off control, and the like according to the operation content of the operation unit 309. Execute. The illumination circuit 310 drives backlights 310 a and 310 b that illuminate the display unit 308 and the operation unit 309. The backlights 310a and 310b are automatically turned on temporarily when the power is turned on or the like, and are turned on by operating the operation unit 309 such as when the user (user) operates the mobile phone in a dark place. However, if the lighting circuit 310 is always turned on, the battery 311 is consumed quickly. Therefore, in the case of battery driving, the lighting is temporarily performed only when the user requests lighting, and the lighting is not always performed. This control is executed by the control unit 307.
[0006]
On the other hand, when the AC adapter is connected, the battery is charged by the AC adapter, and a part of power from the AC adapter can be sent to the lighting circuit 310 and the backlights 310a and 310b. However, the display unit 308 can be constantly lit by setting the operation unit 309 to always turn on the illumination.
[0007]
FIG. 4 shows a conventional mobile telephone device and its AC adapter. In the following, a mobile phone device (mobile phone) will be described as a mobile phone device.
The circuit structure of the connection part of the battery pack 313 which incorporated the AC adapter 400 and the battery 311 is shown. The cellular phone device 300 includes an external connection terminal 320 (consisting of a DC output terminal 320a and a GND terminal 320b) and a battery connection terminal 330 (consisting of a + terminal 330a, a voltage detection terminal 330b, and a − terminal 330c). An AC adapter 400 that receives power supply from a commercial power supply (AC 100 V) 410 is connected to the external connection terminal 320, and a battery pack 313 is connected to the battery connection terminal 330. The AC adapter 400 includes an AC / DC conversion unit 401 and generates a low DC voltage suitable for charging from the commercial power source 410. The battery pack 313 includes a battery 311 and a resistor 314 connected to its + terminal. In the mobile phone device 300, a diode 315 is connected between the charge control circuit 312 and the positive terminal 330 a of the battery connection terminal 330. The diode 315 has a role of preventing current from flowing backward from the battery 311 to the charge control circuit 312. The voltage at the voltage detection terminal 330 b is applied to the charge control circuit 312.
[0008]
In the configuration of FIG. 4, when the AC adapter 400 is connected, the charge control circuit 312 monitors the voltage of the battery 311 via the resistor 314 and the voltage detection terminal 330b. The charging control circuit 312 controls the current flowing through the diode 315 so that the voltage is 4.2 V (when the battery 311 is a lithium ion battery) while charging the battery 311 via the diode 315, and is set in advance. Charging is completed when the charging current is reached.
[0009]
When charging is performed by the user so that the lighting of the display unit 308 and the operation unit 309 is always turned on during charging, or when a call or data communication is performed while charging, the charging is performed from the DC output terminal 320a. At this point, the current supplied from the AC adapter 400 is sent to drive the wireless unit 302, the illumination circuit 310, and the backlights 310a and 310b. For this reason, the charging control circuit 312 flows a current obtained by adding the charging current of the battery 311 and the current flowing through the wireless unit 302, the lighting circuit 310, and the backlights 310a and 310b. At the end of charging, the supply from the battery 311 increases and the supply from the charge control circuit 312 decreases.
[0010]
In the configuration as shown in FIG. 3, when the on-vehicle charger is connected and used, as described above, if the current consumption increases due to the illumination of the display unit 308 and the operation unit 309, the charging time of the battery 311 is increased. Japanese Patent Laid-Open No. 11-284560 discloses an invention for solving the problem of lengthening. As a means for this, an in-vehicle charger is provided with a dedicated power source for lighting, and the lighting-only power source is selected by a changeover switch at the time of lighting, so that the lighting current does not affect the charging control circuit 312 The same charging time is used.
[0011]
[Problems to be solved by the invention]
However, according to the conventional mobile telephone device and its AC adapter, in the case of the configuration shown in FIG. 4, when the user sets the lighting of the display unit 308 and the operation unit 309 to be always on, When communication is performed, the amount of current flowing through the charging control circuit 312 is larger than when charging is performed alone. Therefore, the amount of heat generated by the charging control circuit 312 is increased, and this heat is transmitted to the housing. This may cause discomfort to the user.
[0012]
According to Japanese Patent Application Laid-Open No. 11-284560, the lighting current does not flow to the charging control circuit 312, so the amount of heat generated in the charging control circuit 312 does not increase. In addition, since the battery 311 is charged in parallel, the charger becomes large. Furthermore, the circuit becomes complicated and the cost increases.
[0013]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a mobile telephone device and its AC adapter that can suppress the heat generation of the charge control circuit even when the display unit and the operation unit are always turned on or even when a call or data communication is performed while charging. Is to provide.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides, as a first feature, a wireless unit that performs communication, an illumination circuit that illuminates a display unit and an operation unit, a charging control circuit that controls charging of a built-in secondary battery, and In a mobile telephone device having an external connection terminal to which an AC adapter for charging the secondary battery is connected , a DC output voltage optimal for charging the secondary battery is set as a first output voltage, and the first A DC output voltage that is lower than the output voltage of 1 and capable of charging the secondary battery is set as the second output voltage, and the illumination circuit is set to be constantly lit or the wireless unit is in a transmission state A mobile telephone device comprising: a control unit that outputs a switching signal for switching the output voltage of the AC adapter from the first output voltage to the second output voltage when detected. To do.
[0015]
According to this configuration, when the control unit detects that the illumination circuit is set to be constantly lit or the wireless unit is in a transmission state, the control unit regards that the current passing through the charge control circuit has increased, and outputs the output voltage of the AC adapter. A switching signal for lowering is output. Using this switching signal, the AC adapter can lower the output voltage so that the current through the charging control circuit in the mobile telephone device is reduced. Therefore, even if the display unit or the operation unit is always turned on, or even when a call or data communication is performed while charging, the amount of heat generated by the charge control circuit can be reduced, so that the user does not feel uncomfortable.
[0016]
In order to achieve the above object, the present invention has a second feature in that a secondary battery is used as a power source, and a wireless unit or a lighting circuit is connected to a mobile telephone device that can operate the secondary battery while charging. In the AC adapter that charges the secondary battery with the DC output voltage generated by the AC / DC converter, the DC output voltage optimum for charging the secondary battery is set as the first output voltage, and the first A DC output voltage that is lower than the output voltage of the secondary battery and capable of charging the secondary battery is set as the second output voltage, and the illumination circuit is set to be constantly lit or the wireless unit is in a transmission state wherein with that received the switching signal output from the mobile telephone device comprises a direct current output control circuit for controlling to switch the DC output voltage from said first output voltage to the second output voltage To provide an AC adapter which is characterized the door.
[0017]
According to this configuration, when a switching signal is issued from the mobile telephone device when the illumination circuit is set to be constantly lit or when the wireless unit is in a transmission state, the DC output control circuit lowers the DC output voltage. . As a result, the current consumption of the charge control circuit, which increases due to the constant lighting of the display unit and the operation unit, and the telephone call and data communication while charging, is reduced, and the heat generation of the charge control circuit can be prevented from increasing. As a result, the user is not discomforted.
[0018]
In order to achieve the above object, according to the present invention, as a third feature, the secondary battery is used as a power source, and the radio unit or the lighting circuit is connected to a mobile telephone device that can be operated during charging. In an AC adapter that charges the secondary battery with a DC output voltage generated by the conversion unit, a current detection circuit that detects a state of an output current of the AC / DC conversion unit, and a current detection value by the current detection circuit e Bei a DC output control circuit for controlling the output voltage of the AC / DC converter unit, the DC output control circuit, when the current detecting circuit detects no current value corresponding to the operation of the radio unit or the illumination circuit A DC output voltage optimum for charging the secondary battery is set as a first output voltage, and the current detection circuit detects a current value corresponding to the operation of the radio unit or the illumination circuit. And when providing an AC adapter and sets a possible DC output voltage charging the first output voltage from the low and the secondary battery as a second output voltage.
[0019]
According to this configuration, when the AC adapter is connected to the mobile telephone device, the output current is monitored by the current detection circuit, and when it is detected that the output current exceeds a predetermined value, The output control circuit controls the DC output voltage of the AC / DC converter so that the output current decreases. Therefore, the current consumption of the charge control circuit, which increases because the mobile telephone device is constantly lit on the display unit and the operation unit, and is talking and performing data communication while charging, decreases, and the charge control circuit in the mobile phone device generates heat. Therefore, it is possible to prevent the user from feeling uncomfortable.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 shows a first embodiment of a mobile telephone device and its AC adapter according to the present invention. FIG. 1 shows only the part related to the present invention. The overall configuration of the mobile phone device 100 is the same as that of the mobile phone device 300 of FIG. 3 except that the functions of the control unit are increased. Therefore, the illustration and description of the overall configuration are omitted below.
The external connection terminal 102 is provided with a switching control terminal 102a, a DC output terminal 102b, and a GND terminal 102c. The AC adapter 150 connected to the external connection terminal 102 includes the AC / DC conversion unit 401 and the DC output control circuit 151 shown in FIG.
[0021]
In the configuration of FIG. 1, when the charging AC adapter 150 is connected and charging is being performed, the charging control circuit 312 monitors the voltage of the voltage detection terminal 330b. When the battery 311 is a lithium ion battery, the current flowing through the + terminal 330a is controlled so that the applied voltage is 4.2V, and charging is completed when the charging current reaches a preset charging current.
During charging, when the mobile phone device 100 is not turned on or is performing a standby operation, the current consumed by the wireless unit is very small, so the current flowing through the charging control circuit 312 during charging is the charging current of the battery 311. Almost equal. On the other hand, when the lighting circuit 310 and the backlights 310a and 310b are operating during charging, or when a call or data communication is performed, the charging control circuit 312 includes the lighting circuit 310 and the backlight in addition to the charging current. Current consumed by 310a, 310b or the wireless unit 302 also flows.
[0022]
When the controller 307 detects that a DC voltage is applied from the AC adapter 150 to the charging control circuit 312, the controller 307 can be set to always turn on the illumination by the backlights 310 a and 310 b (by the user). On the other hand, when the AC adapter 150 is not connected to the external connection terminal 102 of the mobile phone device 100, the setting for always lighting the light cannot be performed.
When the control circuit 307 detects that the lighting circuit 310 is set to be always on, or enters a telephone call operation or the like and the wireless unit 302 is in a communication state, it outputs a switching signal 101a to the switching control terminal 102a. The switching signal 101a is taken into the AC adapter 150 and input to the DC output control circuit 151. The DC output control circuit 151 changes the DC voltage output from the AC / DC converter 401 by the switching signal 101a. Specifically, when the lighting circuit 310 is not set to be constantly lit during charging and a relatively large current is not flowing through the wireless unit 302 due to a call operation or the like, the output voltage of the AC adapter 150 is For example, it is set to 5.8V (the output voltage of the AC adapter 150 at this time is set to V1). This value is set to an appropriate value according to the charging voltage (4.2 V) of the lithium ion battery.
[0023]
Next, when the lighting circuit 310 is set to be constantly lit during charging, or when a relatively large current flows through the wireless unit 302 due to a call operation or the like, the output voltage of the AC adapter 150 is lower than 5.8 V (V1). The voltage is switched to, for example, 5.2 V (the output voltage of the AC adapter 150 at this time is set to V2). By reducing V2, the voltage drop in the charge control circuit 312 is reduced, and heat generated in the charge control circuit 312 can be suppressed.
Since the charging voltage when the output voltage of the AC adapter 150 is set to 5.2V is slightly lower than the 4.2V required for the lithium ion battery, it is assumed that the time until the charging is completed is slightly longer. The However, when the lighting is always turned on or a call is made during charging, the charging time becomes longer in the same manner as in the conventional mobile phone device, so that it does not become a big problem. However, if V2 is set too low, the voltage applied to the lithium-ion battery is further reduced from 4.2 V, so that the time until completion of charging becomes too long. Therefore, it is necessary to set V2 appropriately within a range where charging time is not excessively long while suppressing heat generation in the charging control circuit 312.
[0024]
By setting V2 to the above-described range, heat generation in the charging control circuit 312 can be suppressed even if the lighting is always turned on during charging or charging is performed while in a call state. It is possible to reduce the temperature rise. In addition, it is possible to minimize the extension of the charging time.
[0025]
[Second Embodiment]
Next, a second embodiment will be described.
FIG. 2 shows a second embodiment of the present invention.
In this embodiment, the cellular phone device 300 and the battery pack 313 shown in FIG. 4 are used as they are, but the configuration of the AC adapter 200 is different from those in FIGS. In other words, the mobile phone device 300 is the one in which only the AC adapter 200 is adapted to the present invention as it is, and thus, only the new AC adapter is used while using the conventional mobile phone device 300. As a result, the temperature rise of the charging control circuit 312 in the mobile phone device 300 can be prevented, and the user can be prevented from feeling uncomfortable.
The AC adapter 200 includes an AC / DC conversion unit 401 illustrated in FIG. 4, a current detection circuit 201 that detects an output current of the AC / DC conversion unit 401, and an AC / DC based on the detection result of the current detection circuit 201. A DC output control circuit 202 that changes the output voltage of the converter 401 is provided.
[0026]
In the configuration of FIG. 2, the current value during normal charging is set in the DC output control circuit 202 in advance, and the DC output voltage is set to V1 (= 5.8 V) during normal charging. Further, when the charging current increases during lighting or during a call operation, the DC output voltage is set to V2 (= 5.2 V) lower than V1. As a result, heat generation in the charging control circuit 312 can be suppressed, the temperature rise of the mobile phone device 300 can be reduced, and the user can be prevented from feeling uncomfortable.
[0027]
【The invention's effect】
As is clear from the above, according to the mobile telephone device of the present invention, when it is detected that the lighting circuit is set to be constantly lit or the wireless unit is in a transmitting state and the current passing through the charging control circuit is increased, Since the control unit that outputs a switching signal for lowering the output voltage of the AC adapter is provided, even if the display unit and the operation unit are always lit, or during a call or data communication while charging, the charging control circuit A calorific value can be made low and it does not give a user discomfort.
[0028]
Further, according to the AC adapter of the present invention, when a switching signal is issued from the mobile telephone device when the lighting circuit is set to be constantly lit or when the radio unit is in a transmission state, the DC output voltage is lowered. Since the output control circuit is provided, even if the current consumption of the charging control circuit of the mobile telephone device increases, the current flowing through the charging control circuit is reduced and the heat generation of the charging control circuit is prevented from increasing. Therefore, the user is not discomforted.
[0029]
Furthermore, according to another AC adapter of the present invention, the output current of the AC adapter connected to the mobile telephone device is monitored by the current detection circuit, and the AC / DC conversion unit is controlled by the DC output control circuit according to the detected current value. When the output current of the AC / DC converter exceeds a predetermined value, the DC output voltage of the AC / DC converter is lowered and the output current of the AC adapter is reduced. Even if the device is constantly lit on the display unit or operation unit, or is talking or performing data communication while charging, the current consumption of the charge control circuit will decrease, and the heat generation of the charge control circuit in the mobile phone device will increase. This can prevent the user from feeling uncomfortable.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of a mobile telephone device and its AC adapter according to the present invention.
FIG. 2 is a block diagram showing a second embodiment of the mobile telephone device and its AC adapter according to the present invention.
FIG. 3 is a block diagram illustrating an overall configuration of a mobile phone device including an illumination circuit.
FIG. 4 is a block diagram showing a conventional mobile telephone device and its AC adapter.
[Explanation of symbols]
100, 300 Mobile phone device 101, 307 Control unit 102 External connection terminal 102a Switching control terminal 102b DC output terminal 102c GND terminal 150 AC adapter 151 DC output control circuit 201 Current detection circuit 202 DC output control circuit 302 Radio unit 308 Display unit 309 Operation unit 310 Lighting circuit 310a, 310b Backlight 311 Battery 312 Charging control circuit 320 External connection terminal 320a DC output terminal 320b GND terminal 330 Battery connection terminal 330a + terminal 330b Voltage detection terminal 330c-terminal 400 AC adapter 401 AC / DC conversion unit

Claims (4)

Wireless connection unit for communication, illumination circuit for illuminating display unit and operation unit, charging control circuit for controlling charging of built-in secondary battery, and external connection terminal to which AC adapter for charging the secondary battery is connected In a mobile telephone device equipped with
A DC output voltage optimum for charging the secondary battery is set as the first output voltage,
A DC output voltage lower than the first output voltage and capable of charging the secondary battery is set as a second output voltage;
To switch the output voltage of the AC adapter from the first output voltage to the second output voltage when it is detected that the lighting circuit is always turned on or the wireless unit is in a transmission state. The mobile telephone apparatus characterized by including the control part which outputs the switching signal.   The mobile telephone device according to claim 1, wherein the control unit outputs the switching signal to the external connection terminal. The secondary battery is connected to a mobile telephone device that can operate a secondary battery or a lighting circuit while charging the secondary battery using a secondary battery as a power source, and a DC output voltage generated by an AC / DC converter. AC adapter for charging
A DC output voltage optimum for charging the secondary battery is set as the first output voltage,
A DC output voltage lower than the first output voltage and capable of charging the secondary battery is set as the second output voltage;
Having received the switching signal output from the mobile telephone device when the lighting circuit is set to be constantly lit or when the wireless unit is in a transmission state, the DC output voltage is changed from the first output voltage. An AC adapter comprising: a DC output control circuit that performs control so as to switch to the second output voltage . An AC adapter that uses a secondary battery as a power source and is connected to a mobile telephone device that can operate a wireless unit or lighting circuit during charging, and charges the secondary battery with a DC output voltage generated by an AC / DC converter In
A current detection circuit for detecting a state of an output current of the AC / DC converter;
A DC output control circuit for controlling an output voltage of the AC / DC converter according to a current detection value by the current detection circuit ;
The DC output control circuit sets, as the first output voltage, an optimum DC output voltage for charging the secondary battery when the current detection circuit does not detect a current value corresponding to the operation of the wireless unit or the lighting circuit. And
When the current detection circuit detects a current value corresponding to the operation of the wireless unit or the illumination circuit, a second output is generated with a DC output voltage lower than the first output voltage and capable of charging the secondary battery. An AC adapter that is set as a voltage .

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