JP2002271462A - Mobile terminal - Google Patents

Abstract

(57) [Problem] To provide a mobile terminal capable of exhibiting optimal antenna performance according to the state of expansion and contraction of an antenna or the state of folding of a housing. SOLUTION: An antenna detecting unit 12 for detecting a predetermined telescopic state of a telescopic antenna 10, a folding detecting unit 14 for detecting a predetermined folded state of a housing, and a predetermined telescopic state and a predetermined folded state, Matching circuits 30 to 36 for matching the antenna 10 with the internal circuit (transmitting / receiving circuit) 18 of the mobile terminal; switching means (switches) 20 and 22 for connecting the matching circuit to the antenna and the internal circuit;
And the control unit switches the switching unit when the antenna detection unit detects a predetermined expansion / contraction state and the folding detection unit detects the predetermined folding state, and connects one matching circuit to the antenna and the internal circuit. Let it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable terminal having a telescopic antenna or a foldable casing and having a matching circuit for the antenna.

[0002]

2. Description of the Related Art Conventionally, a portable terminal (portable telephone) is equipped with a matching circuit composed of, for example, an LC circuit. This matching circuit is connected between the antenna and an internal circuit (transmitter / receiver circuit, etc.). For example, when the impedance of the antenna is different from the impedance of the internal circuit, matching between the two is obtained to obtain optimal antenna performance. This is to prevent a decrease in communication quality and the like.

Here, it is ideal that the matching circuit has an impedance characteristic that just cancels the impedance difference between the antenna and the internal circuit. On the other hand, when a mobile terminal is used (transmitted / received), it is assumed that the antenna is extended. However, in a standby state or the like, the antenna may be used with the antenna stored. for that reason,
In designing an actual matching circuit, it is necessary not to completely cancel the impedance difference at a specific length when the antenna is extended or stored, but to reduce the impedance difference to some extent regardless of the antenna length. I have it.

[0004]

However, in the case of the above-described conventional matching circuit, the impedance difference cannot be completely canceled at a specific length such as when the antenna is extended or stored. There is a problem that the performance cannot be maximized and the communication quality is reduced accordingly.

[0005] In recent years, portable terminals having a so-called foldable casing have become widespread.
When the housing is opened, the housing interferes with the antenna or the housing itself acts as an antenna, which changes the impedance characteristics of the entire antenna, and the matching conditions of the matching circuit fluctuate. There is a problem that quality is reduced.

An object of the present invention is to solve the above-mentioned problems in a portable terminal, and to provide a portable terminal capable of exhibiting an optimum antenna performance in accordance with the expansion and contraction state of the antenna or the folded state of the housing and improving communication quality. I do.

[0007]

According to a first aspect of the present invention, there is provided a portable terminal having a telescopic antenna, the antenna detecting unit detecting a predetermined telescopic state of the antenna. And a matching circuit that matches the antenna and an internal circuit of the mobile terminal in the predetermined telescopic state, a switching unit that connects the matching circuit to the antenna and the internal circuit, and a control unit. The control unit switches the switching unit when the antenna detection unit detects the predetermined expansion / contraction state, and connects the matching circuit to the antenna and the internal circuit. By doing so, it is possible to select a matching circuit that maximizes antenna performance in a predetermined telescopic state, and to improve communication quality in this state.

3. The portable terminal according to claim 2, wherein the antenna detecting section detects two or more different expansion / contraction states of the antenna, and in each of the two or more expansion / contraction states, the antenna and an internal circuit of the mobile terminal. The control unit switches the switching unit when the antenna detection unit detects any of the expansion and contraction states, and sets the matching circuit corresponding to the expansion and contraction state to the antenna. And the internal circuit. By doing so, it is possible to select a matching circuit that maximizes the antenna performance in a plurality of expanded and contracted states, and it is possible to further improve communication quality.

According to a third aspect of the present invention, in the portable terminal having a foldable casing, a fold detecting section for detecting a predetermined folded state of the casing, and the antenna and the antenna in the predetermined folded state are provided. A matching circuit for matching an internal circuit of the mobile terminal; switching means for connecting the matching circuit to the antenna and the internal circuit; and a control unit. When a folded state is detected, the switching unit is switched, and the matching circuit is connected to the antenna and the internal circuit. By doing so, it is possible to select a matching circuit that maximizes the antenna performance in a predetermined folded state, and it is possible to improve communication quality in this state.

According to a fourth aspect of the present invention, in the portable terminal, the folding detection unit detects two or more different folding states of the housing, and in each of the two or more folding states,
The control unit includes two or more matching circuits for matching the antenna and an internal circuit of the portable terminal, wherein the control unit switches the switching unit when the folding detection unit detects any of the folding states, and A matching circuit corresponding to a state is connected to the antenna and the internal circuit. By doing so, it is possible to select a matching circuit that maximizes the antenna performance in a plurality of folded states, and further improve communication quality.

According to a fifth aspect of the present invention, there is provided a portable terminal having a telescopic antenna and a foldable casing,
An antenna detection unit that detects a predetermined expansion / contraction state of the antenna; a folding detection unit that detects a predetermined folding state of the housing; and the antenna and the portable terminal in the predetermined expansion / contraction state and the predetermined folding state. A matching circuit that matches the internal circuit, a switching unit that connects the matching circuit to the antenna and the internal circuit, and a control unit,
The control unit switches the switching unit when the antenna detection unit detects the predetermined expansion / contraction state, and the folding detection unit detects the predetermined folding state, and switches the matching circuit to the antenna and the internal circuit. And is connected to By doing so, it is possible to select a matching circuit that maximizes the antenna performance in the predetermined telescopic state and the folded state, and it is possible to improve communication quality in this state.

According to a sixth aspect of the present invention, in the portable terminal, the antenna detection unit detects two or more different expansion / contraction states of the antenna, and the fold detection unit detects two or more different fold states of the housing. In each of the states satisfying any one of the two or more expanded states and any one of the two or more folded states, four or more matching circuits that match the antenna and the internal circuit of the portable terminal are provided. The control unit switches the switching unit when the antenna detection unit detects any of the expanded and contracted states and the folding detection unit detects any of the folded states, and performs matching corresponding to the expanded and contracted state and the folded state. A circuit is connected to the antenna and the internal circuit. By doing so, it is possible to select a matching circuit that maximizes antenna performance in a plurality of expanded and contracted states and a folded state, respectively, and it is possible to further improve communication quality.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an appearance of a mobile terminal (mobile phone) 1 according to the present invention. The mobile phone 1 includes substantially rectangular housings 2a and 2b,
One side of each housing is connected to the shaft 2c, and is folded (opened and closed) around the shaft 2c. When the mobile terminal is not used or in a standby state, each of the housings 2a, 2a
b is folded so as to match each other, and when talking, each folded housing is opened, and a display unit and input keys (not shown) are exposed and operated. The mobile phone 1 also includes a telescopic (wireless) antenna 10.
Is attached to the housing 2a side.

FIG. 2 is a configuration block diagram showing an embodiment of the mobile phone 1 according to the present invention. Mobile phone 1
Indicates that the antenna 10, the antenna detection unit 12 that detects the expansion / contraction state of the antenna 10, and the folding (opening / closing) of the housings 2 a and 2 b
The antenna 10 and the transmission / reception circuit 1 are selected by selecting one of the folding detection unit 14 for detecting the state, the control unit 16 for controlling the whole, the transmission / reception circuit 18, the matching circuits 30 to 36, and each of the matching circuits.
And switches (switching means) 20 and 22 connected between them. Here, the transmission / reception circuit 18 includes a wireless unit that transmits and receives signals via the antenna 10 and a signal processing unit that processes the signals. Also, switches 20, 2
Reference numeral 2 is interlocked, and any of the matching circuits 30 to 36 is connected between the antenna 10 and the transmission / reception circuit 18 to form a closed circuit.

Here, the antenna 10 transmits and receives radio signals to and from a base station. Control unit 1
Reference numeral 6 denotes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Rand
om Access Memory). The CPU performs arithmetic processing according to a predetermined control program. The ROM stores the control program and control data, and the RAM temporarily reads and writes various data necessary for the arithmetic processing.

The matching circuits 30 to 36 are matching circuits respectively corresponding to two expansion and contraction states of the antenna (at the time of maximum extension and at the time of storage) and two folding states of the housing (at the time of folding and at the time of opening). , For example, an LC circuit. FIG. 3 shows a state of the mobile phone when each matching circuit operates.

In this figure, when the antenna is housed and the housing is folded (the state of FIG. 3A), the matching circuit 30 is connected between the antenna and an internal circuit (for example, the transmission / reception circuit 18 or the like at the time of communication of a portable terminal such as the transmission / reception circuit 18). This is a matching circuit that is set in advance so that the matching with the circuit is optimized. Here, "matching" refers to matching the impedance between the antenna and the internal circuit. For example, with respect to an internal circuit having a characteristic impedance of 50Ω, the matching circuit is provided with impedance characteristics such that the antenna input impedance becomes 50Ω.

The matching circuit 32 will be described below when the antenna is fully extended and the case is folded (FIG. 3B), and the matching circuit 34 is when the antenna is stored and the case is open (FIG. 3C).
3), the matching circuit 36 is a matching circuit in which the matching is optimized when the antenna is fully extended and the housing is in the open state (the state shown in FIG. 3D). In FIG. 3, when the housing is folded, the length of the housing is L1, and when the housing is open, the length of the housing is L2. Therefore, it is necessary to design each matching circuit accordingly.

Returning to FIG. 2, the cellular phone 1 also includes a voice processing unit (codec) 40, input keys (input operation unit) 42 operated by a user, and a display unit 4 including a liquid crystal screen and the like.
4. Microphone (transmitter) 4 for inputting audio signal
6. A speaker (receiver) 48 for outputting an audio signal.

Next, the processing performed by the mobile phone of the present invention will be described with reference to FIG. In this figure,
When the power of the mobile phone is turned on, the antenna detector 12
And the folding detection part 14 operates. When the antenna detector 12 detects the telescopic state of the antenna 10 (either the maximum expansion or the storage), the controller 16 acquires the detection signal (step S100). Also, the folding detection unit 14
When the control unit 16 detects the folded state of the housing (either in the folded state or the open state), the control unit 16 acquires the detection signal (step S120).

The control unit 16 determines in steps S100 and S12
Based on the signal acquired at 0, a logic signal serving as a switching signal for the switches 20 and 22 is generated (step S140).
This logic signal selects one of the matching circuits 30 to 36 that achieves optimum matching in a specific mobile phone state (any one of the four states shown in FIG. 3), and This is a control signal for connecting to the transmission / reception circuit 18. For example, when the control unit 16 acquires the detection signals “antenna maximum extension” and “housing folding” (corresponding to FIG. 3B), the impedance difference between the antenna 10 and the transmission / reception circuit 18 is completely reduced in this state. A logic signal for selecting (connecting) the matching circuit 32 that cancels out the data is generated. Next, the control unit 16 switches the switches 20 and 22 according to the switching signal (step S160), connects the matching circuit 32 to the antenna 10 and the transmission / reception circuit 18, and starts communication as appropriate (step S180). As a result, the impedance difference between the antenna 10 and the transmission / reception circuit 18 is almost completely canceled, and the optimum matching is obtained, so that the antenna performance can be maximized and good communication quality can be obtained.

In this embodiment, when the power supply is in the ON state, detection information is obtained from each detection unit at predetermined time intervals, and a new switch switching signal is appropriately generated to perform switch switching. ing. Thereby, even when the state of the mobile phone changes, for example, when the housing is folded during a call, a new optimal matching circuit is newly selected (connected) according to the change, thereby always improving the communication quality. be able to.
Further, for example, when there is a call request from the user (for example, when a numeric keypad or a call key is pressed), it may be set to perform the processing up to the acquisition of the detection information and the subsequent switch switching. In this way, an optimum matching circuit is selected for each call.

The present invention is not limited to the above embodiment. An optimum matching circuit may be operated based on only one of the antenna detection unit and the folding detection unit. For example, in the case of a non-foldable mobile phone, only an antenna detection unit is provided, and this detection unit detects two states of maximum extension and storage of the antenna, and a matching circuit adapted to each of the two states. What is necessary is just to prepare two and switch suitably with a switch.

Alternatively, the antenna detector may detect only one of the states of maximum extension and storage of the antenna, and one matching circuit adapted to this state may be prepared. In this case, when the antenna detection unit detects a predetermined state, an optimum matching circuit corresponding to the predetermined state is selected to improve communication quality, but in other states, a normal (conventional) matching circuit is selected. Also, the communication quality remains the same. This makes it simpler than the case where two optimal matching circuits are prepared, and has an advantage in cost.

When the housing is opened, the antenna automatically extends, and when the housing is folded, the mobile terminal can automatically store the antenna.
The antenna is extended when the housing is open, and the antenna is stored when the housing is folded. Therefore, it is only necessary to prepare two matching circuits suitable for these states.
Further, since the antenna contraction and the folded state of the housing are linked, only one of the antenna detection unit and the folding detection unit may be provided. In order to automatically expand and contract the antenna, for example, a vibration motor (vibration motor) that operates according to the open / closed state of the housing may be used.

The antenna detecting section 12 may detect the antenna as a predetermined extended state when the antenna is stored, when the antenna is fully extended, or when the antenna has a specific length, and the extended state is not limited to a specific one. Further, there is no limitation on the detection method. For example, the storage or extension of the antenna may be detected by mechanical switching means or electrical contacts, or may be optically detected by a photocoupler or the like. The same applies to the folding detection unit 14, and when the housing is completely folded, in the maximum open state, or in a specific opening state, it may be detected as a predetermined folded state, and the detection method is the same as the antenna detection unit. Various selections can be made.

[0027]

As described above, according to the first aspect of the present invention, it is possible to select (connect) a matching circuit that maximizes the antenna performance in a predetermined telescopic state. Can be improved over the case of using the conventional matching circuit. According to the second aspect of the present invention, it is possible to select a matching circuit that maximizes the antenna performance in a plurality of expanding and contracting states, respectively, and further improve communication quality.

According to the third aspect of the present invention, a matching circuit that maximizes antenna performance can be selected (connected) in a predetermined folded state, and the communication quality in this state can be reduced by the conventional matching circuit. Can be improved as compared with the case of using. Further, according to the present invention, it is possible to select a matching circuit that maximizes the antenna performance in a plurality of folded states, thereby further improving communication quality.

According to the fifth aspect of the present invention, it is possible to select a matching circuit that maximizes the antenna performance in a predetermined telescopic state and a folded state, and to improve communication quality in this state. . That is, as compared with the present invention described in claim 1 or 3, a matching circuit that is more suitable for a specific state can be selected, and the effect of improving communication quality is further enhanced. Further, according to the present invention, it is possible to select a matching circuit that maximizes antenna performance in a plurality of expanded and contracted states and a folded state, respectively, and it is possible to further improve communication quality.

[Brief description of the drawings]

FIG. 1 is a diagram showing an appearance of a mobile terminal (mobile phone) of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a mobile phone.

FIG. 3 is a diagram showing a use state of the mobile phone.

FIG. 4 is a diagram showing a processing flow in a mobile phone.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mobile terminal (mobile telephone) 2a, 2b Housing 10 Antenna 12 Antenna detecting part 14 Folding detecting part 16 Control part 18 Internal circuit (transmitting / receiving circuit) 20, 22 Switching means (Switch) 30-36 Matching circuit

Claims (6)

[Claims] 1. A portable terminal having a telescopic antenna, wherein: an antenna detecting unit for detecting a predetermined telescopic state of the antenna; and, in the predetermined telescopic state, matching the antenna with an internal circuit of the mobile terminal. A matching circuit; switching means for connecting the matching circuit to the antenna and the internal circuit; and a control unit, wherein the control unit performs the switching when the antenna detecting unit detects the predetermined expansion / contraction state. A portable terminal, wherein means is switched to connect the matching circuit to the antenna and the internal circuit. 2. The antenna detection unit detects two or more different expansion and contraction states of the antenna, and in each of the two or more expansion and contraction states, matches two or more antennas and an internal circuit of the portable terminal. When the antenna detecting unit detects one of the expansion and contraction states, the control unit switches the switching unit, and connects a matching circuit corresponding to the expansion and contraction state to the antenna and the internal circuit. The mobile terminal according to claim 1, wherein 3. A portable terminal having a foldable case, wherein: a fold detection unit for detecting a predetermined fold state of the case; and the antenna and an internal circuit of the portable terminal in the predetermined fold state. A matching circuit for matching; switching means for connecting the matching circuit to the antenna and the internal circuit; and a control unit, wherein the control unit is configured to detect when the folding detection unit detects the predetermined folded state. A portable terminal, wherein the switching unit is switched to connect the matching circuit to the antenna and the internal circuit. 4. The folding detection unit is different from the housing in two different cases.
Each of the above-mentioned folded states is detected, and in each of the two or more folded states, there are provided two or more of the matching circuits for matching the antenna and an internal circuit of the portable terminal. 4. The portable terminal according to claim 3, wherein, when any one of the folded states is detected, the switching unit is switched, and a matching circuit corresponding to the folded state is connected to the antenna and the internal circuit. 5. A portable terminal having a telescoping antenna and a foldable casing, an antenna detector for detecting a predetermined telescoping state of the antenna, and fold detection for detecting a predetermined foldable state of the casing. A matching circuit that matches the antenna with an internal circuit of the mobile terminal in the predetermined telescopic state and the predetermined folded state; and a switching unit that connects the matching circuit to the antenna and the internal circuit. A control unit, wherein the control unit switches the switching unit when the antenna detection unit detects the predetermined expansion / contraction state and the folding detection unit detects the predetermined folding state, and the matching circuit A mobile terminal connected to the antenna and the internal circuit. 6. The antenna detecting unit detects two or more different states of expansion and contraction of the antenna, and the folding detection unit respectively detects two or more different states of folding of the housing, and the two or more states of expansion and contraction. And the four or more matching circuits for matching the antenna and the internal circuit of the mobile terminal in each of the states satisfying any of the above and any of the two or more folded states. The control unit includes: When the detecting unit detects any of the expanding and contracting states, and the folding detecting unit detects any of the folding states, the switching unit is switched, and a matching circuit corresponding to the expanding and contracting state and the folding state is formed between the antenna and the inside of the antenna. The mobile terminal according to claim 5, wherein the mobile terminal is connected to a circuit.