JP3068502B2 - Wireless personal digital assistant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless portable information terminal for processing data transmitted and received by a radio wave to and from a wireless communication unit using an information processing unit. The present invention relates to a wireless portable information terminal that is less susceptible to data quality degradation due to sneaking from an antenna of the wireless communication unit.

[0002]

2. Description of the Related Art Conventionally, portable information terminals (also referred to as information processing units) such as electronic notebooks and electronic boards have been used for PHS telephones or PDC systems (for example, R
2. Description of the Related Art A wireless portable information terminal which inputs and outputs data with a mobile phone (also referred to as a wireless communication unit) of CRSTD-27 is known. In these wireless portable information terminals, the wireless communication section inputs and outputs the data via an antenna connected to the head. In many cases, these wireless portable information terminals are generally housed in the same housing having a movable lid, and execute the operation of the information processing section by opening the lid. Many of the above-mentioned antennas form a fixed directivity pattern.

[0003]

In the above-described conventional wireless portable information terminal, noise generation increases as the operation speed of the information processing unit increases. The generated noise is received by the antenna, thereby deteriorating the S / N ratio of the data input from the antenna and causing communication quality deterioration. In order to improve this, sufficient electromagnetic shielding may be achieved by, for example, partitioning the wireless communication unit (including the antenna) and the information processing unit with a metal plate.
The above countermeasures impose a heavy burden on wireless portable information terminals that need to be miniaturized.

Accordingly, an object of the present invention is to provide a wireless portable information terminal in which information transmitted and received by a wireless communication unit using radio waves is processed by an information processing unit. Is reduced by a simple configuration.

[0005]

A wireless portable information terminal according to the present invention is a wireless portable information terminal in which an information processing unit processes data transmitted and received by a wireless communication unit using a radio wave. Antenna is directional pattern
It consists of multiple different antennas
An antenna having a smaller antenna gain toward the information processing unit is selected as the operation speed of the information processing unit increases .

[0006]

[0007] The wireless portable information terminal end, the is the most wireless communication unit and the information processing unit, are housed in the main body, the antenna is housed inside of the movable lid which lid the body structure Can be taken.

[0008] One of the wireless portable information terminals includes a movable lid open / closed detection switch for detecting opening / closing of the movable lid with respect to the main body, wherein the antenna comprises: a first antenna having a non-directional pattern; A second antenna having a characteristic pattern, and when the closing of the movable lid is detected, the first antenna may be connected to the wireless communication unit.

[0009] Another one of the wireless portable information terminals is the a
The first of the antennas is a dipole antenna having an omnidirectional pattern, the second of the antennas is a Yagi antenna having a directional pattern, and when the opening of the movable lid is detected, the open state of the movable lid is determined. Then, the Yagi antenna arranged so that the antenna gain in the direction of the information processing unit is reduced can be connected to the wireless communication unit.

In the wireless portable information terminal, when the operation speed of the information processing unit is two or more, and the operation speed is equal to or lower than a predetermined value, the opening of the movable lid is detected.
A configuration may be adopted in which a first one of the antennas is connected to the wireless communication unit.

[0011]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of a wireless portable information terminal according to the present invention. FIG. 2 is a perspective view of the embodiment of FIG. 1 when the lid is opened.

Referring to FIG. 1 and FIG. 2, this wireless portable information terminal roughly includes a wireless communication unit 1, an information processing unit 2, a power supply unit 3 and a power supply circuit including a battery 4. The antenna unit including the dipole antenna 5, the antenna switching unit 6, and the Yagi antenna 7 is included in the wireless communication unit 1. Wireless communication unit 1, information processing unit 2, excluding antenna unit
The battery 4 and the power supply unit 5 are housed in a main body 101 made of plastic. The battery 4 and the power supply unit 5 supply power to other circuits.

A movable lid 102 made of plastic is connected to the main body 101 by a well-known hinge structure or the like, and the movable lid 102 is used as a lid for the contents of the main body 101. The movable lid 102 also has a certain depth, and this portion accommodates an antenna unit including the dipole antenna 5, the antenna switching unit 6, and the Yagi antenna 7. In addition, the movable lid 102 is attached to the main body 1 at a position facing the above-mentioned joint between the main body 101 and the movable lid 102.
It is common to have a fastener that stops at 01. Also,
In this wireless portable information terminal, the surface of the movable lid 102 is
It also has a well-known mechanism that can be supported almost vertically on one surface.

A movable lid opening / closing detection switch 9 such as a microswitch is disposed on the main body 101. Switch 9
Is O when the movable lid 102 is closed to the main body 101.
When the FF and the movable lid 102 are opened from the main body 101, they are turned on and the voltage from the power supply unit 3 is applied to the CP of the information processing unit 2.
Input to U23.

The wireless communication section 1 includes a TDMA wireless communication function. The radio wave from the base station is input to and output from the dipole antenna 5 or the Yagi antenna 7. This radio wave is converted into reception data by the reception unit 13 via the antenna switch 6 and the diplexer 12, and the reception data is sent to the information processing unit 2 via the control unit 16. On the other hand, the transmission data received from the information processing unit 2 is transmitted to the transmission unit 1 via the control unit 16.
Sent to 5. The transmitting unit 15 converts the transmission data into a radio wave, and the radio wave is transmitted to the base station via the diplexer 12 and the antenna. The control unit 16
The synthesizer 14, which is controlled to send a local oscillation signal, to the receiving unit 13 and the transmitting unit 15. Control unit 1
Numeral 6 controls transmission timing control, reception timing control of the TDMA signal and switching control of the synthesizer 14. In the wireless communication unit 1, power is supplied to the synthesizer 14, the transmission unit 15, and the control unit 16 at the TDMA transmission timing, and power is supplied to the synthesizer 14, the reception unit 13, and the control unit 16 at the TDMA reception timing.

The information processing unit 2 includes a microprocessor (CPU) 23, a ROM 21 having a built-in program, and a RAM temporarily storing calculation results, as in a general information processing terminal.
22, a display unit 24 for displaying a result during operation or calculation, an operation unit 25 for providing an operation procedure for data processing, a clock generation unit 26, and the like. Performs predetermined data processing such as for an electronic organizer. The clock frequency for operating the information processing unit 2 can be changed to a plurality of frequencies, such as 10 MHz, 40 MHz, and 100 MHz, under the control of the clock generation unit 26 by the CPU 23. Also, as will be described in detail later,
The switch 8 is operated by the antenna switch 6 according to an instruction from the CPU 23.
Is supplied with power for antenna switching control.

The operation of the wireless portable information terminal according to the present embodiment will now be described.

FIGS. 3A and 3B are explanatory views of the antenna used in the embodiment of FIG. 1. FIG. 3A is a schematic diagram of the dipole antenna 5, FIG. 3B is a vertical directivity pattern of the dipole antenna 5, and FIG. 7A is a schematic diagram of the Yagi antenna 7, and FIG. 7D shows a vertical directivity pattern of the Yagi antenna 7, respectively.

The coordinates in FIG. 3 correspond to the state in which the movable lid 102 in FIG. 1 is closed. Referring to (a), the dipole antenna 5 is an antenna that excites a straight metal wire (conductor) from the center with a length of λ / 2 (where λ indicates an effective wavelength of a working frequency). As shown in (b), the directivity pattern aV in the vertical plane is a non-directional pattern.
Therefore, it can be said that the dipole antenna 5 has almost the same gain in any direction but is small.

Referring to (c), the Yagi antenna 7 is
In addition to an antenna 7a (same as the dipole antenna 5) which excites a straight metal wire (conductor) from the center with a length λ / 2, a director 7b of a metal wire shorter than λ / 2 and a longer wire than λ / 2 A metal wire reflector 7c is provided before and after the dipole 7a (in the same plane on both sides). As shown in (d), the directivity pattern bV in the vertical plane of the Yagi antenna 7 has directivity with a large gain in the y-axis direction. Accordingly, the Yagi antenna 7 has a feature that the gain in the y direction, that is, the sensitivity is large, but the gain in the x direction is extremely small.

FIGS. 4A and 4B are diagrams showing antenna directivity patterns when the wireless portable information terminal according to the embodiment of FIG. 1 is used, wherein FIG. 4A shows the antenna directivity pattern when the lid is closed, and FIG. The directional pattern at the time of a cover and high-speed operation is shown.

In the wireless portable information terminal of FIG. 1, the clock frequency for operating the information processing section 2 is 10 MHz, controlled by the clock generation section 26 by the CPU 23.
The frequency can be changed to a plurality of frequencies such as 40 MHz and 100 MHz. Reducing the clock frequency is also for the purpose of reducing power consumption. When the clock frequency increases, not only does the noise level increase, but also it becomes difficult to reduce the noise level. Therefore, the adverse effect on the wireless communication unit 1 increases. These noises are most troublesome to process especially when they are input to the wireless communication unit 1 from an antenna (the dipole antenna 5 or the Yagi antenna 7).

In this wireless portable information terminal, the information processing section 2
The directivity pattern from the antenna to the information processing unit 2 can be changed in accordance with the operation speed of the antenna, that is, the clock frequency.
(Because the progress of the radio wave is reciprocal, the above is the same as changing the directivity pattern of the noise emission from the information processing unit 2). For the sake of simplicity, it is assumed that there are two types of clock frequencies, 10 MHz and 100 MHz. In the case of a clock frequency of 10 MHz, noise generation is small, so that even when the dipole antenna 5 is used, data deterioration (communication deterioration) in the wireless communication unit 1 is small.

The case where the operation speed of the information processing unit 2 may be low is a case where the information processing unit 2 is not performing a special operation. In this case, the movable lid 102 is closed (FIG. 4A).
reference). Accordingly, upon detecting that the movable lid 102 is closed, the movable lid detection switch 9 notifies the CPU 23 of this. Then, the CPU 23 turns on the switch 8, and the antenna switch 6 connects the dipole antenna 5 to the wireless communication unit 1. The switch 8 and the antenna switch 6 can use a mechanical switch and an electronic switch, and may be provided in the information processing unit 2. The dipole antenna 5 has an advantage that it can easily capture radio waves from all directions.

On the other hand, when the information processing section 2 is to perform a special operation, it is necessary to open the movable cover 102 (FIG. 4B).
reference). Therefore, in this case, the movable lid open / close detection switch 9
Detects the opening of the movable lid 102 and notifies the CPU 23 of the detection. When the information processing unit 2 performs a special operation, the information processing unit 2 is normally operated at a high clock frequency of 100 MHz. In this case, a large amount of noise is generated, and when the dipole antenna 5 is used, the data deterioration in the wireless communication unit 1 increases to such an extent that it cannot be tolerated. Therefore, CPU2
3 turns off the switch 8, and the antenna switch 6 connects the Yagi antenna 7 to the wireless communication unit 1. As shown in FIG. 4B, when the movable lid 102 is opened so as to be orthogonal to the main body 101, the direction of the directivity pattern bV of the Yagi antenna 7 is in the z-axis direction with respect to the main body 101, and is in the z-axis direction. Communication sensitivity is good, but the information processing unit 2 of the Yagi antenna 7
The antenna gain in the direction of the main body 101 in which is stored is very small. Therefore, in this state, the noise input from the information processing unit 2 to the Yagi antenna 7 is extremely small.

The movable cover 102 is opened and the information processing section 2 is opened.
In some cases, a high operating speed is not required, and the clock frequency may be about 10 MHz. In this case, the CPU 23 turns on the switch 8 and connects the dipole antenna 5 to the DIP 12. In this case, the noise input to the wireless communication unit 1 is the same as when the movable lid 102 is closed, and the data quality of the wireless communication unit 1 does not deteriorate. The criterion for selecting the dipole antenna 5 with the movable lid 102 opened, that is, the threshold value of the clock frequency is determined by the degree of electromagnetic shielding of the wireless communication unit 1 and the S / S
N-proof strength, dipole antenna 5 and Yagi antenna 7
Is determined by the allowable limit of data quality deterioration in the wireless communication unit 1 related to the directivity pattern of the wireless communication unit 1.

As described above, in the embodiment of FIG. 1, the wireless communication section 1 of the wireless portable information terminal has two antennas 5 and 7
However, the number of antennas may be two or more. Alternatively, only one kind of array antenna or the like may be used, and the antennas may be selected according to the operation state of the wireless portable information terminal. May be changed.

[0029]

As described above, in the wireless portable information terminal according to the present invention, the antenna provided in the wireless communication unit reduces the antenna gain in the direction of the information processing unit as the operation speed of the information processing unit increases. Also, even when the noise generated by the information processing unit is large, noise generated from the information processing unit and input to the antenna of the wireless communication unit can be reduced, and the quality of data passing through the wireless communication unit is degraded. Can be reduced, and good original information processing can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a wireless portable information terminal according to the present invention.

FIG. 2 is a perspective view of the embodiment of FIG. 1 when the lid is opened.

3A and 3B are explanatory diagrams of an antenna used in the embodiment of FIG. 1; FIG. 3A is a schematic diagram of a dipole antenna 5;
Is the vertical directivity pattern of the dipole antenna 5,
(C) is a schematic diagram of the Yagi antenna 7, and (d) is a vertical directivity pattern of the Yagi antenna 7.

4A and 4B are diagrams showing directivity patterns of an antenna when the wireless portable information terminal according to the embodiment of FIG. 1 is used, wherein FIG. 4A shows a state when the lid is closed, and FIG. 3 shows a directivity pattern of an antenna.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wireless communication unit 12 diplexer (DIP) 13 reception unit 14 synthesizer 15 transmission unit 16 control unit 2 information processing unit 21 ROM 22 RAM 23 microprocessor (CPU) 24 display unit 25 operation unit 3 power supply unit 4 battery 5 dipole antenna 6 antenna Switch 7 Yagi antenna 8 Switch 9 Movable lid open / close detection switch 101 Main body 102 Movable lid

Claims (5)

(57) [Claims] An information processing unit for processing data transmitted and received by a wireless communication unit using a radio wave in an information processing unit, wherein the antenna provided in the wireless communication unit has a directional pattern.
A wireless portable information terminal comprising a plurality of antennas different from each other, wherein an antenna having a smaller antenna gain toward the information processing unit is selected as the operation speed of the information processing unit is higher. 2. The wireless communication unit according to claim 1, wherein the wireless communication unit and the information processing unit are housed in a main body, and the antenna is housed inside a movable lid that covers the main body. 2. The wireless portable information terminal according to 1. 3. A movable lid opening / closing detection switch for detecting opening / closing of the movable lid with respect to the main body, wherein an antenna provided in the wireless communication unit includes a first antenna having a non-directional pattern and a first antenna having a directional pattern. and a second antenna, if the closing of the movable cover is detected, wherein, characterized in that for connecting the first antenna to the radio communication unit
Item 2. The wireless portable information terminal according to Item 2 . 4. An antenna according to claim 1 , wherein a first of said antennas is a dipole antenna having an omni- directional pattern, a second of said antennas is a Yagi antenna having a directional pattern, and said opening of said movable lid is detected. The wireless portable information terminal according to claim 2 , wherein the Yagi antenna arranged so that the antenna gain in the direction of the information processing unit is reduced when the movable lid is open, is connected to the wireless communication unit. Operating speed of claim 5 wherein said information processing unit has two or more, if the operation speed is below a predetermined value, even if the opening is detected of the movable lid, the wireless first said antenna The wireless portable information terminal according to claim 4, wherein the terminal is connected to a communication unit.