JPH11249757A - Information terminal device with built-in telephone - Google Patents

Abstract

(57) [Problem] To provide a portable information terminal device that has both performance and design that does not hinder carrying when carrying without deteriorating a data communication function. SOLUTION: The portable information terminal device of the present invention is a portable information terminal device which incorporates a telephone, processes information inputted through a pen 8, and displays the processed information on a liquid crystal unit 9, wherein the liquid crystal unit is mounted. A space 22 for accommodating the pen or a stand 23 is provided at a position on the back of the housing parallel to the center line axis of the antenna 2 which can be freely inserted into and removed from the housing. The distance between the antenna and the center line axis is set to at least λ (wavelength) / 15 with respect to the frequency of the telephone to be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a portable information terminal device for exchanging data by connecting information generated by an information processing device to a telephone via a modem.

[0002]

2. Description of the Related Art Advances in semiconductor technology have led to miniaturization of devices, and the development of software, which is a technology for using such devices, has been activated.
rsonalDigital Assistants) have emerged. Also, the information created by the PDA is stored in the PH via the modem.
S and mobile phones are also frequently used as wireless data communication devices such as facsimile machines.

However, for those who use the PDA mainly as a data transmission device, it is easier to use a built-in modem, PHS or mobile phone function in advance. Built-in P
We are developing DA.

[0004] If the PDA does not have a built-in communication function, it is relatively easy to reduce the size of the device because only the function as an electronic organizer has to be realized. Telephone RF (Radio Frequency)
It is necessary to add a circuit portion, a baseband processing IC, and the like.
Since the power is as large as mW, even if a lithium ion battery is used, it becomes considerably large, and it is difficult to reduce the outer shape of the PDA to a small size. This is especially true when trying to fit a PDA in a shirt breast pocket.

[0005]

By the way, in a PDA with a built-in portable telephone, a PDA having only the function of an electronic organizer is additionally provided with a new 800 MHz or 1.5G.
An RF unit and an RF antenna corresponding to Hz are required. However, in the case of a PDA, besides being used as a telephone by holding it by hand, there is a method of performing data communication while performing pen input while being placed on a flat surface such as a desk. Here, there is no problem if the table is made of an insulating material such as wood or plastic like a desk, but if it is made of metal, the distance between the antenna and the table cannot be sufficiently taken.
The required antenna performance could not be exhibited, and as a result, data communication could not be performed. For this reason, in the case of a PDA with a built-in mobile phone, a problem often arises when trying to achieve both functions and portability.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a portable information terminal device having both performance and design that do not hinder carrying when carrying without deteriorating a data communication function. Aim.

[0007]

A portable information terminal device according to the present invention has a built-in telephone, processes information input via a pen, and displays the processed information on a liquid crystal unit. By providing a space for accommodating the pen at a position on the rear surface of the housing parallel to the center line axis of the antenna that can be freely inserted into and removed from the housing, the housing installation surface and the center of the antenna when the portable information terminal device is used. The distance from the line axis is set to at least λ (wavelength) / 15 with respect to the frequency of the telephone to be used. Also, a stand that is folded and stored in the housing on the back of the housing is provided, and when the portable information terminal is used, an inclination is provided between the housing and the housing installation surface via the stand, so that the portable information terminal device can be used. The distance between the housing installation surface and the center line axis of the antenna is set to at least λ / 15 with respect to the frequency of the telephone to be used.

Thus, even when the portable information terminal is placed on a table made of a metal plate, the performance degradation of the antenna can be minimized, and a situation in which data communication and voice communication are not possible is avoided. be able to.

[0009]

1 and 2 are external views showing an embodiment of the present invention. FIG. 1 shows the PD with the cover 10 opened.
FIG. 2 shows a state in which A is used, and FIG. In the figure, 1 is a PDA main body, 2 is a whip antenna serving as a main antenna, 3 is a speaker, 4 is a microphone, 5 is a call button, 6 is a telephone disconnection button, 7 is a power switch, 8 is an information input pen, and 9 is a display. A liquid crystal screen 10 for inputting is a cover that covers the liquid crystal screen 9 when the PDA is not used.

As shown in FIG. 2, the information input pen 8
The DA main body 1 is arranged in a protruding storage space 22 at a corner on the back surface. The information input pen 8 is taken out, and an image handwritten and input through the pen 8 is displayed on the liquid crystal screen 9. For example, the result of the recognition processing by the PDA main body 1 is whipped by operating the talk button 5. The signal is transmitted to the partner device via the antenna 2. The data including the voice received through the whip antenna 2 is a PDA.
It is taken into the main body 1 and a desired process is performed.

FIG. 3 is a block diagram showing the internal configuration of the PDA main body. In the figure, 11 is an RF switch, 12
Is an RF unit, and 13 is a data processing circuit (DSP: Digi
talSignal Processor), 14 is ECC (Error Cor
rection Controller) circuit, 15 is an input / output circuit (μC
PU), 16 are operation buttons, 17 is an audio codec circuit, 18 is a display controller, and 19 is a tablet controller.

800 MH received by antennas 2 and 20
After passing through the RF switch 11, the RF signal in the z band
The data is converted into a baseband signal by the unit 12 and input to the data processing circuit 13. In the data processing circuit 13, only the slot where the signal exists is selected, and the signal is extracted here. If the extracted signal is audio,
The data is encoded by the audio codec circuit 17 and output via the speaker 3. On the other hand, if the signal is a digital data signal, the error is corrected by an ECC circuit 14 composed of a data link controller IC with error correction control of a mobile phone, and then the liquid crystal screen 9 is transmitted via a display controller 18.
Will display that information.

Whether the signal is voice or data,
How the magnitude of the signal input from the whip antennas 2 and the auxiliary antenna 20 as the main antennas to the RF unit 12 via the RF switch 11 via the RF switch 11 has a great influence on the reception performance of the set. To ensure the reception performance of the set, the whip antenna 2 and the auxiliary antenna 2
Due to the diversity operation (selection and synthesis of output by receiving two or more radio waves) obtained by the cooperation of zero, the effects of fading (propagation disturbance due to time fluctuation) and multipath (distortion in the frequency domain) due to a rapid change in electric field intensity To relax. However, the reason that diversity behavior works properly is that
It is assumed that the whip antenna 2 and the auxiliary antenna 20 maintain the original antenna radiation characteristics. If the antenna cannot maintain its original performance due to some external factors, the diversity operation itself is normal. Will not work.

Unlike a portable telephone alone, a PDA with a built-in data communication function may have various cases in how to use the device. Of course, when using a PDA as a telephone, it is used with the device in a standing position,
When the device is used, the device is laid on the table sideways, and the device is used in the state shown in FIG. In this state, data communication may be performed, or an earphone microphone may be connected to make a telephone call.

The present invention is a measure for preventing the antenna performance from deteriorating when the above-mentioned PDA is used while placed on a table. When the material of the table is made of metal, the degree of performance degradation of the antenna is large, and in some cases, data communication or voice communication may not be possible. According to the present invention, as shown in FIG. 2, a projection 22 serving as a pen storage portion of the information input pen 8 is provided at a position facing the liquid crystal screen 9 of the housing and below the whip antenna 2 on the back surface of the housing. The arrangement improves the degree of deterioration of antenna performance when used on a table.

FIG. 4 is a diagram showing how the reflection loss changes when the distance between the antenna and the metal when the PDA is placed on the metal plate is 10 mm and when the distance is 25 mm, and shows the value. It is. The horizontal axis represents frequency, and the vertical axis represents reflection loss in dB. FIG. 5 is a diagram showing how the reflection loss changes when the distance between the antenna and the metal plate is changed at 825 MHz where the reflection loss is the largest shown in FIG. The distance between the antenna and the metal plate is mm on the horizontal axis
The vertical axis represents the return loss in dB. From these figures, it can be confirmed that when the distance between the antenna 2 and the metal plate is short, the reflection loss increases, and as the distance between the antenna 2 and the metal plate increases, the reflection loss decreases. However, if you look closely, the distance between the antenna 2 and the metal plate is 20 mm.
And the change in the degree of improvement sharply decreases from 20 mm to 30 mm.
Less than dB. This phenomenon is not a phenomenon peculiar to the 800 MHz band mobile phone, but a phenomenon that is commonly seen in PDAs incorporating a 1.5 GHz band mobile phone. 800
In the MHz band, when converted to 25 mm and wavelength (λ), λ / 15
Exceeds 1.5G, the change in the degree of improvement is reduced, and 1.5G
It has been confirmed that the change in the degree of improvement is reduced in the same manner as in the case of 13 mm in the Hz band and exceeding λ / 15 when converted to a wavelength.

From the above, it can be seen that assuming that the PDA is formed of a metal plate, it is effective as a countermeasure to adopt a structure in which the antenna is separated by λ / 15 from the table surface. In FIG. 2, the antenna 2 is arranged in the longitudinal direction of the housing on which the liquid crystal unit 9 is mounted, and a space (projection 22) for accommodating the pen is provided on the rear surface of the housing at a position parallel to the center line axis of the antenna. This shows a structure in which the distance between the housing installation surface and the center line axis of the antenna when the portable information terminal device is used is set to at least λ (wavelength) / 15 with respect to the frequency of the telephone to be used. FIG. 6 shows another embodiment of the present invention, in which a stand 23 is added in place of the protrusion 22 shown in FIG. Specifically, a portable information terminal is provided by adding a stand that is folded and stored in the casing to the rear of the casing and providing an inclination between the portable information terminal and the casing installation surface via the stand when the portable information terminal is used. A structure is shown in which the distance between the housing installation surface and the center line axis of the antenna 2 when the device is used is set to at least λ / 15 with respect to the frequency of the telephone to be used.

As described above, the present invention relates to a PDA having a built-in cellular phone function and capable of performing data communication by performing pen input on a liquid crystal screen, and using an information input pen between an RF antenna and a housing installation surface. Store between, RF
A configuration in which the distance between the central axis of the antenna and the housing installation surface is used is set to at least λ / 15 with respect to the frequency of the telephone, thereby obtaining stable reception performance without deteriorating the antenna performance.

[0019]

As described above, according to the present invention, a projection or a stand for accommodating an information input pen is provided on a surface facing a screen of a portable information terminal. By forming the angle, even when the antenna is separated from the table as the housing installation surface and placed on a metal plate, stable receiving performance can be obtained without deteriorating the antenna performance. Further, since the display screen is inclined, ergonomically easy input can be performed. As a result, it is possible to provide a PDA device with a built-in mobile phone that satisfies both performance and design without deteriorating the data communication function and does not hinder carrying when carrying the device. Also, the operability is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing the appearance of an embodiment of the present invention;

FIG. 2 is a diagram showing the appearance of an embodiment of the present invention;

FIG. 3 is a block diagram showing the internal configuration of the PDA main body shown in FIGS.

FIG. 4 is a graph showing the relationship between frequency and return loss in a graph.

FIG. 5 is a graph showing the relationship between distance (antenna and metal plate) and frequency loss,

FIG. 6 is a diagram showing the appearance of another embodiment of the present invention;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... PDA main body, 2 ... Whip antenna, 3 ... Speaker, 4 ... Microphone, 5 ... Call button, 6 ... Call disconnection button, 7 ... Power button, 8 ... Pen for information input, 9 ... LCD screen, 10 ... Cover, 11 RF switch, 12 RF unit, 13 Data processing circuit (DSP), 14 EC
C circuit, 15: input / output processing circuit (μCPU), 16: operation button section, 17: voice codec circuit, 18: display controller, 19: tablet controller, 22: projection section (information input pen storage section), 23 ... stand,

Claims (2)

[Claims] 1. A portable information terminal device which has a built-in telephone, processes information input via a pen, and displays the processed information on a liquid crystal unit. A space for accommodating the pen is provided at a position on the back of the housing parallel to the center line axis of the antenna, and the distance between the housing installation surface and the center line axis of the antenna when the device is used is at least with respect to the frequency of the telephone used. λ
(Wavelength) / 15. 2. A portable information terminal device having a built-in telephone, processing information input via a pen, and displaying the processed information on a liquid crystal unit. A stand to be stored is provided, and when the device is used, an inclination is provided between the housing installation surface via the stand and the distance between the housing installation surface and the center line axis of the antenna when the device is used. A mobile information terminal device characterized in that the frequency is set to at least λ / 15 with respect to the frequency of a telephone call.