JP2005005892A - Portable information terminal unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable information terminal unit which is restrained from deteriorating its antenna radiation efficiency even in use while keeping a small size and light weight. <P>SOLUTION: The portable information terminal device is composed of a device body 2 equipped with a radio communication module 9 and a display unit 6, an antenna unit 3 which contains a built-in antenna element 18 and is formed separately from the device body 2, and a cable unit 4 which is connected to the antenna 3 so as to be separated from the device body 2 at a prescribed distance, and connects a radio communication module 9 and the antenna element 18 together with a signal transmission line 19. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small portable information terminal device, a portable telephone (generally referred to as a portable information terminal device in the present specification) having a palm-sized outer shape, and the like.
[0002]
[Prior art]
Portable information terminal devices are becoming more functional, complex, and faster due to advances in software technology such as information compression technology, hardware technology such as component mounting technology and high-capacity storage technology, and maintenance of wireless communication networks. Processing, size reduction, weight reduction, etc. are achieved. As a portable information terminal device, for example, a PDA (Personal Digital Assistant) 50 used exclusively for personal use as shown in FIG. 8 is also provided. The PDA 50 receives a liquid crystal display 52 having a display screen of about 4 inches and an input operation unit 53 in a palm-sized casing 51, and exchanges character information, voice information, image information, etc. The input / output information is digitally processed and the result is displayed on the liquid crystal display 52.
[0003]
The PDA 50 can perform operations such as information input and switching of various functions with a touch pen on the display screen of the liquid crystal display 52, and is excellent in operability, and also excellent in portability because of its small size and light weight. It has characteristics. The PDA 50 can handle various character information such as personal information, audio information, or image information, and digitally processes the information data. Further, the PDA 50 is provided with a slot mechanism (not shown), and an external memory, a function expansion module card, and the like are inserted and removed from the slot provided in the housing 51.
[0004]
The PDA 50 also has a wireless communication function such as a short-range wireless communication system such as a wired or 5.2 GHz band narrow-band radio system, a 2.4 GHz band wireless LAN (Local Area Network), or Bluetooth, and has these communication functions. Information is exchanged with a personal computer or a mobile phone. For this purpose, the PDA 50 incorporates a wireless module and the like, and an antenna 54 is provided in the housing 51. In addition, although the antenna 54 has shown the rod antenna protruded from the housing | casing 51 in FIG. 8, the appropriate antenna provided in the side surface of the housing | casing 51 may be sufficient.
[0005]
In the portable information terminal device, as in the PDA 50 described above, the palm-sized outer shape has been reduced in size and weight, so that it can be used quickly and is often attached to the main body for various reasons such as prevention of loss or fashion. It is used hanging from the neck with a tied strap. In portable information terminal devices, it has been proposed to use a strap antenna instead of the rod antenna 54 by using a strap that can secure a sufficient length without obstructing. (For example, see Patent Document 1 to Patent Document 3.)
[Patent Document 1]
JP-A-8-163466 [Patent Document 2]
JP 2001-103398 A [Patent Document 3]
JP-A-2001-257520 [0006]
[Problems to be solved by the invention]
By the way, in a portable information terminal device, when information is exchanged accurately by radio, it is extremely important that it is performed in a stable state without impairing radio communication characteristics. However, in the portable information terminal device (PDA 50), when the palm size is reduced, the antenna 54 is covered by the hand holding the casing 51 as shown in FIG. For this reason, the portable information terminal device 50 has a problem that the antenna radiation efficiency of the antenna 54 is lowered due to the influence of the human body, and accurate information exchange cannot be performed.
[0007]
In the portable information terminal device 50, no matter how the antenna 54 is installed with respect to the casing 51, the antenna 54 is eventually covered by the gripped hand because the casing 51 is small. In the portable information terminal device 50, even if the antenna 54 is a telescopic rod antenna, it is difficult to store a necessary antenna length in the small casing 51, and the entire device is large. There is a problem of becoming.
[0008]
In the portable information terminal device, when the strap antenna disclosed in the above-mentioned prior application is used, there are many portions that touch the human body, and the antenna radiation efficiency is reduced, so that the antenna has a sufficient antenna length. There was a problem that the sensitivity as a whole decreased and became unstable. Further, since the strap antenna is provided from the neck and is in contact with the chest, there has been a problem that, for example, reception characteristics of radio waves from the back side are deteriorated.
[0009]
Therefore, the present invention has been proposed for the purpose of providing a portable information terminal device that suppresses a decrease in antenna radiation efficiency even in a use state while maintaining a reduction in size and weight.
[0010]
[Means for Solving the Problems]
A portable information terminal device according to the present invention that achieves the above-described object includes a device main unit having a wireless communication module and a display, an antenna unit including an antenna element and configured independently of the device main unit, The antenna unit is configured to be connected to the apparatus main body unit at a predetermined interval and to be connected to the wireless communication module and the antenna element through a signal transmission line.
[0011]
According to the portable information terminal device according to the present invention configured as described above, the antenna unit is positioned outside without being covered by the hand holding the device main body. Therefore, according to the portable information terminal device, since the antenna unit is kept in a stable state without being affected by the human body, a decrease in the antenna radiation efficiency is suppressed, and information is exchanged via wireless communication. Will be done accurately. According to the portable information terminal device, if the antenna unit is separated from the human body via the cable unit, the directivity can be improved. According to the portable information terminal device, even if the device main body is firmly and arbitrarily gripped and operated, a decrease in antenna radiation efficiency is suppressed, so that usability can be improved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a PDA 1 shown in the drawings as an embodiment of the present invention will be described in detail. As shown in FIGS. 1 and 2, the PDA 1 includes a device main unit 2, an antenna unit 3 configured independently of the device main unit 2, and the device main unit 2 and the antenna unit 3 with a predetermined length. It is comprised from the cable part 4 connected with length L. Like the conventional device, the PDA 1 is connected to the same portable information terminal device, personal computer, cellular phone, or the like by wire or wireless, and digitally processes appropriate input / output information such as character information, voice information, or image information. It has a function of transmitting and receiving bidirectionally and is used for multiple purposes.
[0013]
Although not described in detail, the PDA 1 is configured by connecting each circuit unit to each other via an internal bus in the apparatus main body unit 2. The entire control operation of the PDA 1 is performed by a central processing unit having, for example, a DRAM (dynamic random access memory) or a flash memory. The PDA 1 is provided with, for example, a USB (Universal Serial BUS) compliant connector connection unit, and is connected to the above-described device by wire to exchange information. For example, the PDA 1 has a wireless communication function with a short-range wireless communication system such as a narrow-band wireless system of 5.2 GHz band, a wireless LAN of 2.4 GHz band, or Bluetooth, and is wirelessly connected to the above-described devices. Give and receive. The PDA 1 is controlled by a central processing unit in which a universal asynchronous receiver transmitter (UART) that configures these wireless transmission / reception units is bidirectionally connected to an internal bus.
[0014]
In addition to the above-described wireless communication function, the PDA 1 may have an infrared communication function compliant with, for example, IrDA (Infrared Data Association). Further, the PDA 1 is provided with a slot mechanism, and a memory can be expanded and various functions can be expanded by inserting / removing a card type external memory medium or an appropriate expansion function module. The PDA 1 is also used as a navigation device by loading, for example, a satellite positioning system (GPS) module body and a map data module body.
[0015]
As shown in FIGS. 1 and 2, the PDA 1 includes a liquid crystal display 6 having a longitudinally long display screen of, for example, about 4 inches as a surface member of the casing 5. And an input operation unit 7 in which various operation buttons are arranged alongside the display screen of the liquid crystal display 6 is provided. The liquid crystal display 6 is configured as a so-called touch panel that inputs and outputs appropriate control signals by inputting various control information by pen input or the like on the display screen and tapping displayed icons.
[0016]
Although not described in detail, the input operation unit 7 includes, for example, a power on / off button, a plurality of scroll buttons, and the like. Regarding the input operation unit 7, not only the main surface of the housing 5, but also a jog dial, a slide button or the like may be provided on the side surface although not shown.
[0017]
Although not shown, the PDA 1 incorporates a speaker and a microphone, and inputs and outputs voice or acoustic information via a drive circuit unit or the like. The PDA 1 has a built-in CCD (Charge-Coupled) camera, for example, and displays a captured image on the liquid crystal display 6 and transmits it to a connected external device. For example, an audio processing circuit unit (audio LSI) having a D / A converter (digital / analog converter) is bi-directionally connected to the PDA 1, for example, and the audio output terminal is connected via the audio processing circuit unit. Headphones and speakers are connected.
[0018]
When digital voice / acoustic data is supplied from each unit to the digital signal processor, the PDA 1 performs digital signal processing directly or after primary storage in a memory and performs analog conversion in the voice processing circuit unit to perform a speaker or the like. Output voice / acoustic information. In the PDA 1, voice / acoustic information input from the microphone is digitally converted in the voice processing circuit unit and supplied to the digital signal processor. The PDA 1 performs voice / sound information digital processing in a digital signal processor, and then supplies voice / sound data to a predetermined circuit unit via an internal bus.
[0019]
Although not described in detail, the PDA 1 includes an image processing unit that processes an image captured by a CCD camera. The image processing unit is bi-directionally connected to the CCD camera, and is also bi-directionally connected to the internal bus, and is a cache memory (SRAM :) that temporarily stores captured image information and image information supplied from a communication-connected partner. (static random access memory). The image processing unit processes image information taken by the CCD camera and displays the information on the liquid crystal display 6 via, for example, an internal bus. For example, the image processing unit processes image data supplied from the other party and displays the processed image data on the liquid crystal display 6 via the internal bus.
[0020]
The PDA 1 includes an electronic circuit unit such as various control units, a signal processing unit, a memory unit, a drive circuit unit, or a communication control unit, although details are omitted in the housing 5 together with the central processing unit and the internal bus described above. It has been. The PDA 1 is provided with a rechargeable battery, a power supply circuit unit, and the like that can supply power to each unit.
[0021]
The housing 5 is made of a vertically long rectangular body made of a suitable synthetic resin material or a lightweight metal material such as an aluminum material or an aluminum alloy material. As shown in FIG. 1, the housing 5 has a size that fits comfortably in the palm of the hand, that is, a palm-sized outer shape. The housing 5 is provided with a liquid crystal display 6 and an input operation unit 7, and a control circuit board 8 on which the above-described electronic circuit unit and the like are mounted as shown in FIG.
[0022]
On the control circuit board 8, a wireless communication module 9 including, for example, a high-frequency signal processing unit, a baseband signal processing unit, a modulation / demodulation processing unit, a storage function unit, or the like is mounted. Since the wireless communication module 9 is the same as the conventional one, its details are omitted, but for example, so-called software-defined radio, which corresponds to the above-described communication methods, use frequency bands, etc. by baseband processing below modulation / demodulation processing. (Software Defined Radio) The module unified by adoption of the technique may be sufficient.
[0023]
In the housing 5, for example, an antenna extraction portion 10 is integrally formed on the side surface portion on the side where the input operation portion 7 is disposed. The antenna lead-out portion 10 has a cylindrical shape or a rectangular tube shape similar to that of a lead portion such as a cable or a power cord in a general electronic device or the like. Protects against removal. The antenna lead-out portion 10 cooperates with the bush 11 so that a tensile force, a twisting force, a bending stress, a rotating force, or the like is not applied to the connection portion of the coaxial cable 19 or the control circuit board 8.
[0024]
Of course, the apparatus main body 2 is not limited to the structure described above. In the apparatus main body 2, for example, the housing 5 may be configured not only in a rectangular shape but also in a folding shape such as an egg shape or a mobile phone. The antenna lead-out portion 10 may have a connector structure in which the coaxial cable 19 is attached / detached in consideration of changes in the antenna specifications, but the integrated structure described above is more preferable in consideration of usage, stress resistance strength, and the like.
[0025]
As shown in FIGS. 3 and 4, the antenna unit 3 includes a housing 12 made of a synthetic resin integrally formed with a cable connection portion 13 in which a bush 14 is fitted, and a housing 12 formed with a ground pattern 16 and a power feeding pattern 17. The antenna board 15 is housed inside and the chip antenna 18 is mounted on the antenna board 15. The casing 12 is formed into a rectangular shape or a cylindrical shape that forms a sealed space inside by using, for example, ABS resin (acrylo-nitrile / butadiene / styrene resin). Since the PDA 1 is carried as a kind of accessory as will be described later, the casing 12 may be made of a transparent acrylic resin, for example, so that the inside can be seen through and a characteristic impression can be given. A cable connecting portion 13 is integrally formed on the side surface of the housing 12.
[0026]
The cable connection portion 13 is configured in substantially the same manner as the antenna lead-out portion 10 on the side of the apparatus main body 2 described above, and has a cylindrical shape or a rectangular tube shape. Protects against removal. The antenna substrate 15 is made of, for example, an appropriate substrate material such as a commonly used FR4 grade (Heat Retardant Grade) flame resistant glass substrate, epoxy resin copper clad laminated substrate, ceramic substrate, or PET (polyethylene terephthalate) substrate. As described above, the ground pattern 16 and the power feeding pattern 17 are formed. The antenna substrate 15 is mounted with a chip antenna 18 by connecting terminals to the ground pattern 16 and the power feeding pattern 17 although details are omitted. As is well known, the chip antenna 18 is composed of a fine ceramic dielectric antenna having a volume of about 40 mm ³ .
[0027]
As described above, the antenna unit 3 is configured such that the chip antenna 18 is mounted on the antenna substrate 15 in the housing 12 and the feeding function and the ground are provided so that the radiation function is completed. The structure is electromagnetically isolated from the apparatus main body 2. Therefore, the antenna unit 3 has a structure that does not exert electromagnetic influences on each other, and the influence of the palm that holds the device main unit 2 is reduced by being connected via the cable unit 4 described later. Stable antenna characteristics are produced.
[0028]
On the other hand, the antenna unit 3 may be used in such a manner that the user hangs the PDA 1 from the neck and uses the housing 12 in contact with the chest of the user. In the antenna unit 3, as described above, the housing 12 does not have a function of an antenna element and does not have a great influence on the antenna characteristics. However, as shown in FIG. A predetermined distance A is maintained between the antenna 18 and the antenna substrate 15. Although the optimum value of the antenna unit 3 is slightly different depending on the relative permittivity of the housing 12, the antenna unit 3 is configured to reduce the influence of the antenna characteristics by the human body by setting the interval A to be about 2 mm or more. It becomes.
[0029]
The cable unit 4 constitutes a high-frequency signal transmission line between the device main unit 2 and the antenna unit 3 described above. As shown in FIG. 4, the cable portion 4 is formed by covering a coaxial cable 19 with an exterior body 20. As is well known, the coaxial cable 19 includes a core wire 21 and a shield wire 22 made of a mesh wire or the like that is coaxial with the core wire 21 via an insulating material. As shown in FIG. 3, the coaxial cable 19 has one end connected to the apparatus main body 2 and the other end connected to the antenna unit 3.
[0030]
The coaxial cable 19 is held by the bush 11 and drawn from the antenna lead-out part 10 into the housing 5 on the apparatus main body part 2 side. Although not described in detail, the coaxial cable 19 is connected to the control circuit board 8 by a connector and is connected to the wireless communication module 8 through an appropriate pattern formed on the control circuit board 8. The coaxial cable 19 is held by the bush 14 and is drawn from the cable connection portion 13 into the housing 12 on the antenna portion 3 side. The details of the coaxial cable 19 are omitted. For example, the core wire 21 is connected to the power feeding pattern 17 formed on the antenna substrate 15 and the shield wire 22 is connected to the ground pattern 16.
[0031]
The PDA 1 has a structure in which the apparatus main body 2 and the antenna unit 3 are separated via the cable unit 4, so that the user holds the antenna unit 3 side and turns the apparatus main body 2 around. There is a case of rough handling. Even in such a case, the coaxial cable 19 is externally mounted so that the coaxial cable 19 does not peel or break at the connection portion described above, and does not break at the lead-out portions of the housings 5 and 12. Protected by body 20.
[0032]
The outer package 20 preferably has mechanical strength and a certain degree of elasticity. For example, the outer package 20 is formed by outsert-molding synthetic rubber such as silicone on the coaxial cable 19. In this case, the exterior body 20 is formed by integrally molding the bushes 11 and 14 at both ends. Of course, the outer package 20 may be formed in a cylindrical shape using silicone as a raw material, and the coaxial cable 19 may be passed therethrough.
[0033]
The exterior body 20 is not limited to synthetic rubber, and may be formed of a suitable synthetic resin material or cloth. Moreover, you may make it comprise the exterior body 30 with the helical tube 31 which has flexibility, as shown in FIG. As the spiral tube 31, as is well known, a single bellows, a bellows tube, an annular tube, or the like, which has some stretchability in the axial direction, is used. The spiral tube 31 is generally formed of stainless steel, iron material or the like that has been subjected to chrome nickel plating treatment, and insulation is maintained with respect to the shield wire 22 of the coaxial cable 19 via an exterior material. Note that the spiral tube 31 is covered with a protective blade that is fixed at both ends to the casings 5 and 12 at the outer peripheral portion to maintain the entire length as needed.
[0034]
As described above, the PDA 1 is gripped in such a manner that the apparatus main body 2 is formed in the size of the palm so that the screen of the liquid crystal display 6 is on the front side as shown in FIG. . In the PDA 1, the antenna unit 3 protrudes from the palm and hangs through the cable unit 4 as shown in FIG. In the PDA 1, the cable portion 4 is set to a predetermined length L so that the antenna portion 3 is not hidden behind the palm.
[0035]
In the PDA 1, by making the cable portion 4 long, the antenna portion 3 can be positioned far from the palm and the contact can be reliably prevented. On the other hand, in the antenna device, as the cable portion 4 becomes longer, the distance between the wireless communication module 9 and the chip antenna 18 becomes larger and the antenna characteristics gradually deteriorate. Therefore, in the PDA 1, although depending on the outer shape of the housing 5 of the apparatus main body 2, the antenna at the distal end is held even when the length L of the cable portion 4 is gripped so as to be wrapped with a standard-sized palm. The length of the portion 3 is set so as not to protrude from the user's hand. The length L of the cable portion 4 is set in consideration of a predetermined factor, for example, with a reference value of 60 mm.
[0036]
By the way, when the PDA 1 is used in a state of being hung from the neck, for example, radio waves coming from the back direction are blocked by the human body and the reception sensitivity is lowered. In the PDA 1, as described above, since the apparatus main body 2 and the antenna unit 3 are connected via the cable unit 4 having a length L of, for example, 60 mm, the radio waves that have passed around the human body by extending the antenna unit 3. Receive well. In this case, the PDA 1 preferably holds the cable part 4.
[0037]
In the antenna device, since the antenna radiation efficiency is lowered by adopting a floating configuration, the floating configuration is hardly employed when used in a portable radio terminal device using the 2.4 GHz band. On the other hand, in the portable wireless terminal device, the antenna touches the hand held by the user regardless of the location of the casing as it is downsized to the palm size. The PDA 1 is configured so that the degradation of the antenna characteristics is minimized and the usability is improved by comparing the degradation of the antenna radiation efficiency due to the floating structure and the degradation of the antenna radiation efficiency due to the influence of the human body. Become.
[0038]
The PDA 1 shown in FIGS. 6 and 7 is provided with a strap function using the antenna unit 40. In a portable wireless terminal device, there are many usage forms that are suspended from the neck like the above-mentioned various prior application devices. Therefore, in the PDA 1, it is possible to integrally form the strap stopper 41 using the housing of the antenna unit 40 and to tie the strap 42 to the strap stopper 41. As shown in FIG. 6, the PDA 1 can be quickly accommodated without worrying about the storage location by putting the strap 42 around the neck. Note that the strap 42 does not have an antenna function like the above-mentioned prior application device, and does not reduce the antenna radiation efficiency of the PDA 1 even if it is in contact around the neck.
[0039]
In the above-described embodiment, the PDA 1 is shown, but it is needless to say that it may be, for example, a mobile phone or various portable terminals having a wireless communication function. In the embodiment, the chip antenna 18 is used as the antenna element of the antenna unit 3. However, the antenna element is configured by a pattern antenna formed in an appropriate shape such as an inverted F type using the antenna substrate 15, for example. Of course, it is also good.
[0040]
【The invention's effect】
As described above in detail, according to the portable information terminal device according to the present invention, the antenna unit is arranged in the free space from the device main body unit via the cable unit having a predetermined length. Since it is located outside without being covered by the hand that holds the main body, the influence of the human body on the antenna is reduced, and a decrease in antenna radiation efficiency is suppressed, information via wireless communication, etc. Will be exchanged accurately. According to the portable information terminal device, by using the antenna unit so as to be separated from the human body via the cable unit, it is possible to receive radio waves that circulate around the human body and to improve directivity. According to the portable information terminal device, even if the device main body is firmly and arbitrarily gripped and operated, a decrease in antenna radiation efficiency is suppressed, so that usability can be improved.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a use state of a PDA shown as an embodiment of the present invention.
FIG. 2 is a perspective view of the PDA.
FIG. 3 is a longitudinal sectional view of a main part of the PDA.
FIG. 4 is a longitudinal sectional view of an antenna unit.
FIG. 5 is a longitudinal sectional view of a main part of another PDA.
FIG. 6 is an explanatory diagram of a usage state of another PDA.
FIG. 7 is a perspective view of a PDA.
FIG. 8 is an explanatory diagram of a use state of a conventional PDA.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 PDA (personal digital assistant device), 2 apparatus main-body part, 3 antenna part, 4 cable part, 5 housing | casing, 6 liquid crystal display, 7 input operation part, 8 control circuit board, 9 wireless communication module, 10 antenna extraction part , 12 Case, 15 Antenna substrate, 16 Ground pattern, 17 Feeding pattern, 18 Chip antenna, 19 Coaxial cable, 20 Exterior body, 30 Cable part, 40 Antenna part 42 Strap

Claims (4)

In a portable information terminal device that is equipped with a wireless communication function to exchange information,
An apparatus body having a wireless communication module and a display;
An antenna part that includes an antenna element and is configured independently of the apparatus main body part;
The antenna unit is connected to the apparatus main body unit so as to be spaced apart from each other with a predetermined interval, and includes a cable unit that connects the wireless communication module and the antenna element through a signal transmission line. A portable information terminal device. The said antenna element is comprised from the antenna substrate in which the ground pattern and the electric power feeding pattern were formed, and the chip antenna connected to the said electric power feeding pattern and mounted on this antenna substrate. Portable information terminal device. 2. The portable information terminal device according to claim 1, wherein the antenna element is built in a housing of the antenna unit at a distance of 2 mm or more from the surface. 3. The portable information terminal device according to claim 1, wherein the cable portion includes a coaxial cable constituting the signal transmission line and an exterior body that sheathes the coaxial cable.

Images