JP2003264355A - Portable information terminals - Google Patents

Abstract

(57) [Summary] [Problem] Keys, tablets, LEDs, cameras, LCDs,
Effectively reduce high-frequency noise in portable information terminals that have a structure in which functional components such as speakers or microphones are mounted on a slide substrate or a rotating substrate, or a structure in which those functional components are hidden behind a slide substrate or a rotating substrate. . A portable information terminal in which a second circuit board (slide board) 2 is slidably (or rotatably) connected to a first circuit board (main board) 1 on a terminal body side. Between the first circuit board 1 and the second circuit board 2, a conductive material (metal foil) 11 is placed on one of the first circuit board 1 and the second circuit board 2 (slide board 2). , And high-frequency noise is reduced by electrically connecting the conductor 11 to the other circuit board (main board 1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure in which functional components such as keys, tablets, LEDs, cameras, LCDs, speakers or microphones are mounted on a slide substrate or a rotary substrate, or these functional components are mounted on the slide substrate or a rotary substrate. The present invention relates to a portable information terminal having a structure hidden behind a substrate.

[0002]

2. Description of the Related Art As a portable information terminal having a sliding structure, as shown in FIGS. 13 (a) and 13 (b), for example, a terminal body (not shown) containing a main substrate 1 and a lower portion of the main substrate 1 are provided. Slide board 2 slidably provided on
And a compact flash 15 having an antenna 4 and a wireless communication card insertion port is arranged on the upper part of the terminal body, and a wireless communication card is attached to the compact flash (registered trademark) 15. There is a portable information terminal of a type that is used after that. In the portable information terminal shown in FIG. 13, a connection point 3 for connection is provided at the bottom of the main board 1 on the terminal body side, and the main board 1 and the slide board 2 are connected via the connection point 3. Are connected to each other.

On the other hand, in a portable information terminal, it is necessary to reduce high frequency noise generated from a circuit board or the like.
As a technique for reducing high frequency noise, Japanese Patent Laid-Open No. 6-30
There is a shield structure disclosed in Japanese Patent No. 1448.

According to the technique disclosed in this publication, copper plating or nickel plating is used as a shield material for electrostatic noise and electromagnetic noise in portable electronic devices such as portable computers and liquid crystal televisions that incorporate a liquid crystal display device and a circuit board. The shielding effect is enhanced by disposing the formed member between the liquid crystal display device and the circuit board.

[0005]

By the way, in a portable information terminal having a slide structure as shown in FIG. 13, when a wireless communication card is inserted into the card slot of the compact flash 15, the wireless communication is received due to the influence of high frequency noise. Since the performance deteriorates, it is necessary to design so that the harmonic of the frequency of the information processing unit does not match the reception frequency of wireless communication. The reason for doing this is that it is difficult to reduce the high-frequency noise generated in each circuit board because the high-frequency potential of the ground wiring, which is the return path of the signal on the key board, does not match the main board.

FIG. 14 shows the reason why it is difficult to reduce high frequency noise.
Will be described in detail with reference to.

First, in FIG. 14, it is assumed that the main board 1 and the slide board 2 are connected to a signal to the key 20 and a ground which is a return path of the signal at a connection point 3 for connection. In this case, the ground at points C and D is the distance CD
However, since the electrical distance B-E is large at points B and E, the potential is different and the ground of the substrate itself becomes weak.

When there is no slide substrate 2, B
It is assumed that noise occurs at point or E point. In this case, since the distance from the point A where the antenna 4 is arranged is large, the noise is less likely to wrap around, and the noise can be reduced by surrounding the noise-generating component with a metal like a conventional shield. It can be greatly reduced.

However, when there is the slide substrate 2, there is no problem if the electrical distance BE is sufficiently short with respect to the wavelength of noise, but if not, there is a potential difference between points B and E. , It becomes easy to radiate high frequency noise.
Moreover, high-frequency noise is excited in the path of distance B-E from point E to point B via point D, point C, and the noise current reaches the antenna 4 at point A directly. Also,
There is a distance B between the state in which the slide key unit is closed, that is, the state in which the slide substrate 2 is at the position shown in FIG. 14 and the state in which the slide substrate 2 slides downward.
Since -E changes, the high frequency noise changes.

In order to prevent these problems, it is necessary to shorten the electric distance BE to the same electric potential, but while maintaining the structure in which the slide substrate 2 slides downward,
It is difficult to electrically connect points B and E.

Therefore, in the conventional portable information terminal having the slide structure, it has been necessary to design so that the harmonic frequency of the frequency of the information processing unit does not match the reception frequency of the wireless communication. However, recently, in addition to the conventional PHS, a communication module using a frequency different from PHS, such as IMT2000 and Bluetooth, has appeared, and the communication speed of wireless LAN wireless communication has been increased, The band used for communication is increasing, and it is becoming difficult to design such that the frequency does not match the received frequency. For this reason, it has become necessary to reduce the noise itself generated from the portable information terminal.

Furthermore, in order to mount multifunctional parts,
In order to increase the number of wirings to the slide substrate, it is necessary to connect with a flexible substrate, but in the case of the conventional structure shown in FIG. 14, when the ground is wired with the flexible substrate, the distance C-D becomes large and the distance B becomes large. -E will be further away. Therefore, it is difficult to increase the number of wires and mount a multifunctional component on the slide substrate.

From the above, in the conventional portable information terminal having the slide structure, only the components which are less likely to be a noise source can be mounted on the slide substrate, and the number of wirings is limited.
It was designed to focus on the main keys.

Furthermore, the fact that high-frequency noise sneaks into the antenna means that the transmission wave of wireless communication is likely to sneak into each functional component from the antenna. Therefore, the transmission wave is transmitted to keys, tablets, microphones, By sneaking into an input device such as a camera, erroneous input and noise are easily mixed. Further, there is a possibility that the LED or the liquid crystal may be erroneously turned on or erroneously displayed. Further, if noise is mixed in the CPU, the memory, or the signal line, malfunction may occur.

The above-mentioned problems can be said to be the same in a portable information terminal having a rotating structure provided with a rotating substrate.

Since the technique disclosed in Japanese Patent Laid-Open No. 6-301448 cannot be applied to a movable structure, it cannot be applied to a sliding key portion of a portable information terminal, and the above-mentioned problem cannot be solved. .

The present invention has been made in view of such circumstances, and includes keys, tablets, LEDs, cameras, LCDs,
High-frequency noise can be effectively reduced with a structure in which functional components such as a speaker or a microphone are mounted on a slide substrate or a rotating substrate, or a structure in which those functional components are hidden behind the slide substrate or the rotating substrate. The purpose of the present invention is to provide a portable information terminal.

[0018]

The portable information terminal of the present invention is a portable information terminal in which a second circuit board is slidably or rotatably connected to a first circuit board on the terminal body side. A conductive material is provided between the first circuit board and the second circuit board.
The circuit board is arranged in a state of being close to one of the circuit boards, and the conductive material is electrically connected (ground connection) to the other circuit board. More specifically, it is characterized in that the conductor is arranged in a state of being close to the second circuit board, and the conductor is electrically connected to the first circuit board.

The portable information terminal of the present invention is the portable information terminal in which the second circuit board is slidably or rotatably connected to the first circuit board on the terminal body side. An insulator provided with a conductive material is arranged between the board and the second circuit board in a state of being close to one of the first circuit board and the second circuit board. It is characterized in that the conductive material of the insulator is electrically connected (ground connection) to the other circuit board. More specifically, the insulator with the conductive material is arranged in the vicinity of the second circuit board, and the conductive material of the insulator is electrically connected to the first circuit board. Is characterized by being present.

According to the portable information terminal of the present invention, the conductor or the insulator attached with the conductor is arranged between the first circuit board on the terminal body side and the second circuit board on the movable side. Therefore, high frequency noise can be effectively reduced.

The reason for this is to refer to FIG. 2 by taking as an example the case where the conductor is arranged in the state of being close to the movable second circuit board and the conductor is connected to the first circuit board on the terminal body side. While explaining. In the following description, the second circuit board will be referred to as the slide board 2.

First, when the conductors are arranged in the above-described manner, as shown in FIG. 2, the slide substrate 2 and the conductors 6 are formed.
Approaches and. Thus, when the slide substrate 2 and the conductive material 6 are sufficiently close to each other, the charges on the surfaces facing each other repel each other due to the Coulomb force, and it becomes possible to have a capacitance. Therefore, since it functions like a capacitor, a high-frequency noise current flows, and points B and E are short-circuited at high frequencies, making it difficult for high-frequency noise to occur. Furthermore, by approaching the same potential between points B and E, it becomes difficult for high-frequency noise to be excited at the conventional distance BE (see FIG. 14). Thereby, the high frequency noise reaching the point A is reduced, and the high frequency noise from the slide substrate 2 is reduced. Moreover, even if the slide substrate 2 slides, the high frequency noise can be reduced regardless of the movement of the slide substrate 2 by maintaining the close state of the slide substrate 2 and the conductive material 6.

In the above description of the operation, the conductive material is the second
Place it close to the circuit board (slide board) of
The case where the conductor is connected to the first circuit board is shown, but in addition, the conductor is arranged in the state of being close to the first circuit board, and the conductor is arranged on the movable second side. Even when a conductive material is connected to the circuit board (slide board), the high frequency noise can be reduced by the same operation as described above.

Further, even when an insulator having a conductive material is arranged between the first circuit board and the second circuit board, the high frequency noise can be reduced by the same operation as described above.

In the portable information terminal of the present invention, a conductive material (or an insulator with a conductive material) may be arranged outside the cabinet that houses the first circuit board on the portable body side. In this case, the conductor can be brought closer to the second circuit board on the movable side, and the coupling between the two can be enhanced. In addition, it becomes easy to perform a process for forming the conductive material, such as a metal plating process or a metal foil attaching process.

In the portable information terminal of the present invention, a conductor (or an insulator attached with a conductor) may be arranged inside the cabinet that houses the first circuit board on the side of the portable body. In this case, since the first circuit board can be partially covered with the conductive material, even when the second circuit board on the movable side is moved, the shield effect of the portion covered with the conductive material can be obtained. Can be secured.

In the portable information terminal of the present invention, a conductive material may be formed on the outer surface or inner surface of the cabinet by metal plating or a metal foil sticking process. When the conductive material is formed on the inner surface of the cabinet, the conductive material is not exposed to the outside even if the movable second circuit board is slid (or rotated). Therefore, the conductive material is not scraped or peeled off due to the abrasion due to the movement of the second circuit board.

In the portable information terminal of the present invention, it is preferable that the conductor or the conductor of the insulator is electrically connected to the first circuit board or the second circuit board at a portion close to the antenna. Further, it is preferable to electrically connect a conductor or a conductor of an insulator to the first circuit board or the second circuit board at a position corresponding to the tip portion of the second circuit board. With such a configuration, high frequency noise can be reduced more efficiently.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

First, a schematic structure of a portable information terminal to which the present invention is applied will be described with reference to FIG.

The portable information terminal shown in FIG. 1 comprises a terminal main body 101 having a display portion 103 such as an LCD and a slide key unit 102 slidably provided on the terminal main body 101.

The display unit 103 is the slide key unit 1
The first display portion 103, which serves as a display area in the state in which 02 is closed (the state shown in FIG. 1A), and the slide key unit 1
A second display unit 103 is provided which can be displayed when 02 is opened (the state shown in FIG. 1B).

An antenna 4 for wireless communication is installed above the terminal body 101. Inside the cabinet 110 forming the exterior of the terminal body 101, the main board 1
Also, the wireless communication unit 5 (see FIG. 2) and the like are housed.

The slide key unit 102 is provided with various keys. The slide board 2 (see FIG. 2) and the like are housed in the case 120 of the slide key unit 102.

Next, an embodiment of the present invention will be described in detail with reference to FIGS. In each of the following embodiments, it is assumed that the antenna 4 and the wireless communication unit 5 are installed above the main board 1.

<Embodiment 1> FIG. 2 is a side view showing the structure of the essential part of an embodiment of the present invention.

In this embodiment, in a portable information terminal having a slide structure in which the main board 1 and the slide board 2 are connected via a connection point 3, a casing-shaped housing is provided between the main board 1 and the slide board 2. By arranging a conductor (for example, made of copper) 6 close to the slide substrate 2 and connecting the conductor 6 to the main substrate 1, high frequency noise generated from the portable information terminal is reduced. The length (length in the up-down direction) of the conductor 6 has a length corresponding to a range in which the upper end (point E) of the slide substrate 2 moves or a length longer than that. Even when 2 (slide key unit 102) slides downward, the state in which the conductor 6 is close to the slide substrate 2 is maintained.

Next, the reason why the high frequency noise is reduced in this embodiment will be described below.

First, as shown in FIG. 2, the slide substrate 2
When the conductive material 6 and the conductive material 6 are sufficiently close to each other, the electric charges on the surfaces facing each other repel each other due to the Coulomb force, and it becomes possible to have a capacitance. Therefore, since it functions like a capacitor, a high-frequency noise current flows, the points B and E are short-circuited at high frequencies, and high-frequency noise is less likely to occur. Furthermore, by approaching the same potential between points B and E, it becomes difficult for high-frequency noise to be excited at the conventional distance BE (see FIG. 14). Thereby, the high frequency noise reaching the point A is reduced, and the high frequency noise from the slide substrate 2 is reduced. Moreover, even if the slide substrate 2 slides, the close state between the slide substrate 2 and the conductive material 6 is maintained, so that high frequency noise can be reduced regardless of the movement of the slide substrate 2.

Here, the closer the slide substrate 2 and the conductive material 6 are to each other, the higher the coupling between them becomes.
If the conductor 6 contacts with the conductor 6, it will hinder the slide structure. Therefore, the conductor 6 should be brought close enough to the extent that the conductor 6 does not contact the slide substrate 2.

In the embodiment shown in FIG. 2, the conductor 6 is arranged between the main substrate 1 and the slide substrate 2, but
Without being limited to this, for example, as shown in FIG.
A plastic casing (insulator) 7 having a metal foil (for example, copper foil) 71 attached to its surface is arranged between the main substrate 1 and the slide substrate 2, and the metal foil 71 is provided at a point B of the main substrate 1. Even if the structure is such that it is connected to the ground by means of the above, the high frequency noise can be effectively reduced by the same operation as above. Moreover, in the case of the structure shown in FIG. 3, since the housing 7 to which the metal foil 71 is attached is made of plastic, it can be molded into any desired shape, and the degree of freedom in design is expanded. It is also possible to add components of the slide mechanism (for example, a guide groove for sliding) to the housing 7.

In the embodiment of FIG. 3, the metal foil 71 is attached to the surface of the housing 7, but instead of this, the surface of the plastic housing 7 is coated with copper or nickel. The conductor may be formed by applying metal plating.

In each of the embodiments shown in FIGS. 2 and 3, the case (insulator) 7 to which the conductor 6 or the metal foil 71 is attached is arranged in the vicinity of the slide substrate 2, and the conductor 6
Alternatively, the metal foil 71 is grounded to the main substrate 1, but the present invention is not limited to this, and the case 7 with the conductor 6 or the metal foil 71 is arranged in the state of being close to the main substrate 1. , Its conductor 6 or metal foil 71
May be electrically connected to the slide substrate 2.

In each of the embodiments shown in FIGS. 2 and 3, the insulator 6 to which the conductor 6 and the metal foil 71 are attached is used as the housing, but the present invention is not limited to this, and the conductors are not limited to this. The insulator may be a block-shaped (solid structure) member.

<Embodiment 2> FIGS. 4 and 5 are a side view and a perspective view, respectively, showing the structure of the main part of another embodiment of the present invention. Note that FIG. 5 shows a state in which the slide substrate 2 is removed.

In this embodiment, a plastic plate 8 having a metal foil (for example, copper foil) 81 attached to one surface thereof is provided between the main substrate 1 and the slide substrate 2, and the attachment surface of the metal foil 81 is attached to the main substrate. 1 side and plastic plate 8
Are arranged close to the slide substrate 2. Then, by connecting the metal foil 81 to the point B of the main substrate 1 via the ground connecting portion 82, reduction of high frequency noise is realized.

The metal foil 81 extends from a position above the upper end of the closed slide substrate 2 (a position of approximately B) to a position near the connection point 3, and the slide substrate 2 (slide key unit 102). Even when the slides downwards (the state of FIG. 1B), the state where the metal foil 81 is close to the slide substrate 2 is maintained.

According to the embodiment of FIG. 4, since the lower half of the main board 1 is covered with the plastic plate 8, the slide board 2 (slide key unit 10) is covered.
2) Slide down (state of Figure 1 (b))
However, the conductive part of the main board 1 is not exposed to the outside, and the designability can be improved. Furthermore, since the lower half of the surface of the main substrate 1 is covered with the metal foil 81, even if the slide substrate 2 is slid downward, the shield effect of the portion covered with the metal foil 81 is reduced. Can be secured.

When the structure shown in FIG. 4 is compared with the structures shown in FIGS. 2 and 3, the distance between the slide substrate 2 and the metal foil (conductive material) 81 increases by the thickness of the plastic plate 8. looks like. However, since the metal foil 81 is not exposed when the slide substrate 2 is slid downward, it is not affected by the abrasion due to the sliding movement of the slide substrate 2, and the metal foil 81 is not scraped or peeled off. Therefore, the slide substrate 2 can be brought as close as possible to the point of contacting the plastic plate 8, and the distance between the slide substrate 2 and the metal foil 81 does not increase.

Further, in the structure of FIG. 4, the slide substrate 2
Since the plastic plate 8 is interposed between the metal foil 81 and the metal foil 81, the dielectric constant of the plastic plate 8 increases the repulsive force of the charges applied to the slide substrate 2 and the metal foil 81. Can also be increased.
Further, as shown in FIG. 5, the ground connection of the metal foil 81 to the main board 1 can be performed near the corner of the upper end of the slide board 2, that is, at a portion closer to the antenna 4.
High frequency noise can be reduced more efficiently.

In the structure shown in FIGS. 4 and 5, the planar shape of the metal foil 81 is a rectangle having a size corresponding to the slide substrate 2. However, as shown in FIG. It may be cut to form a metal foil 81 ′ having a shape (U-shape) along the peripheral edge (three sides) of the slide substrate 2.

If the metal foil 81 'has a shape as shown in FIG. 6, it is presumed that the coupling capacitance with the slide substrate 2 becomes small. However, since high-frequency noise easily flows around the outer periphery of the substrate, the high-frequency current flowing at points D and E (FIG. 4) of the slide substrate 2 hardly flows in the region 80 cut in FIG. Therefore, as shown in FIG. 6, by attaching the metal foil 81 ′ only to the outer peripheral region of the slide substrate 2 and leaving only the metal foil having a high high frequency noise reduction effect, the high frequency noise is maintained while maintaining the noise reduction effect. Noise can be reduced, and moreover, space for slide structure parts and other functional parts can be secured.

<Third Embodiment> FIGS. 7 and 8 are a side view and a perspective view, respectively, showing the structure of the main part of another embodiment of the present invention. Note that the cabinet is not shown in FIG. 8 for convenience of description.

This embodiment shows an example in which the present invention is applied to a portable information terminal of a system in which the main substrate 1 and the slide substrate 2 are connected by using a flexible substrate (FPC) 13.

First, the flexible substrate 13 is pulled out from the main substrate 1 so that the slide substrate 2 can be freely slid downward, and is slid in a state in which the flexible substrate 13 gently wraps around the front side (lower side). It is connected to the substrate 2.

On the other hand, a front wall 111 having a shape extending along the back surface side of the slide substrate 2 is integrally formed in the cabinet 110 that accommodates the main substrate 1. The flexible board 13 is mounted on the front wall 111 of the cabinet 110.
An opening 112 is provided for pulling out to the front side.

In this embodiment, the metal foil (for example, copper foil) 1 is formed on the inner surface of the front wall 111 of the cabinet 110.
1 is attached. The metal foil 11 is connected to the main substrate 1 at a corner of the slide substrate 2 via a ground connecting portion 12. The metal foil 11
Extends from the position of the upper end of the slide substrate 2 in the closed state (the position of approximately B) to the position corresponding to the lower end of the main substrate 1, and the slide substrate 2 (slide key unit 10).
2) Slide down (state of Figure 1 (b))
However, the state where the metal foil 11 is close to the slide substrate 2 is maintained.

In this embodiment, the slide substrate 2
The metal foil 11 and the plastic cabinet 11
Since they are close to each other with the front wall 111 of 0 therebetween and are sufficiently close to each other, the charges on the surfaces facing each other repel each other, and it becomes possible to have the capacitance C.

Here, the front wall 11 of the cabinet 110
If the permittivity at point E of 1 is ε, the area of the metal foil 11 is S, and the distance between the slide substrate 2 and the metal foil 11 is d, the capacitance C = ε
(S / d) and impedance at 2 GHz 1 / ω
When εr = 2, S = 1E-3m ² , and d = 1E-3m, C becomes as small as about 4Ω at a frequency of 2 GHz, which makes it easier for a high-frequency current to pass through points B and E, and slides. High frequency noise from the substrate 2 is reduced.

In this embodiment, the slide substrate 2
Between the metal foil 11 and the metal cabinet 1
10 (front wall 111) is sandwiched between the slide substrate 2
When the distance between the metal foil 11 and the metal foil 11 is halved, the impedance is also halved to about 2Ω, so that the coupling between the slide substrate 2 and the metal foil 11 becomes high. Further, even if the dielectric constant becomes high, the impedance is reduced in inverse proportion to the dielectric constant.
However, when the cabinet 110 is not sandwiched, the relative permittivity is 1, and the impedance is inversely proportional to the relative permittivity, so that it is doubled.

Further, in the embodiment shown in FIG. 7, since the metal foil 11 is attached to the inner surface of the front wall 111 of the plastic cabinet 110, when the slide substrate 2 is slid downward, the metal foil 11 is removed. Since the metal foil 11 is not exposed, the metal foil 11 is not scraped or peeled off because it is not affected by the abrasion due to the sliding movement of the slide substrate 2. Furthermore, since the metal foil 11 and the slide board 2 cover the lower half of the surface of the main board 1, noise emitted from the components mounted from point B to point C of the main board 1 can be reduced. Is.

Further, by reducing the area of the metal foil 11 as shown in FIG. 8, it is possible to secure a space through which the wide flexible substrate 13 can pass. Therefore, it is possible to mount more keys on the slide substrate 2 and to wire more signals. This allows
It becomes possible to mount components such as keys, tablets, LEDs, cameras, LCDs, speakers or microphones on the slide substrate 2. Moreover, a space for mounting a mechanical component for holding the slide substrate 2 can be secured.

Further, by reducing the area of the metal foil 11, it is possible to increase the area of the main substrate 1 exposed when the slide substrate 2 is slid downward. Tablet, LE
It becomes possible to secure a space for exposing functional parts such as D, camera, LCD, speaker or microphone.

However, as described above, reducing the area of the metal foil 11 results in lowering the degree of coupling between the slide substrate 2 and the metal foil 11. Therefore, in this embodiment, in consideration of the high-frequency current flowing through the end surface of the slide substrate 2, the metal foil 11 is arranged only in the edge portion of the slide substrate 2 as shown in FIG. By doing so, although the area of the metal foil 11 is reduced, it is possible to efficiently reduce high frequency noise.

In the above embodiment of FIG. 7, the metal foil 11 is attached to the inner surface of the front wall 111 of the plastic cabinet 110. However, the present invention is not limited to this, and for example, as shown in FIG. 110 front wall 1
A metal foil 21 may be attached to the outer surface of 11. In this case, a strip-shaped metal piece 22 that penetrates the opening 112 of the front wall 111 is provided, and the metal foil 22 is utilized by using this metal piece 22.
1 is grounded to the main board 1.

In the embodiment of FIG. 7 or 9, the metal foils 11 and 21 are attached to the inner surface or the outer surface of the front wall 111 of the cabinet 110, but instead of this, the inner surface or the outer surface of the front wall 111 is replaced. Alternatively, a conductive material may be formed by performing metal plating such as copper plating or nickel plating.

Next, the results of experiments on the noise level of the portable information terminal (embodiment) of the embodiment shown in FIG. 7 will be described. For comparison, the same experiment was performed on a portable information terminal (comparative example) in which a metal foil was not attached to the front wall 111 of the cabinet 110 in the embodiment of FIG. 7.

As shown in FIG. 10, the noise level experiment was carried out by placing the portable information terminal 100 in an operating state in a shield box 201 having an electromagnetic wave absorption band 202 attached to its inner surface.
The antenna output of the portable information terminal 100 is guided to the spectrum analyzer 204 via the low noise amplifier (LNA) 203, and the high frequency noise emitted from the portable information terminal 100 is measured. The experimental results are shown in FIG. 11 (Example) and FIG. 12 (Comparative example).

As is apparent from the experimental results shown in FIGS. 11 and 12, the portable information terminal (Example) of the present invention has high-frequency noise of about 1/10 of that of the Comparative Example. It can be seen that the effect of reducing high frequency noise is excellent.

In the above embodiments, an example in which the present invention is applied to a portable information terminal having a sliding structure has been described, but the present invention is not limited to this, and a portable information terminal having a rotating structure having a rotating substrate is provided. Is also applicable.

[0071]

As described above, according to the present invention,
Users can mount functional parts such as keys, tablets, LEDs, cameras, LCDs, speakers, or microphones on the slide board or rotating board, or hide these functional parts on the back side of the sliding board or rotating board as needed by the user. It is possible to effectively reduce high frequency noise in a portable information terminal having a function of exposing the high frequency. In particular, when equipped with a wireless communication function, it is possible to reduce high-frequency noise that interferes with reception, so that reception sensitivity can be improved. The improvement of the reception sensitivity means that the S / N of the receiver is improved.
Since the S / N will increase 10 times,
Up to 10 times as much information can be received in the same frequency band.

Further, since high-frequency noise is less likely to sneak into the antenna, transmission waves of wireless communication are less likely to sneak into the functional components from the antenna. Therefore, it becomes difficult for the transmitted wave to wrap around even in the functional parts such as the key, the tablet, the LED, the camera, the LCD, the speaker or the microphone, the CPU, the memory, the signal line and the like.

[Brief description of drawings]

FIG. 1 is an external perspective view of a portable information terminal to which the present invention is applied, in which (a) is a state in which a slide key unit is closed,
(B) shows a state in which the slide key unit is opened.

FIG. 2 is a side view schematically showing the configuration of a main part of the embodiment of the present invention.

FIG. 3 is a side view schematically showing a configuration of a main part of another embodiment of the present invention.

FIG. 4 is a side view schematically showing a configuration of a main part of another embodiment of the present invention.

FIG. 5 is a perspective view schematically showing a main part configuration of the same embodiment.

FIG. 6 is a perspective view of a modification of the embodiment of FIG.

FIG. 7 is a side view schematically showing a main part configuration of still another embodiment of the present invention.

FIG. 8 is a perspective view schematically showing a main part configuration of the embodiment.

FIG. 9 is a side view schematically showing a configuration of a main part of still another embodiment of the present invention.

FIG. 10 is a diagram schematically showing the configuration of a noise level measurement system.

FIG. 11 is a graph showing the results of measuring the noise level of the portable information terminal (Example) of the present invention.

FIG. 12 is a graph showing a result of measuring a noise level for a comparative example of the present invention.

FIG. 13 is a perspective view schematically showing a configuration of a main part of a conventional portable information terminal having a slide structure.

14 is an explanatory diagram of a problem of the portable information terminal shown in FIG.

[Explanation of symbols]

1 Main board (first circuit board) 2 Slide board (second circuit board) 3 connection points 4 antenna 5 Wireless communication section 6 conductive materials 7 Plastic case (insulator) 71 metal foil 8 plastic plate (insulator) 81 Metal foil 82 Ground connection 11 metal foil 12 Ground connection 13 Flexible substrate 101 terminal body 110 cabinets 111 Front wall of cabinet 102 slide key unit 120 cases 103 display 131 First display 132 Second display unit

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5E321 AA14 AA32 BB23 GG05                 5E344 AA01 AA15 AA19 AA26 AA28                       BB02 BB06 CD18 CD27 CD38                       DD09 EE08 EE23                 5E348 AA02 AA05 AA07 CC09 EE29                       EF04 EF12 EF36 EF42 FF03                 5K023 AA07 BB06 BB28 DD08 LL01                       QQ02

Claims (9)

[Claims] 1. A portable information terminal in which a second circuit board is slidably or rotatably connected to a first circuit board on the side of a terminal body, wherein the first circuit board and the second circuit are provided. A conductive material is disposed between the circuit board and the circuit board so as to be in proximity to one of the first circuit board and the second circuit board, and the conductive material is electrically connected to the other circuit board. A portable information terminal characterized by being connected. 2. The conductive material is arranged in a state of being close to the second circuit board, and the conductive material is electrically connected to the first circuit board. Portable information terminal. 3. A portable information terminal in which a second circuit board is slidably or rotatably connected to a first circuit board on the terminal body side, wherein the first circuit board and the second circuit are provided. An insulator provided with a conductive material is arranged between the board and the board in a state of being close to one of the first circuit board and the second circuit board, and the insulating material is provided on the other circuit board. A portable information terminal characterized in that a conductor of the body is electrically connected. 4. The insulator having the conductor attached thereto is arranged in the vicinity of the second circuit board, and the conductor of the insulator is electrically connected to the first circuit board. The portable information terminal according to claim 3, wherein 5. The conductive material or the insulating material with the conductive material is arranged outside a cabinet that accommodates the first circuit board, according to any one of claims 1 to 4. The portable information terminal described. 6. The electric conductor or an insulator attached with the electric conductor is arranged inside a cabinet accommodating the first circuit board, according to any one of claims 1 to 4. The portable information terminal described. 7. The method according to claim 5, wherein the conductive material is formed on the outer surface or the inner surface of the cabinet by a metal plating process or a metal foil bonding process.
The portable information terminal described. 8. The conductive material or the conductive material of the insulator is electrically connected to the first circuit board or the second circuit board at a portion close to an antenna. The portable information terminal according to any one of 1 to 7. 9. The conductive material or the conductive material of the insulator is electrically connected to the first circuit board or the second circuit board at a position corresponding to the tip portion of the second circuit board. The portable information terminal according to any one of claims 1 to 8, which is characterized by being.