JPH08274536A - Wearable wireless device - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a wrist-worn wireless device that can improve reception sensitivity in a standby state of received radio waves. [Arrangement] An arm-mounted radio including a slot antenna 23 having a resonance capacitor 36 for resonating with received radio waves, and a band 3 for mounting the radio case 4, 5, 6 housing the slot antenna 23 on an arm. In the device, the slot antenna 23 is arranged so that the main lobe with antenna directivity faces the arm case when the arm-mounted wireless device 1 is mounted on the arm by the band 3.
It was configured to be housed in 5 and 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small portable wireless device, and more particularly, to a wrist-mounted wireless device of a wrist-worn type.

[0002]

2. Description of the Related Art The applicant has already proposed a portable wireless device in which a slot antenna is provided in a wireless device case (Japanese Patent Application No. 6-240227). This portable wireless device
It is a type to be stored in a pocket, and a mark is printed on the surface of the radio case to orient the portable radio device so that the built-in receiver has good sensitivity. .

In the portable wireless device proposed by the applicant, the user should carry the portable wireless device in a pocket or on a belt so that the portable wireless device is oriented in the direction designated by the mark. As a result, the directivity main lobe of the built-in slot antenna points in a certain direction,
The receiver has the best sensitivity.

[0004]

However, in the case of the type worn on the wrist, even if the direction of the portable wireless device is designated by the mark, the directivity of the main lobe of the directivity of the slot antenna depends on the posture and the movement of the arm. The direction will be different. Therefore, there is a point to be improved in the wrist-worn radio device in that it is difficult to recommend a method of use in which the direction of the slot antenna is fixed by marking the mark.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wrist-worn radio device capable of improving the reception sensitivity in a standby state of a received radio wave.

[0006]

In order to achieve the above object,
An arm-mounted wireless device according to claim 1, further comprising a slot antenna having a resonant capacitor for resonating with a received radio wave, and a band for mounting a radio case containing the slot antenna on an arm. The device is characterized in that the slot antenna is housed in a radio case such that a main lobe having an antenna directivity faces a direction of an arm when the arm-mounted wireless device is worn on the arm by a band. And

According to another aspect of the present invention, there is provided a wrist-worn wireless device, wherein a slot antenna having a slit formed therein and having a resonance capacitor for resonating with a received radio wave and a radio case for housing the slot antenna are mounted on the wrist. A wrist-worn wireless device including a band, wherein the opening of the slot antenna slit at the site where the resonance capacitor is attached faces in the direction of the arm when the wrist-worn wireless device is worn on the arm by the band. It is characterized by being formed.

[0008]

In the arm-mounted wireless device according to the first aspect, when the arm-mounted wireless device is mounted on the arm by the band, the directional main lobe of the slot antenna lowers the arm in the direction of the arm, that is, in the upright posture. When turned up or down. In this state, a magnetic field is generated in the circumferential direction of the torso by flowing a current based on the received radio wave into the human body.
As a result, the slot antenna, which is a magnetic field antenna, favorably receives the received radio waves, so that the arm-mounted wireless device can always have good reception sensitivity. By the way, the posture in which the arm is lowered is the most comfortable posture in which the muscle relaxes, and in the standby state of the received radio wave, the user often waits for reception in the upright posture and the posture in which the arm is lowered. Therefore, the reception sensitivity of the wrist-worn wireless device is improved during the reception standby.

In the arm-mounted wireless device according to the second aspect, since the direction of the directional main lobe of the slot antenna is the same as the direction of the opening of the slit, when the arm-mounted wireless device is mounted on the arm by a band, The opening of the slit of the slot antenna at the site where the resonance capacitor is attached is directed upward or downward when the arm is lowered, that is, when the arm is lowered in the upright posture. As a result, the arm-mounted type wireless device operates in the same manner as in the arm-mounted type portable wireless device, and the reception sensitivity of the arm-mounted type wireless device becomes good during reception standby.
Further, since the resonance capacitor is provided, the slot antenna resonates at the frequency of the received radio wave, and as a result, the reception sensitivity of the wrist-worn wireless device becomes better. Further, since the mounting position of the resonance capacitor can be used as a mark, the slot antenna can be housed in the radio case so that the direction of the directional main lobe always faces a constant direction during the manufacturing process.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wrist-worn radio device according to an embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a front view of a wrist-worn radio device 1. The wrist-worn wireless device 1 is a so-called pager, has a predetermined ID number, and transmits various data in the transmission data when its own ID number is transmitted by the POCSAG communication method. To receive. Specifically, the wrist-worn wireless device 1 is constantly performing intermittent reception, and when a preamble signal is transmitted from the transmitter side (not shown), it detects this and switches to continuous reception. After that, the wrist-worn wireless device 1 receives a predetermined block signal among a plurality of block signals transmitted after the transmission of the preamble signal is completed. The block signal includes the ID number of the arm-mounted wireless device to be called and various data.
Compares the transmitted ID number with its own ID number, and when they match, receives various data and
The various data received is stored in a memory (not shown). After that, the wrist-worn wireless device 1 displays various information based on various data on the liquid crystal panel 11.

As shown in FIG. 1, the arm-mounted wireless device 1 has a body 2 and a band 3. The main body 2 is shown in FIG.
As shown in, upper case 4, lower case 5 and battery lid 6
And a radio case is constructed by these. Further, as shown in FIG. 1, the main body 2 is provided with a liquid crystal panel 11 for displaying various information and an LED 12 for indicating reception of various data in the central portion on the front surface side, and the liquid crystal panel 11 is provided above them. A cover glass 13 for protecting and waterproofing the panel 11 and the LED 12 is provided. Also,
The left side portion 14 of the main body 2 accommodates a vibrator 15 (see FIG. 2) that vibrates when various data is received, and below the liquid crystal panel 11, the vibration of the vibrator 15 is stopped or displayed on the liquid crystal panel 11. Switches 16 and 17 are provided for adjusting the time of the clock.

Inside the main body 2, as shown in FIG. 2, a printed circuit board 21 on which an electronic circuit such as a receiver is mounted.
And an air battery 22 that supplies power to the electronic circuit. A slot antenna 23 for reception is attached around the side surface of the printed board 21.

As shown in FIG. 3, the slot antenna 23 includes endless strip-shaped first and second conductor plates 31 and 32.
It is provided with a short-circuit portion 34 that short-circuits a part of both conductor plates 31 and 32 so that both conductor plates 31 and 32 form a slit 33 having a predetermined width. The slot antenna 23 is formed by punching a flat copper plate into a V shape, bending it into a predetermined shape, and then stacking and welding the respective end portions 35, 35 of the first and second conductor plates 31, 32. Thus, the first and second conductor plates 31 and 32 are formed so as to be endless. Further, the slot antenna 23 includes a resonance capacitor 36 that is a chip capacitor for resonating at a specific frequency, and the resonance capacitor 36 is soldered on the capacitor mounting terminal portions 40, 40 while straddling the slit 33. Has been done. The capacitor mounting terminal portions 40, 40 are located at substantially central positions in the extending direction of the slit 33, that is, both conductor plates 31 from the left end portion 34a on the left side of the short circuit portion 34 in the figure to the right end portion 34b of the short circuit portion 34. , 32 are formed substantially at the center in the length direction.

Further, the short-circuit portion 3 of the slot antenna 23
4 and the resonance capacitor 36, a first terminal portion 37 formed by bending the first conductor plate 31 to have a U-shaped planar shape and a second conductor plate 32 at the intermediate portion between the resonance capacitor 36 and the resonance capacitor 36 have a L-shaped planar shape. The second terminal portion 38 formed in a V shape is formed.
The first terminal portion 37 is a high frequency input portion (not shown) of the receiving portion.
The second terminal portions 38 are terminals that are respectively connected to the ground, and are arranged at positions away from the position of the resonance capacitor 36. As a result, the position where the impedance is extremely high (where the resonance capacitor 36 is attached)
As the high-frequency input section of the receiving section is moved away from, the impedance of the portion of the first conductor plate 31 connected to the high-frequency input section becomes low, and as a result, matching between the high-frequency input section and the slot antenna 23 becomes easy.

As shown in FIG. 4, in the slot antenna 23, the protruding portion 37a of the first terminal portion 37 has the printed circuit board 21.
In a state of being inserted into the hole portion 41 of No. 1, it is soldered to a print pattern (not shown) formed around the hole portion 41,
The second terminal portion 38 is soldered to a print pattern (not shown) formed around the cutout portion 42 while being fitted in the cutout portion 42 of the printed circuit board 21. Thereby, the slot antenna 23 is attached along the periphery of the printed board 21. In this state, the first terminal portion 3
7 and the second terminal portion 38 include a hole portion 41 and a cutout portion 42.
Is connected to the high-frequency input section of the receiving section and the ground via the respective print patterns around the. As a result,
The high frequency signal received by the slot antenna 23 is input to the receiving unit via the first terminal portion 37 and the second terminal portion 38.

As shown in FIG. 5, when the printed circuit board 21 is housed in the main body 2, the resonance capacitor 36 is located on the left side of the main body 2. As a result, when the user wears the arm-mounted wireless device 1 on the left wrist and lowers the arm to take an upright posture, the opening 39 (FIG. 3)) is in the direction of the arm and faces upward. That is, the resonance capacitor 36
Is located on the upper side, and the short-circuit portion 34 of the slot antenna 23 is located on the lower side. Conversely, when the portable wireless device 1 is attached to the right wrist, the opening 39 of the slit 33 is directed downward in the direction of the arm, the arm resonance capacitor 36 is on the lower side, and the short-circuit portion 34 is on the upper side. Located respectively.

Next, the directivity of the slot antenna 23 will be described. Generally, as shown in FIG. 6, the slot antenna ST has directivities FP and FP in which the main lobe, which is the maximum radiation direction, is oriented in the direction perpendicular to the slit SL. The symbols E and H in the figure indicate the directions of the electric field and the magnetic field, respectively. On the other hand, the slot antenna S
Connecting the end portions STE and STE of T to each other is equivalent to the slot antenna 23 of this embodiment. Therefore, when the arm-mounted wireless device 1 is worn on the wrist and the user lowers the arm and stands upright, the slot antenna 23 exhibits directivity having a main lobe in an upward or downward direction. At this time, when a vertically polarized radio wave, which is generally used for pagers, reaches a human, a current flows in the extension direction of the human body, a magnetic field is generated in the waist circumference direction, and an electric field is generated in a direction perpendicular to the magnetic field direction. Occurs. That is, the surface of the human body can be considered to be equivalent to a metal conductor, and a so-called image effect can be obtained. Therefore, the directions of the electric field and the magnetic field at this time match the directions of the magnetic field H and the electric field E in FIG. As a result, the vertically polarized radio wave based on the current flowing in the extension direction of the person is received most, and the receiving sensitivity of the receiving circuit is also improved.

Next, the directivity of the slot antenna 23 measured by experiments will be described with reference to FIGS. The broken line in FIG. 7 indicates the gain of the slot antenna 23 when the arm-mounted wireless device 1 according to the present embodiment is worn on the wrist and the arm is lowered to stand upright (see FIG. 9). A slot antenna alone in the same direction (Fig. 10
(See FIG. 10). Also, FIG.
As shown in FIG. 11, the broken line indicates that the arm-mounted wireless device in which the slot antenna 23 in FIG. 10 is rotated by 90 ° clockwise when viewed from the front is stored on the wrist, and the arm is lowered to stand upright. The gain of the slot antenna 23 when taken is shown, and the solid line in the figure shows the gain of the slot antenna 23 alone in the same direction. Note that FIG.
As shown in FIG. 9, a solid line in 8 indicates a front direction (direction from the front side to the back side of the paper), a back direction (direction from the back side to the front side of the paper), and a left side with respect to a person in an upright posture. The gain of the slot antenna 23 is measured with respect to the surface direction, the right side surface direction, and the four directions intersecting these four directions at 45 °. further,
The unit dBd in FIGS. 7 and 8 represents the gain when compared with the dipole antenna.

According to FIG. 7, the gain of the slot antenna 23 when the wrist-worn radio device 1 is worn on the human body has a substantially uniform directivity in eight directions. Also,
In the mounted state, compared with the case of the slot antenna 23 alone, it is improved by 3 dB in the front direction and is significantly improved in the left direction and the right direction. This is because, as described above, a current flows through the human body and receives the power. In the back direction, the directivity deteriorates because the radio waves are blocked by the human body.

According to FIG. 8, the slot antenna 23 is replaced by 9
When it is attached to the human body after being rotated by 0 °, the directivity is extremely deteriorated in all directions as compared with the case of a single body. The front and back directions are less deteriorated than the left and right directions because the extension direction of the slit 33 and the direction of the magnetic field may coincide with each other to receive electric power.

As described above, according to the present embodiment, the slot antenna 23 has its directional main lobe oriented toward the arm when the portable radio apparatus 1 is worn on the arm.
Since it is housed in the arm-mounted wireless device 1, when the arm-mounted wireless device 1 is mounted on the human body and the arm is lowered to stand upright, the main lobe faces upward or downward. On the other hand, the posture in which the arm is lowered is the most comfortable posture in which the muscle relaxes, and in the standby state of the received radio wave, the user often waits for the reception in the upright posture and the posture in which the arm is lowered. Therefore, during reception standby, the reception sensitivity of the portable wireless device 1 becomes good with respect to the received radio waves arriving from all directions.

In this embodiment, the arm-mounted wireless device 1 is housed so that the main lobe of the slot antenna 23 faces upward when it is mounted on the human body. When mounted, it may be stored vertically downward. This is naturally derived from the theoretical directivity of FIG. Further, in the present embodiment, the case where the main lobe of the slot antenna 23 is located almost upward is described. However, in the present invention, "the directional main lobe of the antenna has the arm-mounted wireless device mounted on the arm by the band". When the slot antenna 23 is attached to the arm, the maximum radiation direction of the directivity main lobe of the slot antenna 23 is from directly above or below the vertical direction. It also includes the case of tilting within 45 ° for all directions.
In these cases, the inventor has confirmed by experiments that the receiving sensitivity of the receiving unit is good.

The shape of the slot antenna 23 is not limited to this embodiment, and the short-circuit portion 34 is divided into two in the direction orthogonal to the extending direction of the slit 33, and the first and second conductor plates 3 are formed.
The first and second conductor plates 31 and 32 may be formed in the shape of an end strip, or the first and second conductor plates 31 and 32 may be formed in the shape of a box having openings, and the openings are stacked so that the openings face each other. It may be configured as an antenna. Further, a groove is formed on the outside of the radio case, and the slot antenna 23 is formed in the groove.
You may make it fit. Other than the above, the present invention can be arbitrarily changed within the scope of the present invention.

[0025]

As described above, according to the arm-mounted wireless device of the present invention, when fixed to the arm by the band, the directivity main lobe of the slot antenna faces the arm, so that the received radio wave is transmitted to the human body. When it reaches, it is possible to efficiently receive the magnetic field generated in the circumferential direction of the torso by the current flowing in the human body, and to improve the receiving sensitivity. As a result, the sensitivity of the arm-mounted wireless device can be improved when the user stands in an upright position by lowering the arm, which is often taken by the user in the standby state of the received radio wave. Further, since the resonance capacitor is provided, the slot antenna resonates at the frequency of the received radio wave, and as a result, the reception sensitivity of the wrist-worn wireless device becomes better. Further, since the mounting position of the resonance capacitor can be used as a mark, the slot antenna can be housed in the radio case such that the direction of the directional main lobe always faces a fixed direction during the manufacturing process.

[Brief description of drawings]

FIG. 1 is a front view of an arm-mounted wireless device according to an embodiment.

FIG. 2 is a sectional view taken along line XY in FIG.

FIG. 3 is an external perspective view of the slot antenna according to the present embodiment.

FIG. 4 is an external perspective view when the slot antenna according to the present embodiment is attached to a printed board.

FIG. 5 is a front perspective view of the wrist-worn wireless device according to the present embodiment.

FIG. 6 is a diagram for explaining the directivity of a slot antenna.

FIG. 7 is a diagram showing the directivity of the slot antenna according to the present embodiment.

FIG. 8 is a diagram showing the directivity when the slot antenna is rotated by 90 ° in FIG.

FIG. 9 is a diagram showing each direction when the directivity of FIGS. 7 and 8 is measured.

10 is a diagram showing a measurement direction with respect to the slot antenna when the directivity of FIG. 7 is measured.

FIG. 11 is a diagram showing a measurement direction with respect to the slot antenna when the directivity shown in FIG. 8 is measured.

[Explanation of symbols]

 1 wrist-worn radio device 3 band 4 upper case 5 lower case 6 battery lid 23 slot antenna 31 first conductor plate 32 second conductor plate 33 slit 34 short-circuit portion 36 resonance capacitor 39 opening

Claims (2)

[Claims] 1. A wrist-worn radio apparatus, comprising: a slot antenna having a resonance capacitor for resonating with a received radio wave; and a band for wearing a radio case for housing the slot antenna on an arm. The slot antenna is housed in the radio case such that a main lobe having an antenna directivity faces the direction of the arm when the arm-worn wireless device is worn on the arm by the band. A wrist-worn wireless device. 2. A wrist-worn radio having a slot antenna having a slit formed therein and having a resonance capacitor for resonating with a received radio wave, and a band for mounting a radio case for housing the slot antenna on an arm. In the device, the opening of the slit of the slot antenna at the portion to which the resonance capacitor is attached is formed so as to face the arm when the arm-mounted wireless device is attached to the arm by the band. A wrist-worn wireless device characterized by the above.