JPH069217U - Loop antenna - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a loop antenna in which antenna sensitivity can be improved without increasing the size of a device casing and a metal LCD holder does not adversely affect antenna efficiency. [Structure] Metallic LC for fixing LCD 3 to circuit board 2
The loop antenna 1 is formed by using the D holder 4 as an antenna element.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a loop antenna suitable for use in a portable small radio device.

[0002]

[Prior art]

 In portable radios such as selective call receivers, a loop antenna is generally used as a built-in antenna, and an LCD (liquid crystal display) is used as a means for displaying information. . Further, in the conventional portable radio device, the loop antenna is usually constructed by providing a rod-shaped body or a strip-shaped body plated with a metal having high conductivity in a loop shape on the circuit board. Further, the LCD is attached to the circuit board while being surrounded by a metallic LCD holder so as not to be damaged by an external force.

However, in the conventional portable wireless device, if the loop antenna is enlarged and the aperture area is increased in order to obtain a highly sensitive antenna, the wireless device itself becomes large. There was a problem that it was not possible to reduce the weight. In addition, in this type of wireless device in which electronic components are mounted in high density, the metallic LCD holder is placed near the loop antenna, so the efficiency of the antenna decreases due to the influence of this LCD holder. was there.

[0004]

[Problems to be solved by the device]

 As described above, the conventional portable wireless device has a problem that the wireless device itself must be upsized in order to improve the sensitivity of the built-in loop antenna. There is also a problem that the efficiency of the loop antenna is reduced due to the influence of the metallic LCD holder located near the loop antenna.

The present invention has been made to solve such a conventional drawback, and the sensitivity can be improved without increasing the size of the device housing, and the metallic LCD holder adversely affects the antenna efficiency. The purpose is to provide a loop antenna that does not cause

[0006]

[Means for Solving the Problems]

 The loop antenna of the present invention uses a metallic LCD holder as an antenna element for fixing the LCD to the circuit board.

[0007]

[Action]

 In the loop antenna of the present invention, the metal LCD holder required for mounting the LCD on the circuit board is used as the antenna element, so that the device housing in which the loop antenna is housed is not enlarged. The antenna sensitivity can be improved. Further, since the metallic LCD holder itself is used as the antenna element, the LCD holder does not adversely affect the efficiency of the loop antenna.

[0008]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

FIGS. 1 to 3 are views for explaining the first embodiment. FIG. 1 is a perspective view of a loop antenna formed on a printed wiring board, FIG. 2 is a front view of the loop antenna, and FIG. FIG. 4 is an equivalent circuit diagram of the loop antenna.

The loop antenna 1 of this example is used as an antenna of a selective call receiver, and is a printed wiring board (circuit board) 2 mounted in a casing (not shown) of the selective call receiver. It is formed by providing conductors as antenna elements on both the front and back sides of the.

That is, a metallic LCD holder 4 for attaching the LCD 3 to the printed wiring board 2 is attached to the front surface side of the printed wiring board 2, and the LCD holder 4 has a high conductivity metal. It is plated. Further, on the back surface side of the printed wiring board 2, there is attached a substantially U-shaped rod-shaped body 6 plated with a metal having high conductivity. Then, in this example, the LCD holder 4 and the rod-shaped body 6 are used as antenna elements, and these antenna elements 4 and 6 are connected in series via the pattern 8 and the shortening capacitor 9 for tuning, whereby the single loop antenna 1 Is configured.

4 to 6 are views for explaining the second embodiment. FIG. 4 is a perspective view of a loop antenna formed on a printed wiring board, FIG. 5 is a front view of the loop antenna, and FIG. FIG. 4 is an equivalent circuit diagram of the loop antenna.

In this example, on the front surface side of the printed wiring board 2A, an LCD holder 4 similar to that of the first embodiment and a substantially U-shaped rod-shaped body 11 on which high conductivity metal plating is applied are provided. The rod-shaped body 6 similar to that of the first embodiment is attached to the back side. Then, the LCD holder 4, the rod-shaped body 6 and the rod-shaped body 11 are used as antenna elements, and these antenna elements 4, 6 and 11 are connected in series via the pattern 8 and the shortening capacitor 9 to form a single and half loop antenna 1A. Is configured.

FIG. 7 is a diagram for explaining the third embodiment. In this example, a loop antenna is formed using only the LCD holder 4A attached to the printed wiring board 2B as an antenna element. That is, the LCD holder 4A has a pair of end portions 41, 42 formed by cutting out a part of the frame portion, and these end portions 41, 42 are connected to the printed wiring through the pattern 8 and the shortening capacitor 9. By connecting to the circuit portion (not shown) of the plate 2B, the LCD holder 4A itself constitutes a loop antenna.

[0015]

[Effect of device]

 As described above, in the loop antenna of the present invention, since the metallic LCD holder required for mounting the LCD on the circuit board is used as the antenna element, it is necessary to provide the loop antenna inside. It is possible to improve the antenna sensitivity without increasing the size of the equipment housing. Moreover, since the metallic LCD holder itself is used as the antenna element, the LCD holder does not adversely affect the efficiency of the loop antenna.

[Brief description of drawings]

FIG. 1 is a perspective view of a loop antenna according to a first embodiment of the present invention.

FIG. 2 is a front view of the loop antenna.

FIG. 3 is an equivalent circuit diagram of the loop antenna.

FIG. 4 is a perspective view of a loop antenna according to a second embodiment of the present invention.

FIG. 5 is a front view of the loop antenna.

FIG. 6 is an equivalent circuit diagram of the loop antenna.

FIG. 7 is a perspective view of a loop antenna according to a third embodiment of the present invention.

[Explanation of symbols]

1 loop antenna 2 circuit board 3 LCD 4 LCD holder 6 bar

Continued Front Page (72) Mamoru Ishii 21 Toshiba Communication Technology Co., Ltd., 3-1, Asahigaoka, Hino City, Tokyo

Claims (1)

[Scope of utility model registration request] 1. A metallic L for fixing an LCD to a circuit board.
A loop antenna, wherein a CD holder is used as an antenna element.