JP2720610B2 - Radio selective call receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio selective calling receiver having a local oscillator using a quartz oscillator, and more particularly to a housing structure for accommodating a quartz oscillator.

[0002]

2. Description of the Related Art In a conventional radio selective calling receiver, a superheterodyne system is used as a receiving circuit system of a radio unit, and a local oscillator having an oscillation frequency peculiar to a reception frequency is provided. Further, in order to realize high accuracy of the oscillation frequency of the local oscillator, a crystal oscillator unique to the oscillation frequency is used. FIG. 4 is a sectional view showing an example of a conventional radio selective calling receiver. A printed circuit board 402 is housed in the housing 401, and a circuit component 410 and a quartz oscillator 403 are mounted on the printed circuit board. To mount the crystal unit 403, solder the wiring 406 on the printed circuit board 402 and the terminal electrodes 404 and 405 of the crystal unit 403,
This is done by connecting at 407. Since this receiver is relatively thin, a coin-type battery 409 is used, and the battery 409 is attached and detached through an opening 401b provided in the housing 401. Usually, the opening is closed with a battery cover 408. It has become.

[0003]

In such a conventional receiver, in order to change the receiving frequency, the quartz oscillator 403 is used.
If you are trying to replace
After taking out the printed circuit board 402 from the housing 401,
It is necessary to replace the crystal oscillator 403. However, recent wireless selective call receivers require a structure in which the housing is assembled with a large number of screws, etc., in order to achieve a remarkable miniaturization and thinning of the receiver and to maintain a predetermined strength in the housing. It has been. For this reason, it is extremely difficult to design a housing that allows the printed circuit board to be easily taken out of the housing, or to design a housing that has a socket for a replacement part. Therefore, there is a problem that a considerably large number of steps are required to take out the printed circuit board from the housing. SUMMARY OF THE INVENTION It is an object of the present invention to provide a radio selective calling receiver which makes it possible to easily replace a crystal oscillator.

[0004]

According to the radio selective calling receiver of the present invention, a housing has a first opening for connecting and disconnecting a quartz oscillator and a printed circuit board on which the quartz oscillator is mounted, and a housing.
Second for removing and inserting the crystal oscillator from the body
And a opening. The second opening can also serve as an opening for taking in and out the battery housed in the housing.
The first opening is formed at a position facing the terminal electrode of the crystal unit to be soldered to the printed circuit board, and a soldering iron can be inserted through the first opening to the terminal electrode of the crystal unit. Configure to be able to.

[0005]

According to the present invention, the quartz oscillator can be attached to and detached from the printed circuit board using the first opening, and
The quartz resonator can be put in and taken out of the housing by using the opening of (1), thereby making it easy to replace the quartz resonator.

[0006]

Next, the present invention will be described with reference to the drawings. 1 and 2 are sectional views of a radio selective calling receiver according to the present invention. FIG. 1 is a longitudinal sectional view, and FIG. 2 is a bottom view. FIG. 3 is a block circuit diagram of the radio selective calling receiver. First, the circuit configuration of the radio selective calling receiver will be described with reference to FIG. In the figure, a radio signal received by an antenna 301 is amplified by an RF amplifier 302,
Mixer 303 mixes the output of local oscillator 304 with I
The frequency is converted to the F frequency. The bandpass filter 312 is a filter for extracting only necessary IF frequency components. I
The signal converted to the F frequency is amplified by the IF amplifier 306, demodulated by the demodulator 307, further waveform-shaped, converted to a digital signal, and decoded by the decoder 308 to the ID memory 3.
09, when it receives its own selective calling signal after collation with its own selective calling signal, the decoder 3
08, a control signal is output, and a notification is made by the speaker 311. Battery 310 is the power supply for the receiver. Here, the frequency of the local oscillator 304 adapted to the reception frequency of the receiver is unique to the reception frequency because the difference from the reception frequency must be the IF frequency, and the crystal oscillator that determines the frequency of the local oscillator Since the resonance frequency of 305 is also unique, the quartz oscillator 305 needs to be replaced to change the reception frequency.

A housing structure of a receiver having such a circuit configuration will be described with reference to FIGS. In these figures,
A printed circuit board 2 is housed in the housing 1, and a circuit component 10 and a quartz oscillator 3 are mounted on the printed circuit board. The crystal oscillator 3 is mounted on the mounting hole 2 a provided in the printed circuit board 2, and is mounted on the printed circuit board 2.
Through-hole-shaped terminals 11 and 12 formed on a side section
And the terminal electrodes 4 and 5 provided on the surface of the quartz oscillator 3 on the printed board 2 side are connected by solders 6 and 7, whereby the quartz oscillator 3 is fixed and electrically connected to the printed board 2. The printed circuit board 2 is fixed inside the housing 1, but the housing 1 is provided with mounting holes 2 a provided in the printed circuit board 2.
And a first opening 1a into which a soldering iron for attaching and detaching the crystal resonator 3 from outside the housing is inserted.

In this receiver, a coin-type battery 9 is configured so that a battery can be attached to and detached from a battery chamber 13 provided inside the housing 1 using a second opening 1b provided in the housing 1. The second opening 1 b is closed by a battery lid 8. Further, a part of the printed circuit board 2 extends into the battery chamber 13, and the crystal resonator 3 is mounted on the printed circuit board 2 located in the battery chamber 13. The crystal oscillator 3 can be put in and out of the housing 1 through the second opening 1b through the battery chamber 13.

Therefore, when replacing the crystal unit 3 in order to change the reception frequency of the receiver, a soldering iron is inserted using the first opening 1a provided in the housing 1 to insert the solder 6, 7 is melted, and the terminal connection between the printed circuit board 2 and the crystal unit 3 is disconnected. Then, after removing the battery cover 8 and taking out the battery 9 from the second opening 1b to the outside of the housing 1, the crystal resonator 3 from which the terminal connection has been removed is subsequently taken out. Next, the crystal unit 3 to be replaced is inserted into the battery chamber 1 through the second opening 1b.
3, and after inserting the battery 9, the second
After the opening 1b is closed, a soldering iron is inserted from the first opening 1a to melt the solders 6 and 7 again, and the printed circuit board 2 and the crystal unit 3 are soldered to electrically connect the two. This completes the replacement of the crystal unit. During normal use, the first opening 1 a can be closed by attaching a logo label or the like to the outer surface of the housing 1.

[0010]

The present invention described above, according to the present invention, the row connection and detachment of the printed circuit board for the mounting of this crystal oscillator
A first opening of Utame, Eject from the housing of the crystal oscillator
Second openings for inserting and inserting are provided in the housing, respectively.
The crystal resonator using the first opening.
By integrating or separating the printed circuit board and using the second opening, only the crystal oscillator can be put in and out of the housing, and even if the receiver is small and thin, There is no need to remove the printed circuit board from the housing or to provide a large opening for component replacement, and a small and thin receiver can be realized. Further, even if the housing is formed using screws or the like, the screws do not need to be attached or detached when replacing the crystal unit, so that the strength of the housing can be increased and a receiver having a simple design can be realized. Further, the crystal unit can be fixed and electrically connected through an opening having an area smaller than the size of the crystal unit, so that the strength of the housing can be improved and the degree of freedom in design can be realized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a radio selective calling receiver according to the present invention.

FIG. 2 is a bottom view of the receiver of FIG.

FIG. 3 is a block circuit diagram of one embodiment of the radio selective calling receiver of the present invention.

FIG. 4 is a longitudinal sectional view of a conventional radio selective calling receiver.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Case 1a 1st opening 1b 2nd opening 2 Printed circuit board 3 Crystal oscillator 4,5 Terminal electrode 6,7 Solder 8 Battery cover 9 Coin cell battery 10 Circuit component 13 Battery room

Claims (3)

(57) [Claims] 1. A radio selective calling receiver in which a quartz oscillator constituting a local oscillator is mounted on a printed circuit board mounted in a housing , wherein the quartz oscillator is printed on the housing. A first opening for connection to and disconnection from a substrate , and removal of the crystal unit from the housing;
And radio selective calling receiver characterized by comprising a second opening for performing insertion. Wherein serial the second opening in claim 1 which is also an opening for loading and unloading a battery that interior to the housing
Radio selective call receiver of the mounting. Wherein said first opening is opened at a position opposed to the terminal electrodes of the crystal oscillator to be soldered to the printed circuit board, pledged soldering iron until the terminal electrode through the first opening The radio selective call receiver according to claim 1 or 2 , wherein the radio selective call receiver is configured to be able to receive the call.