JPH0380799A - Transmission/reception unit for telephone handset - Google Patents

Abstract

PURPOSE:To prevent the lead drawing part of a voice coil from being damaged due to collision to the corner part of an upper yoke by providing a partial projecting part confronting with a side opposite to the vocalizing hole side of a diaphragm on which the voice coil is fixed at the upper end face of a frame on which a magnet and a yoke are provided. CONSTITUTION:A projecting ring 21 consisting of three projecting parts 21a, 21b, and 21c is provided at the upper end face of the frame confronting with a plane at the side opposite to the vocalizing hole 10 side of the diaphragm 1, and also, a gap between the tip of the projecting ring 21 and the diaphragm 1 is formed narrower than that between the lead drawing part 3a from the upper end face of the voice coil 2 and the corner part 7a of the upper yoke 7 comprising a magnetic circuit. Also, the lead wire 3 of the lead wire drawing part 3a is connected to terminals 4a, 4b, respectively passing between the projecting parts 21a, 21b. In such constitution, even when high wind pressure is applied to the diaphragm 1 of a transmission/reception unit and the voice coil 2 sinks remarkably, the projecting part provided at the upper end face of the frame 5 is abutted with the diaphragm 1 before the lead wire drawing part 3a is abutted with the corner part 7a of the upper yoke 7, which functions as a stopper.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a transmitting/receiving unit for a telephone handset;
Especially fl! The present invention relates to a dynamic type transmitting/receiving unit used as a microphone for transmitting telephone voice and a speaker for receiving a telephone voice inside a handset.

2. Description of the Related Art A transmitting/receiving unit used in a conventional telephone handset will be described below.

FIG. 4 is a plan view of a conventional transmitting/receiving unit for a telephone handset, and FIG. 5 is a sectional view taken along line AA' in FIG. Fourth
In the figures and FIG. 5, a voice coil 2 is fixed to the lower center of a diaphragm 1 for acoustically vibratory sound generation.
A lead wire 3 is drawn out from the terminal and soldered to terminals 4a and 4b. This voice coil 2 is inserted into a magnetic gap part 9 made up of a yoke 6.7 and a magnet 8, which is held by a frame 5 and forms a field part that drives the voice coil 2, and is inserted into a magnetic gap part 9 in front of the diaphragm l. A front baffle 11 and a back cover 12 having sound emitting holes IO are fixed to each part of the cavity and the back cavity of the yoke 6.

When an audio signal is applied to the voice coil 2 via the terminals 4a and 4b, the voice coil 2 in the magnetic gear part 9 vibrates in response to the audio signal.

Correspondingly, the diaphragm l vibrates and emits sound. In addition, the impedance of the voice coil 2 is generally 1000.
Since the above is required, the wire diameter of the voice coil 2 is 40
Very fine wires of μm or less are often used.

Problems to be Solved by the Invention In recent years, dynamic type transmitting/receiving units have been increasingly used in the handsets of commercial key telephones from the standpoint of sound quality. Reliability of very small wire diameters has become a problem.

On the other hand, telephone handsets are often dropped on the floor or slammed against desks, making them difficult to use. In addition, in most cases when the handset is attached to the ear, there is a small gap between it and the handset, but if it is suddenly attached to the ear opening without a gap, or if the handset's transmitter/receiver is hit by hand. In that case, a large wind pressure is applied to the diaphragm 1 of the transmitting/receiving unit, as shown in FIG.

The diaphragm 1 is forced downward by the wind pressure, and the voice coil 2 glued to the center of the diaphragm 1 sinks greatly as shown in FIG. A problem arises in that the lead-out portion 3a hits the corner portion 7a of the upper yoke 7 constituting the magnetic circuit and is damaged, or in some cases breaks, resulting in a fatal defect.

The present invention solves the above-mentioned conventional problems, and aims to provide a highly reliable transmitting/receiving unit for a telephone handset in which the lead pull-out part is not unduly damaged due to movement of the diaphragm. It is.

Means for Solving the Problems In order to solve the above problems, the transmitting/receiving unit for a telephone handset of the present invention includes a diaphragm having a voice coil fixed to the center thereof to generate sound in an acoustic vibration manner, and a diaphragm having a voice coil fixed to the center thereof, and the voice coil. a frame provided with a magnet and a yoke forming a field portion for driving the diaphragm; and a partial protrusion provided on the upper end surface of the frame to face a surface of the diaphragm opposite to the sound emission hole side. and a lead drawer of the voice coil to which a signal is applied from a terminal provided on the frame, the distance between the tip of the protrusion and the surface of the diaphragm opposite to the sound emission hole side. The distance between the yoke and the upper end surface of the yoke is smaller than the distance between the yoke and the yoke upper end surface.

action The effects of the above configuration are as follows.

In other words, in the transmitting/receiving unit used in a telephone handset, the amplitude of the diaphragm is usually very small, 100 μm or less, because it is used in a state where it is placed against the ear or close to the mouth. The distance between the lead lead-out part at the upper end of the voice coil and the corner of the upper yoke that constitutes the magnetic circuit is usually 500 μm or more.
If the distance between the diaphragm and the tip of the partial protrusion provided on the upper end surface of the frame facing the surface opposite to the sound emitting hole side of the diaphragm is about 150 μm, vibrations caused by normal audio signals will not occur. There is no problem at all. Therefore, in the case of large vibrations caused by the above-mentioned abnormal causes, the partial protrusions serve as a stopper for the diaphragm, so even if the voice coil sinks significantly, as in the conventional case, the voice There is no possibility that the lead-out portion from the upper end of the coil will be damaged by hitting the corner of the upper yoke constituting the magnetic circuit, and a highly reliable telephone handset transmitting/receiving unit can be obtained.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the drawings.6 Note that components that have the same functions and effects as those of the conventional example are given the same reference numerals, and the explanation thereof will be omitted.

FIG. 1 is a plan view of a transmitting/receiving unit for a telephone handset according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line BB' in FIG. In Figures 1 and 2, there are three protrusions 21a, 21b, 21 on the upper end surface of the frame 5, which faces the surface of the diaphragm 1 on the side opposite to the sound emission hole IO side.
Further, the amplitude of the diaphragm 1 is very small and is usually 100 μm or less, and the distance between the tip of the protrusion ring 21 and the diaphragm 1 is approximately 15 μm.
The distance is 0 μm, and this distance is shorter than the distance (usually 500 μm) between the lead lead-out portion 3a from the upper end of the voice coil 2 and the corner portion 7a of the upper yoke 7 forming the magnetic circuit. In addition, the lead wire 3 of the lead wire pull-out portion 3a
is passed through between the protrusions 21a and 21b, and the terminal 4a,
4b, respectively.

With the above configuration, as shown in FIG. 3, even if the voice coil 2 sinks significantly when a large wind pressure is applied to the diaphragm 1 of the transmitting/receiving unit, the lead wire extraction portion 3a of the voice coil 2 forms a magnetic circuit. Before hitting the corner 7a of the upper yoke 7, a protrusion 2 provided on the upper end surface of the frame 5
1a, 21b.

21c hits the diaphragm l and acts as a stopper,
Since the diaphragm 1 is not lowered any further, damage caused by the corner portion 7a of the upper yoke 7 of the lead pull-out portion 3a is prevented, and a highly reliable telephone handset transmitting/receiving unit can be obtained.

Further, as mentioned above, in order to make a part of the upper end surface of the frame 5 into a partial protruding ring 21, since the frame 5 is made by injection molding of plastic, the mold needs to be partially changed. It can be achieved only by

Note that the protruding ring 21 has the same effect no matter where it is placed, and even if it is configured as a separate component, the effect is the same.

Effects of the Invention As described above, according to the present invention, by only partially changing the mold of the frame that constitutes the transmitting/receiving unit for a telephone handset, there is no increase in the number of parts or work, and the voice There is no possibility that the lead-out part of the coil will be damaged by hitting the corner of the upper yoke that constitutes the magnetic circuit, and a highly reliable transmitting/receiving unit for telephone handsets can be provided without increasing manufacturing costs. The effects are significant.

[Brief explanation of drawings]

FIG. 1 is a plan view of a transmitting/receiving unit for a telephone handset according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line BB' in FIG. 1, and FIG. A diagram showing how the three protruding rings on the frame act as stoppers for the diaphragm when it sinks.
FIG. 4 is a plan view of a conventional telephone handset transmitting/receiving unit, FIG. 5 is a sectional view taken along line AA' in FIG. 4, and FIG. 6 is a conventional telephone handset transmitting/receiving unit shown in FIG. Figure 7 is an enlarged view of the area around the voice coil in Figure 6, showing a state in which the voice coil of the unit has sunk significantly and the lead pull-out part of this voice coil is in contact with the corner of the upper yoke that constitutes the magnetic circuit. It is a diagram. 1...Diaphragm, 2...Voice coil, 3...Lead wire. 3a... Lead wire pull-out part, 4a, 4b... Terminal, 5... Frame, 6, 7... Yoke, 8...
- Magnet, 10... Sound emission hole, 21... Protruding ring, 21a. 21b, 21cm protrusion.

Claims (1)

[Claims] 1. A diaphragm with a voice coil fixed to the center to generate sound through acoustic vibration, a frame provided with a magnet and a yoke forming a field section for driving the voice coil, and an upper end surface of the frame. a partial protrusion provided opposite to a surface of the diaphragm opposite to the sound emission hole side, and a tip of the protrusion and a side of the diaphragm opposite to the sound emission hole side; A transmitting/receiving unit for a telephone handset, wherein a distance between the lead-out portion of the voice coil to which a signal is applied from a terminal provided on the frame and the upper end surface of the yoke is configured to be smaller than a distance between the upper end surface of the yoke and the lead-out portion of the voice coil to which a signal is applied from a terminal provided on the frame.