JPS63250995A - Thin type speaker - Google Patents

Abstract

PURPOSE:To constitute a considerably thin type speaker by giving the diaphragm of a bent form, fixing one end of the diaphragm concerned and connecting the other end to the motor end of an electricity/machine converter so that a bent degree changes in accordance with an acoustic signal. CONSTITUTION:The diaphragm 5 has a fixing part 5a, what is called bent parts 5b, 5c and 5d, a driving coil 5f on which a printed circuit is provided, a supporting body 5e which can move the driving end of the diaphragm (side where the driving coil 5f exists) which simultaneously holds the holding body of a connection pattern to a circuit substrate 8 in a lateral direction by the flexibility. A permanent magnet 10 is magnetized reversely in a vertical direction with a right half and a left half, and a magnetic line of force circles counterclockwise within a space through yokes 11 and 12, and a gap between the permanent magnet 10 and the yoke 12. Since the driving coil 5f is wound to the back of the space at the right half of a magnetic field, and to the front of the space at the left half, the right end of the diaphragm 5 receives driving force facing right or left in a horizontal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improved structure of a card-type electronic device having an acoustic function.

[Conventional technology]

Business card-sized and thin electronic devices, which originated from the miniaturization of pocket calculators, are expected to gain importance in the future as personal information devices, stimulated by the development of so-called IC cards. Whatever information it holds, it is often preferable to not only display it on an electro-optical display device, but also to transmit it as audio (because it can handle a large amount of information).

[Problem that the invention seeks to solve]

In the past, for example, as disclosed in Utility Model Publication No. 57-25289, there was a thin box-shaped computer with a piezoelectric element fixed to the bottom plate, but the sound transmission function required by the computer was at most controlled by keyboard switch operation.゛Since it is only a confirmation sound (beep), the vibration frequency is high, over several kllz,
I also liked that the range was narrow.

However, future acoustic information transmission functions will naturally require, for example, audio to be recorded and played back, or synthesized according to internal information, and several ten It becomes necessary to incorporate a sounding body that has a wide band from fiz to several kllz and has a large output so that the details of the voice can be heard.

However, until now, no configuration has been provided that satisfies such requirements. Even in the conventional example described above, the area of the piezoelectric element is too small to cause the bottom plate to vibrate at low frequency and large amplitude, and the vibration of the bottom plate is directly obstructed by the desk top surface on which electronic equipment is placed. It is. (In order to make the acoustic radiation energy as wide as possible, the lower the frequency of the sound, the wider the amplitude is required.) On the page, there was an example of molding a plate made of piezoelectric material into a curved surface and making it move like a bimorph plate.
In addition, as seen in Japanese Utility Model Application Publication No. 59-17695, there was a device that piezoelectrically drives a diaphragm whose periphery is fixed in a bent state, but since these are piezoelectrically driven, it is difficult to obtain low frequency and large amplitude. It had the disadvantage of being a converter.

Also, so-called electrodynamic or electromagnetic speakers are often used when it is desired to obtain good frequency characteristics, but because they have a structure in which the vibration #J temporary and the driving cornerstone device overlap, Thinner than a dragon (preferably 2-3
A structure that allows for dragons (lower than dragon) has not been realized.

An object of the present invention is to provide a thin speaker structure in which a main part of a diaphragm and an electro-mechanical converter are provided together.

[Means for solving problems]

The diaphragm has a slightly bent shape, one end of the diaphragm is fixed, and the other end of the diaphragm moves the acoustic wave in a direction substantially along the surface of the diaphragm so that the degree of curvature changes according to the acoustic signal. It is characterized in that it is connected to the moving end of an electro-mechanical converter that receives a signal as input.

[Effect]

When one end is fixed and the other end of the bent plate is driven almost parallel to the entire plate surface, the degree of bending changes, and the approximately central part of the plate surface moves back and forth perpendicularly to the plate surface. Therefore, sound waves are emitted in that direction.

〔Example〕

FIG. 1 is a cross-sectional view of essential parts of a first embodiment of the present invention, FIG. 3 is a plan view of a card-type electronic device in which a speaker of the present invention is mounted, and FIG. FIG. 4 is a developed view of a diaphragm according to a third embodiment of the present invention, FIG. 5 is a side view of a movement guide mechanism of a diaphragm according to a fourth embodiment, and FIG. It is a side view of a drive mechanism.

In Fig. 2, 1 is the card surface board, 2 is the electro-optical number/character display, 5 is the built-in acoustic diaphragm, 6 is the sound emitting hole, 4 is the battery that serves as the power source, and 6 is the operating device. This is a group of arranged switches. Since it is desirable for card-type electronic devices to be as thin as possible, each element is developed in a two-dimensional manner. Furthermore, in FIG. 1, 7 is a card back plate, 8 is a circuit board on which an integrated circuit, etc. is mounted, and 9 is a fixed part 5a of the diaphragm 5.
A spacer that also serves as a holding part and determines the thickness of the card.
10 is a permanent magnet constituting an electrodynamic electro-mechanical converter;
Similarly, yokes 11 and 12 are made of soft magnetic material.

In addition to the fixed part 5a, the diaphragm 5 has loosely bent parts 5b, 5.
c, 5d, etc., the printed wiring drive coil 5f, and the drive end of the diaphragm (lll0 with the drive coil 5f) that also serves as a carrier for the connection pattern to the circuit board 8 can be moved laterally by its flexibility. The support body 5e is made of a thin sheet of elastic paper, plastic, or metal. The permanent grinding stone 10 is magnetized in the vertical direction, and the left half and the left half are reversely magnetized, and the lines of magnetic force are connected to the yokes 11 and 12 and the permanent magnet 10.
It passes through the gap between the yoke 12 and the yoke 12 and goes around the page counterclockwise. This magnetic field extends perpendicular to the plane of the paper. On the other hand, since the drive coil 5f is wound toward the back of the page on the left half of the magnetic field and toward the front of the page on the left half, when the drive current is supplied from the circuit board 8 to the drive coil 5f, the diaphragm The right end of 5 receives a driving force directed to the right or left in the horizontal direction. Third
Regarding the diaphragm 5 in the figure, there are differences in details from the first embodiment (
For example, there is almost no difference except for slight differences in the bending shape. The pattern of the drive coil 5f is almost the same on both sides of the plate surface.

5g is a through hole connecting the upper and lower patterns, and 5h is a lead pattern to the drive circuit. 20 is a sliding guide,
It is fixed to the card body and serves as a guide and stopper for the driving end of the diaphragm 5 to move horizontally without touching the motherboard, and is made of felt or flexible foamed plastic and guides the diaphragm without friction loss.

The diaphragm 5 shown in FIG. 4 is integrated with the circuit board 8 of the first embodiment, including the main body and its supporting part, and is made of, for example, a flexible circuit board material, and is connected to other parts along with the drive coil. A copper foil wiring pattern for the circuit is formed at the same time. Region A is the fixed portion 5a, and region B is the main portion of the diaphragm 5 that is photographed, and is a portion that is gently bent (it may have a crease or a gently curved surface).

Region C is provided with a drive coil pattern. The area formed by the support spring 5J is bent at right angles at the area C and the drive end 510, and is perpendicular to the thickness inside the card, supporting the drive end 51 of the diaphragm so that it can only be moved horizontally. Region E is again folded back at right angles to the connection point 5 with the region and overlaps regions C and B. The hole 51 is a part for making a detour to area F, which includes a 5 m area where other circuit elements are mounted, avoiding overlap with the driving magnetic circuit and area B, which is bent and vibrates with a large amplitude. be. Drive end 5r
, the support spring 5j, and the back surface of the connection point 5 also serve as a path for the lead pattern of the drive coil. Areas E and P are adhesively fixed to, for example, the back plate of the card.

The width of the support spring 5j is set as wide as possible compared to its plate thickness, so that the drive end 51 is difficult to displace in the thickness direction of the card.

The motion guide mechanism shown in FIG. 5 includes a permanent magnet 5n mounted on the driving end of the diaphragm 5, and a permanent magnet 13 fixed to the card body side.
The magnetomotive force of the yoke 14 causes horizontal movement due to the repulsive force of the magnetic poles formed at the ends of the yoke 14, without contacting each other, and is characterized by completely frictionless guiding.

FIG. 6 shows a structure in which a so-called non-magnetic electro-mechanical converter is applied.
．． There is a magnetic circuit formed through the yokes 5p and 5q mounted on the diaphragm 5 side, and the yokes 5p and 5q are about to be drawn into the gap between the yokes 15 and 16 by the drive coil 19 wound around the auxiliary yoke 17. Since the suction force changes, the drive end can be driven so as to balance the restoring force of the bent shape of the diaphragm 5.

Furthermore, although not shown, the driving end of the diaphragm may be driven by, for example, a piezoelectric actuator (a mechanism that obtains a large displacement in response to an applied voltage by stacking a large number of piezoelectric elements). In addition, there are various other factors such as the initial bending shape given to the diaphragm (not limited to a columnar shape, but also a three-dimensional shape), the support structure of the fixed end and the drive end, the planar shape of the diaphragm, the position of the sound emitting hole (for example, providing it on the back), etc. Modifications and embodiments are possible. Further, the yoke may also be used as the cover plate or back plate of the card.

Furthermore, the speaker structure of the present invention can be applied to electronic devices other than card type, and of course can also be used as a microphone.

〔Effect of the invention〕

Since the vibrating part of the diaphragm and the driving part do not overlap in the thickness direction and are arranged side by side in a plane, an extremely thin speaker can be constructed. Further, a large protection width can be obtained efficiently, and the effect is suitable for low frequency driving.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts of a first embodiment of the present invention, FIG. 2 is a plan view of a card-type electronic device in which a speaker of the present invention is mounted, and FIG. 3 is a main part of a second embodiment of the present invention. FIG. 4 is a developed view of a diaphragm according to a third embodiment of the present invention, FIG. 5 is a side view of a movement guide mechanism of a diaphragm according to a fourth embodiment, and FIG. It is a side view of a drive mechanism. 5... Vibration plate, 5a... Fixed part, 5b to 5d... Bent part, 5f... Drive coil, 6... Release Sound hole, 10...Permanent magnet.゛、-ノ' Figure 2 Figure 4-5 Figure 6

Claims (1)

[Claims] The diaphragm has a slightly bent shape, one end of the diaphragm is fixed, and the other end of the diaphragm moves the acoustic wave in a direction substantially along the surface of the diaphragm so that the degree of curvature changes according to the acoustic signal. A thin speaker characterized in that it is connected to a moving end of an electro-mechanical converter that receives a signal as input.