JPH0759119B2 - TV speaker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a television speaker used in a television set.

Configuration of Conventional Example and Problems Thereof In recent years, audio equipment such as a television and a cassette recorder with a radio are remarkably compact in shape. Here, taking a television set as an example and describing its problems, the speaker shape is one of the factors that hinders compactness. For this reason, measures such as adoption of a rectangular speaker with a good space factor and attachment of the speaker to the side surface of the set have been made.

However, even if the shape of the speaker is rectangular, a space for the speaker is required on the front side of the set, and thus there is a limit to downsizing. Also, when the speaker is attached to the side of the set, the speaker has directivity in sound pressure characteristics, so that the sound pressure in the high frequency range is significantly reduced at a position deviated from the front axis of the speaker, that is, at the front of the set, and the sound quality is deteriorated. There was a problem. Further, in the method of mounting the speaker on the side surface, there is a drawback that sound reproduction becomes difficult if there is an obstacle on the side surface and the installation place of the set is limited.

In order to solve these problems, a reproducing method has been considered in which a driving driver is attached to the front panel of the front surface of the cathode ray tube that constitutes the set to vibrate and the front panel is used as a diaphragm.

The conventional speaker of this type will be described below.

FIG. 1 is a perspective view of a television set adopting this type of speaker, in which 1 is a cabinet, 2 is a cathode ray tube,
Reference numeral 3 is a front panel mounted on the front surface of the cathode ray tube 2 and made of a material having a high light transmittance such as glass or transparent acrylic resin. Reference numeral 4 is an electromagnetic driving driver mounted on the back surface of the front panel 3.

FIG. 2 is a structural view of the driving driver, and FIG. 2 (a) is a top view of the same portion with a cutout, and FIG. 2 (b).
FIG. 3 is a sectional view of the same structure. In FIG. 2, 5 is a plate 6
A center pole integrally or mechanically coupled to the center pole 7, an exciting coil wound around the center pole 5, and a plate 6
The ring-shaped permanent magnets arranged above constitute the exciting part. 9 is an outer peripheral cover fixed to the bottom surface of the plate 6 and made of a non-magnetic material for wrapping the outer periphery of the permanent magnet 8.
Is a diaphragm made of a ferromagnetic material such as soft iron, and the spacer 11
It is fixed to the suspension 12 and the vibrating component 13 with screws 14 via. The outer peripheral portion of the suspension 12 is fixed to the upper surface of the outer peripheral cover 9 by a screw 16 via a spacer 15, and the vibrating plate 12 is arranged with a predetermined gap between it and the exciting portion.

The upper surface of the vibrating component 13 of the driving driver composed of the above components is the front panel 3 of the television set shown in FIG.
It is firmly fixed to the surface with an adhesive or the like.

The operation of the television speaker configured by using the conventional driving driver 4 configured as described above will be described below.

The loudspeaker of the above-mentioned type is one in which an electromagnetic driver is attached to the front panel 3 of the television set, and the driving force vibrates the front panel 3 to reproduce sound.
That is, the magnetic force acting on the diaphragm 10 held by the suspension 12 changes corresponding to the signal current flowing through the exciting coil 7, and a driving force is generated on the diaphragm 10 by this magnetic force. The driving force generated in the diaphragm 10 is transmitted to the vibrating component 13 via the spacer 11 provided on the upper part thereof, and vibrates the front panel 3.

Since the front panel 3 covers the front surface of the cathode ray tube 2, it has a large vibration area and can efficiently convert the driving force of the electromagnetic driver into an acoustic output.

However, in the conventional television set, the cathode ray tube 2 and the cabinet 1 are designed to be closely attached to each other at their contact surfaces, so that the vacant space formed by the front panel 3, the cabinet 1 and the cathode ray tube 2 is almost sealed. It was a thing. As described above, in the speaker of this system, the driving driver 4 vibrates the front panel 3 to reproduce sound, so that the bass range characteristic is greatly affected by the volume of the empty chamber. That is, the empty space acts as an air spring for the front panel 3 that operates as a diaphragm. Therefore, if the volume is small, bass reproduction becomes difficult. To describe this state in detail, the lowest resonance frequency of the speaker that determines the bass reproduction limit.
_o is represented by the following equation (1).

In equation (1), M ... Speaker vibration system mass C ... Speaker support system compliance Further, the support system compliance can be expressed as the sum of the vibration system compliance C _S and the air compliance C _B exhibited by the vacant chamber. Further, the air compliance C _B is expressed by the following equation (2).

In the equation (2), W _{B is} the volume of the vacant chamber ρ _{o is} the density of the air C is the speed of sound of the air S is the area of the diaphragm. Compared with a general speaker system, in this type of speaker, since the front panel 3 that covers the front surface of the set is a diaphragm, the diaphragm area S is too large compared to the vacant volume W _B on the rear surface, and the air compliance is large. C _B became very small, and C _B << C _S, and eventually _o was determined by the vibration system mass M and small air compliance C _B , and the bass was insufficient for the speaker.

An object of the present invention is to solve the above-mentioned drawbacks, and an object of the present invention is to provide a television speaker that realizes a compact television set with an expanded bass reproduction limit.

Structure of the Invention The present invention is provided in a part of a vacant room constituted by a front panel made of glass or transparent acrylic or the like arranged in front of a cathode ray tube and a cabinet of a cabinet to which the front panel and the bellows tube are attached. A front panel drive type television speaker provided with the above-mentioned empty room and holes such as holes or slits for venting the empty room on the back side of the cathode ray tube, and a low range by a hole or slit provided in a part of the empty room. This excludes the increase in air pressure in the front panel rear vacant room.

Description of Embodiments FIG. 3 is a partial cross-sectional view of a television set using a television speaker according to the first embodiment of the present invention. In FIG. 3, 17 is a cushion material for supporting the outer periphery of the front panel 3, 4 is a driver for driving fixed to the front panel 3, and 18 is a stopper provided at each corner of the cathode ray tube 2.
The stopper 18 firmly holds the cathode ray tube 2 in the cabinet 1 with bolts 20 through a cylindrical spacer 19 provided between the cabinets 1.

The operation of the television speaker of this embodiment having the above configuration will be described below.

First, the driving force is transmitted to the front panel 3 according to the electric signal applied to the driving driver 4. Due to the vibration of the front panel 3, the air pressure in the vacant chamber formed by the front panel 3, the cathode ray tube 2 and the cabinet 1 rises in the low sound range. However, since the four corners of the cathode ray tube 2 are held in the cabinet 1 via the spacers 19, the upper, lower, left and right sides of the cathode ray tube 2 form slits with the cabinet 1. Therefore, even if the sound pressure rises, the air flows through the slit to the rear surface of the cathode ray tube 2 as shown by the arrow I.

As described above, according to the present embodiment, since the slits formed on the four sides of the cathode ray tube 2 can eliminate the increase in the air pressure in the rear empty space of the front panel 3, the lowest resonance frequency _o that determines the bass limit. It is possible to eliminate the decrease in air compliance C _B , which was the cause of the increase in

Next, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 4 shows a front view of a television set showing a second embodiment of the present invention.

4, the same members as those in FIGS. 1 and 3 are designated by the same reference numerals, and the description thereof will be omitted. The configuration of FIG. 4 differs from that of FIG. 3 in that a plurality of slits 21 penetrating the back surface of the front panel 3 are provided around the front surface of the cabinet.

In the present embodiment configured as described above, the front panel 3
The increase in the air pressure in the rear vacant chamber is eliminated by passing air through the slit 21 to the rear surface of the cathode ray tube 2, and the drop of the cathode ray tube 2 from the front surface of the cabinet 1 due to the spacer 19 caused in the first embodiment is eliminated. It can be lost.

The driving driver 4 may be an electromagnetic type, an electrodynamic type, or a piezoelectric type.

EFFECTS OF THE INVENTION The present invention expands the bass reproduction limit by providing a slit between the cathode ray tube and the cabinet, or by providing a plurality of slits around the front surface of the cabinet to eliminate an increase in air pressure in the front panel rear room. A compact television set having the intended front panel speaker can be realized, and its effect is great.

[Brief description of drawings]

FIG. 1 is a perspective view of a television set having a conventional front panel driving type speaker, and FIG. 2 (a) is a partially cutaway top view of a driving driver for driving the front panel.
FIG. 3B is a sectional view of the same structure, FIG. 3 is a partial sectional view of a television set using the television speaker according to the first embodiment of the present invention, and FIG. 4 is a television speaker according to the second embodiment. It is a perspective view of a television set using. 1 ... Cabinet, 2 ... CRT, 3 ... Front panel, 4 ... Driving driver, 19 ... Spacer, 21
……slit.

Claims (4)

[Claims] 1. A vacant space provided in a part of a vacant chamber formed by a front panel made of glass or transparent acrylic or the like arranged in front of a cathode ray tube and a cabinet of a television set to which the front panel and the cathode ray tube are attached. A television speaker comprising a room and an opening such as a hole or a slit for ventilating the empty room on the back side of the cathode ray tube, and driving the front panel with a driving driver. 2. A television speaker according to claim 1, wherein a plurality of spacers are inserted between the cabinet and the cathode ray tube of the television set and attached to form a slit between the spacers. 3. The television speaker according to claim 1, wherein a plurality of holes or slits are provided in the cabinet of the television set on the rear surface of the front panel. 4. The television speaker according to claim 1, wherein the driving driver is an electromagnetic type, an electrodynamic type, or a piezoelectric type.