JP2002090887A - Projection screen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a unit constituted of an integrated planar loudspeaker and a projection screen. SOLUTION: A projection screen panel 200 has structure sticking a screen film 210 having small holes to the surface of a supporting panel 220. A mesh panel of honeycomb structure is used for the panel 220. A vibration exciter 250, for receiving a sound signal and generating vibration, is disposed on a prescribed position of the panel 220 and the exciter 250 functions as a loudspeaker by driving a diaphragm 260. The outside of the diaphragm 260 is covered with a panel 240, to be utilized for both of protection and decoration. A mesh panel, having honeycomb structure similar to that of the panel 220, is used for the protective/decorative panel 240 and the panel 240 is formed as a thin panel. Space other than the diaphragm 260 between both the panels 220, 240 is filled with a proper spacer 230.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection screen incorporating a planar speaker.

[0002]

2. Description of the Related Art Conventionally, there has been an apparatus in which a movie projection screen is also used as a diaphragm of a speaker in order to obtain an effect of producing sound from a projected image. When the screen is a diaphragm, it is desirable to split the screen and vibrate acoustically when aiming for a stereo effect or to assign the range to several speakers acoustically. In addition, a method is adopted in which diaphragms that share the respective sound ranges are attached to the back surface of the screen film without dividing the screen film, and each diaphragm is driven by a vibrator.

FIG. 9 is a cross-sectional view of a conventional product having a function as a speaker by vibrating a screen. A conventional screen, generally designated by the reference numeral 10, has a support panel 14 of a frame 12 made of a highly rigid metal or the like, and a vibrator 16 for a low frequency range supported by an iron frame 17 at an appropriate position on the support panel 14. The diaphragm 18 is adhered to the back surface of the screen film 30. Similarly, the vibrator 20 for the middle and high frequency range is supported by the iron frame 21, and the diaphragm 22 is adhered to the back surface of the screen film 30.

[0004] As another method, there has been a device for making a small hole in a cinema projection screen film, transmitting sound through a screen provided from a speaker provided at the rear of the screen and projecting the sound to make the sound appear from the screen. This method is
There is a disadvantage that the entire configuration becomes large.

FIG. 10 shows the principle of this method. Entire projection screen apparatus shown by reference numeral 50, supports the screen film 70 perforated small holes by a frame 62 having a rigid, copy the images P ₁ from projector. On the back of the screen film 60, a speaker set 70
There is arranged, outputs sound S _1. All of these devices are large-scale and are used for business purposes, but their use in ordinary households is limited in part.

[0006]

The problem to be solved by the present invention is to form a thin video projection screen incorporating a speaker having excellent sound quality characteristics and volume characteristics.
That is, it can be installed in general homes, aircraft, vehicles, ships, and the like where the installation location is narrow. When mounted on an airplane, a vehicle, or the like, there is a need to secure the required fire resistance and to isolate and protect the diaphragm from the hands and body of passengers and occupants.

In order to make the projection screen thin, a method of supporting the panel with a panel structure and incorporating a speaker having a flat diaphragm can be considered. However, in order to make the projection screen thin, the supporting structure of the flat diaphragm is changed to a diaphragm. It is necessary to dispose in close proximity to If a large-area planar support structure is arranged near the plane diaphragm, the vibration of the diaphragm will be suppressed by the increase in air pressure generated by the vibration of the diaphragm in the low-frequency range with large amplitude, the vibration of the diaphragm will be suppressed, and the low-frequency characteristics will be degraded. The sound reflection by the planar support structure deteriorates the sound quality. In an experiment in which a normal panel was used as a support structure in order to make the entire screen thin, sound quality was reduced due to these interference phenomena, and a satisfactory result was not obtained.

[0008]

According to the present invention, as a basic means for solving the problem, the entire projection screen is formed as a single panel and a flat speaker is built therein. The problem of sound quality degradation due to the above-described interference phenomenon was solved by imparting sound permeability to the screen panel.

A speaker comprising a flat diaphragm and a vibrator is disposed on the support structure panel, and the sound produced by the speaker is transmitted through the screen, thereby achieving the effect of producing sound from the image. Furthermore, the screen has a sound-transmissive panel structure to compensate for bass, and the entire screen is vibrated by a vibrator to provide the function of a bass speaker. In this case, the mid-high range is shared by a plurality of planar diaphragms installed inside the screen panel. However, since these sounds are transmitted through the screen panel, there is no need to divide the screen.

[0010] The laminated panel having the planar support structure is formed by bonding glass fibers woven in a mesh shape (wire mesh shape) to a honeycomb core having a large aperture ratio. Specifically, the material on the front and back of the panel is a yarn bundle (3,000 strands) made of glass fiber.
Using a cloth woven in a mesh shape with a pitch of 3 mm, sound transmission is ensured. The glass fiber is made of a material impregnated with epoxy resin for bonding. The core material is a honeycomb core made of aramid paper with a cell size of 3.2 mm. The impregnated adhesive resin is heated and pressed to adhere.

The glass fiber yarn bundle exhibits a high compressive strength when the adhesive resin is cured by heating, so that the panel has a high flexural rigidity value and a satisfactory result as a structural panel. The standard thickness of the support structure panel in the present invention is 12 mm.

If carbon fibers are used instead of glass fibers, higher strength or lighter weight can be achieved. In addition, a roll-shaped or corrugated core can be used as the core material instead of the honeycomb core. In order to ensure sound quality and volume, a flat type speaker is required to have a lightweight, high bending rigidity and a high torsional rigidity in order to vibrate integrally without dividing and vibrating the diaphragm.

According to the present invention, as a diaphragm for the mid-high range, a laminated panel structure made of a non-combustible resin polyimid film and an aramid paper honeycomb core realizes weight reduction while maintaining rigidity required for the diaphragm. As a result, the acoustic characteristics were secured, and the fire resistance required for aircraft was satisfied.

In the case where the screen panel is vibrated so as to also serve as a low-frequency range diaphragm, higher bending rigidity and torsional rigidity are required, so that 1,000 (1)
K) triaxial weave of carbon fiber (fiber direction is 0 °, 60 °,
As a result of trial production of a panel laminated with a honeycomb core using a 120 °), it was possible to obtain a light-weight screen panel having high bending and torsional rigidity and excellent characteristics as a low-range speaker.

[0015] The screen film was provided with an infinite number of small holes in order to impart sound transmission, thereby ensuring an aperture ratio. By changing the hole diameter and the number of small holes, an aperture ratio of up to about 22% can be practically secured, but experiments have confirmed that the aperture ratio of small holes required to obtain the acoustic effect is about 8%. It was also confirmed that if the image quality was about 8%, a satisfactory image could be enjoyed.
I kept it. The triaxial woven fabric can secure an aperture ratio of 8% or more by adjusting the basis weight, and thus can be used as a support structure panel having sound transparency.

[0016]

FIG. 1 is a perspective view showing the overall structure of a projection screen panel device according to the present invention, and FIG. 2 is a sectional view. The projection screen panel device generally denoted by reference numeral 100 has a frame 110 rotatably supported by pins 130 by an arm 120, and a projection screen panel 200 is mounted in the frame 110.

The projection screen panel 200 is a screen film 21 having a small hole on the surface of the support panel 220.
0 is attached. This support panel 220
Is a mesh panel having a honeycomb structure. At a predetermined position of the support panel 220, a vibrator 250 that receives the audio signal and generates vibration is disposed. The vibrator 250 functions as a speaker by driving the diaphragm 260.

The outside of the diaphragm 260 is covered with a panel 240 which serves both protection and makeup. This protective and decorative panel 2
Reference numeral 40 denotes a mesh panel having the same honeycomb structure as that of the support panel 220, and is formed to be thin. A portion other than the diaphragm 260 between the support panel 220 and the protection / decorative panel 240 is filled with an appropriate spacer 230.

FIG. 3 is a plan view showing the structure of the support panel 220, and FIG. 4 is a sectional view. The support panel 220 has a structure in which a honeycomb core member 224 is used as a core member, and a front surface member 222 and a rear surface member 226 are bonded to both surfaces thereof with an adhesive 227. As the honeycomb core material 224, for example, a honeycomb core formed from an aramid fiber material is used.

The front member 222 and the back member 226 are made of a glass fiber mesh material. More specifically, a cloth in which a yarn bundle (3,000 yarns) made of glass fiber is woven as a mesh having a pitch of 3 mm is impregnated with an epoxy resin as an adhesive resin. This adhesive resin functions as an adhesive 227 between the mesh members 222 and 226 and the honeycomb core 224. This bonding is performed on both side members 222, 2
26 and the honeycomb core material 224 are bonded by heating and pressing. As a more specific structure of the core member, a honeycomb core made of aramid paper with a cell size of 3.2 mm is used, and both surface materials and the core material are bonded by heating and pressing an adhesive resin impregnated in fibers. are doing.

Since the glass fiber yarn bundle shows a high compressive strength when the adhesive resin is cured by heating, it shows a high bending rigidity value as a panel and a satisfactory result as a structural panel. The standard thickness of the support structure panel in the present invention is 12 mm. If carbon fibers are used instead of glass fibers, higher strength or lighter weight can be achieved. In addition, a roll-shaped or corrugated core can be used as the core material instead of the honeycomb core.

FIG. 5 is a plan view showing the structure of the diaphragm 260, and FIG. 6 is a sectional view. The diaphragm 260 has a honeycomb core member 264 as a core member, and surface members 262 on both surfaces thereof.
And a back member 266 with an adhesive 267. As the honeycomb core material 264, for example, a material obtained by forming an aramid fiber material on a honeycomb core is used.

In order to ensure sound quality and volume, a flat speaker is required to have a light weight and high bending rigidity and torsional rigidity in order to vibrate the diaphragm integrally without dividing and vibrating. According to the present invention, a laminated panel structure made of a non-combustible resin polyimid film and an aramid paper honeycomb core is used as the diaphragm for the mid-high range, thereby realizing a light weight while maintaining the rigidity required for the diaphragm. The characteristics were secured and the fire resistance required for aircraft was satisfied.

When higher bending rigidity and torsional rigidity are required, a carbon fiber woven fabric can be used for the surface member instead of the polyimide film. Since the surface member 262 and the back surface member 266 are desirably made of an isotropic material, a woven fabric obtained by weaving carbon fibers in three axes is used in the present embodiment. The triaxial woven fabric has an isotropic orientation in the fiber direction of 0 °, 60 °, and 120 °, unlike the 0 ° and 90 ° woven fabrics conventionally used as a laminated material for diaphragms. Therefore, it is possible to obtain excellent torsional rigidity by applying to the front and back layers of the laminated structure having a thickness.

In the present embodiment, since the diaphragm is separated from the hands and the body of the passenger and the occupant by the supporting structure panel of the screen, it is suitable for mounting in a narrow space such as an aircraft or a vehicle.

FIG. 7 is a sectional view showing the structure of a projection screen panel according to another embodiment of the present invention. The projection screen panel 200a is provided with the vibration plate 260 of the vibrator 250 attached to the support panel 220 facing the screen film 210 side. Screen film 2
10 is attached to the mesh panel 240 and equipped. Spacers 230 are filled between the support panel 220 and the mesh panel 240, and decorative paper 280 is adhered to the surface of the support panel 220.

With this configuration, when the projection screen panel is not used, the frame 110 is inverted with respect to the arm 120 using the pins 130, and the decorative paper 280 is formed.
The side can be surfaced. Mesh panel 22
Since 0 and 240 and the screen film 210 have sound transmissivity, projected images and sound can be reproduced well.

FIG. 8 is a sectional view showing another embodiment of the present invention. The projection screen panel, generally designated by the reference numeral 200 b, has a mid-high range vibrator 250 attached to the support panel 220, and drives the middle-high range diaphragm 260.
Vibrator 300 for low range mounted on support panel 220
Is connected to the mesh panel 240a via the connection portion 310. The mesh panel 240a serves both as a low-tone range diaphragm and a screen panel, and a screen film 210 having small holes is attached to the surface of the mesh panel 240a.

Since the diaphragm for the low frequency range has a large area and requires high bending rigidity and high torsional rigidity, the diaphragm of the honeycomb panel 220a using a fabric in which carbon fibers are triaxially woven as a surface material is effective. Demonstrate.

[0030]

According to the present invention, a 50 or 60 inch size image projection screen having a plurality of built-in planar diaphragm speakers can be made to a thickness of about 3 cm and the weight can be reduced. The flexibility of selection is high, and it can be used in ordinary households. In particular, in the case of the structure of the first embodiment, as a product to be installed in an aircraft, a vehicle, or a ship that touches hands or bodies of passengers and occupants, the support structure panel separates the speaker diaphragm from the passengers and occupants. Therefore, the screen can be mounted at a short distance from the passenger, and the fire resistance required for aircraft can be secured.

For products for general home use or business use, by employing the structure of the third embodiment, it is possible to provide a screen panel in which the entire surface of the screen is used as a low-frequency range diaphragm to improve low-frequency characteristics.

[Brief description of the drawings]

FIG. 1 is a perspective view of a projection screen of the present invention.

FIG. 2 is a sectional view of a screen.

FIG. 3 is a plan view of a laminated panel according to the present invention.

FIG. 4 is a sectional view of FIG. 3;

FIG. 5 is a configuration diagram of a diaphragm of a honeycomb panel using a triaxial woven fabric according to the present invention.

FIG. 6 is a sectional view of FIG. 5;

FIG. 7 is a sectional view of a projection screen having a configuration in which a flat speaker is protected by a screen panel.

FIG. 8 is a cross-sectional view of a mode in which a screen panel is vibrated to have a function of a bass speaker.

FIG. 9 is a diagram showing the back surface of a conventional flat speaker.

FIG. 10 is an explanatory diagram of a conventional projection screen.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 projection screen panel device 110 frame 120 arm 200 projection screen panel 210 screen film 220 support panel 250 vibrator 260 diaphragm

Claims (3)

[Claims] 1. A speaker comprising a vibrator and a plane diaphragm is disposed on the back surface of a support structure panel having sound transparency.
A projection screen that covers the surface with a sound-transmissive screen, transmits sound through the support structure panel and the screen, and emits sound to the front. 2. A speaker comprising a vibrator and a plane diaphragm is disposed on a front surface of a support structure panel having sound transparency.
Projection screens that cover the screen with a sound-transmissive panel, transmit sound, and emit sound to the front. 3. A screen panel in which a plurality of mid-high range speakers comprising a vibrator and a plane diaphragm are disposed in front of a support structure panel having sound transparency, and functioning as a bass diaphragm having sound transparency. Projection screen that covers the screen, transmits high-frequency sound to the front through the screen, and emits low-frequency sound from the entire screen.