JPH05191758A - Speaker equipment in transmission type video projection - Google Patents

Abstract

PURPOSE:To loudspeak a low sound, to reduce the lateral width of a main body case and to decrease the manufacture cost in the speaker equipment in the transmission video projector 1. CONSTITUTION:An acoustic resonance cabinet 9 is provided so as not to interrupt an optical path at the lower part than a screen 5 in the transmission video projector 1. A speaker unit is fitted to an upper face of the cabinet and a sound guide 7 is fitted in front of a speaker unit 6 and a sound guide opening 8 is provided to the left and right of the screen 5. The sound guide 7 is formed to be a shape not interrupting an optical path 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker device for sound reproduction of a transmissive video projector or television set having a large screen.

[0002]

2. Description of the Related Art In recent years, the number of transmissive video projectors or television sets having a large screen has increased. Of these, it is desirable to arrange speakers on the left and right sides of the screen such as a screen or a cathode ray tube in order to perform stereo sound reproduction, but since the width of the transmissive video projector or the television set itself becomes large, it is generally A speaker is often placed below the screen.

For example, as shown in FIG. 6, in a transmissive video projector 51 (other name: rear projection type projection television), a screen 55 as in the conventional example described in Japanese Utility Model Publication No. 63-22772. A speaker 56 is disposed below the.

However, when the speaker 56 is arranged below the screen 55 and near the floor surface 58 of the room in which it is installed, the ear height of the viewer becomes higher than the axis of the speaker 56. , A sound with less high frequency components that generate directivity will be heard.

Further, since the speaker 55 is arranged near the floor surface 57, the direct sound 58 radiated from the speaker 56 interferes with the reflected sound 59 having a lot of low frequency components reflected from the floor surface to produce a sound. There was a drawback that the pressure frequency characteristics were disturbed and the sound became muffled. As a method of compensating for this drawback, the configuration shown in FIG. 7 is adopted. At this time, the speaker is the speaker system 61, 62 having the structure shown in FIG.
Is built in.

At this time, the speaker system 61 is based on the speaker system having the configuration shown in FIG.

However, in this system, the back cabinet 6 of the speaker system 61 is used to reproduce lower frequencies.
When the volume of 5 is increased, a part of the optical path 60 formed by the projection tube 52, the lens group 53 and the reflecting mirror 54 for projecting on the screen 55 may be blocked. Therefore, the back cabinet 65 is omitted and only the sound path 64 is displayed on the screen 5.
It is provided on the left and right of 5.

Therefore, in order to reproduce lower tones, it is necessary to incorporate a super woofer 62 into the transmissive video projector main body 51 as shown in FIG. As a result, there is a drawback that the manufacturing cost becomes high.

Further, since the super woofer 62 is incorporated in the lower right part of the transmissive video projector main body 51, there may be a case where the reproduced sound has a low-frequency directivity.

The reason for this is that the super woofer 62 generally mixes the left and right channel signals in a mixing circuit,
Although it is driven by a power amplifier through a low-pass filter, most of the cabinet methods of the super woofer 62
Kelton type as shown in FIG. 9 (US Patent 2,689,
This is because the configuration is 016 '54). Therefore, even if the volume of the cabinet 66 is large, the volume of the cabinet 66 is the baffle 6 for mounting the speaker 67.
Since it is divided into two cabinets 66a and 66b by 8, the volume is reduced, and as a result, the reproduction frequency band may be as high as 50 to 200 Hz.

The frequency band in which it is hard to feel the directionality of sound waves is
Since it is in the band of 50 Hz or less, the configuration shown in FIG. 7 has a drawback that the bass emitted from the port 69 causes an unnatural sound that can be heard only from the lower right.

On the other hand, the low-pitched sound 70 radiated from the super woofer 62 and the mid-and high-pitched sound 71 radiated from the sound path 64 of the middle and high-pitched loudspeaker 61 are separate speaker units 63.
Since it is driven by and 67, if the phase is not adjusted correctly at the crossover of the bass 70 and the mid-treble 71,
There is also a case where the sound pressure frequency characteristic is disturbed.

[0013]

As described above, the prior art is based on the back cabinet 65 of the speaker system 61.
When the volume of the back cabinet 65 is increased, the problem of blocking a part of the optical path 60 by the projection tube 52, the lens group 53 and the reflecting mirror 54 for projecting on the screen 55, and the volume of the back cabinet 65 is reduced to avoid this drawback. If you do
The problem of having to provide the super woofer 62 is not considered because the bass is difficult to reproduce.

An object of the present invention is to provide a method of constructing the back cabinet 65 so as not to block the optical path 60 and further expanding the bass.

[0015]

In order to achieve the above object, the back cabinet 65 and the super woofer 62 are integrated. That is, the back cabinet 65 of the speaker system 61 and the acoustic resonance cabinet 66a of the super woofer 61 are shared and integrated, and each speaker unit 63, 67 is configured so that one speaker unit also serves as it.

A sound path is provided on the front surface of the speaker unit, and the sound path openings, which are sound wave emission holes, are guided to the left and right of the screen 55, respectively. An acoustic resonance cabinet is constructed on the rear surface of the speaker unit.

The acoustic resonance cabinet 66a as the super woofer 62 uses a part of the main body housing of the transmissive video projector 51. Further, the acoustic resonance cabinet 66a is provided below the screen 55 so as not to block the optical path 60.

[0018]

The sound wave radiated in front of the speaker unit 6 is guided by the sound path 7 configured so as not to block the optical path 11, and the vertically long openings 8 located on the left and right sides of the screen 5.
Emits mid-to-high range components. The acoustic wave radiated to the rear part of the speaker unit 6 causes acoustic resonance by the acoustic resonance cabinet 9 and radiates a bass component from the port 10.
Since the acoustic resonance cabinet 10 is provided below the screen 5, the optical path 11 is not blocked even if the volume thereof is increased. Furthermore, since the volume of the acoustic resonance cabinet 9 can be increased and the resonance frequency thereof can be lowered, the bass can be reproduced in a lower range.

[0019]

EXAMPLES Example 1 Hereinafter, Example 1 of the present invention will be described with reference to FIGS. 1 (A) (B) (C). 1A, 1B, and 1C are a front view, a top view, and a cross-sectional view showing the features of the present invention of a transmissive video projector 1.

In FIGS. 1A, 1B and 1C, 1 is a transmissive video projector, 2 is a projection tube, 3 is a lens group, 4 is a reflecting mirror, 5 is a screen, 6 is a speaker unit, and 7 is a speaker unit. Is a horn-shaped sound path that guides the sound waves emitted from the speaker unit 6 to the opening portion 8, 8 is the opening portion of the sound passage 7, 9 is an acoustic resonance cabinet, 10 is a port that emits bass by acoustic resonance, and 13 is sound. The throat of the road.

The sound wave radiated to the front of the speaker unit 6 is guided by the sound path 7 and radiated in the middle and high tones through the opening 8. That is, only the sound path 7 is formed in the rear part of the screen 5. Then, the sound path 7 is formed so as to further narrow down from the throat portion 13 in contact with the speaker unit 6 to the opening portion 8 and further in a horn shape so as not to block the optical path 11.

The sound wave radiated to the rear part of the speaker unit 6 causes acoustic resonance by the acoustic resonance cabinet 9 and radiates a low tone from the port 10.

As a result, the width of the transmissive video projector 1 can be reduced by forming the opening 8 into a vertically elongated opening.

Further, since the acoustic resonance cabinet 9 can have a large volume without obstructing the optical path 11 provided below the screen 5, the resonance frequency can be set low, and the bass can be reproduced even more.

Unlike the conventional example, there is no need to divide the cabinet volume into two for reproducing low tones, and if the volume is the same, the reproduction band can be expanded to 1 / √2 as compared with the conventional configuration.

Further, if the port 10 is arranged near the floor surface 12, the reflection from the floor surface can be used, so that the effect of apparently increasing the radiation efficiency can be obtained.

As a result, since the opening 8 for radiating mid-high frequencies is farther from the floor surface 12, it is less susceptible to the reflected sound from the floor surface 12 and a highly distinct voice can be obtained.

Furthermore, since the mid-high range component radiated from the opening 8 of the sound path 7 and the low-pitched sound component radiated from the port are radiated from the same speaker unit 6, the crossover characteristics of the low tone and the mid-high tone are smooth. There is also an advantage.

On the other hand, the acoustic resonance cabinet 9 is constructed by utilizing the main body housing of the transmissive video projector 1 to have an integrated structure, and the speaker unit 6 is attached to the baffle 14 which is a part of the main body housing, and the front side thereof is separated. If the sound path 7 composed of a piece is attached, the manufacturing cost can be significantly reduced.

The acoustic resonance cabinet 9 of the present embodiment shown in FIG. 1 adopts a bass reflex type system, but other types such as a double bass reflex type, a drone cone type and an acoustic tube type may be used.

Embodiment 2 In Embodiment 1, since the sound path 7 has a horn shape,
As shown in the front view and side view of FIGS. 2 (A) and 2 (B), the structure is such that two pieces 15a and 15b of molded plastic are combined (however, FIG. 2 shows the right speaker). Also, the sound path 7 can be configured by one piece,
In consideration of the complexity of the molding die and the die-cutting direction of the molded product, it is difficult to form the sound path 7 in a complicated shape.

In the present invention, the sound path 7 as shown in FIG.
Part 1 of the side wall of the main body housing of the transmissive video projector 1
6 is used and the component 15b is omitted.

That is, in order to form the sound path 7, the component 1
5a is attached to a part 16 of the side wall of the main body housing of the transmissive video projector 1.

As a result, the manufacturing cost can be reduced by omitting the component 15b. As a secondary effect, by omitting the component 15b, the width of the main body of the transmissive video projector 1 can be reduced by the thickness t of the component 15b.

Furthermore, the shape of the sound path can be made complicated by devising the molding of the component 15a.

If a packing 17 is sandwiched between the component 15a of the sound path 7 and the side wall 16, the vibration transmitted to the main body housing of the transmissive video projector 1 caused by driving the speaker unit 6 is blocked and sealed. The degree also improves.

Third Embodiment In the first and second embodiments, the speaker 6 is mounted facing upward. Therefore, the width of the sound path 7 is narrowed from the throat 13 of the sound path to the opening 8, but the throat 13 may block the optical path 11 depending on the shape.

In this embodiment, as shown in FIG. 4, the speaker unit 6 is mounted on the rear surface of the acoustic resonance cabinet 9 and the bent sound path 7 is mounted on the front surface thereof.

As a result, the throat portion 13 of the sound path 7 is located below the screen 5, so that the optical path 11 is not blocked even if the speaker unit 6 having a large diameter is used.

As a result, it becomes possible to reproduce lower tones.

Fourth Embodiment In the first and second embodiments, the speaker unit 6 is attached to the baffle 13 of the acoustic resonance cabinet 9 provided in the main body housing of the transmission type video projector 1.

In this embodiment, as shown in FIG. 5, the speaker unit 6 is attached to the baffle 18 which is a separate piece, and is further inserted into the groove 19 integrally formed in the sound path 7 in advance.
After that, the transmissive video projector 1 is attached to a part 16 of the side wall of the main body housing.

As a result, in Example 1 and Example 2, the emission surface of the speaker unit 6 is at a right angle to the opening 8. However, since the angle can be set freely, the sound wave emitted from the opening 8 is The sound pressure frequency characteristic of can be adjusted.

[0044]

Since the present invention is configured as described above, the following effects can be obtained.

In the rear part of the screen 5, only the sound path 7 having a shape and size that does not block the optical path 11 is arranged, and an acoustic resonance cabinet 9 for producing an acoustic resonance requiring a large volume is located below the screen 5. Since the structure is installed, the optical path 1
Does not block 1.

As a result, the volume of the acoustic resonance cabinet 9 can be increased, so that the frequency at which acoustic resonance is generated can be set low and the bass can be expanded.

Further, the opening 8 for radiating the middle and high frequency components
Are provided on the left and right sides of the screen 5, the sound image localization is improved, and since the sound image is located away from the floor surface, the sound waves are not disturbed due to the reflection from the floor surface, and a highly distinct sound can be obtained.

As a secondary effect, by utilizing a part of the side wall 16 of the main body housing of the transmissive video projector 1 as a part of the sound path 7, the width of the main body of the transmissive video projector 1 can be reduced. It is possible to reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a front view, a top view, and a cross-sectional view showing the features of an embodiment of the present invention.

2A and 2B are a front view and a side view showing characteristics of parts used in an embodiment of the present invention.

FIG. 3 is a front view showing the features of another embodiment of the present invention.

FIG. 4 is a sectional view showing the characteristics of another embodiment of the present invention.

FIG. 5 is a sectional view showing the features of another embodiment of the present invention.

FIG. 6 is a structural cross-sectional view of a conventional example.

FIG. 7 is a perspective sectional view showing the structure of another conventional example.

FIG. 8 is a cross-sectional view showing a structure of a speaker system used in another conventional example.

FIG. 9 is a structural cross-sectional view showing the features of a superwoofer exclusively for bass used in the conventional example shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transmission type video projector, 2 ... Projection tube, 3 ... Lens group, 4 ... Reflecting mirror, 5 ... Screen, 6 ... Speaker unit, 7 ... Sound path, 8 ... Sound path opening, 9 ... Acoustic resonance cabinet, Reference numeral 10 ... Port, 11 ... Optical path, 13 ... Sound path throat, 15a and 15b ... Parts constituting sound path 7, 16 ... Part of side wall of transmissive video projector main body housing, 18 ... Baffle, 19 ... Sound Groove provided on road 7.

Claims (4)

[Claims] 1. A transmission type video projector, wherein a cabinet for acoustic resonance is provided below a screen, a speaker unit is attached to an upper surface or a rear surface of the cabinet, and a sound path is attached to a front surface of the speaker unit. 2. A speaker device in a transmissive video projector, characterized in that the openings are provided on the left and right of the screen. 2. The speaker device in a transmissive video projector according to claim 1, wherein the cabinet system for acoustic resonance is a bass reflex type, a double bass reflex type, a drone cone type, an acoustic tube type or the like. .. 3. The speaker device in a transmissive video projector according to claim 1, wherein a side wall of a main body housing of the transmissive video projector is used as a part of a sound path. 4. A speaker device in a transmissive video projector according to claim 1, wherein a cabinet for acoustic resonance is constituted by a side wall, a bottom plate, a partition plate, etc. of a main body casing of the transmissive video projector.