JPH03228481A - Back plane projection type television - Google Patents

Abstract

PURPOSE:To improve the verisimilitude of voice by mounting the speaker of a back plane projection type television by inclining a directional axis by a specific angle at the upper side over the level. CONSTITUTION:The speaker 8 of the back plane projection type television is mounted by inclining the directional axis at the upper side by 5-30 deg. over the level and additionally directing inside by 5-30 deg.. It is considered that viewing is performed mainly at almost the front plane of a screen 2 when the back plane projection type television is used actually, however, it results that the directional axis of the speaker is directed to the direction of a viewing point by mounting the directional axis facing upward by 5-30 deg. and also, directing inside by 5-30 deg., which increases the component of a direct tone in reproducing sound, and reduces the lowering of a high-pass level due to speaker directivity, and reduces fogging phenomenon due to the separation of the directional axis from a floor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a rear projection television that improves the quality of reproduced sound.

[Conventional technology]

Conventional rear projection televisions, as described in Japanese Utility Model Application Publication No. 62-38385, had speakers mounted on vertical baffles at both left and right corners of the lower part of the housing, each with an angle of 1° and 2°. . That is, the directional axes of the speakers were aligned in the horizontal direction, ignoring practical conditions.

[Invention tries to solve! I topic]

The above-mentioned conventional technology is not sufficiently arranged in terms of playback sound quality, and is particularly unsatisfactory in terms of the realism of sounds such as announcements and dialogues.

This is because the speaker is mounted close to the floor and the directional axis points horizontally.Firstly, the speaker finger coax does not face the listening point when using the speaker, so the amount of direct sound that accounts for the amount of hearing is reduced. There are relatively few components, and secondly, a large amount of reproduced sound reflects from the floor, resulting in fogging in the mid-low range, that is, an unnecessary increase in the mid-bass level. This adversely affected the reproduced sound quality, particularly the clarity and realism of the voice.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rear projection television that improves the reproduction sound quality, particularly the clarity and realism of the sound.

[Means to solve the problem]

In order to achieve the above object, in the present invention, the speakers of the rear projection television are mounted with the vertical axis facing 5° to 10° above the horizontal.

Also, it was installed so that the surface was facing 5° to 300° internally.

[Effect]

In actual use, a rear projection television is considered to be viewed mainly in front of the screen, but in the prior art, the speakers were oriented in the horizontal direction, so the speakers were not directed toward the viewing point. In the present invention, the speaker is mounted with its directional axis opening 5° to 5° above the horizontal, and the speaker is mounted with its directional axis facing 5° to the circular side, so that the speaker directional axis aligns with the viewing point. I started to

On the other hand, a speaker generally radiates the sound energy R in the direction of its direction, and its angle in the direction away from the directional axis.
The f-sha energy decreases according to the Ma wave number. This is particularly noticeable in high-pitched sounds.

In addition, the redirected sound not only reaches the fitted listening point, but also reflects from various parts of the room and reaches it. If there is a considerable amount of folded sound and there is too much darkness compared to the direct sound, It is known that the realism of the voice decreases.

Furthermore, among the reflected sounds, the reflected sound on the floor has a particularly large effect on the reproduced sound. In other words, since the mid-bass range is more omnidirectional than the treble range, it is reflected more from the floor, and this causes what is called a fogging phenomenon, which unnecessarily increases the level of the mid-bass sounds and reduces the clarity of the reproduced sound. Ta.

That is, according to the present invention, since the speaker directivity axis points toward the viewing point, the direct sound component in the reproduced sound increases, reducing the drop in high frequency level due to speaker directivity, and since the directivity axis moves away from the floor, fogging is reduced. The phenomenon is also reduced. As a result, the nasal sound quality is generally as good as above, and the effect is excellent in terms of sound quality such as announcements.

〔Example〕

A complete example of the present invention will be shown below.

Figure m1 is an exploded perspective view of a rear projection television as an embodiment of the present invention. In a military zone, a rear projection television set according to the present invention has a cabinet 1 located in the center, and speakers 8 on both sides of the lower side of the cabinet 1 with a height of approximately 15J.
It is installed at an elevation angle of A cover 6 is arranged and configured. Further, inside the cabinet 1, a lens/projection tube block 4 having a built-in circuit board 5 in its lower part is arranged.

Figure $2 is a vertical sectional view schematically showing the positional relationship between the screen, speakers, and viewers of the rear projection television according to the present invention. - The dashed-dotted line indicates the orientation axis of the speaker 8, and the dashed-dotted line B indicates the central axis of the screen 2. The dot-dashed line B intersects with the dot-dashed line B, and the viewer 11 can enjoy good viewing both visually and sonically at the intersection. However, from a three-dimensional perspective, the speaker orientation axis and the screen center axis do not actually intersect, but in this case, the best viewing point is the intersection of the screen center axis and the plane that includes the orientation axes of both the five and right speakers. It is reasonable to think that.

FIG. m3 is a longitudinal sectional view schematically showing the positional relationship between the screen, speakers, and viewers of a rear projection television according to the prior art. The speaker direction axis does not face the viewer 11, and since the direction axis is close to the floor, there is a lot of fogging due to floor reflection, resulting in a sound quality inferior to that of the bright 111.

Figure m4 is an external perspective view of another embodiment of the present invention with the speaker grill removed. In this example, the directivity axes of the speakers are directed upward by about 15 degrees, and at the same time, they are installed facing the interior by about 7 degrees, so the directivity axes of both the left and right speakers and the center axis of the screen intersect at one point. You can expect even better sound quality.

〔Effect of the invention〕

According to the present invention, it is possible to greatly improve the sound quality of a rear projection type speaker, especially the realism of a single voice.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing one embodiment of the present invention, Fig. 2 is an explanatory diagram of the embodiment including a viewer, Fig. 3 is an explanatory diagram of a rear projection television according to the prior art, and Fig. 94 is an explanatory diagram of the present invention. FIG. 3 is a perspective view of another embodiment of the present invention with the speaker grill removed. l...Cabinet 2...Screen 3...
-Reflector block 4...Lens/projection tube block 5...Circuit board 6...Rear cover 79.
Front cover 8...Speaker 9...Control panel

Claims (2)

[Claims] 1. 1. A rear projection television comprising a cabinet, a screen, an image projection device, and a screen, the rear projection television being characterized in that a speaker is mounted with its directivity axis tilted upward by 5° to 30° above the horizontal. 2. 2. The rear projection television set according to claim 1, wherein the speaker finger coax is oriented at an angle of 5° to 30°.