JPH01258587A - Acoustic reproducing device for video projection system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to measures for improving the sound field sensation and sound image localization in a video and audio reproduction device for a video projection system using a large screen.

[Prior Art] Figure 3 (aOb) shows a conventional video and audio reproduction device for general movie theaters. In these figures, (1) shows the interior of the movie theater including the audience seats, and (2) is the front screen, (3) is the right channel speaker installed on the back of this screen, (4) is also the left channel speaker, (5) is the center channel speaker installed between these, and (6) is the projection room. be.

Figure 4 shows 11 representative examples of video projection systems that have been put into practical use in recent years, (la)
(2a) is the video projection screen, (3a) is the right channel speaker, and (4a) is the left channel speaker, which are installed on both sides of the screen (2a). There is.

(7) is a projector main body arranged logarithmically in the center of the screen (2a). By the way, in movie theaters, the 2-channel audio signal prepared for movie films is decoded by the Dolby Surround System, and the center channel signal is extracted and supplied to the center channel speaker. 2a), the left and right channel speakers (4aH3a) and center channel speaker (5a) can be installed behind the screen (2a), so the audience can hear the screen as if it were on the screen. You can feel as if the sound is coming out, and you can enjoy video and audio playback without feeling any discomfort in the sound field or sound image compared to a single screen.

However, in recent years, 100 to 200
In inch-sized video projection systems, the amount of projected light is very small compared to movies, so a video projector screen with good reflectance is used, but this screen has low sound transmission.
Therefore, each speaker system is placed behind the screen, just like in a movie theater! [As shown in Figure 4, it is impossible to It was often done. [Problem to be Solved by the Invention 3 As mentioned above, in video projection systems, left and right channel speakers are installed on both sides of the screen, so the sound field becomes too large compared to the size of one screen, and the sound is transmitted to the screen. Problems include the sense that the sound is coming from outside the screen, and the sound image localization at the center of the screen is worsened by the wide distance between the left and right channel speakers, resulting in sound playback that seems out of focus. was there.

It is an object of the present invention to solve the above-mentioned problems and to enable a video projection system to provide images with the same sound effects as in a movie theater.

[Means for Solving the Problems] In the case of the present invention, in addition to left and right channel speakers on both outer sides, right side and left side center channel speakers and a center center channel speaker are added at both ends and bottom end of the screen, respectively. It is attached.

[Function] In the case of this invention, the right center channel speaker (5a) and the left center channel speaker (5b)
By adding the left and right channel speakers (4a)
The expansion of the sound field due to (3a) can be suppressed, and the complete image localization at the center of one screen is improved by adding the central center channel speaker (5C), and these effects are exerted synergistically.

[Example] An example of the present invention will be described below. That is, in Fig. 1 (a) and (b), (1a) is the room where the video projection system is installed, (2a) is the screen for video projection, (3a) is the right channel speaker installed on the right outside of this screen, (
4a) is the left channel speaker also installed on the left outer side, (58) is the right center channel speaker additionally attached to the right end of the screen (2a), (5)
b) is the left center channel speaker additionally attached to the left edge of the screen (2a), (5C) is the center center channel speaker additionally attached to the lower center edge of the screen (2a), and (7) is the screen (2a) is a logarithmic projection main body in the center, and (8a) is a cabinet that houses the right channel speaker (3a) and right center channel speaker (5a).

(8b) is a cabinet that houses the left channel speaker (4a) and the left center channel speaker (5b). Next, the operation of this invention will be explained. First, the left and right channel speakers (4a
) When the right and left center channel speakers (5a) (5b) are added to (3a), these center channel speakers emit the same sound from both sides of the screen, so the left and right channel speakers (4a) (3a) This has the effect of restricting the sound field from becoming too expansive compared to when playing back when only the sound field is installed. However, these 2
With the center channel configuration of a book, the sound image localization of, for example, a person's voice in the center of the screen is not sufficient, and the sound image is still too large compared to the size of the person on the screen.

Next, by adding only the center center channel speaker (5C) to the left and right channel speakers (4a) and (3a), the sound image localization at the center of the screen is greatly improved.

Focused playback is possible, but the sound image localization is because the above-mentioned speakers are located below the screen.

It tends to be localized quite low.

When two center channel speakers (5a) (Sb) are added to the above in this state, the sound image localization, which had been pulled downwards, is moved to approximately the center of the height of the screen. 5b) makes it possible to position it almost within the screen, and furthermore, each center channel speaker (5a) (5
The sound field feeling, which could be limited when using only b), can be more effectively increased because the central center channel speaker (5c) is located in the center of the screen.

In addition, each center channel speaker (5a) (5
b) (5c) can be configured as one channel with three speakers by connecting them as shown in Figure 2. By varying the sound pressure balance of each speaker depending on the size of one screen, etc. It can be adapted to that. In addition, the right and left center channel speakers (5a) (5b) are especially connected to the screen (2).
By setting it so that it can rotate toward the central portion of a), the sense of sound image localization can be improved. Furthermore, by emitting the reproduced sound from the central center channel speaker (5c) towards the center of the screen and once reflecting the emitted sound onto the screen (2a), the sound image localization will not be pulled downwards excessively. , it becomes possible to obtain good sound reproduction. In addition, by storing the right channel speaker and the right center channel speaker and the left channel speaker and the left center channel speaker as a set in the same cabinet in advance, it is possible to always maintain a constant positional relationship when mounting them.

[Effects of the Invention] In addition to the right and left channel speakers provided on both sides of the screen as described above, center channel speakers are additionally provided at both ends of the screen and at the lower center of the screen. The system also has the effect of being able to obtain a good sound field feeling and sound image localization similar to those in a movie theater.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are a plan view and a front view of a room in which the audio reproduction device for a video projection system of the present invention is installed, and FIG. 2 is a connection of three additional center channel speakers of the present invention. Circuit diagram, 3rd (a
) (b) is a plan view and a front view of a movie theater in which a conventional general sound reproduction device is installed, and FIG. 4 is a plan view showing a typical installation example of a conventional general video projection system. In the figure, (2a) is the screen, (3a) is the right channel speaker, (4a) is the left channel speaker, and (5a) is the right center channel speaker. (5b) is the left center channel speaker, (5C
) is the central center channel speaker, (8a) (
8b) is a cabinet.

Claims (4)

[Claims] (1) In a device in which a left channel speaker and a right channel speaker are provided on both sides of the screen, and the projector body is placed opposite to the front of the screen, the right and left channel speakers are placed at both ends of the screen and at the lower center of the screen. A sound reproduction device for a video projection system, characterized in that a center channel speaker and a central center channel speaker are additionally provided. (2) Sound reproduction for a video projection system according to claim 1, wherein right and left center channel speakers additionally attached to both ends of the screen are set so as to be rotatable toward the center of the screen, respectively. Device. (3) The right and left center channel speakers additionally attached to both ends of the screen are housed in the cabinets of the right and left channel speakers provided on both outer sides of the screen, respectively. The sound reproduction device for a video projection system according to any one of Item 2. (4) Claim 1, in which the reproduced sound from a central center channel speaker additionally attached to the lower center end of the screen is radiated toward the center of the screen, and the radiated sound is once reflected by the screen. A sound reproduction device for a video projection system as described in 2.