JPH0383036A - Rear type video projector - Google Patents

Abstract

PURPOSE:To facilitate a countermeasure to various uses by unitizing a transmission type screen and making the transmission type screen have a mechanism which can be detached. CONSTITUTION:Light which is synthesized to be an image in a projection unit 300 is projected forward by a projecting lens 308 and the projected light is obtained as an image on a large-sized screen 309 in a figure (a) and on a small- sized screen 309 in a figure (b). The screen part is made the different unit from a housing 12 which holds the projection unit 300, and various sizes of screen 309 can be used by the use of screen adapters 13 and 14. Thus, the countermeasure to various uses is accomplished.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a rear type video projector.

[Prior Art] A conventional rear-type video projector is composed of at least an image projection unit, a transmission screen, and a case for holding these in a proper position and for blocking the outside. Furthermore, among rear-type projectors, there are some that have a folding mirror optical system, especially those that require a smaller housing.

These components of a conventional rear-type video projector are all mechanically fixed in position to prevent optical deviation.

[Problems to be solved by the invention] The most important use of large video equipment is presentations, but the size, brightness, and
Depending on the number of viewers and the intention of the presenter, the video g18! Each device is often required to have different viewing angle characteristics.

However, in conventional rear-type video projectors, all parts are mechanically fixed, so the transmissive screen cannot be removed. The problem was that the tool had to be compatible with presentations and did not necessarily reflect the intentions of the presenter.

Therefore, in order to solve these problems, the present invention has developed a rear-type projector in which the transmissive screen is made into a unit, and the transmissive screen can be removed as needed.
I had it held. Therefore, it is possible to incorporate transmissive screens having different viewing angle characteristics depending on the application. Additionally, by removing the transmission screen, it can also be used as a front projector. Therefore, the purpose of this project is to make the rear projector's transmissive screen into a unit and provide a mechanism that allows the transmissive screen to be removed if necessary, thereby making the rear projector compatible with a wide range of uses. That is.

[Means for Solving the Problems] A one-Noah type video projector of the present invention is a rear type video projector that includes at least an image projection unit and a light-transmitting screen, and has a mechanism for attaching and detaching the light-transmitting screen. It is characterized by

Hereinafter, the details of the present invention will be shown by examples.

[Example] Example 1 Figure 1(a) shows a rear-type projector with a large screen.
This is a diagram. Further, FIG. 2(b) is a diagram of a front type projector with a small screen. Projection unit 30
The image-combined light at 0 is projected forward by the projection lens 308. The projected light is obtained as an image on the large screen 309 in FIG. 1(a) and on the small screen 309 in FIG. 1(b). In the present invention, this screen portion is made into a separate unit from the giant body that holds the projection unit, and by using a screen adapter, screens of various sizes can be used. In FIG. 1(a), the large screen adapter 13 connects the large transmissive screen 3.
09 is installed. Further, in FIG. 1, a small transmission type screen 309 is attached using a small screen adapter 13. By replacing this small transmission screen, images with different viewing angle characteristics can be obtained.

FIG. 2 is a detailed view of the screen attachment/detachment part of this unit. First, the projection unit 5 fixed to the giant body 520
50, first reflection mirror 551, second reflection mirror 552,
The third reflection mirror 553 constitutes a folded image projection optical system. The image light projected from the projection unit 550 is bent diagonally forward and downward by a first reflecting mirror 551, is again bent upward by a second reflecting mirror 552, is bent forward by a zero-order third reflecting mirror 553, and is transmitted. The image is projected onto a mold screen 509. The optical axis of the image light at this time is shown at 540.

The screen 509 includes a screen side fixing plate 513, a screen top fixing plate 514, and a screen bottom fixing plate 5.
15, and these are each attached to the giant body 520 with screws 516. Therefore, the screen fixing plate must be installed using screws 51.
6 and remove the screen side surface fixing plate 513, screen top surface fixing plate 514, and screen bottom surface fixing plate 515, the screen 509 can be replaced. Furthermore, by replacing the screen side surface fixing plate 513, the screen top surface fixing plate 514, and the screen bottom surface fixing plate 515, a screen of a different standard can be attached.

The details of this will be explained later.

Since it is desirable that the projection unit used in the present invention does not require convergence adjustment, a single lens type projection unit using liquid crystal was used.

FIG. 3 is a structural diagram of the liquid crystal projection unit.

Light generated by the light source lamp 101 is focused by a lamp reflector 102. The condensed light is divided into blue, green, and red by a color separation and illumination optical system consisting of a blue separation dichroic mirror 301 which is a wavelength selective transmission film, a green separation dichroic mirror 302, and three reflective reflection mirrors 303. After the light is separated into the three primary colors, it is irradiated onto a blue liquid crystal panel 411, a green liquid crystal panel 412, and a red liquid crystal panel 413.

The three primary colors image-modulated by the three liquid crystal panels are combined into an image by a dichroic prism 312.

The dichroic prism includes a blue reflective dichroic film 321 and a red reflective dichroic film 322, which are wavelength-selective transmission films, and are formed so that they intersect in a diagonal direction.

The light image synthesized by the dichroic prism 312 is transmitted to the light transmission screen 3 by the projection lens 308.
Projected on 09.

FIG. 4 is a diagram in which this unit is applied to a multi-system. Since this unit has a removable screen, the transmissive screens of multiple rear projection units used in a multi-system can be removed and replaced with an integrated transmissive screen 309. Figure 5 shows how this unit can be used as a front projector. This is an applied diagram. The transmissive screen of this rear projection unit was removed and replaced with a reflective screen 309.

In this way, by making the screen a separate unit and detachable, a variety of uses can be developed for the same rear projection.

[Effects of the Invention] As described above, according to the present invention, the transmissive screen of the rear projector is made into a unit, and the rear projector is provided with a mechanism that allows the transmissive screen to be removed as necessary. Therefore, it is possible to incorporate a transmissive screen having different viewing angle characteristics depending on the application. Additionally, by removing the transmission screen, it can also be used as a front projector. Therefore, by making the rear projector's transmission screen into a unit and providing a mechanism that allows the transmission screen to be removed if necessary, it is possible to make the rear projector compatible with current applications. did it.

[Brief explanation of drawings]

FIG. 1(a) is a diagram of a rear type projector with a large screen. 2 3 0 8 9 Viewpoint box Large screen adapter Projection unit Projection lens Transmissive screen Figure 1 (b) shows a rear projector with a small screen.
illustration. 2 4 00 08 09 Viewpoint box Small screen adapter Projection unit Projection lens Large transmissive screen Figure 2 is a detailed view of the screen attachment/detachment part. 09 13 14 15 16 20 40 50 51 52 53 Transmissive screen Screen side fixing plate Screen top fixing plate Screen bottom fixing plate Screen fixing plate Mounted with screws Optical axis Projection unit First reflection mirror Second reflection mirror Third reflection Mirror Figure 3 is a structural diagram of the liquid crystal projection unit. 01 02 01 02 03 08 09 12 21 22 11 12 13 Light source lamp Lamp reflector Blue separation dichroic mirror Green separation dichroic mirror Increased reflection mirror Projection lens Light transmission screen Dichroic prism Blue reflection dichroic film Red reflection dichroic film LCD panel for blue color Green LCD panel for red LCD panel Fig. 4 shows this unit applied to a multi-system. 200 08 09 Perspective giant projection unit Transmissive screen with integrated projection lens Fig. 5 shows this unit applied to a front type projector. 2 4 00 08 09 View point giant small screen adapter projection unit projection lens reflective screen tz Figure 4

Claims (1)

[Claims] (1) A rear-type video projector comprising at least an image projection unit and a light-transmitting screen, the rear-type video projector having a mechanism for attaching and detaching the light-transmitting screen.