JPS631306Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a projection screen.

Recently, proposals have been made regarding so-called video projectors that project images based on television broadcast signals or video signals from a cathode ray tube onto a large projection screen. The screen of a video projector generally has a configuration as shown in FIG. 1, for example. In the figure, screen 1
Projected light from three cathode ray tubes 2, 3, and 4 arranged in a row or in a triangle below is reflected by a reflecting mirror 5 and forms an image on a screen 1. In order to reduce aberrations occurring in this optical system, the screen 1 has a predetermined curvature and forms a concave surface with respect to the projected light.

However, when an image on a projection film is to be formed on the screen 1 using, for example, an 8 mm projector, it is preferable that the surface of the screen 1 be a flat surface rather than an extremely curved surface.

An object of the present invention is to provide a screen device in which the projection surface of the screen can be set to either a flat surface or a curved surface having a predetermined curvature, as required.

The gist of the present invention is to provide: a flexible screen member on which a projected image is formed on one side; a screen support member that holds the screen member and forms a closed space together with the screen member; a guide surface that is disposed behind the screen member and in the closed space, has a concave surface with respect to the projection direction of the projected image, has a predetermined curvature, and has a through hole formed therein; and the screen The projection screen includes an exhaust hole formed in place on the support member and connectable to a pressure reducing means.

The present invention will be explained below based on examples.

FIG. 2 is a schematic perspective view schematically showing the present invention.

The device of the present invention can of course be applied to a type of device in which the electron gun is placed below the screen as shown in Fig. 1, but it can also be suitably used in a type of device in which the electron gun is placed opposite to the screen, for example. It is possible. In FIG. 2, the projection screen device has a closed structure as a whole, and a screen member 11 for forming a projection image from an electron gun is provided on the front surface of the projection screen device. A guide surface 12 is formed at the rear of the screen member, which is concave with respect to the projected light and has a predetermined curvature determined by the specifications of the entire device.

In this embodiment, the screen support member 13 and the screen member 11 form a substantially rectangular parallelepiped structure and are airtightly connected to each other. Further, an edge of the guide surface 12 is coupled to the screen support member 13.

Next, further explanation will be given with reference to FIGS. 3 and 4. This figure is a schematic side sectional view of the apparatus shown in FIG. 2.

In the illustrated example, a small through hole 14 is provided throughout the guide surface 12 . Note that instead of providing the through holes 14, the guide surface 12 may be shaped like a wire mesh. Further, on the rear surface of the screen support member 13, an exhaust hole 15 is provided which can be connected to a pressure reducing means (not shown) such as an exhaust pump.

Next, an example of the use of the projection screen device according to the present invention will be described.

First, when projecting a projection film image, the screen member 11 is used with the screen member 11 flattened by keeping the internal pressure of the closed space within the screen supporting member 13 at atmospheric pressure.

On the other hand, in order to use it as a screen for a video projector, the pressure reducing means is driven to reduce the internal pressure of the sealed space to below atmospheric pressure, and the screen member 1 is
1 is placed in close contact with the guide surface 12 to give a predetermined curvature to the screen projection surface of the screen member 11. As mentioned above, the screen member 11 has a flat shape or a curved shape depending on the mode of use, that is, it is flexible, but in some cases, the screen member 11 may be wrinkled. In order to prevent this, it is preferable that this screen member 11 has elasticity. The screen member 11 itself can be made elastic, or if it is difficult to provide such elasticity to the screen member 11 itself, as shown in FIG. A stretchable coupling member 16 having one end coupled to the screen member and the other end coupled to the edge of the screen member 11 is disposed along the edge of the screen member.

As described above, the present invention provides a screen that can be used both as a regular projection screen and as a video projector screen.
This is extremely useful as it improves the utilization of the screen.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing a conventionally known video projector. FIG. 2 is a schematic perspective view showing a projection screen according to the present invention. FIGS. FIG. 5, which is a schematic side cross-sectional view of the screen, is a partial cross-sectional view of a coupling member used in the projection screen of FIG. 11... Screen member, 12... Guide surface,
13... Screen support member, 14... Through hole,
15...exhaust hole, 16...coupling member.

Claims (1)

[Claims for Utility Model Registration] (1) A flexible screen member on which a projected image is formed on one side, and a screen member that holds the screen member and forms a sealed space together with the screen member. a screen support member; a guide disposed behind the screen member and within the closed space, having a concave surface with respect to the projection direction of the projected image and a predetermined curvature, and further having a through hole formed therein; What is claimed is: 1. A projection screen comprising: a surface; and an exhaust hole formed in place on the screen support member and connectable to a pressure reduction means. (2) The projection type projection screen according to claim 1, wherein the screen member itself has elasticity. (3) Utility model registration claim 1, wherein the screen member has an elastic connecting member disposed along its edge and connecting the screen member and the screen supporting member in an airtight manner. Projection type projection screen as described in Section.