JPS58147728A - Transmission type projecting screen and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a bright video having large contrast, by forming many short optical fibers having the same length, in the shape of a plate, dividing and transferring a projected video at every unit picture element, and displaying it by utilizing a scattering action of light. CONSTITUTION:As for a transmission screen 1, in a state that many short optical fibers 2 having the almost same length are arranged in order so that each end face is on the same plane, they are focused so as to closely adhere to each other, for instance, are fixed by an adhesive agent, and the whole shape is formed like a plate having almost fixed thickness. A video is projected, to the photodetecting face of this screenl, so that the video is seen on the display face. A small part divided by an annular boundary line of a core layer and a clad layer in the photodetecting end face of each fiber 2 is made to a unit picture element, each unit picture element is transferred to the display face, and light is scattered. Accordingly, the display face is visually confirmed as an aggregate of light emitting points for emitting scattered light, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmission type projection screen (hereinafter simply referred to as a transmission screen) and a method for manufacturing the same.

%, it relates to a transparent screen that can brighten the projection image and a simple and easy manufacturing method thereof.

For the purpose of publicity, the film is often enlarged and projected onto a large transmissive screen using a slide projector or the like.

However, the image 4 produced by this slide projector is completely invisible! Although # has the advantage of being easy to use, it has not become a mainstream advertising display stage because it is considered to have little display effect.

One of the reasons is that traditional transparent screens are not.

This is because the light transmission efficiency is low and in order to attract the attention of the first person, a large screen is used and the magnification is increased (combined with this, the image on the screen cannot be made brighter).

Another reason is that this transparent screen is installed in a relatively bright place, such as a station concourse, so the back side of the screen is illuminated.

In addition to the light from the slide projector that is transmitted to the display surface of the screen, ambient light from the surrounding area is reflected by the display surface of the transparent screen and enters the eyes of the display surface.
This is because as the /N ratio becomes smaller, the contrast of the image becomes significantly weaker.

Therefore, it is an object of the present invention to provide a transparent screen that is bright and has a high contrast, and can be used for superior interposition, and a method for manufacturing the same.

In order to achieve the above object, the transmission screen according to the present invention has a plurality of short optical fibers having approximately the same length, arranged so that their end faces are on approximately the same plane, so as to achieve mutual fCW! ! The optical fibers are focused and fixed so that they are in contact with each other, and the overall shape is formed into a plate shape.The image projected on the − surface is divided into unit pixels projected on the layer surface of each optical fiber and transmitted to the other surface@. In addition, the display is characterized by utilizing the scattering effect of light rays due to repeated reflection within the optical fiber.

Also, in the am method of transmission screen.

A step of forming a thick optical fiber cylinder by tightly winding a long optical fiber phase TLK into a cylindrical shape and overlapping several layers of KIl, and rolling the actual part of this optical fiber cylinder in the circumferential direction. A step of cutting out a plurality of screen strips by cutting them at a constant thickness along a pair of parallel planes that include the generatrix and are substantially perpendicular to the optical fiber at multiple locations along the line, and cutting out the edges of these screen strips. The method is characterized in that it includes a step of assembling a projection screen of a desired area by joining the edges to each other.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 designates a transmission screen according to the invention. This transmission screen 1 is made of short optical fibers 2 of approximately the same length as shown in FIGS. 2 and 3.
A large number of them are aligned so that they are aligned in each direction or on the same plane, and are brought together closely together and fixed, for example, with adhesive.

The overall shape is formed into, for example, a rectangular plate shape of approximately constant thickness. In this case, the thickness of the transmission screen 1 is of course approximately equal to the length of the optical fiber 2.

Note that the optical fiber herein refers to an optical fiber having a light transmission mechanism utilizing total reflection of light, and in the present invention, an inexpensive plastic fiber can be used.

The transmissive screen according to the present invention configured as described above is similar to a transmissive screen with appropriate sound. .

The functions of the transparent screen according to the present invention will be explained in comparison with those of conventional transparent screens.

A conventional transmission screen is made of a sheet of material that transmits and scatters light, and as shown in Figures 1 and 4,
1 display surface @
The scattered light DR is defined as the scattered light DR. As is well known,
In order for a bond point to be visually recognized as a bond point, the light from emotion must be scattered light, just as it is for real object points. In this sense, the conventional transmissive screen has the function of converting the projections 1!11 by the slide projector, which are generally invisible, into visible images.

However, conventional transmission screens must be made of nearly opaque materials in order to scatter light, so their light transmittance is low, and the scattered light DR (as shown in FIG. 4, J) is large.

As mentioned above, the image on the screen becomes darker than Iv.

- The transmission screen according to the invention utilizes the original scattering effect of repeated reflections of light inside the optical fiber to convert the projected image into a visible image.

That is, as shown in FIG. 5, when one optical 7-eyeper 2 constituting the transmission screen according to the present invention is exposed to light, an inertia point P projected at an arbitrary distance fK on the light-receiving end surface (right side in FIG. 5) can be expressed as follows. As shown in Figure 1, the condensed light ray R enters the optical fiber 2 while being refracted at the light receiving end face,
The core of the optical fiber that constitutes the light reflecting surface
The light travels toward the exit end (toward the left end in the figure 81!5) while repeating total reflection at the cylindrical interface between the light and the ground layer (not shown).

Then, as shown in the figure, in the process of repeating one reflection, the light ray R loses the direction given by T1 by the projection lens of the slide glodictor, becomes Wl and a scattered light ray DR, and exits from the exit end face.

In the fifth factor, in order to make the situation clearer, only the reflection of a part of the light rays from one fold point P on the light receiving end surface r of the optical fiber 7 is shown.

In reality, the other rays converging on the above-mentioned monk point P are continuous Km
It is of course rumored that the light enters the optical fiber 2 at an incident angle and direction of 2, undergoes repeated reflections uniquely 5i depending on each incident condition, and then exits from the exit end face as a scattered light beam. At the same time, other groups of rays projected onto the light-receiving end face of the optical fiber are similarly scattered within the same optical fiber, and are scattered from the emitting end face in a mixed state. It is emitted as light.

In other words, the transmission screen according to the present invention has an image i projected on the light-receiving end face of each optical fiber 2 constituting the screen.
s, that is, a small portion of the entire sandwich projected on the light-receiving surface of the transmission screen, which is attached to the annular boundary line between the core I and the cladding at the light-receiving end l of the valley optical fiber, is fixed as a unit. As a result, Ktl is transmitted to the water surface for each unit pixel, and the light is scattered.

Therefore, the downward direction of the transparent screen is seen as a collection of light-emitting points that emit scattered light, so that the transparent screen according to the present invention is different from the conventional one in projection 11! Egg is 4A
It functions as a transparent screen.

In a transmission screen using unexploded dA, the angle of incidence of the incident light beam on the receiving end face of each optical fiber 2 is small, and therefore the exit aerial angle of the scattered light from the exit end face is also considerably small, and the trench point condensation light ray is Since the loss of light during the process of passing through the optical fiber and emitting it as a scattered light beam is almost negligible, the projection illumination becomes much clearer than that of a conventional transmission screen. The small emission aerial angle means that the transparent screen can be seen brightly when viewed from the - direction (this causes the spatial range of the festival person to be narrowed, but in general, transparent screens are used for advertising purposes. When viewing images from a distance, it is common to use wide (enlarged) projection to view images from a distance, so the disadvantage caused by the small emission angle of the scattered light is almost negligible.

In addition, most of the external light that is illuminated on the display surface of the transmissive screen, such as illumination light from a station concourse, passes through the optical fiber and passes through the light-receiving surface aK and does not enter the FIILK of the person viewing the display surface. Therefore, the contrast and color of the image projected onto the transparent screen are not weakened, and the contrast and other characteristics of the original slide are maintained as they are.

Note that the transmission screen according to the present invention has a receiving ft, lfi
The light receiving end III! of each optical fiber 2 at ] Since the pinching is divided for each unit pixel projected on the screen and transmitted to the display screen, the final degree of pinching released on one display screen is uniquely determined by the thickness of the optical fiber, and the screen surface If you look at it microscopically, the elephant will look like a mosaic.

However, in the case of advertisements, it is common to increase the magnification and show it from a distance in order to increase the display effect, so in reality, it is possible to obtain the necessary degree of resolution.

For example, the diameter of the optical fiber 20 is 1 fl, and the size of the transmission screen 1 is 1.2 m1. 1
．． In the case of 811, the number of transparent screens 1' and optical 7 eyeglasses that constitute is approximately 2.5 million, but this is
At point 11, there is an enlarged mark #J called the so-called service size (for example, 72 m in length and width, 111
For comparison, if the transparent screen of the above size is reduced in proportion to the service size, the diameter of the optical fiber will be about 0.06 mm, which is equal to the diameter of a hair.

As mentioned above, the transmission screen according to the present invention has an excellent function, but since it is necessary to focus and identify a very large number of optical fibers, it is impossible to internally reduce the warpage in one coupling. It is a cone.

For example, when short optical fibers as thick as the transmission screen 1 are manually layered one by one per second, and when they are bundled in a bag, the 2.5 million optical fibers are It takes about three months, eight hours a day, to manufacture a screen.

However, according to the method of manufacturing a transmission screen according to the present invention, the transmission screen can be manufactured simply and easily.

That is, as shown in No. 6-, first, a long optical fiber 2 is tightly wound into a coil shape while being mutually fixed to the outer surface of a relatively large-diameter core tube 4 with, for example, seven flanges 3. Roll multiple layers.

At this time, i! 1 The core tube 4
While continuously rotating the optical fiber in a certain direction (for example, in the direction of the arrow in Fig. 6), the part of the optical fiber that is about to be wound, the VCG, is moved back and forth in the m-line direction (in the direction of the arrow) of the core tube 4. Bye.

If the optical fiber 2 is set in the direction indicated by the arrow s St v - the diameter of the optical fiber per rotation of the core cylinder 4, the most dense winding can be achieved (see FIG. 2).

Further, adjoining optical fibers may be fixed to each other using an adhesive. That is, the adhesive is continuously supplied and applied to the part of the optical fiber that is about to be wound, or the adhesive is applied with a brush or the like after each winding of the optical fiber to the core tube 4. hand,
Attach a group of optical fiber wires that are radiated into a cylindrical shape on campus. In addition, at this time, the outside of the core tube 4 is 1+111
It must be ensured that the adhesive does not flow between the coil of the first layer Optical Fino (which is in direct contact with the VC). This is to facilitate the removal of the core tube 4.

After winding up the optical fiber to a predetermined thickness K as described in step 5 above, wait for the Soup II 1 to dry and then remove the thick-walled cylindrical optical fiber tube 5 from the core tube 4 as shown in Figure 7. .

Next, as shown in %w, ss, the substantial part of the optical fiber tube 5 is placed at a plurality of points in the circular direction on a pair of parallel planes 6 that include the generatrix and are substantially perpendicular to the optical fiber tube 5, Cut at a constant thickness along 6'. In the illustrated embodiment, one plane 6 of the pair of parallel planes is a plane passing through the central axis #Q of the optical fiber tube 5. Cut 4 plate-shaped sunari strips 7.7 (see Figure 9) from 111''''5°, then
If necessary, each screen strip 70 (optical 7
Yu who polished Ryo Ino (the surface where the cutting trend force I of 2 is gathered), l! These screen strips 7 as shown in 9■
．． Assemble the transparent screen 1 (see Fig. 1) of the same size by joining the @gs edges of 7 and 1 with adhesive.

As is clear from FIG.
It is convex and concave in the length direction, and the curvature of the concave and convex curves is similar to that of the crab.

Screen strips adjacent to each other (7.7σ) If one of the joining edges is convex, the other is concave, and the difference in curvature during machining will hardly be a problem.

The outer diameter of the core tube 4 is, for example, double-sided, and the above-mentioned 1
The unevenness of the W1 edge in the length direction of W1 (2) becomes a rod that can be ignored.

Sara K again. Each screen strip 7Q) Edges are machined.

The sad direction KG is Optical Fine 2σ) #
There are unevenness based on the shape of the mountain, but this is sown into each other g41II2i! ! By shifting the edge in the length direction by the radius of the optical fiber, the concave and convex portions interlock (see Figure 2).

In addition, the joining lines of adjacent screen strips 7.7 are no longer visible, and if necessary, the screen strips 7.7 can also be stiffened in the longitudinal direction, in this way they can be made to any desired size. constitute a transparent screen.

FIG. 10 shows a modified embodiment of the invention, which includes:
The steps up to the step of cutting out the screen strips are the same as the method for sniffing the transparent screen described above.

The joints of these screen strips 7.7 are glued l1rII
This is done not by K but by the tortoise tVC of the screen strip itself. That is, frame 8 having a pair of parallel and opposing vertical neighbors? Prepare this frame 8! 4 to engage the end of the screen shaft piece 7 and drop it downward (at this time, make sure to leave the above-mentioned spacing large so that the screen strip 7 will help slightly in the length direction. ,
The five projections and depressions of the side edge of the screen strip 7 interlock in the direction of erosion, making it possible to pass through the transparent screen with no gaps in the troughs. Note that in Figure @10, boundaries are drawn between adjacent screen strips for convenience of explanation, but in reality, these can be made invisible.

As is clear from the above explanation, the present invention utilizes repeated reflections of light within the optical fiber to scatter the light, so there is almost no loss of light (the scattered light from the exit end face of each optical fiber is Coupled with the small aerial angle, the screen surface can be made much clearer.

It was. Most of the external light emitted from the display surface KFl of the transmissive screen is optical fiber 'Ij! Direction of light receiving through
Because it cannot be seen by the person looking at the display screen.

The colors and contrast of the device projected onto the screen can be made vivid.

Furthermore, in the membrane end method of the transmission screen,
When the optical fiber of the encroaching length is tightly wound into a cylindrical shape while allowing the fibers to pass through, an optical fiber cylinder is formed in the chamber by several layers of winding. A vertical plane Vr is cut to a certain thickness to cut out screen strips, and the screen strips are joined to form a transparent screen)N,
As a result, the extremely large number of short optical fibers constituting the transmission screen are focused at a very high speed in a process with good workability.

Transparent screen company JM [Co., Ltd.]? It can be done efficiently and easily. It has various effects such as

In addition, in the above explanation, the core tube used as a jig for forming the optical fiber tube has a circular cross section, but it may also have a quadrilateral or triangular cross section with rounded corners; This has the advantage that the proportion of wedge-shaped cut pieces (see Figure 8) that are wasted when cutting out screen strips is reduced.

[Brief explanation of the drawing]

Fig. 1 shows the entire transparent screen according to the present invention, Fig. 2 shows a large front view of a part of it, Fig. 3 shows a part IIIT side view of parts 6 and 7, and Fig. 4 shows a conventional transmissive screen. Line diagram explaining the functions of the screen, #! Figure 5 is a diagram illustrating the light scattering device ttPv of the transmission screen according to the present invention, Figures 6 to 5J9
1J is a diagram S for explaining the # selection method of a transmission screen according to the present invention, of which diagram m6 is a perspective view for explaining the formation thickness fj of the optical fiber tube, and FIG. 7 is an external perspective view of the optical fiber tube. Figure 1!8 is a partial end view of the optical fiber tube to explain the cutting ratio of the screen strips, and Figure 9 is a perspective view to explain the joining of the screen strips. Figure 1 ( ) is a modification of the present invention!
! f! similar to FIG. 9 for explaining the example. It is a P+ inkstone drawing. 1... Transparent screen, 2... Optical fiber, 4... Core? i, 5... Optical fiber tube, 7
...Screen strips.

Claims (1)

[Claims] 1. A large number of short optical fibers having the same length,
Each surface is aligned so that it is on the same plane, and it is focused and fixed so that it is closely connected to each other, and the overall shape is formed into a plate shape. - Divide the image projected onto the surface into unit pixels projected onto the end surface of each optical fiber and transfer to the other surface 111411K
What is claimed is: 1. A transmission-type projection screen characterized in that it transmits light and displays by utilizing the scattering effect of light rays due to repeated reflection within an optical fiber. 2. The transmission type projection screen according to item 1, wherein the plurality of optical fibers are fixed to each other with an adhesive. 3. Long optical fibers are tightly wound into a cylindrical shape while being fixed to each other, and several layers of 4M are formed. A simple process of stacking layers to form thick optical fibers. The actual part of the optical fiber strip is cut at a constant thickness at multiple points along its circumferential direction into a pair of parallel planes that include the generatrix and are perpendicular to the optical fiber KFIK. 1. A method for manufacturing a transmission projection screen, comprising the steps of: cutting out a barrel of strips; and assembling a projection screen of a predetermined area by joining the edges of these screen strips to each other.