JP3711450B2 - Projection screen - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a projection screen used to project an image projected from a liquid crystal projector in a company conference room, a university lecture room, a general household room, or the like.
[0002]
[Prior art]
A projection screen using a main screen member made of a knitted structure is already known (Japanese Patent Laid-Open No. 11-38508).
[0003]
[Problems to be solved by the invention]
It said projection screen is a white coating as the having bead system less susceptible to external light polyvinyl chloride layer regression characteristic type having a projected surface side and specular reflection characteristic type surface has conventionally been used long Compared with pearl-types that are relatively insensitive to external light, it has irregular reflection characteristics so that clear images can be seen from any position on the screen surface, and it is diffusive and easily affected by external light. Although there is an advantage that it is less affected by external light than the mat type, the knitting structure is exposed as it is on the projection surface, so that a wood pattern called moire appears at the time of projection. This is because the pixels of the liquid crystal projector interfere with the wales and the course of the knitting structure.
[0004]
An object of the present invention is to provide a projection screen that has irregular reflection characteristics and is less susceptible to the influence of external light, and that does not generate moiré during projection.
[0005]
[Means for Solving the Problems]
A projection screen according to a first aspect of the present invention is a screen main member having a knitted structure, and a black pigment having a thickness such that a three-dimensional shape of a yarn formed on the projection surface side of the screen main member and constituting the knitted structure is raised on the surface. A gray surface coating composed of a mixed binder and a back surface that reflects projection light from a projector that is formed on the opposite side of the projection surface of the main screen member and that passes through the eyes of a knitted structure that is not completely blocked by the black pigment mixed binder A coating layer is provided.
[0006]
The black pigment mixed binder is preferably obtained by mixing 0.01 part to 0.10 part of black pigment with 100 parts of polyester resin .
[0007]
請 Motomeko 2 of the invention, in the projection screen according to claim 1, knitted tissue, in which forced knitted by a double-needle raschel knitting machine front and rear of the needle bar are both oriented in the same direction.
[0008]
In the projection screen, the thickness of all the yarns used in the knit structure is 84 dtex to 280 dtex or are made the same in the range of, or good those made with combinations of different thickness.
[0009]
A third aspect of the present invention, in the projection screen according to claim 1 or 2, wherein all of the yarns used for knitting are those wherein polyester crimped yarn.
[0010]
In the above, in order to form a gray surface film, there are the following two methods. One is a method of dipping the screen main member knitted fabric in a paste-like black pigment mixed binder and then squeezing it with a squeeze roller, followed by drying, and the other is moving the screen main member knitted fabric horizontally. In this method, a paste-like black pigment mixed binder is supplied from above a predetermined portion, and this is coated on a knitted fabric with a doctor knife and then dried. In the former case, the paste-like pigment-mixed binder adheres to the entire circumference of the exposed yarn of the knitted fabric and the peripheral edge of the knitted structure, but this does not completely block the knitted structure. In this method, the entire yarn yarn of the exposed knitted fabric is covered with a pigment-mixed binder. However, when the screen main member is formed by the knitted fabric, the coating on the opposite side of the projection surface is effective for the present invention. Does not contribute. On the other hand, in the latter case, the paste-like pigment-mixed binder covers approximately half the circumference of the yarn of the exposed knitted fabric, and the eyes of the knitted structure are almost closed .
[0011]
Back surface coating layer, those urethane resins of shaped aluminum powder were mixed paste, or ethylene - vinyl acetate resin is coated black, those gray or white-like pigment were mixed paste on the back surface of the screen main member Can be obtained.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0013]
As shown in the partial cross-sectional schematic diagram of FIG. 1, the projection screen (1) has a screen main member (2) made of a knitted structure and a gray surface formed on the projection surface side of the screen main member (2). A coating (3) and a back surface coating layer (4) formed on the opposite side of the projection surface of the screen main member (2) are provided.
[0014]
The gray surface film (3) uses a polyester resin as a binder, and a screen-like material in which 0.03 part of a black pigment is mixed with 100 parts of the polyester resin so that an appropriate screen gain is obtained. (2) It is obtained by coating the knitted fabric for use as described above. Although the pigment is black, the amount of the mixture with the polyester resin is very small, so that the obtained surface film (3) is gray. As shown in FIG. 3, the thickness of the gray surface film (3) is such a thickness that the three-dimensional shape of the yarn (2a) constituting the knitted structure is raised on the surface. However, as shown in FIG. 2 and FIG. 3, the stitches (2b) of the knitted structure are not completely blocked and there are through holes (5). The back surface coating layer (4) is for reflecting the projection light from the projector that has passed through the through hole (5), and a paste-like material in which aluminum powder is mixed with urethane resin is used for the screen main member (2) . Silver color obtained by coating the back of the knitted fabric.
[0015]
The knitting structure used as the screen main member (2) is knitted by a double needle raschel knitting machine in which the front and rear needle bars are directed in the same direction. It is as shown. That is, the knitting structure is substantially zigzag between the post-chain stitch yarn (L1), the pre-chain yarn (L2), the plurality of post-chain yarns (L1) and the plurality of pre-chain yarns (L2). Are knitted with a first rear cut yarn (L3), a front cut yarn (L4) and a second rear cut yarn (L5) which are knitted so as to be sandwiched in a shape. The zigzag directions of L3) and the front cut yarn (L4) are different from each other, and the zigzag direction of the second post cut yarn (L5) is the same at a position shifted vertically from the front cut yarn (L4). FIG. 4 (b), which shows taken out each one of the yarns in the knitting structure (L1) (L2) (L3 ) (L4) (L5), FIG. 4 (c), the knitting structure This indicates the starting point of the yarn (L1) (L2) (L3) (L4) (L5).
[0016]
Since the knitted structure is knitted as described above, a flat fabric surface can be obtained, and the first backcut yarn (L3), front cut yarn (L4), and second back cut yarn that are substantially zigzag-shaped. The presence of (L5) increases the intersection between yarns, reduces the voids in the knitting structure, and facilitates the adhesion of the black pigment mixed binder to the knitting structure. Polyester crimp yarns are used for all the yarns (L1), (L2), (L3), (L4), and (L5) of the knitted structure. The use of crimped yarn further promotes this adhesion. In addition, the thickness of all the yarns (L1), (L2), (L3), (L4), and (L5) is 167 dtex. Because the knitting structure is knitted by a double needle raschel knitting machine in which the front and back needle bars are oriented in the same direction, rather than the usual double needle raschel knitting machine where the front and back needle bars are back to back Therefore, it is possible to use a thick thread, and to secure an appropriate thickness and weight for a projection screen. Of course, it is not always necessary that all the yarns have the same thickness, and the mutual thicknesses may be appropriately changed.
[0017]
【The invention's effect】
A projection screen according to the present invention comprises a screen main member made of a knitted structure, and a gray surface film having a thickness formed on the projection surface side of the screen main member and having a thickness in which the three-dimensional shape of the yarn constituting the knitted structure is raised on the surface. Since the gray surface coating is made of a black pigment mixed binder, the presence of the gray surface coating smoothes the knitting structure wales and courses, so that there is no moiré during projection. In addition, the screen projection surface is not completely flattened by the surface film, but the thickness is limited to the extent that the three-dimensional shape of the yarn constituting the knitting structure is raised, so it has irregular reflection characteristics and a field of view. corners widely, the external light effects also less susceptible.
[Brief description of the drawings]
FIG. 1 is a partial vertical sectional view of a projection screen.
FIG. 2 is an enlarged partial front view of a projection screen.
FIG. 3 is a cross-sectional view taken along line III-III in FIG.
[Fig. 4] (a) is a knitting structure diagram, (b) is an exploded view of five yarns with different knitting methods in the knitting structure, and (c) shows the starting point of the yarn of the knitting structure. It is explanatory drawing shown.
[Explanation of symbols]
(1): Projection screen
(2): Main screen material
(3): Gray surface coating
(4): Back coating layer
(2a): Yarn constituting knitting structure
(2b): Eyes of the organization
(5): Through hole
(L1): Yarn after chain stitch
(L2): Yarn before chain stitch
(L3): First trailing thread
(L4): Pre-cut thread
(L5): Second trailing thread

Claims (3)

A screen main member made of a knitted structure, a gray surface film made of a black pigment mixed binder formed on the projection surface side of the screen main member and having a thickness in which the three-dimensional shape of the yarn constituting the knitted structure is raised on the surface ; A projection screen comprising a back surface coating layer that reflects projection light from a projector that is formed on the opposite side of the projection surface of a main member and passes through the eyes of a knitted structure that is not completely blocked by a black pigment mixed binder .   2. The projection screen according to claim 1, wherein the knitting structure is knitted by a double needle raschel knitting machine in which the front and rear needle bars are oriented in the same direction. The projection screen according to claim 1 or 2 , wherein all yarns used in the knitted structure are polyester crimped yarns.

Images