JP2009192874A - Screen and projection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen, capable of improving contrast of a projection image in bright room or the like by reducing an influence due to external light, and capable of properly reflecting and diffusing projection light having largely different incident angle into the front direction, and to provide a projection system. <P>SOLUTION: In the screen 10, the screen 10 is divided into a first region 10a and a second region 10b, respectively having different structures, according to the incident angle of a projection light PL, and scattering and reflection suited for the projection light PL, made incident to respective regions are carried out. Furthermore, the external light OL from above side is not reflected to the observer side by virtue of a side surface SS and a light-absorbing sheet 3, and even at use in a bright room, or the like, image of high contrast can be formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a screen that reflects projection light from a projection device such as a front projector and displays a projected image, and a projection system using the screen.

A screen using an integrated microlens and a reflective surface, in which the direction of the reflective surface arranged behind the microlens is tilted in the normal direction of the center of the screen, is particularly known. One that gradually changes the inclination angle from the portion toward the peripheral portion is known (see Patent Document 1). In addition, there is also known one in which a lenticular lens is used on the screen surface and the cross-sectional shape of the lenticular lens is a non-arc shape (see Patent Document 2).
Japanese Patent Laid-Open No. 3-156435 JP-A-5-72631

  However, in the use of a reflective screen that reflects the projection light from a projection device such as a front projector and displays a projected image, the projection on the screen is performed, for example, when projecting from a very close position. The incident angle of light may be significantly different depending on the incident position. As described above, when the difference in incident angle of the projection light depending on the incident position becomes large, the shape and arrangement of the lens corresponding to the projection light incident on the lens array forming the screen surface and the reflecting surface arranged behind this lens. Only by gradually changing the adjustment, etc., a state in which the projection light cannot be reflected appropriately may occur.

  As another problem, in the use of a reflective screen, a part of the external light that is unnecessary light may be reflected in the direction of the observer of the screen, and the reflected external light is projected image. This may cause a decrease in contrast.

  Therefore, the present invention reduces the influence of external light, can improve the contrast of a projected image in a bright room, etc., and can appropriately reflect and diffuse projection light having a significantly different incident angle in the front direction. An object is to provide a projection system.

  In order to solve the above problems, a screen according to the present invention includes (a1) a lens array having a plurality of element lenses arranged on a two-dimensional plane on the front side of the screen, and (a2) two-dimensionally on the back side of the lens array. (A) a screen sheet having a plurality of reflecting surfaces arranged to be inclined with respect to a plane; and (a3) a plurality of scattering portions that scatter light emitted from the plurality of reflecting surfaces to the screen front side. (B) In the screen sheet, the relative positional relationship between the element lens for entering the projection light and the element lens for emitting the projection light through the corresponding reflecting surface is different from each other in relation to the incident angle range of the projection light. A first region and a second region.

  First, in the screen described above, a reflective surface inclined with respect to the plane on which the lens array is arranged is provided on the back side of the lens array, and further, a scattering portion that scatters light emitted from the reflective surface is provided, thereby providing the screen with Incident projection light can be reflected in a properly scattered state. At this time, in particular, in relation to the incident angle range of the projection light incident on the screen, in the first region and the second region of the screen sheet, the element lens for entering the projection light and the element lens for emitting the projection light By making the relative positional relationships different from each other, the type of reflection is changed between a place where the incident angle of the projection light is very large and a place where the incident angle is relatively small. Thus, display can be performed with high efficiency in a state where the scattering and reflection of the projection light are in an appropriate direction and have an appropriate viewing angle. In addition, the influence of external light can be reduced, and the contrast of the projected image in a bright room can be improved. In addition, in order to appropriately scatter and reflect the projection light in each of the first region and the second region, the reflection surface also has a relative relationship between the element lens that enters the projection light and the element lens that emits the projection light. Corresponding to various positional relationships, the first region and the second region have different shapes.

  Further, as a specific aspect of the present invention, a lens array includes a plurality of cylindrical lenses as a plurality of element lenses, and the plurality of cylindrical lenses are arranged in a direction perpendicular to the longitudinal direction of each cylindrical lens. Composed. In this case, a screen can be easily produced by using a lenticular lens as the lens array.

  As a specific aspect of the present invention, the screen sheet emits the projection light from the element lens adjacent to the element lens on which the projection light is incident in the lens array of the first region, and the lens array of the second region. The projection light is emitted from the same element lens as the element lens on which the projection light is incident. In this case, by having different types of reflection modes in the first region and the second region, it is possible to effectively scatter / reflect without waste according to the incident angle of the projection light incident on each region.

  Further, as a specific aspect of the present invention, the screen sheet has a first region on the side where the incident angle of the projection light with respect to the two-dimensional plane is large, and the second is on the side where the incident angle of the projection light with respect to the two-dimensional plane is small. Has a region. In this case, the incident angle of the projection light incident on the first region is larger than the incident angle of the projection light incident on the second region, and the screen has a configuration corresponding to this.

  As a specific aspect of the present invention, in the screen sheet, a region where the incident angle of the incident light incident on the screen center axis is 60 degrees or more is the first region. In this case, with respect to the incident angle of the projection light incident on the screen center axis, scattering and reflection suitable for the incident angle of the projection light are performed in each of the first region and the second region by using 60 degrees as a reference. Can do.

  Further, as a specific aspect of the present invention, the side cross-sectional shape of each element lens constituting the lens array is a non-arc shape with a curvature that decreases as it approaches an adjacent element lens. In this case, the portion from the reflective surface to the surface of the lens array can be thickened to make the screen more durable.

  Further, as a specific aspect of the present invention, the lens array provided in at least one of the first region and the second region includes a combined lens having a pair of two lens portions that are decentered from each other as an element lens. In this case, the combined lens can adjust the optical path of the incident light according to the incident position on the lens surface, and the thickness of the entire screen can be kept thin, or the thickness from the reflecting surface to the surface of the lens array can be reduced. It is possible to maintain the strength of the screen.

  As a specific aspect of the present invention, at least one group of element lenses in the lens array provided in at least one of the first region and the second region is tilted in relation to the incident angle range of the projection light. Yes. In this case, the optical path can be changed in order to appropriately scatter and reflect the light incident on the first region and / or the second region.

  Moreover, as a specific aspect of the present invention, a light absorbing surface formed of a light absorbing material is further provided at least around the reflecting surface on the back side of the lens array. In this case, the light absorbing surface can absorb unnecessary light such as outside light and form a high-contrast image.

  As a specific aspect of the present invention, in the first region, the reflection surface is smaller than the light absorption surface, and in the second region, the reflection surface is larger than the light absorption surface. In this case, it is possible to perform appropriate scattering and reflection in each of the first region and the second region according to the difference in light collection and the like.

  As a specific aspect of the present invention, the screen sheet has a transition region between the first region and the second region, and the shapes of the reflection surface and the light absorption surface gradually change in the transition region. In this case, the transition from the scattering / reflection mode in the first region to the scattering / reflection mode in the second region can be performed gradually.

  As a specific aspect of the present invention, the lens array has an antireflection coating on the surface. Thereby, reflection on the screen surface can be prevented.

  Further, as a specific aspect of the present invention, the lenticular lens can be rolled up and has a structure in which the longitudinal directions of a plurality of cylindrical lenses are arranged along the direction of the axis of rolling. Thereby, when the screen is rolled and stored, the boundary portion between the plurality of cylindrical lenses is mainly bent, so that the deformation amount of the main body portion of the cylindrical lens can be reduced.

  As a specific aspect of the present invention, a projection system according to the present invention includes (a) any of the screens described above, and (b) an image projection device that projects a projected image on the screen. In this case, by using the screen, the projection system can scatter and reflect the projection light appropriately and can be used effectively, and the influence of external light is reduced, and the contrast of the projection image in a bright room or the like is reduced. Can be improved.

[First Embodiment]
Hereinafter, a screen according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view schematically showing a screen according to the present embodiment. The screen 10 of this embodiment is a reflective screen, and includes a light-transmissive screen sheet 2 provided with a lens array, and a light-absorbing sheet 3 attached to the entire back surface of the screen sheet 2.

  As shown in the figure, the projection light PL is projected onto the screen 10 from the projection light source point S of the projection lens PO included in the projection device or the like, thereby performing image projection. The projection light source point S is installed at a lower position close to the screen 10. Further, here, the light beam axis AX of the projection light PL is at the incident angle α at the center position O located at the center of the screen center axis LX passing through the center of the screen 10 from the lower side to the upper side. Is incident. In the illustrated example, in particular, the light beam axis AX is set to an incident angle α = 60 °. The screen 10 is divided into an upper first region 10a and a lower second region 10b with an incident angle α = 60 ° as a reference. In other words, in the screen sheet 2, the side where the incident angle of the projection light PL is large is the first region 10a, and the side where the incident angle of the projection light PL is small is the second region 10b. The first region 10a and the second region 10b have different shapes. That is, in this example, the upper half of the screen 10 corresponds to the first area 10a, and the lower half of the screen 10 corresponds to the second area 10b.

  2A is a side sectional view schematically showing the structure of the screen 10 in the first region 10a, and FIG. 2B is a side sectional view schematically showing the structure of the screen 10 in the second region 10b. FIG. Here, the screen sheet 2 is provided periodically corresponding to each cylindrical lens CL on the back side of the lenticular lens 1 which is a lens array in which the cylindrical lenses CL are two-dimensionally arranged on the front side. A groove GT. In addition, the scattering part 4 is formed in the screen sheet 2 by apply | coating a scattering material to the groove | channel GT, and the light absorption sheet 3 is affixed after the scattering part 4 is formed in the screen sheet 2. FIG.

  A large number of lenticular lenses 1 formed on the front side of the screen sheet 2 are arranged in the y direction perpendicular to the longitudinal direction (x direction) using a cylindrical lens CL having a substantially semi-cylindrical outer shape and extending in the x direction as an element lens. Thus, a surface that extends in parallel to the xy plane is formed as a whole. That is, these cylindrical lenses CL are arranged on a two-dimensional plane so as to constitute the entire surface of the screen 10 (see FIG. 1). Each cylindrical lens CL causes the projection light PL to be incident and condensed, and emits the projection light PL scattered and reflected inside the screen 10 at a predetermined divergence angle.

  On the other hand, on the back side of the screen sheet 2, a groove GT is formed along the longitudinal direction of the cylindrical lens CL, that is, the x direction, corresponding to each cylindrical lens CL. The shape of the yz section of each groove GT is greatly different between the first region 10a and the second region 10b. First, in the case of the upper first region 10a, as shown in FIG. 2A, the groove GT includes a side surface SS that is substantially perpendicular to the y direction in which the cylindrical lenses CL are arranged, and an inclined reflecting surface RS. And the yz section is triangular. On the other hand, in the case of the lower second region 10b, as shown in FIG. 2B, side surfaces SS that are substantially perpendicular to the y direction in which the cylindrical lenses CL are arranged are formed on both the upper surface side and the lower surface side. The groove GT is defined by these side surfaces SS and the inclined reflecting surface RS, and the yz section has a trapezoidal shape. As shown in the figure, the shapes of the grooves GT in both the regions 10a and 10b are different in that the depth of the reflection surface RS is different. In addition, the reflection surface RS is different in the incident angle of the projection light PL in order to increase the tendency to reflect the projection light PL which is collected by each cylindrical lens CL and is inclined obliquely upward and reflected in the front direction, that is, the + z direction. Accordingly, the first region 10a and the second region 10b are inclined at different predetermined inclination angles α1 and α2. Each scattering portion 4 fills each groove GT having the shape as described above, and has a shape obtained by inverting the shape of the groove GT. The scattering portion 4 is formed so as to be filled by spraying ink made of a material containing a scattering component as a main component along the groove GT located behind each cylindrical lens CL so as to cover the reflection surface RS all over. ing. The scattering unit 4 is in a state of being scattered with appropriate dispersion characteristics when light incident from the reflecting surface RS is reflected in the + z direction. Thereby, the effect which guides the projection light PL which entered into the screen 10 from the lower part which adjoined to the front can be produced. As the scattering component, for example, barium sulfate or barium sulfate mixed with white reflective ink (for example, white pearl ink) is used.

  The light absorbing sheet 3 provided on the back surface of the screen sheet 2 is formed by covering the entire back surface side of the screen sheet 2 with a light absorbing material after filling the grooves GT with the scattering portions 4. The light absorbing sheet 3 forms a light absorbing surface AS that absorbs unnecessary light such as outside light around the scattering portion 4. The thickness of the entire screen 10 is preferably about 0.3 mm to 0.5 mm.

  Hereinafter, the operations in the first region 10a and the second region 10b of the screen 10 will be described by describing the optical path of the projection light PL with reference to FIGS. 2 (a) and 2 (b).

  First, the operation in the first region 10a located on the upper side of the screen 10 will be described with reference to FIG. As shown in FIG. 2A, when the cylindrical lens CL1 positioned at the bottom in the y direction in the drawing is viewed as an element lens for incidence of the projection light PL1 among the cylindrical lenses CL, one of the cylindrical lenses CL1. The cylindrical lens CL2 located on the upper side corresponds as an element lens for emission. In this case, the reflection surface RS2 located behind the upper cylindrical lens CL2 corresponds to the case where scattering and reflection are performed. That is, first, the projection light PL1 incident on the lower cylindrical lens CL1 is condensed and scattered and reflected by the reflection surface RS2. Next, the projection light PL1 scattered and reflected by the reflecting surface RS2 is emitted in a state of being appropriately diverged from the upper cylindrical lens CL2. The same applies to the case where the cylindrical lens CL2 functions as an element lens for incidence of the projection light PL2, and the projection light PL2 that has entered the cylindrical lens CL2 is scattered by the reflection surface RS3 positioned on the upper side of the cylindrical lens CL2. Reflected and emitted from the upper cylindrical lens CL3. Similarly, the projection light PL3 incident on the cylindrical lens CL3 is emitted from the cylindrical lens CL4, and the projection light PL4 incident on the cylindrical lens CL4 is emitted from the cylindrical lens CL5. That is, in the first region 10a, the projection light PL is emitted from the cylindrical lens CL adjacent to the cylindrical lens CL to which the projection light PL is incident.

  Next, the operation in the second region 10b located on the lower side of the screen 10 will be described with reference to FIG. As shown in FIG. 2B, among the cylindrical lenses, the projection light PL1 incident on the cylindrical lens CL1 positioned at the bottom in the y direction in the drawing is condensed and reflected at the back of the cylindrical lens CL1. Scattered and reflected by the surface RS1. The projection light PL reflected by the reflecting surface RS1 is emitted in a state of being appropriately diverged from the cylindrical lens CL1. That is, the projection light PL1 incident on the cylindrical lens CL1 is emitted from the cylindrical lens CL1, which is the same element lens as the incident element lens. Similarly, the projection lights PL2 to PL5 respectively incident on the cylindrical lenses CL2 to CL5 are emitted from the cylindrical lenses CL2 to CL5, respectively.

  As described above with reference to FIG. 2 (a), in the first region 10a of the screen 10 where the incident angle of the projection light PL is very large, the incident projection light PL is scattered in an appropriate direction and a viewing angle. In order to reflect the light, the projection light PL incident from the lower cylindrical lens CL in the y direction out of the two adjacent cylindrical lenses CL is projected by using the upper reflection surface RS and the cylindrical lens CL to be projected. The light PL is scattered and reflected. On the other hand, as described with reference to FIG. 2B, in the second region 10b of the screen 10 where the incident angle of the projection light PL is relatively small, one cylindrical lens CL and the reflecting surface RS are used. The incident projection light PL can be emitted, and the projection light PL is scattered and reflected by the same cylindrical lens CL. Thus, since the first region 10a and the second region 10b are different types of reflection modes, the optical path after incidence of the projection light PL, the degree of light collection, and the like are different. Therefore, in each of the first region 10a and the second region 10b, in order to scatter and reflect the projection light PL so as to have an appropriate direction and viewing angle, the shape of the reflecting surface RS and the surface shape of the cylindrical lens CL Or, it is necessary to change at least one of the state of the scattering portion 4 and the like. In particular, in the specific examples shown in FIGS. 2A and 2B, the cross-sectional shape of the reflective surface RS, that is, the shape related to the depth, width, etc. of the groove GT is greatly different between the first region 10a and the second region 10b. .

  2A and 2B, in order to appropriately scatter and reflect the projection light PL in each of the first region 10a and the second region 10b, as described above, first, the first region The reflecting surface RS is inclined at different inclination angles α1 and α2 depending on the incident angle of the projection light PL incident on the 10a and the second region 10b. In addition, in each area | region 10a, 10b, it is not necessary to make inclination-angle (alpha) 1, (alpha) 2 constant, and it can finely adjust according to the position of ay direction. 2 (a) and 2 (b), the thicknesses Ta and Tb of the entire screen sheet 2 are set to 0.3 mm to 0.35 mm, and the length PT of one cylindrical lens CL, that is, the length PT of one pitch. Is about 0.3 mm. On the other hand, with respect to the vertical width of the groove GT constituting each reflecting surface RS, the vertical width Da of the groove GT in the first region 10a is about 0.1 mm, and the vertical width Db of the groove GT in the second region 10b. It is about 0.16 mm. That is, the reflective surface RS in the second region 10b is larger than the reflective surface RS in the first region 10a. In this case, the reflection surface RS of the first region 10a is smaller than the light absorption surface AS of the light absorption sheet 3, whereas the reflection surface RS of the second region 10b is larger than the light absorption surface AS. In addition, the reflection surface RS of the second region 10b is positioned on the upper side in one unit of the cylindrical lens CL, that is, one pitch, compared to the reflection surface RS of the first region 10a in order to suppress light loss. The upper end of the reflective surface RS tends to be closer to the lens surface of the cylindrical lens CL. In this case, if the upper end of the reflective surface RS is too close to the cylindrical lens CL, the viewing angle is widened, but the necessary reflective surface becomes large, or the portion becomes thin and the screen sheet 2 tends to be easily broken. However, in the case of the specific example shown in FIG. 2B, light loss is suppressed, scattering and reflection with an appropriate direction and a viewing angle are performed, and the upper end of the reflection surface RS is on the surface of the cylindrical lens CL. It is designed to the extent that it does not get too close and the part becomes thinner and not easily broken. On the other hand, the reflective surface RS in the first region 10a of FIG. 2A tends to increase the distance from the cylindrical lens CL, and the entire screen sheet 2 tends to be thick, that is, the value of the thickness Ta of the screen sheet 2 Tends to grow. Therefore, when the value of the thickness Ta and the value of the thickness Tb do not match, the thickness Tb is adjusted by raising the back side of the screen sheet 2 in the second region 10b to increase the thickness of the first region 10a. It may be adapted to Ta.

  Note that illumination light or the like that generates external light OL that is not necessary for image projection is often installed, for example, on the ceiling side of a room to illuminate the room. As described above, most of the external light OL projected from the upper side of the screen 10 is the side surface SS of the groove GT (the upper surface of the upper and lower side surfaces SS in FIG. 2B) or light absorption. The light enters the light absorption surface AS of the sheet 3. The external light OL incident on the side surface SS of the groove GT is reflected from the angle of the side surface SS without going to the front of the screen 10 on which the observer is present, and the external light OL incident on the light absorbing sheet 3 is also reflected on the screen 10. Absorbed without heading forward.

  Further, an AR coating CT which is an antireflection coating is applied to the surfaces of the plurality of cylindrical lenses CL constituting the surface of the lenticular lens 1. Thereby, reflection of light is prevented.

  Further, the screen 10 can be rolled up in the direction of the arrow AW shown in FIG. In this case, the boundary portion BP connecting the cylindrical lenses CL of the lenticular lens 1 is mainly bent, so that the cylindrical lens CL itself can be rolled and stored without being deformed so much.

  As described above, in the screen 10 according to the present embodiment, the screen 10 is divided into the first region 10a and the second region 10b having different shapes or structures according to the incident angle of the projection light PL, and is incident on each. By performing scattering / reflection suitable for the projection light PL, it is possible to scatter / reflect the projection light PL from below at an appropriate viewing angle toward the viewer. Further, the external light OL from above is not reflected to the viewer side by the side surface SS or the light absorbing sheet 3, and an image with high contrast can be formed even in use in a bright room or the like.

  3 (a), 3 (b) and 3 (c) are diagrams for explaining a modified example of the manufacturing method of the present embodiment, each for one cylindrical lens CL, that is, one pitch of the first region 10a. It is a sectional side view which shows a minute typically. Among these, first, in the example shown in FIG. 3A, a light absorption film 103 is formed instead of the light absorption sheet 3 shown in FIG. That is, after forming the scattering portion 4, for example, the light absorbing film 103 is formed by applying light absorbing ink so as to cover the entire back surface side of the screen sheet 2. 3 (b) and 3 (c) show another example of the manufacturing method step by step. In this modification, as shown in FIG. 3B, first, light-absorbing ink is applied to the back side of the screen sheet 2 before the scattering portion 4 is applied to form the light-absorbing film 103. . Thereafter, as shown in FIG. 3C, the scattering portion 4 is formed by applying a scattering material to the entire back surface of the screen sheet 2 so as to fill the groove GT. In this case, the groove GT may be formed after the light absorbing film 103 is formed by applying light absorbing ink. In addition, the above is an illustration of the modification of a manufacturing method, and if it has the same structure, you may be a manufacturing method other than these.

  In addition, the scattering portion 4 may be anything as long as it has a scattering effect on the reflection surface RS, and the entire groove GT may not be filled with the scattering material. Therefore, for example, the scattering portion 4 may be formed by applying a scattering material only to the reflective surface RS of the groove GT. In addition to the scattering material, for example, a scattering effect may be provided by forming an uneven surface on the reflecting surface RS.

[Second Embodiment]
Hereinafter, the screen of the second embodiment will be described. The screen 110 of the present embodiment is a modification of the screen 10 of the first embodiment, and is the same as the screen 10 of FIG. 1 except for the shape of the surface of the cylindrical lens CL. The illustration and detailed description are omitted. FIG. 4A illustrates the structure of the lower portion of the structure of the screen 110 according to the present embodiment, that is, the region corresponding to the second region 10a of FIG. More specifically, FIG. 4A schematically shows one cylindrical lens CL arranged in order to constitute the lenticular lens 101 of the screen 110, that is, one pitch in an area corresponding to the second area 10 a of the screen 110. FIG. FIG. 4B is a diagram of a comparative example.

  As shown in FIG. 4A, in the screen 110 of the present embodiment, the contour CN of the side cross section of the cylindrical lens CL has a non-arc shape. More specifically, the shape of the surface of the cylindrical lens CL shown in FIG. 4A goes to the peripheral side as compared with a contour CN of a side cross section by a semicircle as shown in FIG. 4B as a comparative example. That is, the closer to the adjacent cylindrical lens CL (not shown), the gentler the curvature than the arc. As a specific contour CN curve, for example, a hyperbolic shape or the like is used. As a result, the distance d1 from the upper end UE of the reflective surface RS, which is the thinnest part indicated by the reciprocating arrow in the drawing, to the surface portion FP of the cylindrical lens CL has an arc shape as in the comparative example of FIG. Bigger than the ones can be taken. That is, on the lower side of the screen 110, that is, on the second region side, the portion from the reflective surface RS, which tends to be thin, to the surface of the cylindrical lens CL is thickened, so that the screen sheet 102 is more difficult to break, and the screen 110 is more It can be strong.

  In the screen 110 according to the present embodiment, the cylindrical lens CL described with reference to FIG. 4A may be used for the entire region corresponding to the second region 10a of FIG. It may be a partially used mode in which only a part of the region corresponding to the region 10a is used.

[Third Embodiment]
Hereinafter, the screen of the third embodiment will be described. The screen 210 of the present embodiment is a modification of the screen 10 of the first embodiment, and is the same as the screen 10 of FIG. 1 except for the shape of the surface of the cylindrical lens CL. The illustration and detailed description are omitted. 5A and 6A are side sectional views for explaining the structure of the screen 210 according to the present embodiment. FIG. 5A is an upper side of the screen 210, that is, the first region. 210a and FIG. 6A are diagrams of the lower side of the screen 210, that is, the second region 210b. Moreover, FIG.5 (b) and 6 (b) are figures of each comparative example.

  First, as can be seen from FIG. 5A, the upper side of the screen 210 of the present embodiment, that is, the first region 210a, is lenticular compared to the standard arrangement shown in FIG. 5B. Each cylindrical lens CL of the lens 201 has an optical axis tilted upward in the lens, that is, in the + y direction. Thereby, the condensing direction of the projection light PL can be changed, and the entire screen sheet 202 can be made thinner.

  Next, as shown in FIG. 6A, in the case of the lower side of the screen 210, that is, the second region 210 b, each cylindrical lens CL of the lenticular lens 201 has an optical axis downward in the lens, that is, in the −y direction. It is tilted. This makes it possible to widen the viewing angle with respect to the upward direction, that is, the + y direction of the projection light PL scattered and reflected by the reflection surface RS, as compared with the case where the tilt is not performed as shown in FIG. 6B. Moreover, since the reflective surface RS is still located on the upper side in one cylindrical lens CL, the light loss of the projection light PL can be suppressed. Further, as a further modification of FIG. 6A, as shown in FIG. 6C, it is possible to use a state where the surface CN of the cylindrical lens CL has a non-arc shape and is further tilted. . In this case, the strength of the screen 210 can be further increased by maintaining a sufficient distance from the upper end of the reflective surface RS to the surface portion of the cylindrical lens CL while keeping the thickness of the entire screen 210 thin.

  In the screen 210 according to this embodiment, the cylindrical lens CL described with reference to FIGS. 5A and 6A or 6C may be used in all the regions 210a and 210b. Alternatively, it may be a partially used mode in which only one of the regions 210a and 210b is used for a part of the region.

[Fourth Embodiment]
The screen according to the fourth embodiment will be described below. The screen 310 of the present embodiment is a modification of the screen 10 of the first embodiment, and is the same as the screen 10 of FIG. 1 except for the shape of the surface of the cylindrical lens CL. The illustration and detailed description are omitted. FIG. 7A is a side sectional view showing one cylindrical lens CL of the lenticular lens 301, that is, one pitch of the screen 310 in order to show the structure of the screen 310 according to this embodiment, and FIG. FIG. 4 is a diagram for explaining a surface shape of a cylindrical lens CL of a screen 310.

  In the screen 310 of the present embodiment, the contour CN of the side cross section of the cylindrical lens CL is formed by one curve in which two arcs are combined. In other words, the cylindrical lens CL is configured by one merged lens including a lens portion UP that occupies the upper side and a lens portion DP that occupies the lower side from the upper and lower central positions CP in one pitch of the cylindrical lens CL. Hereinafter, the shape of the cylindrical lens CL will be described more specifically with reference to FIG. First, as a reference for forming the two lens portions UP and DP, a semicircular virtual lens VL indicated by a one-dot chain line in the figure is determined. The virtual lens VL has a semicircular cross section that is symmetric about the center position CP, that is, the optical axis. The lens portion UP corresponds to a shape obtained by shifting the virtual lens VL upward, that is, in the + y direction. More specifically, of the virtual lens UL (dotted line and solid line in the figure) having the optical axis UX above the center position CP by shifting the virtual lens VL upward, a portion occupying the upper side from the center position CP indicated by the solid line Is the lens portion UP. Similarly, the lens portion DP corresponds to a shape obtained by shifting the virtual lens VL downward, that is, in the −y direction. More specifically, of the virtual lens DL (dotted line and solid line in the figure) having the optical axis DX below the center position CP by shifting the virtual lens VL downward, it occupies the lower side from the center position CP indicated by the solid line. The portion is a lens portion DP. As described above, by shifting up and down in the y direction, the shape of the merged lens can be obtained by combining the two decentered lens portions UP and DP, and the cylindrical lens CL is constituted by such a merged lens. Yes. In this case, the thickness of the entire screen 210 is kept thin by appropriately adjusting the amount of eccentricity, that is, the shift amount, or the screen sheet 302 is kept while keeping the thickness from the upper end portion of the reflective surface RS to the surface of the cylindrical lens CL. It is possible to make the screen 310 sufficiently strong without being easily broken. In particular, in FIG. 7A, the distance from the central position CP to the optical axis UX is equal to the distance from the central position CP to the optical axis DX. That is, the shift amounts from the center position CP of the lens portion UP and the lens portion DP are equal. In this case, the lens surface of the cylindrical lens CL is relatively easy to produce by having symmetry with respect to the central position CP.

[Fifth Embodiment]
In the fifth embodiment, a projection system using the screen of the present invention will be described. FIG. 8 is a diagram illustrating an example of the projection system according to the present embodiment, and illustrates a projection system when a projector is used as the image projection apparatus for the screens 10, 110, 210, and 310 according to the first to fourth embodiments. ing. In FIG. 8, the projector 100 includes a projector main body 50, a projection lens 20, and a reflection mirror RM. Each mechanism of projector 100 is housed in casing SC. Here, as an installation environment of the screens 10 to 310 and the projector 100, the illumination device 200 suspended in the room is illuminated by the external light OL from above, and the projector 100 includes the screens 10 to 310. Projection is performed from below.

  The image light formed by the control of the projector 50 is emitted from the projection lens 20 and further emitted as the projection light PL from the projector 100 in a state where a desired angle is given by reflection by the reflection mirror RM. . Accordingly, in this case, the projector 100 performs oblique projection in which the light beam axis of the projection light PL is inclined with respect to the normal line of the screens 10 to 310. The projection light PL projected on the screens 10 to 310 is reflected on the screens 10 to 310 as described above. At this time, as described above, since the screens 10 to 310 are configured corresponding to the projection angle of the projection light PL, the projected image reduces the influence of the external light OL and is projected in a bright room or the like. In addition to improving the contrast of the image, the projection light PL can be appropriately emitted in the front direction.

  In addition, this invention is not restricted to said embodiment, In the range which does not deviate from the summary, it can implement in a various aspect, For example, the following deformation | transformation is also possible.

  First, in the above embodiment, the screens 10 to 310 are divided into two upper and lower parts with the incident angle α = 60 ° as a reference, and the projection light PL is reflected and scattered in two different patterns. The dividing method is not limited to the upper and lower dividing methods, and various dividing methods can be used on the basis of the incident angle α = 60 °. For example, a transition region is provided between the first region 10a and the second region 10b in the vicinity of the incident angle α = 60 °, and the transition region shown in FIGS. 2 (a) and 2 (b) Two different patterns of operation in the first area 10a and the second area 10b may be mixed and gradually changed from one pattern to the other pattern. Further, for example, the number of screen patterns is not limited to two, and may be three or more patterns.

  In the above embodiment, the incident angle α = 60 ° at the center position O, but the incident angle α = 60 ° of the projection light PL is a place other than the center position O on the screen center axis LX. It may be. In this case, the place where the incident angle α = 60 ° other than the center position O is a reference for separating the first region 10a and the second region 10b. Further, the incident angle as a reference for dividing the region may be an angle other than 60 ° according to the screen mode and the like.

  In each of the above embodiments, the first region 10a is emitted from the cylindrical lens CL adjacent to the cylindrical lens CL on which the projection light PL is incident, and the second region 10b is projected from the same cylindrical lens CL. By emitting the light PL, the first region 10a and the second region 10b have different types of reflection modes. However, the present invention is not limited to this. For example, in the second region 10b located on the lower side, the projection light PL is emitted from the cylindrical lens CL adjacent to the cylindrical lens CL and incident on the first region 10a located on the upper side. The light may be emitted from a cylindrical lens CL that is further above the cylindrical lens CL adjacent to the cylindrical lens CL. That is, in the first region 10a, for example, in FIG. 2A, the projection light PL1 incident from the cylindrical lens CL1 is scattered and reflected by the reflecting surface RS3 positioned further above the reflecting surface RS2, and is emitted from the cylindrical lens CL3. May be.

  In the above embodiment, the lenticular lens 1 constitutes a lens array. However, the lens array of each of the screens 10 to 310 is, for example, a microlens arranged on a two-dimensional plane. Also good.

  Moreover, in said embodiment, although the scattering part 4 is formed by apply | coating the ink containing a scattering component, the scattering part 4 is not only by ink but by sticking a scattering sheet, for example to reflective surface RS. It may be formed.

  The light absorbing film 103 covers the entire back surface of the lenticular lens 1. For example, in order to increase the contrast, the light absorbing film 103 is partially applied around the reflecting surface RS on which the scattering portion 4 is applied. It may be provided.

  In the above embodiment, the pitch of the grooves GT is not particularly defined, but the pitch of the grooves GT in the vertical direction of the screens 10 to 310 may be gradually changed according to the incident angle of the projection light PL. Good.

  In the embodiment described above, the direction of the light beam axis AX with respect to the projection light PL is from below in consideration of the use environment of a general projection apparatus or the like, and the shape of the reflection surface RS of the lenticular lens 1 corresponding to this. However, when the projection light PL is incident from other than the lower side, the configuration of the lenticular lens 1 may be different depending on this. That is, for example, when the projection from the projector is performed from the side of the screen, the configuration of the lenticular lens 1 and the inclination of the reflection surface RS may be changed corresponding to the incident direction of the projection light PL.

It is the side view which showed typically the screen which concerns on 1st Embodiment. (A), (b) is a figure explaining the structure of a screen. (A)-(c) is a figure explaining the other manufacturing method of a screen. (A), (b) is a figure explaining the screen which concerns on 2nd Embodiment. (A), (b) is a figure explaining the screen which concerns on 3rd Embodiment. (A)-(c) is a figure explaining the screen which concerns on 3rd Embodiment. (A), (b) is a figure explaining the screen which concerns on 4th Embodiment. It is a schematic diagram about the projection system which concerns on 5th Embodiment.

Explanation of symbols

  10, 110, 210, 310 ... screen, 10a ... first region, 10b ... second region, 1, 101, 201, 301 ... lenticular lens, 2, 102, 202, 302 ... screen sheet, 3 ... light absorbing sheet, 4 ... Scattering part, CL ... Cylindrical lens, GT ... Groove, RS ... Reflecting surface, 100 ... Projector, 200 ... Illumination device

Claims (14)

A lens array having a plurality of element lenses arranged on a two-dimensional plane on the front surface side of the screen; a plurality of reflecting surfaces arranged on the back side of the lens array with an inclination with respect to the two-dimensional plane; A screen sheet having a plurality of scattering portions that scatter light emitted from the reflecting surface to the front side of the screen;
In the screen sheet, the relative positional relationship between the element lens that makes the projection light incident and the element lens that emits the projection light through the corresponding reflecting surface are different from each other in relation to the incident angle range of the projection light. A screen having a first region and a second region.   The lens array includes a plurality of cylindrical lenses as the plurality of element lenses, and is configured by a lenticular lens that arranges the plurality of cylindrical lenses in a direction perpendicular to a longitudinal direction of each cylindrical lens. screen.   The screen sheet emits the projection light from an element lens adjacent to the element lens to which the projection light is incident in the lens array of the first region, and the projection light is incident on the lens array of the second region. The screen according to claim 1, wherein the projection light is emitted from the same element lens as the element lens.   The screen sheet has the first region on the side where the incident angle of the projection light with respect to the two-dimensional plane is large, and has the second region on the side where the incident angle of the projection light with respect to the two-dimensional plane is small. The screen according to any one of claims 1 to 3.   The screen according to any one of claims 1 to 4, wherein in the screen sheet, a region where an incident angle of projection light incident on a screen central axis is 60 degrees or more is the first region.   6. The screen according to claim 1, wherein a side cross-sectional shape of each element lens constituting the lens array is a non-circular arc shape having a curvature that decreases toward an adjacent element lens. 7.   The lens array provided in at least one of the first region and the second region includes a merged lens having a pair of two lens portions that are decentered from each other as an element lens. The screen according to any one of the above.   The at least one group of element lenses in the lens array provided in at least one of the first region and the second region is tilted in relation to the incident angle range of the projection light. The screen according to any one of 7 to 7.   The screen according to any one of claims 1 to 8, further comprising a light absorbing surface formed of a light absorbing material at least around the reflecting surface of the back side of the lens array.   The screen according to claim 9, wherein in the first region, the reflection surface is smaller than the light absorption surface, and in the second region, the reflection surface is larger than the light absorption surface.   The screen according to claim 10, wherein the screen sheet has a transition region between the first region and the second region, and the shape of the reflection surface and the light absorption surface gradually changes in the transition region. .   The screen according to any one of claims 1 to 11, wherein the lens array has an antireflection coating on a surface thereof.   The lenticular lens can be rolled up and has a structure in which a longitudinal direction of the plurality of cylindrical lenses is arranged along a direction of a rolling axis. Screen described. A screen according to any one of claims 1 to 13,
A projection system comprising: an image projection device that projects a projection image on the screen.

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