JP2009198941A - Screen and projection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen by which the contrast of a projection image in a bright room, etc. can be improved by reducing the influence of external light and projection light having an incident angle can be properly reflected and diffused in a front direction and which has sufficient strength, while keeping thinness and to provide a projection system using the screen. <P>SOLUTION: The shape, etc. of a reflecting surface RS are made suitable for scattering and reflecting of incident projection light PL, so that the projection light PL from below can be scattered and reflected to the side of an observer at a proper viewing angle. The surface of a cylindrical lens CL is made into such a non-circular arc shape that curvature becomes more gradual than a circular arc as it goes to a circumferential side, so that the sufficient strength is obtained while keeping the thinness. Further, the external light OL from above is not reflected to the side of the observer by a side surface SS and a light absorption sheet 3, so that even when in use in the bright room, etc. an image having high contrast is 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 a projection light from a projection device such as a front projector and displays a projection image, for example, a large angle is given to the projection light incident at a large incident angle, and the front direction is set. When reflecting, in order to efficiently scatter and reflect the incident projection light in the front direction with an appropriate viewing angle, it is desirable to place a reflecting surface before the focal position of each microlens, etc. It is necessary to bring the reflecting surface close to the lens surface of each microlens. In this case, if the lens surface and the reflecting surface are too close to each other, a very thin portion is formed at a series of approaching locations, which may cause manufacturing problems and may cause problems in strength.

  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 can reduce the influence of external light, improve the contrast of the projected image in a bright room, etc., and can appropriately reflect and diffuse the incident light having an incident angle in the front direction. An object of the present invention is to provide a screen having sufficient strength while maintaining thinness, and a projection system using the screen.

  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) At least one of the plurality of element lenses is a curvature changing lens in which the curvature of one side portion on the side where the incident angle of the projection light with respect to the two-dimensional plane is large becomes smaller toward the circumferential end direction, (C) The front surface of the curvature change lens, wherein the curvature change lens is perpendicular to the first line segment and the first line segment connecting the one end point of the curvature change lens and the other end point opposite to the one side. Through the apex of the side Distance from the intersection of the second line segment to one end point has a non-arc-shaped cross-section is greater than the distance from the intersection to the vertex.

  First, in the screen described above, the screen is provided with a reflecting surface inclined with respect to the plane on which the lens array is arranged on the back side of the lens array, and further includes a scattering portion that scatters light emitted from the reflecting surface. Incident projection light can be reflected in a properly scattered state. At this time, the curvature changing lens has a smaller curvature on one side, which is the side on which the incident angle of the projection light is larger, and in particular, the shape of the non-arc-shaped cross section of the curvature changing lens. A first line segment connecting the one end point and the other end point opposite to the one side, and a second line segment perpendicular to the first line segment and passing through the apex on the front side of the curvature-changing lens. Since the distance from the intersection point to the one side end point is larger than the distance from the intersection point to the apex, even if the reflecting surface is brought close to the lens surface of the curvature change lens, It is easy to increase the distance of the closest part. Therefore, it is possible to keep the reflecting surface close to the lens surface of the curvature change lens while having sufficient strength. By bringing the reflecting surface closer to the lens surface, it is possible to efficiently scatter and reflect incident projection light in an appropriate direction and with a viewing angle. In addition, since the curvature change lens has a smaller curvature on one side portion in the circumferential direction, it can reduce total reflection on the lens surface when the projection light is emitted from the curvature change lens, Light can be used efficiently. In addition, the influence of external light can be reduced, and the contrast of the projected image in a bright room can be improved.

  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.

  Further, as a specific aspect of the present invention, the curvature change lens has a smaller refractive power in the peripheral portion than in the central portion of the lens. In this case, it is possible to scatter and reflect the projection light with an appropriate viewing angle by adjusting the refractive power between the lens center and the periphery.

  As a specific aspect of the present invention, the shape of the curvature change lens is formed in a plurality of patterns corresponding to the position on the screen sheet. In this case, for example, while the projection light is projected from below, by appropriately determining the shape of the curvature change lens with a plurality of patterns in the vertical direction of the screen sheet, it is possible to appropriately scatter and reflect according to the incident position of the projection light. Reflection can be performed.

  As a specific aspect of the present invention, the screen sheet causes the projection light to be incident on the lens array, and a first region in which the projection light is emitted from an element lens different from the element lens on which the projection light is incident on the lens array. A second region that emits the projection light from the same element lens as the element lens, and the lens array includes a curvature change lens in the second region. 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 incident light incident on each of the first region and the second region. In particular, since the lens array in the second region includes the curvature change lens, the lens array of the curvature change lens can be kept sufficiently strong while being close to the lens surface.

  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, 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. In addition, 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 extending vertically from the left and right center of the screen 10 from below. Incident toward

  FIG. 2 is a side sectional view schematically showing the structure of the screen 10. 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 applying a scattering material to the groove GT, and the light absorbing sheet 3 is formed after the scattering part 4 is formed on the back side of the screen sheet 2. Affixed so as to cover the scattering portion 4.

  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 obliquely upward projection light PL from the projection lens PO of FIG. 1 to be incident and condensed, and is reflected by a later-described reflecting surface RS inside the screen 10 and scattered by the scattering unit 4. The projection light PL is emitted forward at a predetermined divergence angle. Here, the contour CN, which is a cross section of the surface shape of the cylindrical lens CL, is not an accurate semicircle, but has a shape having a gentler curvature toward the peripheral side, that is, toward the adjacent cylindrical lens CL. . That is, the cylindrical lens CL is a curvature change lens in which the curvature is changed so that the refractive power in the peripheral portion is smaller than the refractive power in the central portion of the lens.

  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. In the groove GT, side surfaces SS substantially perpendicular to the y direction in which the respective cylindrical lenses CL are arranged are formed on both the upper surface side and the lower surface side, and the groove GT and these side surfaces SS and inclined reflections It is demarcated by the surface RS, and the yz section has a trapezoidal shape. The reflection surface RS has an incident angle of the projection light PL of a predetermined inclination angle so as to increase the tendency to reflect the projection light PL that is collected by each cylindrical lens CL and is inclined obliquely upward and incident in the front direction, that is, the + z direction. It is inclined at β. 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 the screen 10 from the lower side close to the front with a certain spread 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. The screen sheet 2 is made of a light-transmitting resin or the like, and its refractive index is preferably about 1.45 to 1.60.

  Hereinafter, the operation of the screen 10 will be described by explaining the optical path of the projection light PL with reference to FIG.

  First, as shown in FIG. 2, among the cylindrical lenses, the projection light PL1 incident on the cylindrical lens CL1 positioned at the bottom in the y direction in the figure is condensed and reflected at the back of the cylindrical lens CL1. Scattered and reflected by the surface RS. The projection light PL1 reflected by the reflecting surface RS is emitted forward in a state where it is appropriately diverged through the cylindrical lens CL1. That is, the projection light PL1 incident on the cylindrical lens CL1 is emitted from the same cylindrical lens CL1. Similarly, the projection light PL incident on each cylindrical lens CL above the cylindrical lens CL1 is also emitted from the same cylindrical lens CL.

  As shown in FIG. 2, when the projection light PL is scattered and reflected by the same cylindrical lens CL, the reflection surface RS is located on the upper side within one unit of the cylindrical lens CL, that is, one pitch, 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. If the upper end of the reflecting surface RS is too close to the cylindrical lens CL having a general shape, that is, a circular cross section, the projection light PL tends not to have a sufficient viewing angle in the upward direction, or the portion becomes thin and the screen sheet 2 becomes thin. There is a tendency to break easily. For this reason, the cylindrical lens CL has a non-arc-shaped cross section.

  3A and 3B are side sectional views showing one cylindrical lens CL of the lenticular lens 1, that is, one pitch of the screen 10, in order to explain the surface shape of the cylindrical lens CL. b) is a diagram of a comparative example.

  As shown in FIG. 3A, in the screen 10 of the present embodiment, the contour CN of the side cross section of the cylindrical lens CL has a non-arc shape. On the other hand, in the comparative example of FIG. 3B, the contour CNc of the side cross section of the cylindrical lens CLc has an arc shape. Hereinafter, the shape of the contour CN in FIG. As can be seen from the contour CNc of FIG. 3B, the shape of the contour CN of the embodiment has a gentler curvature than the circular arc as it goes to the peripheral side, that is, as it approaches an adjacent cylindrical lens CL (not shown). It has become a thing. Among the points at both ends on the contour CN in FIG. 3A, the end point far from the light source S of the projection light PL, that is, the side where the incident angle of the projection light PL is large is set as the upper end point UP, and the near side, that is, the opposite side. The end point of is the lower end point DP. A line connecting the upper end point UP and the lower end point DP is defined as a line segment SG. Moreover, a perpendicular is drawn with respect to line segment SG from vertex PP of the front side of the screen 10 which is the top part which is the point farthest from line segment SG among the points on contour CN which is convex, A point where the line segment SG intersects is defined as an intersection CS. In the above, the contour CN in FIG. 3A has a shape such that the distance a from the intersection CS to the upper end UP is greater than the distance b from the intersection CS to the vertex PP. In the case of the contour CNc shown in FIG. 3B, since the shape of the contour CNc is a semicircular shape, the intersection CS defined similarly is the center of the circle forming the contour CNc, and the upper end point UP, vertex PP is a point on the circle. Accordingly, the distance from the intersection CS to the upper end point UP and the distance from the intersection CS to the vertex PP are both the radius r of the circle forming the contour CNc, and these distances are equal. On the other hand, regarding the contour CN of the embodiment shown in FIG. 3A, as described above, the relationship between the distances a and b is a> b. Thus, the distance d1 which is the thinnest portion indicated by the reciprocating arrow in the drawing, that is, the distance from the upper end UE of the reflecting surface RS to the surface portion of the cylindrical lens CL (upper end point UP in FIG. 3A) is shown. It can be made larger than that of the circular arc shape as in the comparative example of 3 (b). Thus, by making the portion of the screen sheet 2 that tends to be thinnest thicker, the screen sheet 2 becomes more difficult to break, and as a result, the screen 10 can be made stronger. Further, by relaxing the curvature of the cylindrical lens CL, it is possible to reduce total reflection on the lens surface of the cylindrical lens CL when the projection light PL is emitted from the cylindrical lens CL, and light can be used efficiently. 4 (a) and 4 (b) are comparative views showing the difference in the reflected light at the reflecting surface RS when the curvature of the cylindrical lens CL is different. That is, the cylindrical lens CL in FIG. 4A has a gentler curvature than that in FIG. On the other hand, in FIGS. 4A and 4B, the reflected light RL is emitted from substantially the same point on the reflecting surface RS. From the comparison of the reflected light RL between FIGS. 4 (a) and 4 (b), it can be seen that total reflection is easier in the case of FIG. 4 (b) where the curvature is tight in this case. Moreover, the viewing angle of light may be adjusted by appropriately adjusting the curvature of the cylindrical lens CL.

  FIG. 5A is a diagram for explaining the optical path of the projection light PL in the non-arc-shaped cylindrical lens CL as in the embodiment shown in FIG. 3A, for example, and FIG. is there. That is, FIG. 5A shows the optical path of the projection light PL of the embodiment, and FIG. 5B shows, for comparison, an arc-shaped cylindrical lens CLc (contour CNc) as shown in FIG. 3B, for example. ) And the optical path of the projection light PL incident from the contour CNc. In FIG. 5A, the projection light PL that has entered from the contour CN corresponding to the surface of the cylindrical lens CL is scattered and reflected by the reflection surface RS and emitted from the screen 10 as reflected light RL. On the other hand, similarly in the comparative example of FIG. 5B, the projection light PL incident from the contour CNc is scattered and reflected by the reflection surface RS and emitted as reflected light RLc. In the configuration of the present embodiment shown in FIG. 5A, since the cylindrical lens CL has a smaller curvature in the peripheral region than in the central region, the projection light PL is appropriately reflected and diffused in the front direction. Without being deteriorated, the distance between the surface of the cylindrical lens CL and the reflecting surface can be secured and the strength can be maintained while maintaining the thinness of the entire screen sheet 2.

  In addition, in the screen 10 according to the present embodiment described above, the cylindrical lens CL with the curvature described with reference to FIG. 3A may be used as a whole, and the cylindrical lens CL may be used as a part of the screen 10. It is good also as an aspect used partially, such as using only for.

  Further, the cylindrical lens CL is a curvature-changing lens whose curvature is changed so that the refractive power at the peripheral portion is smaller than the refractive power at the central portion of the lens, but the change in curvature is at least based on the projection light PL as the light source S. On the other hand, the curvature of the far side portion should be smaller toward the far side, that is, the curvature of the one side portion on the side where the incident angle of the projection light is larger should be smaller toward the circumferential end direction. That is, for example, in FIG. 3A, the curvature of the contour CN is small from the vertex PP toward the upper end point UP in the portion of the contour CN that is above the vertex PP that is the portion far from the projection light PL. If so, it is possible to increase the distance d1.

  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 above is incident on the upper surface of the upper and lower side surfaces SS of the groove GT or the light absorbing surface AS of the light absorbing sheet 3 in the screen 10. . The external light OL incident on the side surface SS above the groove GT is reflected from the angle of the upper 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 absorbed without going to the front of the screen 10.

  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 projection light PL from below is directed to the viewer side by making the shape of the reflection surface RS suitable for scattering and reflection of the incident projection light PL. It can be scattered and reflected at an appropriate viewing angle. In addition, the screen 10 has a sufficient strength while maintaining thinness by making the surface shape of the cylindrical lens CL a non-arc shape having a curvature that is gentler than the arc as it goes to the peripheral side. The side light SS and the light absorbing sheet 3 do not reflect the external light OL from above to the observer side, and it is possible to form an image with high contrast even when used in a bright room or the like.

  6 (a), 6 (b) and 6 (c) are diagrams for explaining a modification of the manufacturing method of the present embodiment. Each of the cylindrical lenses CL, that is, one pitch of the screen 10 is shown. It is a side sectional view showing typically. Among these, first, in the example shown in FIG. 6A, a light absorbing film 103 is formed instead of the light absorbing sheet 3 in FIG. That is, after the scattering portion 4 is formed, 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. FIGS. 6B and 6C show further examples of other manufacturing methods in stages. In this modified example, as shown in FIG. 6B, first, a light-absorbing ink is applied to the back side of the screen sheet 2 before the scattering portion 4 is applied to form a light-absorbing film 103. . Thereafter, as shown in FIG. 6C, a scattering material is applied to the entire back surface of the screen sheet 2 so as to fill the grooves GT, thereby forming the scattering portion 4. 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]
FIG. 7 is a side view schematically showing the screen according to the present embodiment. The screen 110 of the present embodiment is a reflective screen, similar to the screen 10 of FIG. 1 of the first embodiment, and a light-transmissive screen sheet 102 provided with a lens array, and the entire back surface of the screen sheet 102. A light absorbing sheet 103 to be attached.

  Also in the case of FIG. 7, similarly to FIG. 1, the projection light PL is projected on the screen 110 from the projection light source point S of the projection lens PO arranged at a close lower position. Compared to the case, the incident angle of the projection light PL is very large, and the light beam axis AX of the projection light PL is set to an incident angle α = 60 °. In such a case, the incident angle of the projection light PL on the screen 110 differs significantly depending on the incident position between a very large incident angle and a relatively small incident angle of the projection light PL, and the type of reflection depends on the incident position. Need to be different. Accordingly, the screen 110 is divided into a first area 110a on the upper surface side of the screen and a second area 110b on the lower surface side of the screen on the basis of the incident angle α = 60 °. In the first area 110a and the second area 110b, They have different shapes or arrangements.

  Of the first region 110a and the second region 110b, the structure of the screen 110 in the second region 110b having a relatively small incident angle is as shown in FIG. 2 in the first embodiment. That is, the projection light PL is scattered and reflected by the same cylindrical lens CL. On the other hand, the structure of the screen 110 in the first region 110a has a different reflection mode from that of the second region 110b.

  FIG. 8 is a side sectional view schematically showing an example of the structure of the screen 110 in the first region 110a. In the case of the first region 110a, the shape of the groove GT is different from the groove GT of the second region 110b having the structure shown in FIG. 2, and one side surface substantially perpendicular to the y direction in which the cylindrical lenses CL are arranged. It is demarcated by SS and the inclined reflecting surface RS, and the yz section is triangular. That is, the shape of the groove GT in both the regions 110a and 110b is different in that the depth of the reflective surface RS is different, and the reflective surface RS in the first region 110a directs the projection light PL in the front direction, that is, in the + z direction. In order to increase the tendency to reflect light, the second region 10b is inclined at a predetermined inclination angle γ different from the inclination angle β according to the difference in the incident angle of the projection light PL.

  Hereinafter, the operation of the screen 110 will be described by describing the optical path of the projection light PL in the first region 110a with reference to FIG.

  As shown in FIG. 8, among the cylindrical lenses CL constituting the lenticular lens 101, the projection light PL1 incident on the cylindrical lens CL1 positioned at the bottom in the y direction in the figure is positioned one upper side of the cylindrical lens CL1. The light is emitted from the cylindrical lens CL2. That is, the projection light PL1 is scattered and reflected by the reflection surface RS2 located behind the cylindrical lens CL2 located one upper side of the cylindrical lens CL1, and is emitted from the cylindrical lens CL2. Similarly, the projection light PL2 incident on the cylindrical lens CL2 is emitted from the cylindrical lens CL3 via the reflection surface RS3, and the projection light PL3 incident on the cylindrical lens CL3 is emitted from the cylindrical lens CL4 and incident on the cylindrical lens CL4. The projected light PL4 is emitted from the cylindrical lens CL5. That is, in the first region 110a, 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.

  As described above, the screen 110 according to the present embodiment divides the region into the first region 110a and the second region 110b according to the incident angle of the projection light PL, and has different types of reflection modes in the respective regions. In addition, a non-arc-shaped cylindrical lens CL having a gentler curvature than the arc-shape is used in the second region 110b which is a part of the region. Thereby, it is possible to effectively scatter and reflect the projection light incident on each of the regions 110a and 110b without waste. In particular, in the second region 110b, the reflecting surface RS is brought close to the lens surface of the cylindrical lens CL. However, it can be kept at a sufficient strength. Note that the cylindrical lens CL in the first region 110a does not need to be non-arc-shaped, but the surface may be non-arc-shaped here. In this case, by relaxing the curvature of the cylindrical lens CL, when the projection light PL is emitted from the cylindrical lens CL, it is possible to reduce total reflection on the lens surface of the cylindrical lens CL, and to efficiently use the light. It becomes possible to do.

  In the second embodiment, the screens 10 and 110 are divided into two upper and lower screens with the incident angle α = 60 ° as a reference, and the projection light PL is reflected and scattered in two different modes. , 110 is not limited to the upper and lower division methods, and various division methods can be used on the basis of the incident angle α = 60 °. For example, in the vicinity of the incident angle α = 60 °, a transition region is provided between the first region 10a and the second region 10b, and the first region 110a and the second region 110b are different in the transition region. A pattern operation may be mixed and gradually changed from one pattern to the other. Further, for example, the number of screen areas is not limited to two areas of two patterns, and may be three or more.

  In the second embodiment, the projection light PL is emitted from the cylindrical lens CL adjacent to the cylindrical lens CL on which the projection light PL is incident in the first region 10a. Different types of reflection modes may be used.

  In the second embodiment, the incident angle α is 60 ° at the center position O. However, the incident angle α of the projection light PL is 60 ° except for the center position O on the screen center axis LX. It may be a place. 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. Also, the incident angle as a reference for dividing the region may be an angle other than 60 ° according to the aspect of the reflection pattern of the screen.

[Third Embodiment]
FIG. 9 is a diagram showing an example of a projection system according to the third embodiment, and shows a projection system when a projector is used as an image projection apparatus for the screens 10 and 110 of the first and second embodiments. In FIG. 9, the projector 100 includes a projector body 50, a projection lens 20, and a reflection mirror RM. Each mechanism of projector 100 is housed in casing SC. Here, as the installation environment of the screens 10 and 110 and the projector 100, the illumination device 200 suspended from the ceiling is illuminated by the external light OL from above, and the projector 100 includes the screens 10 and 110. 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 and 110. As described above, the projection light PL projected on the screens 10 and 110 is reflected in the front direction on the screens 10 and 110 with an appropriate divergence angle. At this time, as described above, since the screens 10 and 110 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 lens array is configured by the lenticular lens 1, but the lens array of each of the screens 10 and 110 is, for example, a microlens arranged on a two-dimensional plane. Also good. In this case, the longitudinal section of the microlens is as shown in FIG.

  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.

  In addition, the light absorption film 103 covers the entire back side of the lenticular lens 1. However, for example, in order to increase the contrast, the light absorption film 103 needs to be partially applied around the reflective surface RS to which the scattering portion 4 is applied. It may be provided accordingly.

  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 and 110 may be gradually changed according to the incident angle of the projection light PL. Good.

  Moreover, in the said embodiment, although each inclination | tilt angle (beta) of reflective surface RS shall be uniform, an inclination angle may differ for every groove | channel GT of the screens 10 and 110 also about this.

  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. It is a sectional side view explaining the structure of a screen. (A), (b) is a comparison figure explaining the shape of a screen. (A), (b) is a comparison figure for demonstrating total reflection. (A), (b) is a figure explaining the optical path of projection light. (A)-(c) is a figure explaining the other manufacturing method of a screen. It is the side view which showed the screen which concerns on 2nd Embodiment typically. It is a sectional side view explaining the screen which concerns on 2nd Embodiment. It is a schematic diagram about the projection system which concerns on 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,110 ... Screen, 1, 101 ... Lenticular lens, 2, 102 ... Screen sheet, 3 ... Light absorption sheet, 4 ... Scattering part, CL ... Cylindrical lens, GT ... Groove, RS ... Reflective surface, 100 ... Projector, 200 ... Lighting device

Claims (9)

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;
At least one of the plurality of element lenses is a curvature change lens in which the curvature of one side portion on the side where the incident angle of the projection light with respect to the two-dimensional plane is large is reduced in the circumferential direction,
The curvature change lens includes a first line segment connecting the one end point of the curvature change lens and the other end point opposite to the one side, and is perpendicular to the first line segment and has the curvature change. A screen having a non-arc-shaped cross section in which a distance from an intersection with a second line segment passing through a vertex on the front side of the lens to the one end point is larger than a distance from the intersection to the vertex.   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 according to any one of claims 1 and 2, wherein the curvature change lens has a refractive power at a peripheral portion smaller than a refractive power at a central portion of the lens.   The shape of the said curvature change lens is a screen as described in any one of Claim 1- Claim 3 formed with a some pattern corresponding to the position in the said screen sheet.   The screen sheet includes a first region in which the projection light is emitted from an element lens different from an element lens in which the projection light is incident in the lens array, and an element lens that is the same as the element lens in which the projection light is incident in the lens array. The screen according to claim 1, further comprising: a second region that emits the projection light, wherein the lens array includes the curvature change lens in the second region.   The screen according to any one of claims 1 to 5, 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 any one of claims 1 to 6, 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 8,
A projection system comprising: an image projection device that projects a projection image on the screen.

Images