Floating image display apparatus and manufacturing method of prism film for floating image display apparatus

Abstract

This floating image display apparatus comprises: a display configured to output light corresponding to an image; and a prism film configured to reflect light output from the display, to form a floating image, wherein the prism film includes a plurality of prism strips stacked in a first direction, at least one prism strip among the plurality of prism strips includes: a base layer extending in a second direction perpendicular to the first direction; and a plurality of prisms provided on a first surface of the base layer along the second direction.

Description

Floating image display device and method for manufacturing prism film for floating image display device

[0001] The present disclosure relates to a floating image display device and a prism film as an optical member used therein.

[0002] A floating image display device is a display device that displays images in the air (mid-air). A floating image display device can utilize the principle of retroreflection or a dihedral corner reflector array (DCRA) to form a floating image.

[0003] The dihedral corner reflector array reflects the light containing the original image twice to form a floating image, which is a real image, on the opposite side of the original image. The floating image can be formed at a location that is the same distance from the dihedral corner reflector array as the original image is.

[0004] A dihedral corner reflector array can be formed by stacking a secondary mirror structure composed of thin glass plates aligned parallel to each other on top of a primary mirror structure composed of thin glass plates aligned parallel to each other, so that they intersect. However, this method requires cutting, aligning, and stacking thin glass plates, making processing difficult and potentially costly.

[0005] One aspect of the present disclosure discloses a floating image display device using a prism film that reflects light.

[0006] One aspect of the present disclosure discloses a method for manufacturing a prism film for a floating image display device.

[0007] Additional aspects are presented in some of the subsequent descriptions, and some will be self-evident from the descriptions or may be learned by practice of the embodiments presented.

[0008] According to one embodiment of the present disclosure, a floating image display device includes: a display configured to output light corresponding to an image; and a prism film configured to reflect the light output from the display to form a floating image; wherein the prism film includes a plurality of prism strips stacked in a first direction, and at least one prism strip among the plurality of prism strips includes a substrate layer extending in a second direction perpendicular to the first direction, and a plurality of prisms provided on a first surface of the substrate layer along the second direction.

[0009] At least one prism among the above plurality of prisms may have a triangular prism shape.

[0010] At least one of the prisms may include a first bottom surface having a right triangle shape; a second bottom surface having a shape corresponding to the first bottom surface; a first side surface having a rectangular shape; a second side surface having a shape corresponding to the first side surface and forming a right angle with the first side surface; and a diagonal surface connecting the first side surface and the second side surface.

[0011] The above diagonal surface may face one side of the substrate layer.

[0012] At least one of the prisms may receive light output from the display through the first bottom surface, reflect it sequentially at the first side surface and the second side surface, and then emit the light from the at least one prism through the second bottom surface.

[0013] The at least one prism may be configured to form the floating image based on light emitted through the second bottom surface.

[0014] The plurality of prisms may include a translucent material having a higher refractive index than air.

[0015] Each of the plurality of prism strips may include an adhesive layer provided on a second surface opposite to the first surface of the substrate layer.

[0016] The above prism film may include a filler layer filled between the plurality of prism strips.

[0017] The refractive index of the above filler layer may be lower than the refractive index of the plurality of prisms.

[0018] The above filler layer may have a black color.

[0019] Among the plurality of prism strips, the first prism strip and the second prism strips laminated on the first prism strip may be arranged along the second direction so as to correspond to each other.

[0020] Among the plurality of prism strips, the first prism strip and the second prism strip laminated on the first prism strip may be arranged to be offset along the second direction.

[0021] According to one aspect of the present disclosure, a prism film may include: a plurality of substrate layers stacked in a first direction; a plurality of prisms in the shape of triangular columns arranged along a second direction on a first surface of each of the plurality of substrate layers. The plurality of prisms may be configured to reflect light output by a display to form a floating image.

[0022] Each of the plurality of prisms may include: a first bottom surface having a right triangle shape; a second bottom surface having a shape corresponding to the first bottom surface; a first side surface having a rectangular shape; a second side surface having a shape corresponding to the first side surface and forming a right angle with the first side surface; and a diagonal surface connecting the first side surface and the second side surface.

[0023] The above plurality of prisms may be configured to receive light output by the display through the first bottom surface, sequentially reflect the light along the first side and the second side, and emit the light through the second bottom surface to form a floating image.

[0024] The above prism film may further include a filler layer between the plurality of prisms and the plurality of substrate layers, the filler layer having a black color, and a refractive index of the filler layer may be lower than a refractive index of the plurality of prisms.

[0025] Among the plurality of substrate layers, a first substrate layer is laminated on a second substrate layer, and a plurality of prisms formed on the first substrate layer can be arranged to correspond to a plurality of prisms formed on the second substrate layer along the second direction.

[0026] Among the plurality of substrate layers, a first substrate layer is laminated on a second substrate layer, and a plurality of prisms formed on the first substrate layer can be arranged to be misaligned with a plurality of prisms formed on the second substrate layer along a second direction.

[0027] According to one embodiment of the present disclosure, a method for manufacturing a prism film for a floating image display device includes: preparing a plurality of prism sheets, each of which includes a plurality of prisms arranged in a first direction; stacking the plurality of prism sheets in a second direction perpendicular to the first direction to form a prism stack structure; and cutting the prism stack structure along a cutting surface.

[0028] The above cutting surface can extend along the Y direction and the Z direction.

[0029] Preparing the plurality of prism sheets may include preparing a substrate layer; and forming the plurality of prisms on one surface of the substrate layer.

[0030] The method for manufacturing a prism film for the floating image display device may further include forming an adhesive layer on the opposite surface of the substrate layer.

[0031] The method for manufacturing a prism film for the floating image display device may further include filling a filler layer between the plurality of prism sheets.

[0032] Each of the plurality of prisms may extend in the X direction perpendicular to the Y direction and the Z direction.

[0033] The above plurality of prisms may have a triangular prism shape.

[0034] According to one embodiment of the present disclosure, the manufacturing of a prism film and a floating image display device using the same can be easily performed and the manufacturing cost can be reduced.

[0035] According to one embodiment of the present disclosure, the quality of a floating image formed by a floating image display device can be improved.

[0036] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0037] Other aspects, features and advantages of the above and specific embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings.

[0038] FIG. 1 is a diagram illustrating the operation of a floating image display device according to one embodiment of the present disclosure.

[0039] FIG. 2 is a drawing illustrating a prism film according to one embodiment of the present disclosure, and is an enlarged view of the 'O' portion of FIG. 1.

[0040] FIG. 3 is a diagram illustrating a prism and a path of light incident on the prism according to one embodiment of the present disclosure.

[0041] Figure 4 is a side view of the prism of Figure 3.

[0042] Figure 5 is a plan view of the prism of Figure 3.

[0043] FIG. 6 is a diagram illustrating a path of light incident on a prism film according to one embodiment of the present disclosure.

[0044] Figure 7 is a side view of the light path of Figure 6.

[0045] FIG. 8 is a drawing illustrating a method for manufacturing a prism film for a floating image display device according to one embodiment of the present disclosure.

[0046] FIG. 9 is a drawing illustrating a prism sheet according to one embodiment of the present disclosure.

[0047] FIG. 10 is a drawing illustrating a prism stack structure according to one embodiment of the present disclosure.

[0048] Fig. 11 is a plan view illustrating an operation of cutting the prism laminated structure of Fig. 10.

[0049] FIG. 12 is a drawing illustrating a prism film formed by an operation of cutting the prism laminate structure of FIG. 11.

[0050] FIG. 13 is a drawing illustrating a prism stack structure according to one embodiment of the present disclosure.

[0051] Fig. 14 is a drawing showing a prism film formed by cutting the prism laminate structure of Fig. 13.

[0052] FIG. 15 is a drawing illustrating a prism stack structure according to one embodiment of the present disclosure.

[0053] Fig. 16 is a drawing showing a prism film formed by cutting the prism laminate structure of Fig. 15.

[0054] It should be understood that the various embodiments of the present disclosure and the terminology used therein are not intended to limit the technical features described in the present disclosure to specific embodiments, but rather to encompass various modifications, equivalents, or alternatives of the embodiments.

[0055] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0056] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0057] In this disclosure, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0058] The term “and / or” includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0059] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0060] In addition, terms such as 'front', 'rear', 'top', 'bottom', 'side', 'left', 'right', 'upper', and 'lower' used in the present disclosure are defined based on the drawings, and the shape and position of each component are not limited by these terms.

[0061] The terms “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the present disclosure, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0062] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0063] When we say that a component is “on” another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0064] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0065] FIG. 1 is a diagram illustrating the operation of a floating image display device according to one embodiment of the present disclosure.

[0066] A floating image display device (1) is a display device that forms a floating image (5) in the air. The floating image display device (1) may include an image forming unit (3, for example, a display) that forms an original image (4), and a prism film (10; 20; 30) that reflects light provided from the image forming unit (3) multiple times to form a floating image (5).

[0067] The image forming unit (3) can provide light to form an original image (4). The type of the original image (4) is not particularly limited, and may be, for example, a two-dimensional image or a three-dimensional image. The image forming unit (3) may be a display device that outputs an image or an actual object. For example, the image forming unit (3) may include an LCD (Liquid Crystal Display) element, an OLED (Organic Light Emitting Diode) display element, a Micro LED, a QD (Quantum Dot) LED, etc. When the display element provided in the image forming unit (3) is a non-luminous element such as an LCD, the image forming unit (3) may further include a light source that provides light for forming an image.

[0068] The original image (4) illustrated in the drawing is conceptually illustrated to explain the progression of light containing the original image (4) and may be an image displayed on the display surface of the image forming unit (3).

[0069] Light provided from the image forming unit (3) and incident on the inside of the prism film (10; 20; 30) can be reflected inside the prism film (10; 20; 30) and then emitted to the outside of the prism film (10; 20; 30). In another aspect, light provided from the image forming unit (3) can transmit through the prism film (10; 20; 30). For example, light incident on the prism film (10, 20, or 30) can be totally reflected multiple times and then emitted to the outside of the prism film (10, 20, or 30). That is, as illustrated in FIG. 1, light provided from the image forming unit (3) can transmit through the prism film (10) in the X direction.

[0070] The floating image (5) is a real image that is actually created when the light provided from the image forming unit (3) is reflected by the prism film (10; 20; 30) and then gathered. In other words, the floating image (5) is a real image of the original image (4) formed by the light provided from the image forming unit (3) projected in the air.

[0071] The floating image (5) may have a planar symmetrical relationship with respect to the original image (4) and the prism film (10). Accordingly, the distance between the floating image (5) and the prism film (10) may be the same as the distance between the original image (4) and the prism film (10). The larger the size of the prism film (10), the larger the distance and viewing angle between the floating image (5) and the prism film (10) can be secured.

[0072] The floating image display device (1) may further include a sensor (2) that recognizes a user's touch, gesture, etc., with respect to an area in the air where the floating image (5) is located. The sensor (2) may include various sensors such as a position sensor, an acceleration sensor, a 3D sensor, a proximity sensor, an IR (Infrared) sensor, a biometric sensor, etc.

[0073] The user can control the image display device (1) by touching an area in the air where a floating image (5) is located, and non-contact interaction between the user and the air display device (1) can be possible.

[0074] FIG. 2 is a drawing illustrating a prism film according to an embodiment of the present disclosure, which is an enlarged view of part 'O' of FIG. 1. FIG. 3 is a drawing illustrating a prism and a path of light incident on the prism according to an embodiment of the present disclosure. FIG. 4 is a side view of the prism of FIG. 3. FIG. 5 is a plan view of the prism of FIG. 3. FIG. 6 is a drawing illustrating a path of light incident on the prism film according to an embodiment of the present disclosure. FIG. 7 is a side view of the path of light of FIG. 6.

[0075] Referring to FIG. 2, the prism film (10) may include a plurality of stacked prism strips (40). Each prism strip (40) extends in the Y direction, and the plurality of prism strips (40) may be stacked in the Z direction perpendicular to the Y direction.

[0076] Each of the plurality of prism strips (40) may include a substrate layer (50) and a plurality of prisms (60) formed on a first surface (51) of the substrate layer (50). The substrate layer (50) may extend in the Y direction. The plurality of prisms (60) may be arranged in a row along the Y direction. The plurality of prisms (60) may be arranged continuously along the Y direction such that prisms (60) arranged next to each other among the plurality of prisms (60) are in contact with each other. That is, an edge of one prism (60) among the plurality of prisms (60) may be in contact with an edge of a prism (60) arranged next to the one prism (60).

[0077] At least one prism (60) among the plurality of prisms (60) may have a triangular prism shape. Specifically, the prism (60) may include a first bottom surface (61), a second bottom surface (62), a first side surface (63), a second side surface (64), and a diagonal surface (65).

[0078] The first bottom surface (61) may have a right triangle shape. The second bottom surface (62) may have a shape corresponding to the first bottom surface (61) and may be parallel to the first bottom surface (61). The first side surface (63) may have a rectangular shape. The second side surface (64) may have a shape corresponding to the first side surface (63). The first side surface (63) and the second side surface (64) may be in contact with each other and form a right angle. The diagonal surface (65) may have a rectangular shape and may connect the first side surface (63) and the second side surface (64).

[0079] The prism (60) can be formed on the first surface (51) of the substrate layer (50) so that the diagonal surface (65) faces the first surface (51) of the substrate layer (50). The prism (60) can be formed on the first surface (51) of the substrate layer (50) so that the diagonal surface (65) contacts the first surface (51) of the substrate layer (50).

[0080] The edge between the first side surface (63) and the second side surface (64), the edge between the second side surface (64) and the diagonal surface (65), and the edge between the diagonal surface (65) and the first side surface (63) can be parallel to the X direction.

[0081] The substrate layer (50) and the prism (60) may be formed of a light-transmitting material having a refractive index higher than that of air. For example, the substrate layer (50) and the prism (60) may be formed of glass or transparent resin. Here, the transparent material means a material that allows light in the visible light band to pass through, and does not mean that the transparency is 100%, and may have a predetermined color. However, the materials of the substrate layer (50) and the prism (60) are not limited thereto.

[0082] As illustrated in FIGS. 3 to 5, light (L) provided from the image forming unit (3) can be incident on the prism (60) through the first bottom surface (61). For example, light (L) provided from the image forming unit (3) can be refracted at the first point (P1) of the first bottom surface (61) and incident on the prism (60).

[0083] Light (L) incident on the prism (60) may be totally reflected sequentially at the first side surface (63) and the second side surface (64). For example, light (L) incident on the prism (60) may be totally reflected at the second point (P2) of the first side surface (63) and then totally reflected at the third point (P3) of the second side surface (64). According to one embodiment, light may be totally reflected at the second point P2 and the third point P3. Therefore, light may be totally reflected multiple times within the prism (60).

[0084] Light (L) totally reflected at the first side surface (63) and the second side surface (64) can be emitted from the prism (60) through the second bottom surface (62). For example, light (L) totally reflected at the first side surface (63) and the second side surface (64) can be refracted at the fourth point (P4) of the second bottom surface (62) and emitted from the prism (60).

[0085] As shown in FIGS. 6 and 7, a plurality of lights (e.g., L1 and L2, etc.) provided from the image forming unit (3) are incident on the prism (60), are sequentially totally reflected at the first side surface (63) and the second side surface (64) of the prism (60), and are emitted from the prism (60) can be gathered to form a floating image (5).

[0086] FIG. 8 is a diagram illustrating a method for manufacturing a prism film for a floating image display device according to an embodiment of the present disclosure. FIG. 9 is a diagram illustrating a prism sheet according to an embodiment of the present disclosure. FIG. 10 is a diagram illustrating a prism laminate structure according to an embodiment of the present disclosure. FIG. 11 is a plan view illustrating an operation of cutting the prism laminate structure of FIG. 10. FIG. 12 is a diagram illustrating a prism film formed by an operation of cutting the prism laminate structure of FIG. 11.

[0087] Referring to FIGS. 8 to 12, a method for manufacturing a prism film (10; 20; 30) for a floating image display device according to one embodiment of the present disclosure is described.

[0088] A method for manufacturing a prism film for a floating image display device may include preparing (210) a plurality of prism sheets (140).

[0089] The prism strip (40) illustrated in the aforementioned FIG. 2 may be a single segment formed by dividing a prism sheet (140).

[0090] Preparing a plurality of prism sheets (140) may include preparing a substrate layer (150) and forming a plurality of prisms (160) on a first surface (151) of the substrate layer (150).

[0091] As illustrated in Fig. 9, the prism sheet (140) may include a substrate layer (150) and a plurality of prisms (160) formed on a first surface (151) of the substrate layer (150). The substrate layer (150) may be formed as a flat plate extending along the X direction and the Y direction perpendicular to the X direction.

[0092] A plurality of prisms (160) may be arranged in a row along the Y direction. The plurality of prisms (160) may be arranged continuously along the Y direction so that prisms (160) arranged next to each other among the plurality of prisms (160) are in contact with each other. The plurality of prisms (160) may be formed on the first surface (151) of the substrate layer (150) through a roll imprinting method or the like. However, the method of forming the plurality of prisms (160) on the first surface (151) of the substrate layer (150) is not limited thereto. The plurality of prisms (160) and the substrate layer (150) may also be formed integrally.

[0093] At least one prism (160) among the plurality of prisms (160) may have a triangular prism shape. Specifically, the prism (160) may include a first bottom surface, a second bottom surface, a first side surface, a second side surface, and a diagonal surface.

[0094] The first base may have a right triangle shape. The second base may have a shape corresponding to the first base and may be parallel to the first base. The first side may have a rectangular shape. The second side may have a shape corresponding to the first side. The first side and the second side may form a right angle. The diagonal may have a rectangular shape and may connect the first side and the second side.

[0095] The prism (160) may be formed on the first surface (151) of the substrate layer (150) such that the diagonal surface faces the first surface (151) of the substrate layer (150). The prism (160) may be formed on the first surface (151) of the substrate layer (150) such that the diagonal surface (165) contacts the first surface (151) of the substrate layer (150).

[0096] The prism sheet (140) may have a length (S) along the X direction. Since the prism (160) formed on one side (151) of the substrate layer (150) extends in the X direction, the length (S) of the prism (160) along the X direction may be the same as the length (S) of the substrate layer (150) along the X direction.

[0097] The substrate layer (150) and the prisms (160) may be formed of a light-transmitting material having a refractive index higher than that of air. For example, the substrate layer (150) and the prisms (160) may be formed of glass or transparent resin. However, the materials of the substrate layer (150) and the prisms (160) are not limited thereto.

[0098] A method for manufacturing a prism film for a floating image display device includes stacking (220) a plurality of prism sheets (140) to form a prism stack structure (110; 120; 130) (FIGS. 10, 13 and 15). The plurality of prism sheets (140) can be stacked along a Z direction perpendicular to the X direction and the Y direction.

[0099] In order to laminate a plurality of prism sheets (140), the plurality of prism sheets (140) may include an adhesive layer (170) formed on the second surface (151) of the substrate layer (150). That is, a method for manufacturing a prism film for a floating image display device may include forming an adhesive layer (170) on the second surface (151) of the substrate layer (150).

[0100] Among the plurality of prism sheets (140), a prism (160) of one prism sheet (140) may be bonded to an adhesive layer (170) of an adjacent prism sheet (140) so as to be laminated on one prism sheet (140) among the plurality of prism sheets (140). The adhesive layer (170) may include an adhesive or a pressure-sensitive adhesive.

[0101] A method for manufacturing a prism film for a floating image display device may include cutting (230) a prism laminate structure (110; 120; 130) to form a prism film (10; 20; 30).

[0102] As illustrated in FIG. 11, the prism laminate structure (110; 120; 130) can be cut along at least one cutting plane (CL). The at least one cutting plane (CL) can extend along the Y direction and the Z direction. That is, the at least one cutting plane (CL) can be parallel to the YZ plane. Each segment cut along the at least one cutting plane (CL) can form a prism film (10; 20; 30).

[0103] A plurality of prism films (10; 20; 30) can be formed by cutting the prism laminate structure (110; 120; 130) along at least one cutting surface (CL).

[0104] As described above, each prism film (10; 20; 30) may include a plurality of prism strips (40) stacked on each other in the Z direction. The plurality of prism strips (40) may include an adhesive layer (see 170 of FIG. 10) provided on the second surface (52) of the substrate layer (50).

[0105] The spacing (D) between the cutting planes (CL) that cut the prism laminated structure (110; 120; 130) may be constant. As illustrated in FIG. 12, the spacing (D) between the cutting planes (CL) may be the length (D) along the X direction of the prism film (10; 20; 30). In addition, it may be the length (D) along the X direction of the prism (60) provided on the prism film (10; 20; 30).

[0106] As illustrated in FIG. 12, among the plurality of prism strips (40a, 40b), the first prism strip (40a) and the second prism strip (40b) adjacent to the first prism strip (40a) can be arranged to correspond to each other. That is, the prisms (60a) of the first prism strip (40a) and the prisms (60b) of the second prism strip (40b) can be aligned to correspond to each other along the Z direction, which is the stacking direction.

[0107] However, it is not limited thereto. For example, as illustrated in FIG. 16, among the plurality of prism strips (40c, 40d), the first prism strip (40c) and the second prism strip (40d) adjacent to the first prism strip (40c) may be arranged in a staggered manner. For example, with respect to the Y direction, the center of the diagonal surface of the prism (60c) may be misaligned from the center of the diagonal surface of the prism (60d). That is, the prisms (60c) of the first prism strip (40c) and the prisms (60d) of the second prism strip (40d) may be arranged in a zigzag manner in a staggered manner along the Z direction, which is the stacking direction of the first prism strip (40c) and the second prism strip (40d).

[0108] FIG. 13 is a drawing illustrating a prism laminate structure according to one embodiment of the present disclosure. FIG. 14 is a drawing illustrating a prism film formed by cutting the prism laminate structure of FIG. 13.

[0109] Referring to FIGS. 13 and 14, a method for manufacturing a prism film (20) for a floating image display device according to one embodiment of the present disclosure will be described.

[0110] The method for manufacturing a prism film for a floating image display device described above can be equally applied to the method for manufacturing a prism film (20) for a floating image display device according to the embodiments of FIGS. 13 and 14.

[0111] A method for manufacturing a prism film (20) for a floating image display device may further include filling a filler layer (180) between a plurality of prism sheets (140). By providing the filler layer (180) between the prism sheets (140), the structural stability of the prism film (20) can be increased and deformation of the shape can be prevented.

[0112] The filler layer (180) may have a resin material having a lower refractive index than the prisms (160). Since the filler layer (180) has a lower refractive index than the prisms (160), total light reflection may occur inside the prisms (60).

[0113] In addition, the filler layer (180) may have a black color to absorb light that does not contribute to the formation of the floating image (5). That is, the filler layer (180) may include carbon black, a polyene pigment, an azo pigment, an azomethine pigment, a diimmonium pigment, a phthalocyanine pigment, a quinone pigment, an indigo pigment, a thioindigo pigment, a dioxadin pigment, a quinacridone pigment, an isoindolinone pigment, etc.

[0114] By filling the filler layer (180) between the plurality of prism sheets (140), the prism laminate structure (120) may include the filler layer (180) filled between the plurality of prism sheets (140). In addition, the prism film (20) formed by cutting the prism laminate structure (120) may include the filler layer (80) filled between the plurality of prism strips (40).

[0115] The filler layer (80) filled between the plurality of prism strips (40) may be formed of a resin material having a lower refractive index than the prisms (60). The filler layer (80) may have a black color and may absorb unnecessary light that does not contribute to the formation of a floating image (5).

[0116] For example, the filler layer (80) can absorb light provided from the image forming unit (3) that does not enter the first bottom surface (61) of the prism (60) or is totally reflected odd times inside the prism (60). Such light cannot form a floating image (5) and may instead damage the clarity of the floating image (5). By absorbing such unnecessary light by the filler layer (80), the clarity of the floating image (5) can be improved.

[0117] FIG. 15 is a drawing illustrating a prism laminate structure according to one embodiment of the present disclosure. FIG. 16 is a drawing illustrating a prism film formed by cutting the prism laminate structure of FIG. 15.

[0118] As described above, among the plurality of prism strips (40c, 40d), the first prism strip (40c) and the second prism strip (40d) adjacent to the first prism strip (40c) may be arranged in an alternating manner. With respect to the Y direction, the center of the diagonal surface of the prism (60c) may be offset from the center of the diagonal surface of the prism (60d).

[0119] That is, the prisms (60c) of the first prism strip (40c) and the prisms (60d) of the second prism strip (40d) can be arranged in a zigzag manner so as to be staggered along the Z direction, which is the stacking direction of the first prism strip (40c) and the second prism strip (40d).

[0120] While the technical concept of the present invention has been described above through specific examples, the scope of the present invention is not limited to these examples. Various embodiments that can be modified or altered by those skilled in the art without departing from the spirit of the present invention as defined in the claims are also within the scope of the present invention.

Claims

1. A display configured to output light corresponding to an image; and A prism film configured to reflect light output from the display to form a floating image; The above prism film comprises a plurality of prism strips stacked in a first direction, A floating image display device, wherein at least one prism strip among the plurality of prism strips includes a substrate layer extending in a second direction perpendicular to the first direction, and a plurality of prisms provided along the second direction on a first surface of the substrate layer.

2. In paragraph 1, A floating image display device, wherein at least one prism among the plurality of prisms has a triangular prism shape.

3. In paragraph 2, At least one of the above prisms, A first base having the shape of a right triangle; A second bottom surface having a shape corresponding to the first bottom surface; A first side surface having a rectangular shape; A second side surface having a shape corresponding to the first side surface and forming a right angle with the first side surface; and A floating image display device comprising a diagonal surface connecting the first side surface and the second side surface.

4. In paragraph 3, A floating image display device in which the above diagonal surface faces one side of the substrate layer.

5. In paragraph 3, A floating image display device in which at least one prism receives light output from the display through the first bottom surface, reflects it sequentially at the first side surface and the second side surface, and then emits the light from the at least one prism through the second bottom surface.

6. In paragraph 5, A floating image display device wherein the at least one prism is configured to form the floating image based on light emitted through the second bottom surface.

7. In paragraph 1, A floating image display device in which the plurality of prisms include a light-transmitting material having a higher refractive index than air.

8. In paragraph 1, A floating image display device in which the plurality of prism strips include an adhesive layer provided on a second surface opposite to the first surface of the substrate layer.

9. In paragraph 1, A floating image display device in which the prism film includes a filler layer filled between the plurality of prism strips.

10. In paragraph 9, A floating image display device in which the refractive index of the above filler layer is lower than the refractive index of the plurality of prisms.

11. In paragraph 9, The above filler layer is a floating image display device having a black color.

12. In paragraph 1, A floating image display device in which a first prism strip among the plurality of prism strips and a second prism strip laminated on the first prism strip are arranged along the second direction so as to correspond to each other.

13. In paragraph 1, A floating image display device in which a first prism strip among the plurality of prism strips and a second prism strip laminated on the first prism strip are arranged to be offset along the second direction.

14. Preparing a plurality of prism sheets each including a plurality of prisms arranged in a first direction; Stacking the plurality of prism sheets in a second direction perpendicular to the first direction to form a prism stack structure; and A method for manufacturing a prism film for a floating image display device, comprising: cutting the above prism laminate structure along a cutting surface;

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