JP2023006458A - Display device - Google Patents

Abstract

To provide a display device with which, while suppressing an increase in size, it is possible to extend the length of optical path of light emitted from a display unit.SOLUTION: A display device 10 comprises an optical element 40 having a first plane 42 and a second plane 44 and a reflection member 50 having a reflection plane 52. The optical element 40 and the reflection member 50 are formed so as to enlarge the light emitted from a display unit 30. The light emitted from the display unit 30 enters the first plane 42 after passing through a reflection type polarization element 60 and a λ/4 phase difference element 70, is reflected by the reflection plane 52 after entering the first plane 42, exits the first plane 42 after being reflected by the reflection plane 52, is reflected by the reflection type polarization element 60 after passing through the λ/4 phase difference element 70, passes through the λ/4 phase difference element 70 after being reflected by the reflection type polarization element 60, reenters the first plane 42, is reflected again by the reflection plane 52 after reentering the first plane 42, exits the first plane 42 after being reflected by the reflection plane 52, and passes through the λ/4 phase difference element 70 and the reflection type polarization element 60.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to display devices.

2. Description of the Related Art Conventionally, display devices for displaying images are known. For example, as an example of a display device, Patent Document 1 discloses a display device that includes a display, a half mirror that reflects an image displayed on the display, and a concave mirror that reflects the image reflected by the half mirror. there is

JP 2017-210229 A

However, in the display device of Patent Document 1, if the optical path length of the light emitted from the display is increased, the display device becomes large.

Accordingly, the present disclosure provides a display device capable of increasing the optical path length of light emitted from the display section while suppressing the increase in size.

A display device according to an aspect of the present disclosure includes a display unit, an optical element having a first surface and a second surface, and directing light emitted from the display unit and incident from the first surface toward the first surface. a reflecting member provided on the second surface, the reflective polarizing element disposed on the first surface side of the optical element, and the optical element and the reflective polarizing element and a λ/4 retardation element disposed between the optical element and the reflecting member are formed to expand the light emitted from the display unit, and the light emitted from the display unit is It is transmitted through the reflective polarizing element and the λ/4 phase difference element and enters from the first surface, enters from the first surface, is reflected by the reflective surface, and is reflected by the reflective surface and then is the first light. Emitted from the surface, transmitted through the λ/4 phase difference element, reflected by the reflective polarizing element, reflected by the reflective polarizing element, transmitted through the λ/4 phase difference element, and from the first surface After being incident again, being incident again from the first surface, being reflected again by the reflecting surface, being reflected again by the reflecting surface, being emitted from the first surface, and being the λ/4 retardation element and the reflective polarizing element pass through.

According to the display device of the present disclosure, it is possible to lengthen the optical path length of light emitted from the display section while suppressing an increase in size.

FIG. 1 is a diagram showing a state in which a display device according to a first embodiment is installed in a vehicle. FIG. 2 is a diagram showing the display device of FIG. 3 is a perspective view showing optical elements and the like of the display device of FIG. 1. FIG. 4 is a cross-sectional view showing the optical element and the like of FIG. 3. FIG. 5A and 5B are trihedral views showing the optical element of FIG. FIG. 6 is a diagram showing optical paths of light emitted from the display section of the display device of FIG. FIG. 7 is a perspective view showing an optical element and a reflecting member included in the display device according to the second embodiment. 8A and 8B are trihedral views showing the optical element and the reflecting member in FIG. 7. FIG. FIG. 9 is a perspective view showing the positions of condensing points of light emitted from the optical element of FIG. FIG. 10 is a diagram showing display devices according to third to sixth embodiments. FIG. 11 is a diagram showing display devices according to seventh to ninth embodiments. FIG. 12 is a diagram showing a display device according to tenth and eleventh embodiments.

A display device according to an aspect of the present disclosure includes a display unit, an optical element having a first surface and a second surface, and directing light emitted from the display unit and incident from the first surface toward the first surface. a reflecting member provided on the second surface, the reflective polarizing element disposed on the first surface side of the optical element, and the optical element and the reflective polarizing element and a λ/4 retardation element disposed between the optical element and the reflecting member are formed to expand the light emitted from the display unit, and the light emitted from the display unit is It is transmitted through the reflective polarizing element and the λ/4 phase difference element and enters from the first surface, enters from the first surface, is reflected by the reflective surface, and is reflected by the reflective surface and then is the first light. Emitted from the surface, transmitted through the λ/4 phase difference element, reflected by the reflective polarizing element, reflected by the reflective polarizing element, transmitted through the λ/4 phase difference element, and from the first surface After being incident again, being incident again from the first surface, being reflected again by the reflecting surface, being reflected again by the reflecting surface, being emitted from the first surface, and being the λ/4 retardation element and the reflective polarizing element pass through.

According to this, the light emitted from the display section is reflected by the reflective surface, reflected by the reflective polarizing element after being reflected by the reflective surface, reflected by the reflective polarizing element, and then reflected again by the reflective surface. be able to. In this way, by repeatedly reflecting the light emitted from the display section, the optical path length of the light emitted from the display section can be made longer while suppressing an increase in size of the display device.

Further, in the display device according to one aspect of the present disclosure, the λ / 4 retardation element is a λ / 4 retardation film, is attached to the first surface, and the reflective polarizing element is a reflective polarizing It is a film and may be attached to the λ/4 retardation element.

According to this, since the λ/4 retardation element and the reflective polarizing element can be easily arranged on the first surface side of the optical element, the optical path of the light emitted from the display unit can be suppressed while suppressing the increase in size of the display device. The length can easily be made longer.

Further, in the display device according to one aspect of the present disclosure, at least one of the first surface and the second surface may be a convex cylindrical surface.

According to this, the light emitted from the optical element can be prevented from concentrating on one point, and the optical path length of the light emitted from the display section can be increased while suppressing the display device from becoming large.

Further, in the display device according to an aspect of the present disclosure, the first surface is a convex cylindrical surface, the second surface is a convex free-form surface, and the reflecting surface is a concave free-form surface. may be

According to this, the light emitted from the display section can be easily expanded, and the optical path length of the light emitted from the display section can be made longer while suppressing an increase in size of the display device.

Further, in the display device according to an aspect of the present disclosure, the first surface is a convex cylindrical surface whose axial direction is the first direction, and the second surface is a second surface perpendicular to the first direction. The reflecting surface may be a convex cylindrical surface whose axial direction is the direction, and the reflecting surface may be a concave cylindrical surface whose axial direction is the second direction.

According to this, it is possible to further suppress the light emitted from the optical element from concentrating on one point, and to lengthen the optical path length of the light emitted from the display unit while suppressing an increase in size of the display device.

Further, in the display device according to one aspect of the present disclosure, the dimension of the first surface in the first direction may be larger than the dimension of the second surface in the second direction.

According to this, it is possible to easily display an elongated image while suppressing an increase in the thickness of the optical element.

Further, in the display device according to one aspect of the present disclosure, the position of the condensing point in the first direction of the light emitted from the first surface and the condensing point in the second direction of the light emitted from the first surface The positions of the points may differ from each other in a third direction orthogonal to the first direction and orthogonal to the second direction.

According to this, it is possible to further suppress the light emitted from the first surface from concentrating on one point, and to lengthen the optical path length of the light emitted from the display section while suppressing an increase in size of the display device.

Further, in the display device according to an aspect of the present disclosure, the thickness between the first surface and the second surface at one end of the optical element is equal to the thickness between the first surface and the second surface at the other end of the optical element. It may be smaller than the thickness between the second surface.

According to this, when the light emitted from the display unit is reflected by the first surface, the direction in which the light reflected by the first surface travels and the direction in which the light reflected by the reflecting surface and emitted from the first surface travels. can be easily made different, it is possible to suppress glare due to light reflected by the first surface.

Further, the display device according to one aspect of the present disclosure may further include an infrared cut member arranged on the first surface side of the optical element.

According to this, it is possible to suppress the infrared rays contained in sunlight or the like from entering the optical element from the first surface, so it is possible to suppress the temperature rise in the condensing part and increase the size of the display device. The optical path length of the light emitted from the display section can be made longer while suppressing the

Further, in the display device according to one aspect of the present disclosure, the λ / 4 retardation element is a λ / 4 retardation film, is attached to the first surface, and the reflective polarizing element is a reflective polarizing It may be a film and attached to the λ/4 retardation element, and the infrared cut member may be an infrared cut film and attached to the reflective polarizing element.

According to this, since the λ/4 retardation element, the reflective polarizing element, and the infrared cut member can be easily arranged on the first surface side of the optical element, it is possible to easily suppress the temperature rise in the light collecting section. In addition, the optical path length of the light emitted from the display section can be easily increased while suppressing an increase in size of the display device.

It should be noted that each of the embodiments described below is a specific example of the present disclosure. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are examples, and are not intended to limit the present disclosure. Further, among the constituent elements in the following embodiments, constituent elements not described in independent claims will be described as optional constituent elements.

In addition, in the following embodiments, expressions indicating relative orientations in two directions, such as parallel and orthogonal, may be used, but these expressions include cases where these orientations are not strictly speaking. For example, when two directions are parallel, unless otherwise specified, it means not only that the two directions are completely parallel, but also that they are substantially parallel, that is, for example, a few percent It is also meant to include varying degrees.

In addition, the optical paths illustrated in the drawings of the following embodiments show the principle concept, and do not necessarily reflect the actual optical paths.

(First embodiment)
FIG. 1 is a diagram showing a state in which a display device 10 according to the first embodiment is installed in a vehicle 1. FIG. In FIG. 1, the vehicle 1 and the housing 20 are shown in cross section.

As shown in FIG. 1, the display device 10 is a device for displaying images. In this embodiment, the display device 10 is installed inside the vehicle 1 . For example, the display device 10 displays an image captured by a camera that captures the rear of the vehicle 1 . Accordingly, the driver 2 of the vehicle 1 can visually recognize the situation behind the vehicle 1 by looking at the display device 10 (see the dashed arrow in FIG. 1).

For example, the display device 10 may display an image showing the vehicle speed of the vehicle 1, the detection result of an object approaching the vehicle 1, navigation information from the current location of the vehicle 1 to the destination, or the like.

FIG. 2 is a diagram showing the display device 10 of FIG. In FIG. 2, the housing 20 is shown in cross section.

As shown in FIG. 2, the display device 10 includes a housing 20, a display unit 30, an optical element 40, a reflecting member 50, a reflective polarizing element 60, a λ/4 retardation element 70, and a translucent A cover 80 is provided.

The housing 20 accommodates the display section 30 , the optical element 40 , the reflecting member 50 , the reflective polarizing element 60 and the λ/4 retardation element 70 . In this embodiment, housing 20 is suspended from the ceiling of vehicle 1 . The housing 20 has an emission section 22 for emitting the light emitted from the display section 30 to the outside of the housing 20 . The emission part 22 is a through hole that allows communication between the space inside the housing 20 and the space outside.

The display unit 30 emits light representing an image. For example, the display unit 30 emits light representing an image captured by a camera that captures an image behind the vehicle 1 . For example, the display unit 30 is realized by including an LCD (Liquid Crystal Display), an organic EL (Electro Luminescence) display, a micro LED (Light Emitting Diode) display, or the like.

FIG. 3 is a perspective view showing the optical element 40 and the like of the display device 10 of FIG. FIG. 4 is a cross-sectional view showing the optical element 40 and the like in FIG. 4A is a cross-sectional view taken along line IVa-IVa of FIG. 3, and FIG. 4B is a cross-sectional view taken along line IVb-IVb of FIG. 5A and 5B are trihedral views showing the optical element 40 of FIG. 5(a) is a front view, FIG. 5(b) is a plan view, and FIG. 5(c) is a side view.

As shown in FIGS. 2-5, the optical element 40 has a first surface 42 and a second surface 44 . The optical element 40 allows the light emitted from the display unit 30 to enter from the first surface 42, and emits the light reflected by the reflecting member 50 provided on the second surface 44 from the first surface 42 (see FIG. 2). (see bold arrows). For example, optical element 40 is a lens.

The first surface 42 is a convex cylindrical surface whose axial direction is the first direction. That is, the first surface 42 is a surface along the circumferential direction centered on the axis A (axial direction: see (a) of FIG. 5) extending in the first direction. The first direction is the direction indicated by the X-axis in FIG. 2 and the like.

The first surface 42 allows light emitted from the display unit 30 to enter. That is, the light emitted from the display section 30 enters the optical element 40 through the first surface 42 . Also, the first surface 42 emits the light reflected by the reflecting member 50 . That is, the light reflected by the reflecting member 50 after being incident on the inside of the optical element 40 from the first surface 42 is emitted from the first surface 42 to the outside of the optical element 40 . Thus, the first surface 42 is an incident/exiting surface for incident/exiting light.

The second surface 44 is a convex free-form surface. In this embodiment, the second surface has an axis B (axial direction: (a) in FIG. 5) extending in a second direction perpendicular to the first direction along a circumferential direction centered on an axis extending in the first direction. ) along the circumferential direction. The second direction is the direction indicated by the Y-axis in FIG. 2 and the like.

The second surface 44 is a surface opposite to the first surface 42 and is aligned with the first surface 42 in a third direction orthogonal to the first direction and orthogonal to the second direction. That is, the second surface 44 overlaps the first surface 42 when viewed from the third direction. The third direction is the direction indicated by the Z axis in FIG. 2 and the like.

The second surface 44 protrudes in the direction opposite to the first surface 42 . Specifically, the first surface 42 projects to one side in the third direction (the positive side in the Z-axis direction), and the second surface 44 projects to the other side in the third direction (the negative side in the Z-axis direction). protrudes to

In this embodiment, when viewed from the first direction, a straight line C connecting one end and the other end of the first surface 42 in the second direction (see (c) of FIG. 5) parallel. Further, in this embodiment, when viewed from the second direction, a straight line D (see FIG. 5B) connecting one end and the other end of the second surface 44 in the first direction is the first parallel to the direction. In this embodiment, when viewed from the first direction, a straight line I connecting one end and the other end of the second surface 44 in the second direction (see (c) of FIG. 5) is the second parallel to the direction. In addition, for example, each of the straight lines C and I may not be parallel to the second direction, and the straight line D may not be parallel to the first direction.

The dimension E of the first surface 42 in the first direction (see FIG. 5(a)) is greater than the dimension F of the second surface 44 in the second direction (see FIG. 5(c)). In this embodiment, when viewed from the third direction, the dimension of the first surface 42 in the second direction is equal to the dimension F of the second surface 44 in the second direction, and the dimension of the second surface 44 in the first direction is is equal to the dimension E of the first surface 42 in the first direction. Note that, for example, the dimension E of the first surface 42 in the first direction does not have to be larger than the dimension F of the second surface 44 in the second direction. Also, for example, when viewed from the third direction, the dimension of the first surface 42 in the second direction does not have to be equal to the dimension F of the second surface 44 in the second direction. may not be equal to the dimension E of the first surface 42 in the first direction.

The reflecting member 50 is provided on the second surface 44 and has a reflecting surface 52 that reflects the light incident from the first surface 42 toward the first surface 42 . For example, the reflecting member 50 is made of metal film, resin, or the like.

The reflecting surface 52 is a concave free-form surface. In this embodiment, the reflecting surface 52 is a surface along the circumferential direction centered on the axis extending in the first direction and along the circumferential direction centered on the axis B extending in the second direction. The reflecting surface 52 is curved along the second surface 44 and recessed on the other side in the third direction. The reflective surface 52 is in contact with the second surface 44 .

The reflecting surface 52 is aligned with the first surface 42 in the third direction. That is, the reflecting surface 52 overlaps the first surface 42 when viewed from the third direction.

In this embodiment, when viewed from the third direction, the dimension of the reflective surface 52 in the first direction is equal to the dimension E of the first surface 42 in the first direction and the dimension of the second surface 44 in the first direction, and The dimension of the reflective surface 52 in the second direction is equal to the dimension of the first surface 42 in the second direction and the dimension F of the second surface 44 in the second direction. For example, when viewed from the third direction, the dimension of the reflecting surface 52 in the first direction does not have to be equal to the dimension E of the first surface 42 in the first direction and the dimension of the second surface 44 in the first direction. Well, the dimension of the reflective surface 52 in the second direction need not be equal to the dimension of the first surface 42 in the second direction and the dimension F of the second surface 44 in the second direction.

Optical element 40 and reflecting member 50 are formed to magnify the light emitted from display section 30 . For example, the uneven shape of the first surface 42 , the curvature of the first surface 42 , the uneven shape of the second surface 44 , the curvature of the second surface 44 , the curvature of the reflective surface 52 are adjusted so that the light emitted from the display unit 30 is expanded. The concave-convex shape, the curvature of the reflecting surface 52, and the like are determined.

As described above, in this embodiment, the first surface 42 is a convex cylindrical surface whose axial direction is the first direction, the second surface 44 is a convex free-form surface, and the reflecting surface 52 is a concave free-form surface. Thereby, the light emitted from the display section 30 is expanded by the optical element 40 and the reflecting member 50 . In other words, the image represented by the light emitted from the display section 30 is magnified by the optical element 40 and the reflecting member 50 .

For example, the first surface 42 may be a convex cylindrical surface whose axial direction is the second direction, or may extend in the second direction along the circumferential direction centered on the axis extending in the first direction. It may be a convex free curved surface along the circumferential direction around the axis. Further, for example, the first surface 42 may be a concave cylindrical surface whose axial direction is the first direction, may be a concave cylindrical surface whose axial direction is the second direction, or may be a concave cylindrical surface whose axial direction is the second direction. It may be a concave free curved surface along the circumferential direction centering on the axis extending in the second direction and along the circumferential direction centering on the axis extending in the second direction.

Further, for example, the second surface 44 may be a convex cylindrical surface whose axial direction is the first direction, and the reflecting surface 52 may be a concave cylindrical surface whose axial direction is the first direction. Further, for example, the second surface 44 may be a convex cylindrical surface whose axial direction is the second direction, and the reflecting surface 52 may be a concave cylindrical surface whose axial direction is the second direction.

Further, for example, the second surface 44 may be a concave cylindrical surface whose axial direction is the first direction, and the reflecting surface 52 may be a convex cylindrical surface whose axial direction is the first direction. Further, for example, the second surface 44 may be a concave cylindrical surface whose axial direction is the second direction, and the reflecting surface 52 may be a convex cylindrical surface whose axial direction is the second direction.

Further, for example, the second surface 44 is a concave free curved surface along the circumferential direction centered on the axis extending in the first direction and along the circumferential direction centered on the axis extending in the second direction. , a convex free curved surface along the circumferential direction centered on the axis extending in the first direction and along the circumferential direction centered on the axis extending in the second direction.

The optical element 40 and the reflecting member 50 may be formed so as to magnify the light emitted from the display section 30 .

The reflective polarizing element 60 is arranged on the first surface 42 side of the optical element 40 . The reflective polarizing element 60 transmits only light vibrating in a specific direction and reflects light other than the light. In this embodiment, the reflective polarizer 60 transmits S-polarized light and reflects light other than S-polarized light. Also, in this embodiment, the reflective polarizing element 60 is a reflective polarizing film and is attached to the λ/4 retardation element 70 . Note that, for example, the reflective polarizing element 60 may not be a reflective polarizing film, and may be arranged at a position apart from the λ/4 retardation element 70 .

A λ/4 retardation element 70 is arranged between the optical element 40 and the reflective polarizing element 60 . The λ/4 phase difference element 70 changes the phase of light incident on the λ/4 phase difference element 70 by imparting a phase difference of 1/4 wavelength. In this embodiment, the λ/4 retardation element 70 is a λ/4 retardation film and attached to the first surface 42 . Note that, for example, the λ/4 retardation element 70 may not be a λ/4 retardation film, and may be arranged at a position separated from the first surface 42 .

For example, the function of imparting a phase difference of 1/4 wavelength may be applied to the wavelength range of visible light visible to humans among the light emitted from the display unit 30 . For example, the wavelength range is from 400 nm to 700 nm. Further, for example, the function of imparting a phase difference of 1/4 wavelength may be applied to a wavelength range that can sufficiently cover the wavelength range of visible light. For example, the wavelength range is from 350 nm to 850 nm.

The light-transmitting cover 80 is provided on the emitting portion 22 and allows the light emitted from the optical element 40 to pass therethrough. For example, the translucent cover 80 is made of transparent glass, transparent resin, or the like.

FIG. 6 is a diagram showing optical paths of light emitted from the display section 30 of the display device 10 of FIG. A thick arrow in FIG. 6 indicates the optical path of light emitted from the display unit 30, and a thick broken arrow in FIG. 6 indicates the optical path of light entering the display device 10 from the outside. In FIG. 6, the reflective polarizing element 60 and the λ/4 phase difference element 70 are shown separately in order to facilitate understanding of the change in the phase of light, and the λ/4 phase difference element 70 and the optical element 40 are separated from each other.

As shown in FIG. 6 , the light emitted from the display section 30 is transmitted through the reflective polarizing element 60 and the λ/4 phase difference element 70 and enters from the first surface 42 . In this embodiment, the display section 30 emits S-polarized light. The light emitted from the display unit 30 is changed to circularly polarized light by the λ/4 retardation element 70 after passing through the reflective polarizing element 60 in the state of S-polarized light, and passes through the optical element from the first surface 42 in the circularly polarized state. 40.

Light emitted from the display unit 30 is reflected by the reflecting surface 52 after being incident from the first surface 42 . In this embodiment, the light emitted from the display section 30 is reflected by the reflecting surface 52 in the state of circularly polarized light.

Light emitted from the display unit 30 is reflected by the reflecting surface 52 , then emitted from the first surface 42 , transmitted through the λ/4 phase difference element 70 , and reflected by the reflective polarizing element 60 . In this embodiment, the light emitted from the display unit 30 is reflected by the reflecting surface 52 in a circularly polarized state, then emitted from the first surface 42 in a circularly polarized state and passed through the λ/4 phase difference element 70. It changes to P-polarized light and is reflected by the reflective polarizing element 60 in the P-polarized state.

The light emitted from the display section 30 is reflected by the reflective polarizing element 60 , passes through the λ/4 retardation element 70 , and enters again from the first surface 42 . In this embodiment, the light emitted from the display unit 30 is reflected by the reflective polarizing element 60 in the P-polarized state, and then changed to circularly polarized light by the λ/4 retardation element 70. It enters the optical element 40 again from the first surface 42 .

The light emitted from the display unit 30 is reflected again by the reflecting surface 52 after being incident again from the first surface 42 . In this embodiment, the light emitted from the display unit 30 is reflected again by the reflective surface 52 in a circularly polarized state.

Light emitted from the display unit 30 is reflected again by the reflecting surface 52 , then emitted from the first surface 42 and passes through the λ/4 phase difference element 70 and the reflective polarizing element 60 . In this embodiment, the light emitted from the display unit 30 is reflected again by the reflecting surface 52 in the state of circular polarization, and then emitted from the first surface 42 in the state of circular polarization to the λ/4 retardation element 70 . , and passes through the reflective polarizing element 60 in the S-polarized state.

The light emitted from the display unit 30 is reflected again by the reflective surface 52, then emitted from the first surface 42, transmitted through the λ/4 phase difference element 70 and the reflective polarizing element 60, and then transmitted through the translucent cover 80. Then, the light is emitted to the outside of the housing 20 .

It should be noted that, of the light that has entered the display device 10 from the outside, light other than S-polarized light is reflected toward the display section 30 by the reflective polarizing element 60 . On the other hand, of the light incident on the display device 10 from the outside, the S-polarized light passes through the reflective polarization element 60, the λ/4 phase difference element 70, the optical element 40, and the λ/4 phase difference element 70 in this order. , the P-polarized light is reflected by the reflective polarizing element 60 . After that, the P-polarized light is changed to circularly polarized light by the λ/4 phase difference element 70, reflected by the reflecting surface 52, and changed to S-polarized light by passing through the λ/4 phase difference element 70 again. The S-polarized light passes through the reflective polarizing element 60, but its direction is toward the display section 30 as shown in FIG. Therefore, it is possible to suppress the light that has entered the display device 10 from the outside from being reflected in the housing 20 and emitted from the light-transmitting cover 80 , thereby reducing the influence of external light on the driver.

The display device 10 according to the first embodiment has been described above.

The display device 10 according to the first embodiment includes a display section 30, an optical element 40 having a first surface 42 and a second surface 44, and light emitted from the display section 30 and incident from the first surface 42. A reflecting member 50 having a reflecting surface 52 that reflects toward the first surface 42 and provided on the second surface 44, a reflective polarizing element 60 disposed on the side of the first surface 42 of the optical element 40, and an optical element 40 and a λ / 4 phase difference element 70 disposed between the reflective polarizing element 60, the optical element 40 and the reflecting member 50 are formed to expand the light emitted from the display unit 30, Light emitted from the display unit 30 passes through the reflective polarizing element 60 and the λ/4 phase difference element 70 and enters from the first surface 42. After entering from the first surface 42, the light is reflected by the reflecting surface 52, After being reflected by the reflective surface 52, the light is emitted from the first surface 42, transmitted through the λ/4 phase difference element 70, reflected by the reflective polarizing element 60, and reflected by the reflective polarizing element 60 before being reflected by the λ/4 phase difference element. After passing through 70, it enters again from the first surface 42, enters again from the first surface 42, is reflected again by the reflective surface 52, is reflected again by the reflective surface 52, and then exits from the first surface 42 to λ/4. It passes through the retardation element 70 and the reflective polarizing element 60 .

According to this, the light emitted from the display unit 30 is reflected by the reflective surface 52, reflected by the reflective polarizing element 60 after being reflected by the reflective surface 52, reflected by the reflective polarizing element 60, and then reflected. It can be reflected again at surface 52 . By repeatedly reflecting the light emitted from the display unit 30 in this way, the optical path length of the light emitted from the display unit 30 can be made longer while suppressing the display device 10 from becoming large.

Further, in the display device 10 according to the first embodiment, the λ/4 retardation element 70 is a λ/4 retardation film and is attached to the first surface 42, and the reflective polarizing element 60 is a reflective It is a type polarizing film and is attached to the λ/4 retardation element 70 .

According to this, since the λ/4 retardation element 70 and the reflective polarizing element 60 can be easily arranged on the first surface 42 side of the optical element 40, the display device 10 can be prevented from becoming large, and the display unit 30 can The optical path length of the emitted light can easily be made longer.

Moreover, in the display device 10 according to the first embodiment, at least one of the first surface 42 and the second surface 44 is a convex cylindrical surface.

According to this, the light emitted from the optical element can be prevented from concentrating on one point, and the optical path length of the light emitted from the display section can be increased while suppressing the display device from becoming large.

Further, in the display device 10 according to the first embodiment, the first surface 42 is a convex cylindrical surface, the second surface 44 is a convex free-form surface, and the reflecting surface 52 is a concave surface. It is a free-form surface.

According to this, the light emitted from the display section 30 can be easily expanded, and the optical path length of the light emitted from the display section 30 can be made longer while suppressing the display device 10 from becoming large.

(Second embodiment)
FIG. 7 is a perspective view showing an optical element 40a and a reflecting member 50a included in the display device according to the second embodiment. 8A and 8B are trihedral views showing the optical element 40a and the reflecting member 50a of FIG. (a) of FIG. 8 is a front view, (b) of FIG. 8 is a plan view, and (c) of FIG. 8 is a side view. In (c) of FIG. 8, illustration of the reflecting member 50a is omitted.

The display device according to the second embodiment mainly differs from the display device 10 in that it includes an optical element 40 a different from the optical element 40 and a reflecting member 50 a different from the reflecting member 50 .

As shown in FIGS. 7 and 8, the optical element 40a mainly differs from the optical element 40 in that it has a second surface 44a different from the second surface 44. As shown in FIGS.

The second surface 44a is a convex cylindrical surface whose axial direction is the second direction. That is, the second surface 44a is a surface along the circumferential direction centered on the axis B (axial direction: see (a) of FIG. 8) extending in the second direction.

The dimension E of the first surface 42 in the first direction (see (a) of FIG. 8) is greater than the dimension F of the second surface 44a in the second direction (see (c) of FIG. 8). Note that the dimension E of the first surface 42 in the first direction does not have to be larger than the dimension F of the second surface 44a in the second direction.

The reflective member 50 a is mainly different from the reflective member 50 in that it has a reflective surface 52 a different from the reflective surface 52 .

The reflecting surface 52a is a concave cylindrical surface whose axial direction is the second direction. That is, the reflecting surface 52a is a surface along the circumferential direction centered on the axis B extending in the second direction. The reflecting surface 52a is curved along the second surface 44a and recessed on the other side in the third direction. The reflecting surface 52a is in contact with the second surface 44a.

FIG. 9 is a perspective view showing the positions of condensing points of light emitted from the optical element 40a of FIG. FIG. 9 shows the position of the condensing point on the central axis (indicated by the dashed-dotted line) of the optical element 40a.

As shown in FIG. 9, the position of the condensing point G in the first direction of the light reflected by the reflecting surface 52a and emitted from the first surface 42, and the condensing point of the light emitted from the first surface 42 in the second direction. The positions of the points H are mutually different in the third direction.

In this embodiment, the condensing point G is positioned farther from the optical element 40a than the condensing point H is. Note that, for example, the condensing point G may be positioned closer to the optical element 40a than the condensing point H is.

For example, the position of the converging point G and the position of the converging point H can be determined by the curvature of the first surface 42, the curvature of the second surface 44a, the distance between the first surface 42 and the second surface 44a, and the like. .

Since the first surface 42 is a convex cylindrical surface with the first direction being the axial direction (parallel to the X-axis), the light emitted from the first surface 42 passes through the condensing point H and is parallel to the X-axis. The light is condensed in an elliptical shape with a long line segment as the major axis. Similarly, the second surface 44a is a convex cylindrical surface with the second direction as the axial direction (parallel to the Y axis), and the reflecting surface 52a has the second direction as the axial direction (parallel to the Y axis). Since it is a concave cylindrical surface, the light reflected by the reflecting surface 52a and emitted from the first surface 42 is condensed in an elliptical shape having a major axis of a line segment parallel to the Y axis passing through the condensing point G. Therefore, unlike a spherical lens, light is not condensed at one point, so that temperature rise in the condensing portion can be suppressed.

The display device according to the second embodiment has been described above.

In the display device according to the second embodiment, the first surface 42 is a convex cylindrical surface whose axial direction is in the first direction, and the second surface 44a is in a second direction orthogonal to the first direction. The reflection surface 52a is a convex cylindrical surface whose axial direction is the axial direction, and the reflecting surface 52a is a concave cylindrical surface whose axial direction is the second direction.

According to this, it is possible to further suppress the light emitted from the optical element 40a from concentrating on one point, and to lengthen the optical path length of the light emitted from the display unit 30 while suppressing an increase in size of the display device.

Moreover, in the display device according to the second embodiment, the dimension E of the first surface 42 in the first direction is larger than the dimension F of the second surface 44a in the second direction.

According to this, it is possible to easily display an elongated image while suppressing an increase in the thickness of the optical element 40a.

Further, in the display device according to the second embodiment, the position of the condensing point G of the light emitted from the first surface 42 in the first direction and the condensing point of the light emitted from the first surface 42 in the second direction The position of point H differs from each other in a third direction orthogonal to the first direction and orthogonal to the second direction.

According to this, it is possible to further suppress the light emitted from the first surface 42 from concentrating on one point, and to lengthen the optical path length of the light emitted from the display unit 30 while suppressing an increase in the size of the display device. .

(Third Embodiment)
FIG. 10 is a diagram showing display devices according to third to sixth embodiments. In FIG. 10, illustration of the reflecting member 50 and the like is omitted.

As shown in FIG. 10(a), the display device according to the third embodiment further includes a Fresnel mirror 90 that reflects light emitted from the display unit 30 toward the optical element 40. , the display device 10 is mainly different. In (a) of FIG. 10, the Fresnel mirror 90 is shown in cross section.

The Fresnel mirror 90 has a reflecting surface 92 that reflects the light emitted from the display section 30 toward the optical element 40 . The reflecting surface 92 is a surface having a substantially sawtooth cross section.

The light emitted from the display unit 30 is reflected by the Fresnel mirror 90, then passes through the reflective polarizing element 60 and the λ/4 phase difference element 70, and passes through the first surface 42 to the optical element 40 as in the display device 10. incident on. The light emitted from the display unit 30 enters the optical element 40 from the first surface 42 , repeats reflection in the same manner as in the display device 10 , and then exits from the first surface 42 .

With such a configuration, the light from the display section 30 can be reflected by the Fresnel mirror 90, so that the display section 30 can be arranged more freely. Furthermore, since the reflection angle of the light from the display section 30 can be adjusted by using the Fresnel mirror 90, the display section 30 can be placed almost directly in front of the Fresnel mirror 90, and the housing 20 can be reduced in size accordingly.

(Fourth embodiment)
As shown in FIG. 10(b), the display device according to the fourth embodiment mainly differs from the display device 10 in that the display unit 30 is housed in the overhead console (OHC) 3. .

Light emitted from the display unit 30 passes through the reflective polarizing element 60 and the λ/4 phase difference element 70 and enters the optical element 40 from the first surface 42 in the same manner as in the display device 10 . The light emitted from the display unit 30 enters the optical element 40 from the first surface 42 , repeats reflection in the same manner as in the display device 10 , and then exits from the first surface 42 .

With such a configuration, the display unit 30 can be housed in the overhead console 3, so that the housing 20 can be made smaller.

(Fifth embodiment)
As shown in (c) of FIG. 10, the display device according to the fifth embodiment further includes a non-polarizing half mirror 100 that reflects light emitted from the display section 30 toward the optical element 40. It differs from the display device 10 mainly in that.

Light emitted from the display unit 30 is reflected by the non-polarizing half mirror 100, and then passes through the reflective polarizing element 60 and the λ/4 phase difference element 70 in the same manner as in the display device 10, and is optically emitted from the first surface 42. incident on the element 40 . Light emitted from the display unit 30 enters the optical element 40 from the first surface 42, repeats reflection in the same manner as in the display device 10, then exits from the first surface 42, and then exits from the first surface 42. It passes through the non-polarizing half mirror 100 .

With such a configuration, the light emitted from the display section 30 is reflected by the non-polarizing half mirror 100, and the light emitted from the optical element 40 is transmitted through the non-polarizing half mirror 100 again. can be lengthened.

(Sixth embodiment)
As shown in (d) of FIG. 10, the display device according to the sixth embodiment further includes a plane mirror 110 that reflects light emitted from the display section 30 toward the optical element 40. , the display device 10 is mainly different.

Light emitted from the display section 30 passes through the reflective polarizing element 60 and the λ/4 phase difference element 70 and enters the optical element 40 from the first surface 42 . The light emitted from the display unit 30 enters the optical element 40 from the first surface 42, repeats reflections in the same manner as the display device 10, then exits from the first surface 42, and then exits from the first surface 42. Reflected by plane mirror 110 .

With such a configuration, the optical path length can be lengthened while suppressing the attenuation of light at the plane mirror 110 .

Note that the display device according to the sixth embodiment may include a concave mirror having a concave reflecting surface instead of the plane mirror 110 .

In this case, a concave mirror can be used to further enlarge the display.

(Seventh embodiment)
FIG. 11 is a diagram showing display devices according to seventh to ninth embodiments. In FIG. 11, illustration of the reflecting member 50 and the like is omitted.

As shown in (a) of FIG. 11, the display device according to the seventh embodiment is mainly different from the display device 10 in that an optical element 40b different from the optical element 40 is provided.

The optical element 40b mainly differs from the optical element 40 in that it has a first surface 42b different from the first surface 42. As shown in FIG.

The first surface 42b is a convex cylindrical surface whose axial direction is a direction perpendicular to the first direction and inclined with respect to the second and third directions.

A thickness J between the first surface 42b and the second surface 44 at one end of the optical element 40b is smaller than a thickness K between the first surface 42b and the second surface 44 at the other end of the optical element 40b. .

Specifically, when viewed from the first direction, the dimension (thickness J) in the third direction between the first surface 42b and the second surface 44 at one end of the optical element 40b in the second direction is Less than the dimension (thickness K) in the third direction between the first surface 42b and the second surface 44 at the other end of the optical element 40b in the two directions, the optical element 40b is generally wedge-shaped.

The λ/4 retardation element 70b is attached to the first surface 42b, and the reflective polarizing element 60b is attached to the λ/4 retardation element 70b.

In the display device according to the seventh embodiment, the thickness J between the first surface 42b and the second surface 44 at one end of the optical element 40b is equal to the thickness J between the first surface 42b and the second surface 44 at the other end of the optical element 40b. It is smaller than the thickness K between the two surfaces 44.

According to this, when the light emitted from the display unit 30 is reflected by the first surface 42b, the direction in which the light reflected by the first surface 42b travels and the direction in which the light reflected by the reflective surface 52 is emitted from the first surface 42b Since the direction in which the reflected light travels can be easily changed, it is possible to suppress the glare caused by the light reflected by the first surface 42b.

(Eighth embodiment)
As shown in FIG. 11(b), the display device according to the eighth embodiment is different from the display device 10 in that it includes an optical element 40c different from the optical element 40 and a light shielding portion 120. different.

The optical element 40c is mainly different from the optical element 40 in that it further includes gate traces 46 . The gate marks 46 can be formed when the optical element 40c is injection molded.

The light shielding portion 120 is arranged on the first surface 42 side of the gate mark 46 . As a result, it is possible to prevent light or the like emitted from the display section 30 from entering the gate marks 46 and emitting unnecessary reflected light caused by the gate marks 46 .

(Ninth embodiment)
As shown in (c) of FIG. 11, the display device according to the ninth embodiment mainly differs from the display device 10 in that it further includes a transmissive polarizing element 130 .

The transmissive polarizing element 130 is arranged on the opposite side of the reflective polarizing element 60 from the optical element 40 . In this embodiment, transmissive polarizer 130 is a transmissive polarizer film and is attached to reflective polarizer 60 .

Light emitted from the display section 30 passes through the transmissive polarizing element 130 , the reflective polarizing element 60 , and the λ/4 phase difference element 70 in this order, and enters the optical element 40 from the first surface 42 . The light emitted from the display unit 30 enters the optical element 40 from the first surface 42 , repeats reflection in the same manner as in the display device 10 , and then exits from the first surface 42 .

With such a configuration, the transmissive polarizing element 130 absorbs, for example, P-polarized light that enters the display device 10 from the outside, thereby suppressing reflection of the light from the outside.

(Tenth embodiment)
FIG. 12 is a diagram showing a display device according to tenth and eleventh embodiments.

As shown in (a) of FIG. 12, the display device according to the tenth embodiment is mainly different from the display device 10 in that an infrared cut member 140 is further provided.

The infrared cut member 140 is arranged on the first surface 42 side of the optical element 40 . In this embodiment, the infrared cut member 140 is arranged on the side of the reflective polarizing element 60 opposite to the optical element 40 . In this embodiment, the infrared cut member 140 is an infrared cut film and attached to the reflective polarizing element 60 . In addition, for example, the infrared cut member 140 may not be an infrared cut film, and may be arranged at a position separated from the reflective polarizing element 60 .

Light emitted from display unit 30 passes through infrared cut member 140 , reflective polarizing element 60 , and λ/4 phase difference element 70 in this order, and enters optical element 40 from first surface 42 . The light emitted from the display unit 30 enters the optical element 40 from the first surface 42 , repeats reflection in the same manner as in the display device 10 , and then exits from the first surface 42 .

The display device according to the tenth embodiment further includes an infrared cut member 140 arranged on the first surface 42 side of the optical element 40 .

According to this, infrared rays contained in sunlight or the like can be suppressed from entering the optical element 40 from the first surface 42, so that it is possible to suppress an increase in the temperature in the condensing section and increase the size of the display device. The optical path length of the light emitted from the display section 30 can be made longer while suppressing the occurrence of light.

Further, in the display device according to the tenth embodiment, the λ/4 retardation element 70 is a λ/4 retardation film and is attached to the first surface 42, and the reflective polarizing element 60 is a reflective It is a polarizing film and is attached to the λ/4 retardation element 70 , and the infrared cut member 140 is an infrared cut film and is attached to the reflective polarizing element 60 .

According to this, the λ/4 retardation element 70, the reflective polarizing element 60, and the infrared cut member 140 can be easily arranged on the side of the first surface 42 of the optical element 40, so that the temperature in the condensing part does not rise. can be easily suppressed, and the optical path length of the light emitted from the display unit 30 can be easily increased while suppressing an increase in size of the display device.

(Eleventh embodiment)
As shown in FIG. 12(b), the display device according to the eleventh embodiment differs from the display device 10 mainly in that an optical element 40d different from the optical element 40 is provided.

The optical element 40d mainly differs from the optical element 40 in that it has a first surface 42d different from the first surface 42 . The first surface 42d is a concave cylindrical surface whose axial direction is the first direction. That is, the first surface 42d is a surface extending in the circumferential direction around the axis extending in the first direction.

Light emitted from the display section 30 passes through the reflective polarizing element 60 and the λ/4 phase difference element 70 in this order, and enters the optical element 40d from the first surface 42d. The light emitted from the display unit 30 is incident on the optical element 40d from the first surface 42d, and then emitted from the first surface 42d after being repeatedly reflected in the same manner as in the display device 10. FIG.

With such a configuration as well, the light emitted from the display section 30 can be enlarged.

(Other embodiments, etc.)
Although the display device according to one or more aspects of the present disclosure has been described above based on the embodiments, the present disclosure is not limited to these embodiments. As long as it does not deviate from the spirit of the present disclosure, various modifications that a person skilled in the art can think of are applied to the present embodiment, and a form constructed by combining the components of different embodiments may also be one or more of the present disclosure. may be included within the scope of the embodiments.

INDUSTRIAL APPLICABILITY The present disclosure can be used for display devices and the like for displaying images.

REFERENCE SIGNS LIST 10 display device 20 housing 22 output section 30 display section 40, 40a, 40b, 40c, 40d optical element 42, 42b, 42d first surface 44, 44a second surface 46 gate mark 50, 50a reflecting member 52, 52a, 92 Reflective surface 60 Reflective polarizing element 70 λ/4 retardation element 80 Translucent cover 90 Fresnel mirror 100 Non-polarizing half mirror 110 Plane mirror 120 Light shielding part 130 Transmissive polarizing element 140 Infrared cut member

Claims (10)

a display unit;
an optical element having a first surface and a second surface;
a reflecting member provided on the second surface, the reflecting surface having a reflecting surface for reflecting light emitted from the display unit and incident from the first surface toward the first surface;
a reflective polarizing element arranged on the first surface side of the optical element;
A λ / 4 retardation element disposed between the optical element and the reflective polarizing element,
The optical element and the reflecting member are formed to magnify light emitted from the display unit,
The light emitted from the display unit is
enters from the first surface through the reflective polarizing element and the λ/4 phase difference element,
After being incident from the first surface, reflected by the reflecting surface,
After being reflected by the reflective surface, the light is emitted from the first surface, transmitted through the λ/4 retardation element, and reflected by the reflective polarizing element,
After being reflected by the reflective polarizing element, it passes through the λ/4 phase difference element and enters again from the first surface,
After being incident again from the first surface, reflected again by the reflecting surface,
After being reflected again by the reflective surface, it is emitted from the first surface and transmitted through the λ / 4 retardation element and the reflective polarizing element.
display device. The λ / 4 retardation element is a λ / 4 retardation film, is attached to the first surface,
The reflective polarizing element is a reflective polarizing film and is attached to the λ / 4 retardation element.
The display device according to claim 1. At least one of the first surface and the second surface is a convex cylindrical surface,
3. The display device according to claim 1 or 2. The first surface is a convex cylindrical surface,
The second surface is a convex free-form surface,
The reflective surface is a concave free-form surface,
The display device according to claim 3. The first surface is a convex cylindrical surface whose axial direction is the first direction,
The second surface is a convex cylindrical surface having an axial direction in a second direction orthogonal to the first direction,
The reflective surface is a concave cylindrical surface whose axial direction is the second direction,
The display device according to claim 3. the dimension of the first surface in the first direction is greater than the dimension of the second surface in the second direction;
The display device according to claim 5. The position of the condensing point of the light emitted from the first surface in the first direction and the position of the condensing point of the light emitted from the first surface in the second direction are orthogonal to the first direction and mutually different in a third direction orthogonal to the second direction,
7. The display device according to claim 5 or 6. The thickness between the first surface and the second surface at one end of the optical element is smaller than the thickness between the first surface and the second surface at the other end of the optical element,
The display device according to any one of claims 1 to 7. Further comprising an infrared cut member arranged on the first surface side of the optical element,
The display device according to any one of claims 1 to 8. The λ / 4 retardation element is a λ / 4 retardation film, is attached to the first surface,
The reflective polarizing element is a reflective polarizing film and is attached to the λ / 4 retardation element,
The infrared cut member is an infrared cut film and is attached to the reflective polarizing element.
The display device according to claim 9.

Images