HOLOGRAPHIC PROJECTION OPERATING DEVICE, HOLOGRAPHIC PROJECTION DEVICE AND HOLOGRAPHIC OPTICAL MODULE THEREOF

A holographic projection operating device, holographic projection device and holographic optical module thereof are illustrated. The holographic optical module has a first and a second prism array. The first prism array has a plurality of first prisms with first faces in contact with each other to form a first optical interface. The second prism array has a plurality of second prisms with second faces in contact with each other to form a second optical interface. Light is incident on the first optical interface at a first incident angle to undergo total internal reflection and generate a first reflected ray or at a second incident angle to undergo total internal reflection and generate a second reflected ray. The first or second reflected ray enters the second prism array and hits the second optical interface at a third incident angle to undergo total internal reflection and generate a third reflected ray.

BACKGROUND

Technical Field

The present disclosure relates to optical projection equipment, and more particularly to a holographic optical module comprising multiple prisms to bend optical paths, a holographic projection device comprising the holographic optical module to generate a holographic image to be viewed by an observer, and a holographic projection operating device comprising the holographic projection device to form an operation interface.

Related Art

Holographic projection technology enables image-related light rays generated by a display unit to be reflected to thereby alter optical paths of propagation of the light rays, thereby allowing an observer to view a holographic image as soon as the light rays enter the observer's eyes. Holographic projection employs holographic imaging technology so that the holographic image looks more realistic, thereby augmenting a sense of interaction between the holographic image and the observer or user. Thus, holographic projection equipment is recently widely used in various performances.

Light rays reflect off holographic optical elements (HOE) of existing holographic projection devices and then enter the user's eyes, thereby generating a holographic image. The existing holographic optical elements are mirrors with surfaces that are plated and adapted to reflect the light rays. Thus, the existing holographic optical elements require a plating process and material and thereby not only incur higher manufacturing cost but also increase the steps of manufacturing the holographic optical elements.

SUMMARY

Accordingly, it is an objective of the present disclosure to provide a holographic projection operating device, a holographic projection device and a holographic optical module thereof. The holographic optical module of the present disclosure comprises prisms for reflecting light rays. After entering the prisms, the light rays travel from a more dense medium (i.e., prisms) into a less dense medium (i.e., air) with an incident angle (also known as “angle of incidence”) greater than a critical angle to undergo total internal reflection, thereby allowing the reflected light rays to enter a user's eyes from an appropriate angle to generate a holographic image.

In an embodiment of the present disclosure, the holographic optical module comprises a first prism array and a second prism array. The first prism array comprises a plurality of first prisms. Each first prism has a first face. The first faces of every two first prisms are in contact with each other to form a first optical interface. The second prism array comprises a plurality of second prisms. Each second prism has a second face. The second faces of every two second prisms are in contact with each other to form a second optical interface. A light ray enters the first prism array and is incident on the first optical interface at a first incident angle to undergo total internal reflection at the first face of one of the first prisms, thereby turning into a first reflected ray. Another light ray enters the first prism array and is incident on the first optical interface at a second incident angle to undergo total internal reflection at the first face of the other first prism, thereby turning into a second reflected ray. The first reflected ray or the second reflected ray enters the second prism array and is incident on the second optical interface at a third incident angle to undergo total internal reflection at the second face of one of the second prisms, thereby turning into a third reflected ray.

In another embodiment, the first incident angle is greater than or equal to 45 degrees.

In another embodiment, the second incident angle is greater than or equal to 45 degrees.

In another embodiment, an included angle between the third reflected ray and a horizontal line is greater than or equal to 45 degrees but less than or equal to 60 degrees.

In another embodiment, the second prism array is disposed on top of the first prism array such that a third face of one first prism and a fourth face of one second prism are in contact with each other to form a third optical interface which the first or second reflected ray penetrates to enter the second prism array.

In another embodiment, each first prism is a triangular prism and further comprises a fifth face such that each two of the first face, the third face and the fifth face adjoin each other, thereby allowing each first prism to have an included angle of 90 degrees defined between the third face and the fifth face, an included angle of 45 degrees defined between the first face and the third face, and an included angle of 45 degrees defined between the first face and the fifth face.

In another embodiment, each second prism is a triangular prism and further comprises a sixth face such that each of two the second face, the fourth face and the sixth face adjoin each other, thereby allowing each second prism to have an included angle of 90 degrees defined between the fourth face and the sixth face, an included angle of 60 to 65 degrees defined between the second face and the fourth face, and an included angle of 25 to 30 degrees defined between the second face and the sixth face.

In another embodiment, each second prism is a triangular prism and further comprises a sixth face such that each two of the second face, the fourth face and the sixth face adjoin each other, thereby allowing each second prism to have an included angle of 90 degrees defined between the fourth face and the sixth face, an included angle of 25 to 30 degrees defined between the second face and the fourth face, and an included angle of 60 to 65 degrees defined between the second face and the sixth face.

The present disclosure provides a holographic projection device comprising a display module and a holographic optical module. The display module emits light rays to form an image. The holographic optical module bends optical paths of the light rays to allow the light rays to travel in a viewing direction and thereby enter an observer's eyes, thereby generating a holographic image visually.

In another embodiment, the holographic projection device further comprises an image enlargement module which the light rays pass through to allow the image to be enlarged before entering the holographic optical module.

In another embodiment, the image enlargement module comprises a Fresnel lens, and the light rays pass through the Fresnel lens.

In another embodiment, the holographic projection device further comprises an optical path adjustment module such that the light rays sequentially pass through the image enlargement module and the optical path adjustment module, thereby allowing the light rays to be focused on a position of the holographic optical module before entering the holographic optical module.

In another embodiment, the optical path adjustment module comprises a plurality of optical microstructures arranged in a two-dimensional pattern.

In another embodiment, the optical microstructures are convex lens of equal or unequal size.

The present disclosure provides a holographic projection operating device comprising the holographic projection device, a signal emitter, a signal receiver and a processor. The signal emitter continuously emits a detection signal. The detection signal and at least one of the light rays forming the image synchronously pass through the holographic optical module and thereby travel in the viewing direction. The signal receiver continuously receives the detection signal in the viewing direction. The processor connects to the signal receiver. When the signal receiver receives the detection signal, the detection signal is continuously sent to the processor. If the processor does not receive the detection signal, the processor will generate a control signal.

To sum up, the holographic projection device provided by the present disclosure comprises a first prism array and a second prism array and allows light rays for forming an image to be incident on a first optical interface and a second optical interface at an appropriate angle so that the light rays undergo total internal reflection at the first optical interface and the second optical interface, thereby allowing the light rays to travel along a specific optical path to enter the observer's or user's eyes and generate a holographic image visually.

DESCRIPTIONS OF EXEMPLARY EMBODIMENTS

Referring toFIG.1,FIG.2,FIG.3AandFIG.4, there are shown a holographic optical module100according to an embodiment of the present disclosure. In this embodiment, the holographic optical module100comprises a first prism array10and a second prism array20. The first prism array10and second prism array20are each formed in an acrylic substrate by a pressing process.

As shown inFIG.1andFIG.2, the first prism array10comprises a plurality of first prisms11, and the each two corresponding first prisms11comprise a first prism11awith a leg in a lower part of the first prism array10and a first prism11bwith a leg in an upper part of the first prism array10. In this embodiment, each first prism11is a triangular prism and comprises a first face111, a third face113and a fifth face115. Each two of the first face111, third face113and fifth face115adjoin each other to form a micro structure of a triangular prism with a triangular cross section. The first face111is the hypotenuse of a triangle. The third face113and fifth face115are the legs of the triangle. Each first prism11has an included angle of 90 degrees defined between the third face113and fifth face115, an included angle of 45 degrees defined between the first face111and third face113, and an included angle of 45 degrees defined between the first face111and fifth face115. The first prism11awith the leg in the lower part of the first prism array10and first prism11bwith the leg in the upper part of the first prism array10are of the same structure. The first face111of the first prism11awith the leg in the lower part of the first prism array10and the first face111of the first prism11bwith the leg in the upper part of the first prism array10are in contact with each other to form a first optical interface12. The first face111of the first prism11awith the leg in the lower part of the first prism array10and the first face111of the first prism11bwith the leg in the upper part of the first prism array10are in airtight contact with each other.

As shown inFIG.1,FIG.2andFIG.3, the second prism array20comprises a plurality of second prisms21, and the each two corresponding second prism21comprises a second prism21awith a leg in a lower part of the second prism array20and a second prism21bwith a leg in an upper part of the second prism array20. In this embodiment, each second prism11is a triangular prism and comprises a second face212, a fourth face214and a sixth face216. Each two of the second face212, fourth face214and sixth face216adjoin each other to form a micro structure of a triangular prism with a triangular cross section. The second face212is the hypotenuse of a triangle. The fourth face214and sixth face216are the legs of the triangle. Each second prism21has an included angle of 90 degrees defined between the fourth face214and sixth face216, an included angle of 61 degrees defined between the second face212and fourth face214, and an included angle of 29 degrees defined between the second face212and sixth face216. The second prism21awith the leg in the lower part of the of the second prism array20and second prism21bwith the leg in the upper part of the second prism array20are of the same structure. The second face212of the second prism21awith the leg in the lower part of the second prism array20and the second face212of the second prism21bwith the leg in the upper part of the second prism array20are in contact with each other to form a second optical interface22. The second face212of the second prism21awith the leg in the upper part of the second prism array20and the second face212of the second prism21bwith the leg in the upper part of the second prism array20are in airtight contact with each other.

The fourth face214of the second prism21awith the leg in the lower part of the second prism array20and the third face113of the first prism11bwith the leg in the upper part of the first prism array10are in contact with each other to form a third optical interface30.

As shown inFIG.3A, light ray L1from a display module200or a single light source is incident on the third face113of the first prism11awith the leg in the lower part of the first prism array10to enter the first prism array10. With the light ray L1being incident perpendicularly on the third face113, a portion of the light ray L1reflects off the third face113, but the remaining portion of the light ray L1penetrates the third face113to enter the first prism11awith the leg in the lower part of the first prism array10before being incident on the first optical interface12at the first incident angle, wherein the first optical interface12is the face on which the first face111of first prism11athe leg in the lower part of the first prism array10is located. As mentioned above, both the first prism11and second prism21are made of an acrylic material, and the acrylic material has a refractive index of around 1.49. As mentioned above, light rays traveling from a more dense medium (i.e., a prism) into a less dense medium undergo total internal reflection. Under Snell's law, a law of refraction expressed by the formula n1sin θ1=n2sin θ2, n1denotes the refractive index (the acrylic material has a refractive index of 1.49) of the first prism11a, andn2denotes the refractive index (1.000027≈1) of air, wherein θ2is equal to 90 degrees when total internal reflection occurs. Thus, by substituting the abovementioned into the Snell's law formula, the critical incident angle θ1at which the light rays are incident on the first face111to undergo total internal reflection is calculated to be equal to 42.1 degrees. In this embodiment, the light ray L1is incident on the first face111at the first incident angle of 45 degrees, which is greater than the critical incident angle of 42.1 degrees. Thus, the light ray L1undergoes total internal reflection at the first face111to turn into first reflected ray L11. Then, the first reflected ray L11travels in a direction parallel to the first face111to enter another adjacent first prism11bwith a leg in the upper part of the first prism array10. In this embodiment, the first reflected ray L11enters the first prism11bwith the leg in the left and upper part of the first prism array10, but the present disclosure is not limited thereto. An inclination direction of the first face111in another embodiment is opposite to an inclination direction of the first face111in this embodiment, and thus the first reflected ray L11in the other embodiment enters the first prism11bwith the leg in the right and upper part of the first prism array10

The first reflected ray L11is incident on the first optical interface12, i.e., the first face111of the first prism11bwith the leg in the upper part of the first prism array10, at the second incident angle of 45 degrees. Similarly, with the second incident angle being greater than the critical incident angle for total internal reflection, the first reflected ray L11reflects off the first face111of first prism11bwith the leg in the upper part of the first prism array10once again to turn into a second reflected ray L12. After that, the second reflected ray L12penetrates the third optical interface30formed by the third face113of the first prism11band the fourth face214of the second prism21awith the leg in the lower part of the second prism array20and then is incident on the second face212(at the second optical interface22) at the third incident angle of 61 degrees to undergo total internal reflection at the second face212, thereby turning into a third reflected ray L13. In this embodiment, the included angle between the third reflected ray L13and the fourth face214of the second prism21bwith the leg in the upper part of the second prism array20is 30 degrees.

Another light ray L2emitted from the display module200leaves the third face113of another one first prism11awith the leg in the lower part of the first prism array10and enters first prism array10before reflecting off the first optical interface12, i.e., the first face111of the first prism11awith the leg in the lower part of the first prism array10, to turn into a first reflected ray L21. Similarly, the first reflected ray L21enters the adjacent first prism11bwith the leg in the upper part of the first prism array10and reflects off the first optical interface12, i.e., the first face111of first prism11bwith the leg in the upper part of the first prism array10, to turn into a second reflected ray L22. After that, the second reflected ray L22enters the second prism21awith the leg in the lower part of the second prism array20and reflects off the second optical interface22, i.e., the second face212of the second prism21awith the leg in the lower part of the second prism array20, to turn into a third reflected ray L23. Similarly, the included angle between the third reflected ray L23and the fourth face214of the second prism21bwith the leg in the upper part of the second prism array20is 30 degrees.

Referring toFIG.5, there is shown a cross-sectional view of a holographic projection device1000according to an embodiment of the present disclosure. The holographic projection device1000in this embodiment comprises a holographic optical module100and a display module200. Light rays L1-Ln, which are emitted from the display module200on a horizontal plane and adapted to form an image, enter the holographic optical module100. Then, the holographic optical module100bends optical paths of the light rays to allow the light rays to enter an observer's or user's eyes at an inclination angle (an included angle of 30 degrees between the third reflected ray L23and the fourth face214horizontally positioned), i.e., in a viewing direction. When the observer's or user's eyes perceive the third reflected ray L23, a holographic image Q is visible to the observer's or user's eyes and similar to a projected image that originates from an image generated by the display module200in an inclination direction of 30 degrees.

Referring toFIG.3B, there is shown a front view of the holographic optical module according to another embodiment of the present disclosure. Unlike the embodiment illustrated byFIG.3A, this embodiment is characterized by an included angle of 63.4 degrees defined between the second face212and fourth face214of the second prisms21a,21b, an included angle of 26.6 degrees defined between the second face212and sixth face216of the second prisms21a,21b, and an included angle of 45 degrees defined between the fourth face214and the third reflected rays L13and L23.

Referring toFIG.3C, there is shown a front view of the holographic optical module according to yet another embodiment of the present disclosure. Unlike the embodiment illustrated byFIG.3A, this embodiment is characterized by an included angle of 30 degrees defined between the second face212and fourth face214of the second prisms21a,21b, and an included angle of 60 degrees defined between the second face212and sixth face216of the second prisms21a,21b. Thus, the third reflected rays L13and L23travel in the direction toward the first prism array10. This embodiment is applicable to the generation of a holographic image when the third reflected rays L13and L23travel downward to enter the user's eyes while the holographic optical module100is located at a position higher than the user.

Referring toFIG.6, there is shown a cross-sectional view of a holographic projection device1000′ according to another embodiment of the present disclosure. The holographic projection device1000′ in this embodiment comprises the holographic optical module100, the display module200and an image enlargement module300. The image enlargement module300comprises a Fresnel lens. The light rays L1-Ln pass through the Fresnel lens to enable the enlargement of images generated by the display module200; thus, the display module200of a relatively small size works well. In this embodiment, the holographic projection device1000′ further comprises an optical path adjustment module400so that the light rays L1-Ln sequentially pass through the image enlargement module300and optical path adjustment module400, thereby allowing the light rays L1-Ln to be focused on the position of the holographic optical module100before entering the holographic optical module100. The optical path adjustment module400converges the light rays being diffused to concentrate the light rays toward the middle of the light rays, and comprises a plurality of optical microstructures (not shown in drawings). The optical microstructures (not shown in drawings) can be a microconvex lens array or a microtriangular prism array, and the present disclosure is not limited thereto.

Referring toFIG.7, there is shown a cross-sectional view of a holographic projection operating device according to an embodiment of the present disclosure. The holographic projection operating device in this embodiment comprises the holographic projection device1000or1000′, a signal emitter2000, a signal receiver3000and a processor4000. The signal emitter2000continuously emits a detection signal Si. The detection signal Si and at least one of the light rays forming the image, e.g., the light ray Lm, synchronously pass through the holographic optical module100and thereby travel in the viewing direction. The signal receiver3000continuously receives the detection signal Si in the viewing direction. The processor4000connects to the signal receiver3000; thus, when the signal receiver3000receives the detection signal Si, the detection signal Si is continuously sent to the processor4000. If the processor4000does not receive the detection signal Si, the processor4000will generate a control signal So. In this embodiment, the holographic projection operating device is applicable to various operating equipment and uses a holographic image as an operation interface, such as the keyboard of a computer or the operating buttons of an elevator. The holographic projection device1000or1000′ generates an image of a holographic operation interface, and the path of propagation of the detection signal Si corresponds in position to the image of the button of the operation interface. When the user's hand presses the holographic button image, the hand blocks the detection signal Si to thereby prevent the processor4000from receiving the detection signal Si. Thus, the processor4000generates the control signal So corresponding to the operation of the button to control the operation of the equipment.

A holographic projection device of the present disclosure comprises a first prism array and a second prism array and allows light rays for forming an image to be incident on a first optical interface and a second optical interface an appropriate angles so that the light rays undergo total internal reflection at the first optical interface and the second optical interface, thereby allowing the light rays to travel along a specific optical path to enter the observer's or user's eyes and generate a holographic image visually.

Although particular embodiments of the present disclosure have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present disclosure. Accordingly, the present disclosure is not to be limited except as by the appended claims. Furthermore, it is not necessary for the claims or any embodiments of the present disclosure to achieve all the objectives, advantages or features disclosed in the present disclosure. Moreover, the abstract and the title of the invention serve to assist with a patent search but are not intended to limit the scope of the claims of the present disclosure. In addition, ordinal numbers, such as “first” and “second,” used herein are intended to distinguish or correlate identical or similar elements or distinguish an embodiment from another embodiment but are not intended to define the upper and lower limits of a range of number of the elements.