Head-mounted display and display device thereof

Abstract

The invention discloses a head-mounted display and a display device thereof. The display device comprises a display and an image focal length adjuster. The display has a plurality of partitions. The partitions respectively send a plurality of image light beams with a plurality of different polarization state directions. The image focal length adjuster is disposed adjacent to the display. The image focal length adjuster adjusts the focal length of each image light beam according to each polarization state of each image light beam.

Description

Technical Field

[0001] The present invention relates to a head mounted display and a display device thereof, and in particular to a head mounted display and a display device thereof capable of generating display images with multiple depths of field. Background Art

[0002] Whether the dizziness in virtual reality head-mounted display (VRHMD) (or smart eyewear) can be reduced is a very important indicator in optical products. Therefore, there are countless discussions on the design of multiple depths. For example, using multiple image planes to solve the problem of vergence-accommodation conflict can effectively help alleviate the visual discomfort of wearing head-mounted displays. However, the architecture of multiple depth displays often requires the addition of many components and component volumes, making it difficult to balance the pursuit of visual anti-dizziness comfort, the pursuit of lightness and comfort of wear, and the affordable cost of consumer electronics. Summary of the invention

[0003] The present invention is directed to a head mounted display and a display device thereof, which can generate display images with multiple depths of field.

[0004] According to an embodiment of the present invention, a display device includes a display and an image focus adjuster. The display has a plurality of partitions. The partitions respectively send a plurality of image light beams having a plurality of different polarization state directions. The image focus adjuster is disposed adjacent to the display. The image focus adjuster adjusts the focus of each image light beam according to each polarization state direction of each image light beam.

[0005] According to an embodiment of the present invention, a head mounted display includes a main body portion and the display device as described above.

[0006] Based on the above, the display device of the present invention can generate a plurality of image light beams with a plurality of different polarization states in a plurality of partitions, and cooperate with a polarization selection lens group that adjusts the focal length of each image light beam according to the polarization state of each image light beam, so that multiple parts of the displayed image can have imaging planes with different depths of field, so as to effectively produce an image display effect with multiple depths of field. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A schematic diagram of a display device according to an embodiment of the present invention;

[0008] Figure 2 is a schematic diagram of an implementation of a display in a display device in an embodiment of the present invention;

[0009] Figure 3 A schematic diagram of an implementation of an image focus adjuster for a display device according to an embodiment of the present invention;

[0010] Figure 4A as well as Figure 4B They are schematic diagrams of an implementation of an image focus adjuster for a display device according to an embodiment of the present invention;

[0011] Figure 5A is a schematic diagram of a display device according to another embodiment of the present invention;

[0012] Figure 5B as well as Figure 5C They are light path diagrams of image light beams in different polarization directions in the display device;

[0013] Figure 6 FIG. 4 is a schematic diagram of a head mounted display device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0014] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0015] Please refer to Figure 1 , Figure 1 A schematic diagram of a display device according to an embodiment of the present invention is shown. The display device 100 includes a display 110 and an image (image) focus adjuster 120. The display 110 and the image focus adjuster 120 are disposed adjacent to each other and overlap each other. The display 110 has a plurality of partitions 111 and 112. The display 110 is used to generate a display image and send different image beams IML1 and IML2 to different partitions 111 and 112, respectively. In this embodiment, the image beams IML1 and IML2 may have a plurality of different polarization state directions.

[0016] The image focus adjuster 120 is used to receive the image light beams IML1 and IML2 sent by the display 110. The image focus adjuster 120 can adjust the focus of the image light beams IML1 and IML2 according to the polarization directions of the image light beams IML1 and IML2. Since the polarization directions of the image light beams IML1 and IML2 are different, the image focus adjuster 120 can make the image light beams IML1 and IML2 have different focal lengths. In this way, the image light beams IML1 and IML2 can be imaged on two non-overlapping imaging planes, respectively, and the displayed image has a multiple depth of field effect.

[0017] In this embodiment, the display 110 may have two or more partitions. Figure 1The two partitions 111 and 112 shown are merely illustrative examples and are not intended to limit the scope of the present invention.

[0018] Please refer to Figure 2 , Figure 2 A schematic diagram of an implementation of a display in a display device in an embodiment of the present invention is shown. The display 200 includes a display panel 210, a polarizer 220, and a liquid crystal array substrate 230. The display panel 210 is used to generate a display image. The polarizer 220 and the display panel 210 are arranged to overlap each other and are used to receive a light beam of the display image generated by the display panel 210. In this embodiment, the polarizer 220 can be a linear polarizer, which is used to convert the polarization state direction of the light beam of the display image generated by the display panel 210 to be parallel to the linear transmission axis of the polarizer 220. In this embodiment, the polarizer 220 can be in contact with the surface of the display panel 210 that generates the light beam of the display image.

[0019] In addition, the liquid crystal array substrate 230 is disposed adjacent to the polarizer 220. The liquid crystal array substrate 230 may have a plurality of liquid crystal partitions 231 and 232. The display panel 210 and the polarizer 220 may respectively send partition images DIM1 and DIM2 to the liquid crystal partitions 231 and 232. The liquid crystal partitions 231 and 232 respectively control the polarization state directions of the partition images DIM1 and DIM2 to generate image beams IML1 and IML2.

[0020] In detail, the liquid crystal partitions 231 and 232 can receive control voltages respectively, and decide whether to adjust the polarization directions of the partition images DIM1 and DIM2 according to the receiving state of the control voltage. For example, when the liquid crystal partition 231 receives the control voltage, the liquid crystal array in the liquid crystal partition 231 can be deflected, and the partition image DIM1 can pass directly to generate the image beam IML1. Under such conditions, the polarization direction of the partition image DIM1 will not be adjusted and remains unchanged. On the other hand, when the liquid crystal partition 232 does not receive the control voltage, the liquid crystal array in the liquid crystal partition 232 will not be deflected, and the polarization direction of the partition image DIM2 can be rotated by a preset angle to generate the image beam IML2. In this embodiment, the preset angle is, for example, 90 degrees. In this way, the image beams IML1 and IML2 can have different polarization directions.

[0021] and Figure 1 Similar to the embodiment of FIG. 1 , the number of liquid crystal partitions of the liquid crystal array substrate 230 may be two or more than two. Figure 2The two liquid crystal partitions 231 and 232 of the liquid crystal array substrate 230 shown in the figure are only examples for illustration and are not intended to limit the scope of the present invention. In addition, the liquid crystal array substrate 230 of the present invention may be a twisted nematic (TN) liquid crystal array.

[0022] Please refer to the following Figure 3 , Figure 3 A schematic diagram of an embodiment of an image focus adjuster of a display device according to an embodiment of the present invention is shown. In this embodiment, the image focus adjuster 300 is a polarization path selection lens group. The image focus adjuster 300 can be used to adjust the traveling light path of the image light beam. The image focus adjuster 300 includes a first optical delay plate 311, a beam splitter 312, a second optical delay plate 313, a reflective linear polarizer 314, and a lens group 320. The first optical delay plate 311 and the beam splitter 312 are arranged to overlap with each other, and the first optical delay plate 311 is used to receive the image light beam from the display. The second optical delay plate 313 is arranged to overlap with the reflective linear polarizer 314. Among them, the second optical delay plate 313 has a light incident surface corresponding to the light exit surface of the beam splitter 312. There may be a medium 330 between the second optical delay plate 313 and the beam splitter 312. In this embodiment, the medium 330 may be an air medium.

[0023] Please note that the reflective linear polarizer 314 can produce different effects on image beams with different polarization directions. For example, the reflective linear polarizer 314 can produce a reflection effect on an image beam with a first polarization direction, and the reflective linear polarizer 314 can produce a transmission effect on an image beam with a second polarization direction. The first polarization direction is different from the second polarization direction. Accordingly, the reflective linear polarizer 314 can adjust the traveling light path of the image beam according to the polarization direction of the image beam, and further adjust the focal length and imaging position of the image beam.

[0024] Specifically, when the image beam entering the image focus adjuster 300 is in the first polarization state (linear polarization state) direction, the first retarder 311 can convert the image beam into the first circular polarization state, and then after passing through the beam splitter 312 and the second retarder 313, the image beam can be converted into the first polarization state direction. In addition, the reflective linear polarizer 314 can reflect the image beam in the first polarization state direction, and the retarder 313 converts the reflected image beam into the first circular polarization state. Then, the image beam is transmitted to the beam splitter 312, and the beam splitter 312 can reflect the image beam in the first circular polarization state to the retarder 313. This time, the retarder 313 converts the image beam into the second polarization state (linear polarization state) direction and allows the image beam to pass through the reflective linear polarizer 314.

[0025] On the other hand, when the image beam entering the image focal length adjuster 300 is in the second polarization state (linear polarization state), the image beam is converted into the second circular polarization state through the first retarder 311, and then converted into the second polarization state through the beam splitter 312 and the second retarder 313. In this way, the image beam can directly pass through the reflective linear polarizer 314.

[0026] Incidentally, in this embodiment, the first optical delay plate 311 and the second optical delay plate 313 may be 1 / 4 optical delay plates.

[0027] In addition, the lens group 320 is disposed adjacent to the light-emitting surface of the reflective linear polarizer 314. The lens group 320 is used to receive the image light beam and generate an imaging image.

[0028] According to the above description, the image focus adjuster 300 can perform different degrees of adjustment according to the traveling light paths of image light beams with different polarization states, so that image light beams with different polarization states can be imaged on different imaging planes, thereby improving the depth of field of the displayed image.

[0029] Please refer to the following Figure 4A , Figure 4A A schematic diagram showing an embodiment of an image focus adjuster of a display device according to an embodiment of the present invention. In this embodiment, the image focus adjuster 400 is a polarization directed lens. In this embodiment, the image focus adjuster 400 can be constructed by a liquid crystal array substrate. The image focus adjuster 400 can have different focal lengths in different polarization states through special liquid crystal alignment. Figure 4A In the embodiment, the focal length f is a value greater than 0, and the image focal length adjuster 400 can make the light traveling path of the received image light beam IML1 be in a focused state.

[0030] exist Figure 4B In the example, the focal length f is a value less than 0, and the image focal length adjuster 400 can make the light path of the received image light beam IML2 be in a defocused state; wherein the image light beams IML1 and IML2 have different polarization directions.

[0031] Please refer to FIG. 5A to FIG. 5C , Figure 5A A schematic diagram showing a display device according to another embodiment of the present invention; Figure 5B as well as Figure 5CThe light path diagrams of image beams with different polarization directions in the display device are shown respectively. The display device 500 includes a display 510 and an image focus adjuster 520. The display 510 and the image focus adjuster 520 are arranged adjacent to each other. The display 510 may have a plurality of partitions Z1 and Z2, and the partitions Z1 and Z2 may respectively generate a plurality of image beams IML1 and IML2 with different polarization directions. The polarization direction of the image beam IML1 is orthogonal to the polarization direction of the image beam IML2. The travel details of the light path P1 of the image beam IML1 may be as shown in FIG. Figure 5B As shown, the image light beam IML1 can travel through multiple refractions. The details of the light travel path P2 of the image light beam IML2 can be as shown in FIG. Figure 5C As shown, the image light beam IML2 can travel through two reflections and multiple refractions.

[0032] By adjusting the light paths of the image beam IML1 and the image beam IML2 by the image focal length adjuster 520, the image beam IML1 can form a first virtual image on the imaging plane M1; and the image beam IML2 can form a second virtual image on the imaging plane M2. The imaging plane M1 and the imaging plane M2 do not overlap. With respect to the position of the observer's eyeball EYE, the first virtual image corresponding to the image beam IML1 can have an image distance d1, and the second virtual image corresponding to the image beam IML2 can have an image distance d2. The image distance d1 is smaller than the image distance d2.

[0033] From the above description, it can be known that the display device 500 generates image beams with different polarization directions for display images of different partitions by using the display 510, and then adjusts the focus of the image beam according to the polarization direction through the image focus adjuster 520. In this way, in the display image, the display objects corresponding to different partitions can be imaged on imaging planes with different image distances. The display image generated by the display device 500 can have multiple depths of field, effectively improving the display quality of the display image.

[0034] Please refer to the following Figure 6 , Figure 6 A schematic diagram of a head mounted display device according to an embodiment of the present invention is shown. The head mounted display device 600 includes a main body 610 and a display device 620. The display device 620 is disposed in the main body 610 and is used to project a display image into the user's eye.

[0035] The display device 620 can be implemented by applying the display device 100 or 500 of the aforementioned embodiment. The implementation details of the display device 620 are described in detail in the aforementioned multiple embodiments and implementation methods, which will not be repeated here.

[0036] It is worth mentioning that the setting position of the display device 620 in the main body 610 can be appropriately adjusted according to the structural setting of the head-mounted display device 600. Figure 6 The examples shown are only for illustration purposes and are not intended to limit the scope of implementation of the present invention.

[0037] In summary, in the display device of the present invention, by making the display generate image beams with different polarization directions, and then using the image focal length adjuster to adjust the focal length of the image beam according to the polarization direction, the imaging distance of each part of the display screen can be effectively controlled, and a display image with multiple depths of field can be effectively generated, thereby improving the display quality.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A display device, comprising: A display having a plurality of partitions, wherein the plurality of partitions respectively transmit a plurality of image light beams having a plurality of different polarization state directions; as well as The image focus adjuster is disposed adjacent to the display and adjusts the focus of each image light beam according to the polarization state direction of each image light beam.

2. The display device according to claim 1, wherein the display comprises: A display panel for generating display images; A polarizer, arranged to overlap with the display panel, for converting the polarization state of the displayed image; as well as The liquid crystal array substrate is disposed adjacent to the polarizer and has a plurality of liquid crystal partitions corresponding to the plurality of partitions respectively. The plurality of liquid crystal partitions respectively receive a plurality of partition images of the display image and control the polarization state directions of the plurality of partition images to respectively generate the plurality of image light beams. 3 . The display device according to claim 2 , wherein each of the liquid crystal partitions of the liquid crystal array receives a corresponding control voltage and rotates each of the polarization state directions of each of the image light beams by a preset angle according to the control voltage. 4 . The display device according to claim 3 , wherein when each of the liquid crystal partitions does not receive the control voltage, each of the liquid crystal partitions maintains the polarization state direction of each of the image light beams unchanged. 5 . The display device according to claim 1 , wherein the image focus adjuster adjusts the traveling light path of each of the image light beams according to the polarization state direction of each of the image light beams.

6. The display device according to claim 1, wherein the image focus adjuster is a polarization selection lens group, and the polarization selection lens group comprises: A first optical delay plate, for receiving the plurality of image light beams; A beam splitter, arranged to overlap with the first optical delay plate; A second optical delay plate, arranged adjacent to the beam splitter; as well as The reflective linear polarizer is overlapped with the second optical delay plate and is used to reflect or transmit each of the image light beams according to the polarization state direction of each of the image light beams.

7. The display device according to claim 6, wherein there is a medium between the second optical delay plate and the beam splitter.

8. The display device according to claim 6, wherein the polarization selective mirror group further comprises: The lens group is disposed adjacent to the light emitting surface of the reflective linear polarizer.

9. The display device according to claim 1, wherein the image focus adjuster is a polarization direction lens.

10. The display device according to claim 1, wherein a first partition of the display sends a first image beam having a first polarization state direction, and a second partition of the display sends a second image beam having a second polarization state direction, and the polarization selection mirror group adjusts the transmission path of the first image beam according to the first polarization state direction of the first image beam, and controls the first image beam to be imaged on a first plane, and the polarization selection mirror group adjusts the transmission path of the second image beam according to the second polarization state direction of the second image beam, and controls the second image beam to be imaged on a second plane, wherein the first plane does not overlap with the second plane.

11. A head mounted display, comprising: Body part; as well as The display device according to claim 1, provided in the main body portion.

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