Method and apparatus for projecting content displayed on a display

Abstract

An apparatus for projecting content displayed on a display, the apparatus can include a first array of first microlenses comprising a plurality of first microlenses; a second array of second microlenses spaced apart from the first array of microlenses and comprising a plurality of second microlenses; wherein a width of each first microlens and each second microlens is several times smaller than a pixel pitch of the display; wherein the second array of second microlenses is located at a conjugate plane of the display; wherein a focal plane of each second microlens is located at a corresponding first microlens; wherein the apparatus is configured to project different images of the display located at different distances from the display; wherein each image of the display comprises a plurality of image segments; wherein a light path of each image segment passes through a pair of dedicated second microlenses and a corresponding first microlens.

Description

BACKGROUND

[0001] Today, digital displays are very popular. They are used in mobile phones, smartphones, wearables, tablets, computers, cars, digital cameras, televisions, etc. However, in some cases, users encounter challenges that significantly reduce their viewing experience.

[0002] Most people approaching 40 years of age or older have lost their eye's auto-focusing ability because their eye's lens has lost its flexibility. Their eye's focus is fixed at some location, so their clear vision field is only at a certain distance: most of them are "presbyopic", clear to see far distances ("infinity"), so they need reading glasses for close distances. Another part of them is "myopic", clear to see close distances, so they can read without glasses, but they need optical glasses for far distances, to drive, watch TV, watch movies, etc.

[0003] To solve this problem, "presbyopic" people use reading glasses, which enable them to focus on objects close by. However, they do not need glasses to see images far away. In a typical scenario, they do not wear glasses most of the day, so when people need to read information from their digital displays (mobile phones, tablets, digital watches, etc.), they need their reading glasses, which are not found, which is very common. This is annoying because they need to look for their glasses. There are many people who do not want to use reading glasses in public. It would be very attractive to these people to provide the ability to read digital displays without glasses.

[0004] In addition, ophthalmologists warn of the effects on our vision of the excessive use of laptops, tablets, cell phones, and now smart watches. As mobile devices become more and more popular, most of us spend more and more time interacting with the world on small screens that emit light.

[0005] There is a large body of evidence that, while having the world at our fingertips has many benefits, spending too much time focusing close up can harm our eyes. There is evidence that the proportion of children and adults who need glasses has risen dramatically in recent decades, especially since the exponential growth in the use of displays by children, due to the fact that their eyes are tired every day because they focus their eyes on displays at short distances for long periods of time.

[0006] There is an increasing need to provide a method and device that significantly improves the user experience and reduces eye strain in the above-mentioned situations. SUMMARY

[0007] A device and method for projecting content displayed on a display can be provided.

[0008] The device can comprise a first array of first microlenses, which can comprise a plurality of first microlenses; a second array of second microlenses can be spaced apart from the first array of first microlenses and can comprise a plurality of second microlenses; wherein a width of each first microlens and each second microlens can be several times smaller than a pixel pitch of the display; wherein the second array of second microlenses can be located at a conjugate plane of the display; wherein a focal plane of the second microlenses can be located at the first microlenses; wherein the device can be configured to project different planes that are each distinct from one another and can be located in the vicinity of the focal plane of the second microlenses; wherein each plane carries visual information that can comprise a plurality of segments; and wherein a light path of each segment passes through a dedicated pair of second microlenses and corresponding first microlenses.

[0009] The several times can be four times, can be less than four times or more than four times.

[0010] The different planes can be located within a depth of field of the second array of second microlenses.

[0011] Different pairs of lenses can have optical axes that are not parallel to each other, wherein each pair of lenses can comprise a second microlens and a corresponding first microlens.

[0012] A distance between adjacent second microlenses can be smaller than a distance between corresponding adjacent first microlenses.

[0013] Different pairs of lenses can exhibit optical axes that intersect each other.

[0014] An area of a second microlens can be smaller than an area of a corresponding first microlens.

[0015] A ratio between a width (Dc2) of a second microlens and a width (Dc1) of a corresponding first microlens can be substantially equal to L / (L+H1), wherein H1 can be a distance between the second microlens and the corresponding first microlens, wherein L can be a distance between the display and an intersection between the optical axes of the different pairs.

[0016] The device can comprise at least one transparent element located between the first array of microlenses and the second array of microlenses.

[0017] An air gap can exist between the at least one transparent element and the first array of microlenses. BRIEF DESCRIPTION OF DRAWINGS

[0018] What is regarded as the subject matter of the application is particularly pointed out and distinctly claimed in the concluding portion of the specification. The application, however, both as to organization and method of operation, together with objects, features, and advantages thereof, can best be understood by reference to the following detailed description when read with Figure One taken in conjunction with the accompanying drawings in which:

[0019] Figure 1 are examples of one or more components of a device and display;

[0020] Figure 2 are examples of one or more components of a device;

[0021] Figure 3 are examples of one or more components of a device;

[0022] Figure 4 、 4A , 5 and 6 are examples of one or more components of a device, display and various optical paths; and

[0023] Figure 7 are examples of methods. DETAILED DESCRIPTION

[0024] A method and device are provided that can eliminate the need to use reading glasses to read the content of a digital display.

[0025] This is done by adding to the top of the display a device that can be a thin film of a specific shape and specific size that transforms the image of the display to the user's eye as if it is far away for a "far-sighted" user and at close range for a "near-sighted" user, thus enabling "far-sighted" and "near-sighted" users to view it at high resolution without the use of glasses. The method can be embedded as an additional thin layer to the display or can be used as an additional transparent thin film or device that covers the display.

[0026] The method and device can be suitable for "far-sighted" and "near-sighted" eyes as well as for people with perfect vision and who do not need glasses at all. Using the proposed device and method, the display will be visible at high resolution to most eyes and no further eye correction will be needed.

[0027] The method and device can prevent eye fatigue by providing the user of a display located in the normal reading range (~ 25-40 cm) with an image at infinity, with no apparent change in magnification, resolution, color, brightness and other display characteristics.

[0028] The method and device overcome the need to tailor the optics according to the user's focusing ability to see distant objects. In addition, the method and device reduce the reflection of the sun and the background scene when the display is used outdoors on sunny days.

[0029] The device can include a combination of different optical layers that can be embedded as an addition as a special thin film on top of the display, see Figure 1or embedded as a special layer in the display, see for example Figure 6 .

[0030] The thin layer consists of a 3D Microlens Array (MLA) layer, whose cross section is shown in Figure 1 . Figure 2 and Figure 2A A top view example of a rectangular microlens array is given. It is important to note that any shape of microlens that can completely cover the display area can be considered, such as triangular, rectangular, hexagonal array, etc. For simplicity of description, we take the rectangular as an example.

[0031] Referring to Figure 1 , the digital display 105 consists of an array of red - R, blue - B and green - G color sub-pixels 104 combinations. Without loss of generality and for simplicity, they are drawn along a line, but they can have any two-dimensional (2D) or three-dimensional (3D) configuration. The linear combination of the relative intensities of the sub-pixels creates the actual color of the pixel. The spacing between the pixels depends on the resolution of the display. In today's cell phones, the spacing is about 40-80 pm. The pixel array is attached to a glass cover 110, whose typical optical thickness is about 0.5-1 mm.

[0032] This configuration is typical for various types of digital displays. Figure 1 In our thin layer element 150 is attached to 110, taking as an example its composition of 4 layers, as follows:

[0033] a. Layer 115 can consist of an index matching glue between the display and the glass cover, which significantly reduces the reflection of the glass cover and the next interface.

[0034] b. The first Microlens Array (MLA) layer 120, width Dc1, focal length fl. Preferably, Dc1 (the MLA's cell size) is below the eye's resolution capability at normal reading distance. Typically, Dc1 can be in the order of the pixel pitch of the display.

[0035] c. The intermediate transparent layer 130. It can consist of a transparent solid layer or an air gap, to facilitate production and eliminate the requirement for too small and unproducible lens radii. The air gap will ensure a larger difference in refractive index (An) at the interface with the lens, thus ensuring a larger, manufacturable radius. Small and very thin pillars at the partial corners between some of the lenses can serve as spacers 132, see Figure 3 at the expense of a negligible fraction of the fill factor of the entire microlens array.

[0036] d.The second microlens array layer 135 has almost the same width Dc2 and a focal length f2 located on layer 130. The focal plane of the second MLA lens is on the plane of the first MLA lens 125, so it projects its image to infinity. The preferred relationship between Dc1 and Dc2 will be explained later.

[0037] We call the configuration of Figure 1 a pinhole image double microlens array (PIDMLA). Figure 1 and Figure 3 The configuration of Figure 2 is called aperture image double microlens array (AIDMLA).

[0038] The following is a short description of the optical system proposed for one MLA cell (see Figure 3): Figure 4

[0039] Each lens of the first microlens array 120 produces an image of a tiny portion of the display of size D. This image is formed on the plane of the second lens 135, which is part of the second MLA. It is an inverted image of D with a magnification factor M = H1 / H, filling the second lens. Thus, the size of the imaged portion of the display is D = Dc2 / M. For simplicity and without loss of generality, H and H1 are the "optical thickness" of the materials, including their refractive indices, respectively.

[0040] The first lens 120 is located on the focal plane of the second lens 135, so along the optical axis, the aperture image of the first lens 120 is projected to infinity by the second lens. Each point of this image (of the aperture of the first lens) receives a light ray from each point of D on the display, so this is a perfect blend of the RGB sub-pixels that make it up. Since Dc1 and Dc2 (the lens dimensions on both sides of the cell) are below the resolution capability of the eye, the eye of the observer of the display will see, on the display, an indistinguishable tiny spot of color D, imaged onto his / her eye, along the optical axis.

[0041] As mentioned above, each cell images a tiny portion of the display of size D to infinity, so it emits parallel light rays to the eye. These light rays focus on a point on the retina. Since the size of the cell is much smaller than the input pupil of the eye (50-100 pm compared to 2-3 mm), several such parallel light rays, which come from different areas on the display and are parallel to each other, will enter the eye from the same direction, so will focus on the same point on the retina. This will result in a mixing of colors from adjacent but different portions of the display. This will result in blurring and loss of resolution. To prevent this from happening, the optical axes of all the cells that image the entire display need to be directed to the center of the eye pupil, not parallel to each other. In other words, the center of each pair of cell lenses and the center of the eye pupil must lie on the same line over all areas of the display. ​

[0042] This is achieved by:

[0043] Assume:

[0044] a. The observer's eye is located on the main axis (a vertical line from the center of the display).

[0045] b. The centers of the lenses on both sides of the central cell are also located on this main axis (see Figure 4A ).

[0046] c. The inner dimension of the cell is Dci, and the outer dimension of the cell is Dc2.

[0047] d. A small area of the display, which is (X, Y) coordinates from the center (0, 0), is imaged onto the observer's eye by each MLA cell.

[0048] Then, for the requirement that the optical axis of the eye and the optical axis of the two relevant cell lenses are located on a straight line, it leads to the requirement that the center of the inner lens is slightly higher (or lower) than the height of the outer lens from the main axis (see Figure 4 , 4A ).

[0049] Using the similar triangle relationship, we get: Y1 / Y2 = (L-H) / (L-H-H1). Then the required vertical offset (OSy) between the lenses of a certain cell at a distance Y from the main axis is: OSy = Y1-Y2 = Y*H1 / L.

[0050] Let Ny = Y / Dc2 be the approximate number of outer lenses 135 between the center of the display and Y, then OSy = (Y / Dc2)*Dc2*H1 / L, then OSy = Ny*Dc2*H1 / L.

[0051] Multiply the number of lenses (Ny) by their size difference (Dc1-Dc2) to equal the total offset between the lenses at a height Y from the center: OSy = Ny*(Dc1-Dc2). From the above, replace OS, we get Ny*(Dc1-Dc2) = Ny*Dc2*H1 / L, then Dc1-Dc2 = Dc2*H1 / L. And Dc1 = Dc2*(1+H1 / L).

[0052] Similar evaluation along the X direction leads to the same requirement. This is the relationship between the sizes of the inner and outer cells, so that on the entire display, all the centers of the lens pairs of each cell will be located on an optical axis with the eye. Therefore, the resolution of the display will be maintained.

[0053] First example

[0054] a. Dc2= 100 pm, H1= 1 mm, L = 250 mm, then Dc1= 100.4 mm

[0055] b. For simplicity, in the following discussion we will approximate with the average of Dc1and Dc2: Dc= (Dc1+ Dc2) / 2

[0056] All the above optical concepts are similar for all lens pairs of the two MLA layers.

[0057] The center of the entrance pupil of the eye and the center of each lens of the second (outer) MLA constitute an optical axis along which the above mentioned part of the display (square of size D) is imaged on the retina as an indistinguishable spot of the correct color of the area of the display.

[0058] The optical axis of the eye and the neighboring lens of the outer MLA form optical axes with a slight difference in direction, therefore the collection of images of all the spots on the retina of the eye forms a perfect imaging replica of the overall display on the retina.

[0059] It is expected that the appearance of the display will be insensitive to the viewing angle (relative to the vertical direction of the display).

[0060] The resolving element of the image on the retina of the eye is D, and as mentioned above, its size is D = Dc / M. Since M = H1 / H, three cases can be analyzed:

[0061] a. Assume H1= H, M = 1 and D = Dc. In this case, the size of the resolving element is the same as the size of the unit of the MLA (Dc), and the resolution of the displayed image is preserved as long as it remains well below the resolving power of the eye. The MLA rays entering the observer’s eye are very close to parallel, therefore the brightness of the display does not change significantly.

[0062] b. Assume H1< H, M < 1 and D > Dc. In this case, the imaging areas of neighboring lenses of the MLA can partially overlap, therefore the resolving element is ~D. This case can be used for practical reasons by minimizing the size of H1to avoid excessive thickness of the MLA elements above the display. In addition, by partially mixing the images of neighboring units, the risk of jaggies and Moire artifacts is minimized. Furthermore, the brightness of the display is preserved due to the compensating effect of the larger area (D) of the light source imaged on the retina and the larger solid angle from which the same amount of light is emitted from the MLA. The resolution of the displayed image is preserved as long as D is well below the resolving power of the eye.

[0063] c.Assuming H1>H, M>1 and D<Dc. In this case, there is an unimaged gap between the cells. This can result in a loss of display brightness and a thicker MLA and higher risk of jaggies and Moire artifacts, so this case is not desirable.

[0064] In summary, as long as D is kept below the resolving power of the eye, the resolution of the display can be maintained.

[0065] Furthermore, as will be detailed in some examples below, if the observer's eye loses its auto-focusing ability (for example, for an elderly person who needs reading glasses) and is fixedly focused at a distance different from infinity, the displayed image on the eye's retina is still perfect because it will draw the image from a very close plane, within the focal depth of the focal plane of the outer lens (in the nanometer range...) (see Figure 4 and 5 ). In Figure 4 we refer to Figure 1 a cell of the lens array.

[0066] The sub-pixels 104 are mixed on the lens 120 to be colored spots, where the intensity of the spots and their color are almost the same along the optical axis, near the plane of the lens 120, and denoted as planes 121-126.

[0067] The planes 121-126 are examples of different planes, which are different from each other and are located near the focal plane of a second microlens of the second array of microlenses. Each plane 121-126 carries visual information representing the visual information displayed by the display, but not the image of the display. The planes are close to each other - for example, within a distance of microns or sub-millimeters. The visual information has segments - each segment passes through a pair of lenses including a first microlens and a second microlens.

[0068] The eye of user A, which is fixedly focused at infinity, gets its image from the focal plane 530 of the second lens. This image is projected by the second lens 135 to infinity, and the lens of the user's eye 510 focuses it on its retina 515.

[0069] In Figure 5 we refer to the case where the user is fixedly focused at a close distance ("myopic"). In this case, his eye will receive a sharp image from a plane 520 that is slightly closer to the lens 135 and in front of the lens 120. The image of this plane is sharp on the retina 515.

[0070] It can be seen that even on a slightly offset plane, along the optical axis, the image of each cell contains a very good representation of the color of that part of the display (seeFigure 1 and Figure 3 representing color spots around the lens 120. Thus, the present invention proposes a solution that eliminates the need for reading glasses with any prescription correction at any diopter, even in the case of different corrections for both eyes. It should be noted that only a part of the above layers can be used, or they can be organized in a different order, or more layers can be added or these layers can be merged into one layer.

[0071] The method and device can also reduce the effects of ambient light reflections. As mentioned above, in Figure 1 and 3 the outer surface is composed of a microlens array 135, each microlens being below the resolution of the human eye. This surface acts as a perfect diffuser of nearby very bright images, dispersing them and preventing them from interfering with the image displayed in the current situation. Although the outer surface is a perfect diffuser, it allows the viewer to see the display perfectly through it, even without reading glasses.

[0072] The imaging system proposed by the AIDMLA is robust and not sensitive to small variations in the thickness of the layers and the glass. This can be seen from the following examples.

[0073] The system is also not sensitive to small errors in the radii of the lenses, their shape and the surface. Due to the small size of its optical elements (of the order of the display pixel pitch), below the resolution capacity of a perfect eye, the proposed invention eliminates the need for correction of possible optical aberrations of its optical elements (chromatic aberration, spherical aberration, coma, etc.). This feature of the invention guarantees its low price of development and production.

[0074] AIDMLA example and analysis (M = 1).

[0075] Example A: Myopic eye focusing at 0.5 m

[0076] a. Here is a brief reasoning and calculation:

[0077] b. Let's assume that the system is composed of the following subsystems:

[0078] c. 1000 pm thick glass cover, 100 pm PET base, first MLA made of UV resin A and second MLA made of UV resin B:

[0079] d. Note: for simplicity, we use the optical thickness (thickness divided by refractive index) of the flat elements (glass cover, base, adhesive, etc.).

[0080] e. The minimum distance of the first lens from the display is the thickness of the glass: 1000 pm + 100 pm (PET base) + 100 pm UVRA (UV resin A) and 2f = 1200 pm, so f = 600 pm is the focal length of the first lens.

[0081] f. The radius of the first lens is: R1 = f * (n2 - n1) = 600 * (1.62 - 1.52) = 60 pm. If an air gap 131 is used, as shown in Figure 3 .

[0082] g. R = f * (1.52 - 1) = 600 * 0.52 = 312 pm.

[0083] h. The thickness and focal length of the second layer is F = 2f = 1200 pm

[0084] i. We can use the same UVRA for the outer layer.

[0085] j. In this case, R2 = F * (1.52 - 1) = 1200 * 0.52 = 624 pm.

[0086] k. Total foil thickness: 100 (PET) + 100 (UVRA) + 1200 = 1.4 mm

[0087] Sensitivity to the amount of vision correction needed:

[0088] Assume the eye is fixed corrected for 0.5 m distance and the display is viewed from 0.25 m. This means that the image is a virtual image at a distance U = 0.25 m from the second (projective) lens. By using the Newton lens formula, we find that the object plane is closer to the lens than the focal plane, by a distance of See Figure 4 and 5 .

[0089] In the worst case, we assume that the different sub-pixel colors of RGB are aligned along a line that occupies the entire cell size, so the maximum distance between the R color and the B color is Dc. From each point, a cone of light hits the first lens 125 at a slightly different angle, see Figure 4 and 5 . On the plane of the lens 120, the color cones overlap and merge perfectly. When we move from this plane along the optical axis by a distance x to the plane of the sharpest image with the uncorrected eye described above, there is a slight separation of the cross-sections of the RGB cones, which can cause a slight change in the color of the cell. See Figure 5 . From simple geometry, we can find that the maximum relative separation S between the cross-sections of the two R and B color cones is S = x / F, where F is the focal length of the second (outer) lens.

[0090] Substituting x in the above equation, we get S = F / U. In our example, we get S = 624 / 250000 S = 0.0025 = 0.25%. This worst case separation is an order of magnitude smaller than the limit of the color noticeable change (3%). Figure 4 and 5 As shown, the color of 104 around the plane 530 is almost the same.

[0091] This also means that an error of about 10-15 pm (~10*x) in the focal length and layer thickness is tolerable as well, thus the system is robust and manufacturable.

[0092] Second example

[0093] Assume the system is similar to the above, but now the fictitious image should be at a distance U = 2.25m - 0.25m = 2m from the display.

[0094] Substituting the above equation, we get and a maximum color separation S = 624 / 2000000 = 0.03%, which is even two orders of magnitude lower than the color noticeable change (3%).

[0095] AIDMLA example and analysis (M = 0.5)

[0096] a. Following the above calculation method, it can also be shown that for a smaller magnification, e.g. M = 0.5, we get f = 300 pm, and a total foil thickness of 100 (PET) + 100 (UVRA) + 600 = 0.8 mm. This lower thickness can be easier to handle as a glass protector for the display or as an integrated internal part of the display. The rest of the features will be similar to the explanation in the above example.

[0097] In summary, the proposed AIDMLA provides the following important features and advantages - resolution and no need for refractive correction of the observer's eye.

[0098] The resolution is determined by the cell size and the magnification.

[0099] Since the eye is at a relatively far distance compared to the size of the cell, each cell determines its line of sight to the eye, and since the size of the cell is below the human resolution, the original resolution of the display is maintained. From a viewing distance of 25 cm, the resolving element of a perfect eye is larger than 90 pm.

[0100] The resolution is similar over a wide angular range. As the line of sight moves from the normal to the display, some rays can come from adjacent inner lenses, but since they are identical, the resolution and color of the display do not change.

[0101] Each type of eye will see a slightly different apparent plane of the outer MLA (135) in focus, but, as mentioned above, the color of the display will not change significantly.

[0102] Figure 1 is Figure 2 a cross section of one row of the array. Note that, Figure 2 shows a top view of the array of elements, each being a 3D element of size Dc x Dc. Typical values of Dc can be in the micrometer range. In some cases, for large displays such as TVs, Dc can also be in the mm range. Dc can be in the order of the pixel pitch to maintain the resolution of the display, but somewhat different to avoid possible Moire artifacts.

[0103] As an example of a multi-layer approach, we use layers composed of arrays of rectangular micro-elements, as Figure 2 shown. Note that any shape that can completely cover the display area can be considered, for example arrays of triangles, rectangles, hexagons, etc. Other geometries (circular, etc...) can also be applied, but they will have dead space between the elements and thus will have lower display energy transmission efficiency. In Figure 1 and Figure 2 we show the case of rectangles, each element of size dl * d2 and height Hl being composed of transparent elements 130. Preferably, dl and d2 are of size below the resolution of the human eye.

[0104] Layer 135 has two functions:

[0105] a. It recollimates the light rays from plane 120 into parallel rays entering the observer's eye and creating an image of plane 120 at infinity.

[0106] b. Since the pitch of the repeating, possibly convex or concave, outer elements is about the pitch of the display pixels (below the resolution of the human eye), it also acts as a matte surface and diffuses the incoming ambient light and will resist scratches and fingerprint marks.

[0107] It should be noted that these layers can be combined in different ways or use a portion of these layers. This layer structure is provided as an example of how to implement the system and method. The proposed method can be embedded as a special layer 150 into the display of the device or can be used as an additional transparent element covering the display.

[0108] Figure 6An example of how the AIDMLA can be embedded in a cell phone is shown. There are multiple options to do this. We present an example where our device 150 is located between the display and the glass cover, underneath the glass cover. The digital display 105 is composed of a combination of arrays of R, G, B color sub-pixels 104, where the combination of three sub-pixels represents the color of a pixel. Note that different color sub-pixel configurations can be used, this configuration is used as an example. In today's cell phones, the pitch is about 40-80 microns. The pixel array is connected to Figure 6 a thin layer element 150. The glass cover 110 is connected to 150.

[0109] As an example, the device 150 is composed of 4 layers, as follows:

[0110] a. Layer 115 can be composed of a transparent spacer and index matching glue between the display and the lens array layer 120.

[0111] b. Micro-lens array layer 120, with square aperture of width Dcl and focal length fl.

[0112] c. Intermediate transparent layer 130.

[0113] d. Second lens array layer 135 with square aperture of width Dc2 and focal length f2 located on layer 130, which re-collimates the light and image plane 125 to the observer's eye at an infinite distance or a desired image distance suitable for the user's eye 137.

[0114] The focal length f2 of the micro-lens array 135 is equal to Hl, which ensures that the plane 125 located at the center of the lens 120 is projected to infinity. Given H and Hl, the focal length fl of 120 is chosen to image the display 105 onto the external MLA 135 with a magnification factor of M = Hl / H.

[0115] Figure 7 Method 300 is illustrated. The method 300 can include a step 310 of projecting, by a device, different planes different from each other and located near a focal plane of a second micro-lens of a second array of second micro-lenses of the device. Wherein the device further comprises a first array of first micro-lenses, wherein the second array of second micro-lenses is spaced apart from the first array of first micro-lenses, wherein a width of each first micro-lens and each second micro-lens is several times smaller than a pitch of pixels of the display, wherein the second array of second micro-lenses is located at a conjugate plane of the display, wherein the focal plane of the second micro-lens is located at the first micro-lens; wherein each plane carries visual information comprising a plurality of segments; and wherein a light path of each segment passes through a dedicated pair of second micro-lens and corresponding first micro-lens.

[0116] The device can be added to the display, integrated with the display, an additional apparatus of the display, etc.

[0117] In the detailed description, numerous specific details are set forth in order to provide a thorough understanding of the application. However, it will be apparent to one skilled in the art that the application can be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the application.

[0118] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, can best be understood by reference to the following detailed description when read with the accompanying drawings in which:

[0119] It is understood that the elements shown in the figures are not necessarily drawn to scale. For example, the dimensions of some of the elements can be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding or analogous elements.

[0120] Since the illustrated embodiments of the application can be implemented using electronic elements and circuits known to those skilled in the art, details will not be explained to a greater extent than considered necessary as to understanding and appreciating the underlying concepts of the application for the purposes of the patent monopoly on the best mode of carrying it out.

[0121] Any reference in the specification to a method should be applied mutatis mutandis to a device capable of carrying out the method.

[0122] Any reference in the specification to a device should be applied mutatis mutandis to a method which can be carried out by said device.

[0123] The term "and / or" means either or both.

[0124] In the foregoing specification, the application has been described with reference to specific examples of embodiments of the application. It is evident, however, that various modifications and changes can be made thereto without departing from the broader spirit and scope of the application as set forth in the appended claims.

[0125] Also, the terms "front," "back," "top," "bottom," "over," "under," and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in other orientations than described or otherwise shown in the figures.

[0126] Any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermediate components. Likewise, any two components so associated can also be viewed as being "operably connected," or "operably coupled," to each other to achieve the desired functionality.

[0127] Furthermore, those skilled in the art will recognize that boundaries between the functionality of the above described operations merely illustrative. The multiple operations can be combined into a single operation, a single operation can be distributed in additional operations and operations can be executed at least partially overlapping in time. Moreover, alternative embodiments can include multiple instances of a particular operation and the order of operations can be altered in various other embodiments.

[0128] However, other modifications, variations and alternatives are also possible. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive sense.

[0129] The phrase "can be" indicates potentially or possibly can be. This phrase also indicates that there are instances where the condition does not occur. For example, any mention of a device including a component should be taken to also cover instances where the device does not include the component.

[0130] The terms "comprise," "include," "have," "contain," and "comprising," "including," "have," "contain," and "containing," are used in an open-ended way. For example, any method can include at least the steps disclosed in the appended claims, only the steps disclosed in the appended claims. The same applies to devices and mobile computers.

[0131] It will be appreciated that, for clarity and simplicity, the elements illustrated in the figures can not be drawn to scale. For example, the size of some of the elements can be exaggerated relative to other elements. In addition, the reference numerals can be repeated in the figures to indicate corresponding or analogous elements throughout the several views.

[0132] However, other modifications, variations and alternatives are also possible. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive sense.

[0133] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. Further, the word "a" preceding an element or step does not exclude the presence of more than one such element or step. Moreover, any introductory phrases, such as "at least one" and "one or more", shall not be construed as limiting the claim to the specific elements or steps recited therein. The use of introductory phrases such as "at least one" and "one or more" in the claims shall not be construed to imply that the incorporating claim is ha ing only one of the elements specified in the claim. Likewise, the use of introductory phrases such as "at least one" and "one or more" in the claims shall not be construed to imply that the incorporating claim is ha ing only one of the elements specified in the claim. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.

[0134] While certain features of the application have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the application.

[0135] Any combination of any components of any assembly and / or device unit shown in any of the drawings and / or the specification and / or claims can be provided.

[0136] Any combination of any devices shown in any of the drawings and / or the specification and / or claims can be provided.

[0137] Any combination of steps, operations and / or methods shown in any of the drawings and / or the specification and / or claims can be provided.

[0138] Any combination of operations shown in any of the drawings and / or the specification and / or claims can be provided.

[0139] Any combination of methods shown in any of the drawings and / or the specification and / or claims can be provided.

[0140] Furthermore, while illustrative embodiments have been described herein, those skilled in the art will appreciate that any and every modification, combination, sub-combination, permutation, adaptation, and / or variation demonstrating the equivalent or more specific result are within the scope of any and all embodiments. The limitations in the claims are to be construed as limiting only to the precise systems, compositions, and methods described in the claims. These examples are to be construed as non-exhaustive. Further, the steps of the disclosed methods can be modified in any manner, including by reordering steps and / or inserting or deleting steps. It is intended, therefore, to be bound only by the broadest interpretation of the following claims and their equivalents.

Claims

1. A device for projecting content displayed on a display, the device comprising: a first array of first microlenses comprising a plurality of first microlenses; a second array of second microlenses spaced apart from the first array of first microlenses and comprising a plurality of second microlenses; a spacer between the first microlenses; wherein a width of each first microlens and each second microlens is several times smaller than a pixel pitch of the display; wherein the second array of second microlenses is located at a conjugate plane of the display; wherein a focal plane of the second microlenses is located at the first microlenses; wherein the device is configured to project different planes that are different from each other and located near the focal plane of the second microlenses, wherein each of the different planes carries visual information that represents visual information displayed by the display but is not an image of the display; wherein each plane carries visual information comprising a plurality of segments; and wherein an optical path of each segment passes through a pair of dedicated second microlenses and corresponding first microlenses.

2. The apparatus of claim 1, wherein, The several times is four times.

3. The apparatus of claim 1, wherein, The different planes are located within a depth of field of the second array of second microlenses.

4. The apparatus of claim 1, wherein, Different pairs of lenses have optical axes that are not parallel to each other, wherein each pair of lenses comprises a second microlens and a corresponding first microlens.

5. The apparatus of claim 1, wherein, A distance between adjacent second microlenses is smaller than a distance between corresponding adjacent first microlenses.

6. The apparatus of claim 1, wherein, The different pairs of lenses exhibit optical axes that intersect each other.

7. The apparatus of claim 1, wherein, An area of a second microlens is smaller than an area of a corresponding first microlens.

8. The apparatus of claim 1, wherein, A ratio between a width (Dc2) of a second microlens and a width (Dc1) of a corresponding first microlens is substantially equal to L / (L+H1), wherein H1 is a distance between a second microlens and a corresponding first microlens, and wherein L is a distance between the display and an intersection of optical axes of the different pairs of lenses.

9. The device of claim 1, further comprising at least one transparent element between the first array of microlenses and the second array of microlenses.

10. The apparatus of claim 9, wherein, An air gap is present between the at least one transparent element and the first array of microlenses.

11. A method for projecting content displayed on a display, the method comprising: projecting, by a device, different planes that are different from each other and located near a focal plane of second microlenses in a second array of second microlenses of the device; wherein the device further comprises a first array of first microlenses, wherein the second array of second microlenses is spaced apart from the first array of first microlenses, wherein a width of each first microlens and each second microlens is several times smaller than a pixel pitch of the display, wherein the second array of second microlenses is located at a conjugate plane of the display, wherein the focal plane of the second microlenses is located at the first microlenses; wherein each plane carries visual information comprising a plurality of segments that represents visual information displayed by the display but is not an image of the display; and wherein an optical path of each segment passes through a pair of dedicated second microlenses and corresponding first microlenses.

12. The method of claim 11, wherein, The several times is four times.

13. The method of claim 11, wherein, The different lens pairs have optical axes that are not parallel to each other, wherein each lens pair comprises a second microlens and a corresponding first microlens.

14. The method of claim 11, wherein, The distance between adjacent second microlenses is smaller than the distance between corresponding adjacent first microlenses.

15. The method of claim 11, wherein, The different lens pairs present optical axes that intersect each other.

16. The method of claim 11, wherein, The area of the second microlenses is smaller than the area of the corresponding first microlenses.

17. The method of claim 11, wherein, The ratio between the width (Dc2) of the second microlenses and the width (Dc1) of the corresponding first microlenses is substantially equal to L / (L+H1), wherein H1 is the distance between the second microlenses and the corresponding first microlenses, and wherein L is the distance between the display and the intersection of the optical axes of the different lens pairs.

18. The method of claim 11, wherein, The device further comprises at least one transparent element located between the first microlens array and the second microlens array.

19. The method of claim 18, wherein, An air gap is present between the at least one transparent element and the first microlens array.

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