Display, method for projecting an image and method for producing a display

Abstract

The invention relates to a display for representing an image, comprising a condenser lens array (12) having a plurality of condenser lenses (14); a projection lens array (16) having a plurality of projection lenses (18); a plurality of optical channels (22) which each comprise at least one condenser lens (14) and one projection lens (18) and are designed to project the image (24) to be represented by the display; and a plurality of convergent lenses (26) arranged between beam paths of adjacent condenser lenses (14). A respective convergent lens is designed to concentrate incident light and guide it to regions beyond the projection lenses.

Description

[0001] Display, method for projecting an image and method for manufacturing a display

[0002] Description

[0003] The present invention relates to a display for displaying an image, to a system comprising such a display, to a method for projecting an image, and to a method for producing an image. The present invention particularly relates to a light field device for 3D direct-view displays.

[0004] Light field displays enable glasses-free and fatigue-free 3D viewing. Compared to holographic processes, light field displays require less computational effort and enable larger display sizes, see [1].

[0005] For such displays, the 3D image is represented by reconstructing a light field. A typical architecture of such a light field display is shown in Fig. 8a. A slide array 1002, which contains the light field information of a subject, is illuminated. The individual images 1004, projected by a lens array 1006, overlap in the space in front of or behind the display in an area 1008, giving the viewer a 3D impression.

[0006] Fig. 8b shows a schematic front view of the light field display 1000, in which the respective positioning of a slide 1004j,j with i denoting the row and j denoting the column of the array is arranged with respect to the projection lenses 1006j,j.

[0007] Examples of light field displays based on this architecture are described in [2]. However, there are disadvantages to this architecture.

[0008] For a light field display, a precise positioning of approximately ± 1 pixel of the slide mask relative to the projection lenses is required across the entire array. In practice, the slide mask and the lens array are manufactured using different processes and then aligned and assembled in a particularly complex process. The stringent assembly requirements require specialized manufacturing techniques such as duplication in modified mask aligners [3] or advanced injection molding processes [4]. Such specialized manufacturing techniques limit the size of the display and simultaneously increase costs, which scale with the display size.

[0009] What would be desirable would be displays that allow for large sizes without significant additional effort and that provide high viewing quality.

[0010] An object of the present invention is therefore to provide a display for displaying a pattern, a method for projecting an image and a method for manufacturing a display which makes it possible to provide a high quality of display without limiting the size of the display and at the same time keep the costs low.

[0011] This problem is solved by the subject matter of the independent patent claims.

[0012] According to one embodiment, a display for displaying a pattern comprises a condenser lens array with a plurality of condenser lenses. The display comprises a projection lens array with a plurality of projection lenses and a plurality of optical channels, each comprising at least one condenser lens and one projection lens and configured to project the image to be displayed by the display. The display comprises a plurality of converging lenses arranged between beam paths of adjacent condenser lenses. Each converging lens is configured to collect incoming light and direct it to areas away from the projection lenses. By directing the light in this way away from the projection lenses, which in some embodiments may include scattering or blocking the light, it is possible to prevent this light from impairing the quality of the display.At the same time, these converging lenses can be manufactured simultaneously with the condenser and, if applicable, projection lenses, eliminating the need for complex positioning of the condenser lens array and the projection lens array. By eliminating the effort required to align the two lens arrays, it is possible to manufacture even large displays without increasing costs.

[0013] According to one embodiment, a method for projecting an image comprises illuminating a condenser lens array having a plurality of condenser lenses, in which at least one respective condenser lens forms part of an optical channel with a respective projection lens of a projection lens array, and the projection lenses are configured to project the image to be presented by means of the display. The method comprises directing light from spaces between adjacent condenser lenses to regions away from the optical channels.

[0014] According to one embodiment, a method for manufacturing a display comprises manufacturing a condenser lens array with a plurality of condenser lenses and a projection lens array with a plurality of projection lenses. The method is implemented such that a plurality of optical channels each comprise at least one condenser lens and one projection lens and are configured to project the image to be displayed by the display. The method is implemented such that a plurality of converging lenses are configured between beam paths of adjacent condenser lenses, and a respective converging lens collects incoming light and directs it to regions away from the projection lenses.

[0015] Preferred embodiments of the present invention are explained below with reference to the accompanying drawings. In the drawings:

[0016] Fig. 1 is a schematic side sectional view of a display according to an embodiment;

[0017] Fig. 2a is a schematic front view of at least part of a display according to an embodiment with a two-dimensional arrangement of lenses;

[0018] Fig. 2b is a schematic side sectional view of the display of Fig. 2a;

[0019] Fig. 3 is a schematic side sectional view of at least part of a display according to an embodiment with non-imaging regions arranged between opposing lens arrays and the non-imaging regions being buried relative to projection lenses;

[0020] Fig. 4a is a schematic side sectional view of a display according to an embodiment in which at least one non-imaging region is arranged on a region elevated relative to a projection lens;

[0021] Fig. 4b is a schematic front view of the display of Fig. 4a; Fig. 5 is a schematic block diagram of a system according to an embodiment;

[0022] Fig. 6 is a schematic flow diagram of a method for projecting an image according to an embodiment;

[0023] Fig. 7 is a schematic flow diagram of a method for manufacturing a display according to an embodiment; and

[0024] Fig. 8a is a schematic side sectional view of a known light field display; and

[0025] Fig. 8b is a schematic front view of the light field display from Fig. 8a.

[0026] Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally equivalent or equivalent elements, objects and / or structures in the different figures are provided with the same reference numerals, so that the description of these elements shown in different exemplary embodiments is interchangeable or can be applied to one another.

[0027] The embodiments described below are described in conjunction with numerous details. However, embodiments may also be implemented without these detailed features. Furthermore, for clarity, embodiments are described using block diagrams instead of detailed illustrations. Furthermore, details and / or features of individual embodiments may be readily combined with one another, unless explicitly described otherwise.

[0028] The following exemplary embodiments relate to displays for representing an image, at least one symbol or the like, to methods for projecting an image, and to methods for manufacturing a display. Some of the displays used or manufactured for this purpose can be referred to as light field displays. However, embodiments of the present invention are not limited to this, but also enable other implementations of displays, for example as a projection display using a projection screen. This also does not contradict some embodiments that are directed towards the design of the display in such a way that the display is configured to display at least parts of the image with a three-dimensional effect. This means that at least parts of the image are displayed in such a way that they appear to be located at one or more different distances in front of or behind the display.In a three-dimensional light-field display for direct viewing, it can be advantageous for all channels to display the characters visible at the corresponding location on the display. According to an advantageous embodiment, this can be distributed across small to very small channel clusters of, for example, 5, 10, 15, 16, or similar optical channels. In advantageous embodiments, a channel cross-section geometry is selected that enables a high area fill factor of the overall arrangement, e.g., a square or hexagonal geometry. Corresponding to a rectangular or hexagonal array symmetry, channel clusters with a number of 4, 9, 16, ... channels (square) or 3, 7, ... channels (hexagonal) can prove useful or advantageous.

[0029] With screen projection, the 3D information is not fundamentally lost; it may only become visible, for example, as blurring of the characters / pattern or image displayed at different distances. The advantageous design of directing unwanted light to other areas using converging lenses thus remains valid even for displays that are not configured as light-field displays.

[0030] Fig. 1 shows a schematic side sectional view of a display 10 according to an embodiment.

[0031] The display 10 comprises a condenser lens array 12 with a plurality of condenser lenses 14i-14s, wherein the number of condenser lenses 14 can be arranged in at least one column, at least one row, or in any other one-dimensional or two-dimensional arrangement. The number of condenser lenses is arbitrary and can be, for example, at least 3, at least 4, at least 5, at least 10 or more, such as at least 20 or more.

[0032] The display 10 further comprises a projection lens array 16 with a plurality of projection lenses 181-185. A plurality of optical channels 22i-22s can each comprise one of the condenser lenses 14 and an associated projection lens 18 and can be configured to project the image 24 to be displayed by the display 10. The image 24 is, for example, an arrow, although any other images, patterns, or depictions can also be projected. As an alternative to arranging a single condenser lens 14 in an optical channel, a larger number of condenser lenses can also be arranged; thus, a single or a larger number of condenser lenses can be assigned to a projection lens. This configuration can be the same for all channels or different for each channel. In the case of multiple condenser lenses, these can, for example, have different shapes for displaying different images or characters.Embodiments are not limited to the projection of a single image. According to one embodiment, the optical channels can be divided into at least a first subset for displaying a first image and at least a second subset for displaying a second image. The projection locations of the images can overlap to display superimposed images or can be spatially separated or disjoint. Different images from different optical channels or groups thereof can be displayed in different colors. The use of different colors can be used to mix the colors of superimposed images. Alternatively, it is readily possible to display the same or different images or patterns in different colors next to each other.

[0033] For the representation of more complex overall images with at least two individual images, it is possible to arrange optical channels for the joint representation of a respective individual image in a cluster associated with the respective individual image, so that, for example, the condenser lenses of the cluster are formed identically or similarly. Alternatively or additionally, a partial array of optical channels can be formed, forming at least part of the overall array, which has adjacent channels with condenser lenses that may be differently shaped from one another, corresponding to the different partial images.

[0034] For color representation, two different but nevertheless combinable concepts exist within the scope of the embodiments described herein. As just explained, exemplary embodiments provide for mixed arrays of different individual channels. In this case, a channel-by-channel arrangement of color filters per channel as part of the array can be advantageous, for example similar to a Bayer pattern. This configuration is particularly advantageous for direct-view displays. For the arrangement of channel clusters, local color segmentation of the collimated light source with corresponding color filters and / or the use of individually collimated light sources, such as LEDs of different colors, is also possible. At least one of a plurality of converging lenses 261-264 can be arranged between the beam paths of adjacent condenser lenses 14i and 142; 142 and 14a; 14a and 144 and / or 144 and 14s.This applies both to adjacent condenser lenses of different optical channels and to condenser lenses of the same optical channel. These are designed to collect incoming light and direct it to areas away from the projection lenses 18. The converging lenses can at least partially solve the task of keeping the light incident on them away from the projection area of ​​the image 24 and can be referred to as blocking lenses or blocker lenses. Collecting light can, for example, comprise at least partial focusing or bundling, although this is not necessarily required. However, at least partial focusing or bundling of incoming light makes it possible to be error-tolerant with regard to position inaccuracies regarding the target of the light captured and collected by the converging lenses 26.

[0035] The display 10 is configured, for example, to receive a light 28 that may, but is not necessarily, collimated and may be provided by an optional light source 32. The light source 32 may thus be configured to provide the light 28 to the condenser lens array 12 as collimated light.

[0036] In a preferred embodiment, each of the plurality of condenser lenses 14 of the condenser lens array 12 is configured to image a light source illuminating the condenser lens, such as the light source 32, into the projection lens 18 associated with the condenser lens. This can be understood as Köhler illumination, for which collimated light can advantageously be used, even if this is not necessarily required for the implementation of the invention.

[0037] According to one embodiment, one or more of the converging lenses 26 are configured to direct the incoming light onto a non-imaging region 34i-344 associated with the respective converging lens. Each of the non-imaging regions can be configured individually or collectively as a light-absorbing region and / or a light-scattering region, or a combination thereof. At least one of the non-imaging regions 34i-344 can comprise or form a light-absorbing region having a metal layer arrangement, in particular a chromium layer arrangement. As shown by way of example in Fig. 1, embodiments provide for the condenser lens array 12, on the one hand, and the projection lens array 16, on the other, to be arranged on opposite sides of a lens substrate 38.Manufacturing, possibly simultaneously, the condenser lens array 12 and the projection lens array 16, and optionally the converging lenses 26, enables precise and error-free positioning of the lenses relative to one another. However, this does not preclude, according to exemplary embodiments, the condenser lens array 12, on the one hand, and the projection lens array 16, on the other hand, from being manufactured on an individual, separate substrate, which are subsequently joined together. This enables, for example, an arrangement of non-imaging regions in a plane between the lens arrays 12 and 16.

[0038] The exact position of the non-imaging regions 34 along an imaging direction 36, starting from a light source 32 toward the image 24, can be configured differently. For example, as shown in Fig. 1, a surface of the projection lens array 16 could serve as a base surface or application surface for the non-imaging regions 34. Alternatively or additionally, non-imaging regions can also be provided between a plane of the condenser lens array 12 and a plane of the projection lens array 16, for example in the form of a diaphragm structure or the like arranged in the substrate 38 supporting the condenser lens array 12 and / or the projection lens array 16.

[0039] Alternatively or additionally, one or more of the non-imaging regions 34 can be arranged elevated relative to a plane of the projection lenses 18, which will be described in more detail later. Furthermore, the use of non-imaging regions is a possibility for designing the image 24 with high quality. It is also conceivable to direct the light captured by the converging lenses 26 to regions away from the image 24, where it also has minimal interference with the image 24.

[0040] Fig. 2 shows a schematic front view of at least part of a display 20 according to one embodiment. The condenser lenses 14i,i-143,3 are shown in an exemplary three-row and three-column matrix arrangement. The converging lenses 26i,i-263,4 are arranged in intermediate regions between the condenser lenses 14i,i-143,3. Their segmentation into three columns and four rows is merely exemplary and could, for example, be continued in additional rows enclosing the condenser lenses 143,i-143,3. Fig. 2a illustrates that, according to embodiments, it is possible to design the contour of the condenser lenses 14i,i-143,3 such that it corresponds to at least a partial region of the image to be displayed by the display, for example, the image 24. The condenser lenses 14i,i-143,3 can also be called shaping lenses.For example, the condenser lenses 14I, 14S, 14B, 14C, 14D, 14E, 14F, 14I, 14I, 14S, 14B, 14S, 14I ...

[0041] As illustrated by the matching geometries of the condenser lenses 14i, 14i-143, 14i, each of the optical channels of the display can be configured to display an elementary image of a plurality of matching elementary images. The plurality of optical channels is configured to superimpose the plurality of elementary images in a projection plane, such as a projection plane of a light field display or a target area of ​​a projection screen, i.e., for example, in an area in which the image 24 is displayed and / or perceived by the viewer with a three-dimensional effect, as is possible for both displays projecting onto a projection surface and light field displays.

[0042] As shown in Fig. 2a, the condenser lens array 12 may comprise an array of irregularly edged lenses, which may, for example, be adapted to the part of the image to be displayed.

[0043] Fig. 2b shows a schematic side sectional view of the display 20. Using edge rays 42i-42e and central rays 44i-44s, it is illustrated in Fig. 2 that the condenser lenses 14i,i-14s,i are designed to focus the incoming light into a plane 46 which corresponds to a plane of the projection lenses I81-I83.

[0044] In other words, Fig. 2a-b show the arrangement of the entrance lens array. The shaper lenses 14a consist of or comprise decentered lens segments to direct the light incident from a collimated light source to the center of the apertures of the projection lenses. Arbitrarily sized "blocking" lenses 26 are provided between the shaper lenses to direct light away from the transmissive regions of the projection lenses, e.g., by directing the light to the center of the non-imaging dead zones of the projection lens array, which are covered, e.g., by an absorbing aperture layer 34. Fig. 3 shows a schematic side sectional view of at least part of a display 30 according to an embodiment in which the condenser lens array 12, together with the converging lenses 261-264, is arranged on or molded onto a first lens substrate 38i.The projection lens array 16 is formed or molded, for example, on a second lens substrate 382, ​​and the non-imaging regions 34i-34e, which in this exemplary embodiment can also form apertures for the optical channels of the display 30, can be arranged between the substrates 38i and 382. The non-imaging regions can be arranged in a plane between the condenser lens array and the projection lens array 16. This distinguishes the display 30, for example, from the display 10, because there the non-imaging regions can be arranged on or in the surface of the projection lens substrate in an intermediate region between the adjacent projection lenses and thus on or in the same surface on which the projection lenses 14 are arranged. In both cases, the non-imaging regions 34 can define apertures of the projection lenses 14.

[0045] Although the relative positioning of the substrates 38i and 382 is accepted for this purpose, the converging lenses 261-264 can be designed in a simple manner such that an imaging plane of these lenses can be adjusted with high tolerances, as long as the condenser lenses 14i-14s enable imaging outside the non-imaging areas 34i-34e and the light of the converging lenses strikes the non-imaging area.

[0046] One, several, or all of the converging lenses 26 of the displays described herein can be configured to focus the incoming light 28 onto the associated non-imaging area within a tolerance range of 20%, 15%, particularly preferably 10% or less, relative to the focal length of the converging lens 26. In the design of the display 30, the requirement for this tolerance range can be more generous, since a relatively larger area is available to capture the collected light.

[0047] As shown in Fig. 1 as well as in Fig. 3, some of the displays described herein can be configured such that a combination of the condenser lens array 12 and the converging lenses defines an optically active input side of the display. This can cover at least 90% of the input side of the display, meaning that at least 90% or more of the light 28 incident on the display is directed either to a condenser lens or to a converging lens. This enables particularly high efficiency and low optical losses. According to some embodiments, the plurality of converging lenses 26 can be configured such that the amount of light incident on the plurality of converging lenses is directed entirely onto the non-imaging regions 34 within a tolerance range of at most 10%, at most 7%, or at most 5%, preferably less than 1%.In embodiments of displays described herein, the condenser lens array 12 and / or the projection lens array 16 can be formed as a microlens array. This enables particularly good reproducibility of the displays.

[0048] Fig. 4a shows a schematic side sectional view of a display according to an embodiment. In the embodiment of the display 40, the non-imaging regions 34 can be arranged on raised regions 48I-484, for example, as a coating. The non-imaging regions 34 can be arranged, for example, as a color layer. The raised regions 48I-484 can extend at least up to a height plane 52. The height plane 52 can be at least partially defined by vertices of the projection lenses 18 and describe a height by which the projection lenses 18 rise relative to the substrate 38 along the imaging direction 36. Preferably, the raised regions 48I-484 protrude at least slightly above the height plane 52, which can simplify the application of the non-imaging regions 34 or the color layer or coating with respect to avoiding contamination of the projection lenses 18.

[0049] Fig. 4b shows a schematic front view of the display 40. From Fig. 4b it is clear that the non-imaging region 34, like the raised regions 48I-484 of Fig. 4a, can be formed as a one-piece region which is opened or perforated by the apertures or the projection lenses 181,1-183,3.

[0050] The at least one raised region 48 can be manufactured together with the projection lenses 181.1-183.3, for example, within the same manufacturing process, such as an injection molding process. While it is also possible to manufacture the at least one raised region separately, possibly already with the non-imaging region 34, and then arrange it on the substrate 38, the effort required for precise alignment can be avoided.

[0051] In the embodiment of the display 40, the light incident on the converging lenses 26i, 1-263, 4 can be focused independently of this onto the at least one non-imaging region 34, as is illustrated, for example, for the converging lens 26i, 1. However, this is not required, as is illustrated, for example, with the converging lens 263, 1, which allows for sufficient avoidance of stray light even without focusing.

[0052] It is possible, but not necessary, for the non-imaging region 34 to define apertures for the optical channels. However, if the aperture angle of the condenser lenses 14 and / or an associated projection lens 18 is unnecessarily large, the optical channel can be limited by the non-imaging region 34.

[0053] The projection lenses 181,1-183,1 can be formed as regular or decentered lens segments, wherein the implementation as decentered lens segments provides advantages in directing the image, see for example the projection lens 183,I.

[0054] Further embodiments of the present invention, which can also be readily used in other displays described herein, will be explained with reference to Fig. 4a and Fig. 4b. According to one exemplary embodiment, at least one condenser lens of the condenser lens array can be configured to project a first subset of light incident on the condenser lens onto the associated projection lens and to direct a second subset of the incoming light onto at least one non-imaging region arranged adjacent to the associated projection lens. For example, at least one of the condenser lenses 14i,i-14s,i could not focus the incoming light entirely onto the associated projection lens 181,1-183,1, but rather focus at least a portion of the incoming light onto the non-imaging region arranged adjacent to the projection lens 181,1-183,1.The resulting loss can be perceived as a grayscale in the image shown.

[0055] The respective condenser lens to be used to display a gray level can, alternatively or in addition to directing the light onto the non-imaging area, have a diffuser formed from a statistical roughness or a deterministic micro-optical structuring of the condenser lens surface. Alternatively or additionally, a condenser lens can be formed as a freeform lens in order to couple out a corresponding portion of the light output via the lens geometry. Alternatively or additionally, it is possible for one or more condenser lenses to have at least two or more condenser lens sub-regions, which can functionally subdivide the area onto which the incoming light strikes. Each of these solutions is suitable for separating the aforementioned first subset from the second subset.According to embodiments of the displays described herein, an arrangement of condenser lenses and / or an arrangement of projection lenses can comprise at least 6, at least 8, or more, approximately at least 20 lenses in an arrangement with at least three columns and at least two rows. Higher numbers of lenses, a higher number of columns, and / or a higher number of rows are easily possible, since even larger displays can be manufactured precisely.

[0056] Fig. 5 shows a schematic block diagram of a system 50 according to an embodiment, which may include a display 10' described herein. The display 10' may be formed substantially in accordance with one of the displays 10, 20, 30 and / or 40, wherein the image 24 may be comprised, for example, of one or more partial images 54i-54 n can be formed with n > 1. A positioning of different partial images 54i-54 nThe relative position of the display elements relative to one another can be adjusted as desired and via the display's optics. According to one exemplary embodiment, a plurality of displays can be used for this purpose, and / or one display can be configured to project multiple subregions of the overall image 24 to be displayed.

[0057] For example, the system 50 may be configured to provide or include a touchless keyboard. The image 24 to be displayed may include keyboard keys that appear to float in front of the display. For example, a respective subarea 54i-54 n be assigned to a key. A sensor device of the system 50 can detect whether a user has selected one of the partial images 54i-54 n touches or otherwise interacts with the partial image 54, from which it can be deduced in the system 50 that a keystroke has been triggered.

[0058] For example, using the three-dimensional effect, the touchless keyboard can be represented as a floating structure, such as floating freely in space.

[0059] An alternative embodiment of the system 50 may, for example, relate to a tail light or a brake light or another lighting device, which may, however, not necessarily be attached to a vehicle or form part of such a vehicle. Such light-emitting devices can be used to display one or more three-dimensional characters in an area of ​​the exemplary automotive light. For example, a logo, a warning notice or another information element can form at least part of the image to be displayed. According to one exemplary embodiment, the system 50 can also be designed as a vehicle light and can be designed to dynamically display the image 24 for communication with another road user. For example, this can be a direction indicator, a change in speed or other information.This is advantageously displayed against a diffusely radiating background created by scattering, non-imaging areas. This allows the far-field distributions required by lighting standards, for example, and the 3D character display to be realized simultaneously.

[0060] Displays described herein can be designed individually or in combination with other displays to show multi-part characters, symbols or graphics. Two possibilities are conceivable for this. Multiple characters can be displayed by displaying an individual character in each channel or by distributing the different characters across multiple channels. For a design as a so-called direct-view (3D) display, it is advantageous to arrange the channels displaying the individual characters close to one another, for example analogous to an RGB Bayer pattern, as described in connection with Fig. 1. This is not necessary for screen projection. The brightness of the individual characters can be controlled by the number of projecting channels used.This means that different sub-areas of the overall image or different sub-patterns of an overall pattern can be adjusted with the same or, to control the brightness, different number of optical channels.

[0061] Fig. 6 shows a schematic flow diagram of a method 600 for projecting an image according to an embodiment. A step 610 comprises illuminating a condenser lens array with a plurality of condenser lenses, in which a respective condenser lens forms part of an optical channel with a respective projection lens of a projection lens array, and the projection lenses are configured to project the image to be presented by means of the display. A step 620 comprises directing light from spaces between adjacent condenser lenses to regions away from the optical channels.

[0062] Fig. 7 shows a schematic flow diagram of a method 700 according to an embodiment. A step 710 comprises producing a condenser lens array with a plurality of condenser lenses and a projection lens array with a plurality of projection lenses, for example in separate or a common production step. The method is carried out such that a plurality of optical channels each comprise a condenser lens and a projection lens and are configured to project the image to be presented by means of the display. The method is further carried out such that a plurality of converging lenses are arranged between beam paths of adjacent condenser lenses and such that a respective converging lens collects incoming light and directs it to regions away from the projection lenses.

[0063] Manufacturing 710 may, in particular, comprise an injection molding process. Independently thereof, method 700 may comprise, as a further step, manufacturing non-imaging regions, which may be separate from one another or contiguous, as the target region of the converging lenses by performing a coating or coloring process on regions of a projection lens substrate that are elevated relative to the projection lenses, as explained in connection with Figs. 4a and 4b.

[0064] In other words, embodiments propose a modified architecture of light field displays or other displays in which the slide array shown in Figs. 8a-b is formed by an array of irregularly shaped input lenses, ie, condenser lenses and converging lenses, to display the individual images or elementary images. This can lead to a two-sided MLA architecture (MLA = microlens array), as shown, for example, in Fig. 1.

[0065] A display proposed herein, such as a light field display, has an entrance array of irregularly shaped lenses 14 / 26 and an array of projection lenses 18 at the exit side. The elementary image for each channel is generated by a combination of condenser lenses or shaper lenses 14 and blocker regions 26. In the simplest case, these regions consist of only one lens. The shape of the aperture of the shaper lenses is identical to the geometry of the elementary images. The shaper lenses act as condenser lenses that image the light source into the addressed projection lens, thereby realizing Köhler illumination and enabling imaging of the shaper lens. In contrast, the blocker lenses direct the incident light so that it is not imaged by the addressed projection lenses. This can, for example,This can be achieved by focusing the light source image onto blocking apertures or non-imaging regions 34, which are, for example, buried beneath the projection lenses or, for example, elevated above the projection lenses; or onto non-imaging piano regions between adjacent projection lenses with optional scattering behavior, or by directing light onto adjacent projection lenses. This latter option, however, is not preferred, as it leads to channel crosstalk and creates undesirable ghost images.

[0066] In general, it is advantageous, or in some embodiments required, that the contour of each shaper region be identical to the contour of the image to be projected. This contour can be filled by one or more shaper lenses. This also applies to the blocking regions. Dividing the region into multiple shaper / blocker lenses can help reduce lens deflection, which facilitates manufacturing. For simplicity, it is assumed below that a region is represented by only a single lens. This is advantageous with regard to the homogeneity of the luminance (direct-view display) or illuminance (projection display) of the image.

[0067] Analogous to Fig. 8a-b, the projection lenses project the apertures of the shaper lenses into the far field, see Figure 24 in Fig. 1.

[0068] Additionally, shades of gray can be created in the displayed image by manipulating the light distribution of the former lenses so that only a portion of the incident light is directed to the imaging lens 18, while the remaining light is sent to a blocking area 34 between the projection lenses 18. This division into transmitted and blocked portions can be achieved, for example, by scattering diffusers on the former lenses, by special freeform layouts that distribute the light in a controlled manner, or by dividing the lenses into multiple lenses, some of which direct the light into the blocking dead zones, as in a halftone image.

[0069] By using an array of specially shaped shaper-blocker regions, for example at the entrance MLA, the function of a slide mask can be realized purely refractively using the same manufacturing technique as for projection lenses.

[0070] To suppress the possibility of crosstalk and improve the resolution of the display, the aperture layer covering the dead spaces directly beneath the projection lenses can be placed at an intermediate distance from the projection lens and the entrance lens array to act like an aperture stop. Such a remote aperture stop introduces vignetting into the system by clipping oblique rays and improves the resolution of the projection system at the expense of transmission [5].

[0071] The schematic of a light field display with such a remote aperture stop is shown in Fig. 3. Because the array of aperture stops 34 is farther away from the projection lenses, stray light generated due to channel crosstalk or misalignment can be effectively blocked before the stray light reaches the projection lenses.

[0072] The accuracy requirements for aligning such a buried aperture stop with respect to the lens array are much lower (about an order of magnitude) than the required lateral positioning accuracy of elemental images relative to the addressed projection lens. The relaxed alignment tolerances enable simpler manufacturing, e.g., by two-component plastic injection molding or injection molding with an inlaid metal aperture layer. offer, among other things Advantages:

[0073] • Easier to maintain tolerances for alignment of two lens arrays with an optional aperture mask layer facilitates alignment and assembly.

[0074] • Creation of 3D motifs by eliminating slide masks and using purely refractive elements with the possibility of creating grayscale in the displayed image.

[0075] • Light field displays can be manufactured using simple injection molding techniques.

[0076] • Simple, proven manufacturing and assembly of micro-optical elements using grayscale and reflow mastering processes. find in:

[0077] • Decorative art installations

[0078] • 3D icons / symbols for advertising and branding, e.g. for the exterior signage of motor vehicles

[0079] • General lighting design

[0080] • 3D effects in automotive turn signal / tail light clusters.

[0081] • Contactless interfaces for public buildings / operating rooms.

[0082] Although some aspects have been described in connection with a device, it is understood that these aspects also represent a description of the corresponding method, so that a block or component of a device can also be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also represent a description of a corresponding block, detail, or feature of a corresponding device.

[0083] The above-described embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

[0084] References

[0085] [1] Park, JH, Hong, K., & Lee, B. (2009). Recent progress in three-dimensional information processing based on integral imaging. Applied Optics, 48(34), H77-H94. [2] S. Jensch et.al., DE102017210762A1 - Lighting device for a motor vehicle, BMW AG,

[0086] Realeyes GmbH.

[0087] [3] P. Dannberg et al., "Wafer-Level Hybrid Integration of Complex Micro-Optical Modules", Micromachines 2014, 5, 325-40.

[0088] [4] F. von Laffert et. al., DE102011000947A1 - Flat 3D display unit, Realeyes GmbH. [5] W. S. Smith, Modern Optical Engineering 2. Ausgabe, 3.4 "The Effect of Lens Shape and Stop Position on the Aberrations".

Claims

Patent claims 1. A display for displaying an image, comprising: a condenser lens array (12) having a plurality of condenser lenses (14); a projection lens array (16) having a plurality of projection lenses (18); a plurality of optical channels (22), each comprising at least one condenser lens (14) and one projection lens (18) and configured to project the image (24) to be displayed by means of the display; a plurality of converging lenses (26) arranged between beam paths of adjacent condenser lenses (14); wherein each converging lens (26) is configured to collect incoming light and direct it to regions away from the projection lenses (18).

2. Display according to claim 1, wherein at least a subset of the plurality of converging lenses (26) are designed to direct the incoming light onto a non-imaging region (34) associated with the converging lens (26) between projection lenses (18) or between optical channels (22).

3. Display according to claim 2, wherein the non-imaging region (34) comprises a light-absorbing and / or light-scattering region.

4. Display according to claim 2 or 3, wherein at least one non-imaging region comprises a light-absorbing region having a metal layer arrangement, in particular a chromium layer arrangement.

5. Display according to one of claims 2 to 4, wherein the non-imaging region (34) is arranged on regions (48) which are raised relative to a plane (52) of the projection lenses (18) relative to the plurality of projection lenses (18).

6. Display according to one of claims 5, wherein the non-imaging region (34) is arranged on the raised regions (48) as a coating, in particular comprising a color layer.

7. Display according to one of claims 2 to 6, wherein the non-imaging region (34) is arranged in a plane between the projection lens array (16) and the condenser lens array (12).

8. A display according to one of claims 2 to 7, wherein projection lenses (18) of the projection lens array (16) are formed on or in a surface of a projection lens substrate (38; 382); and the non-imaging region (34) is arranged on or in the surface of the projection lens substrate (38; 382) in an intermediate region between the adjacent projection lenses (18).

9. Display according to one of claims 2 to 8, wherein the non-imaging region (34) defines apertures of the projection lenses (18).

10. Display according to one of claims 2 to 9, wherein at least one converging lens (26) of the plurality of converging lenses is configured to focus the incoming light onto the non-imaging region (34) within a tolerance range of 20% relative to the focal length of the converging lens (26).

11. Display according to one of claims 2 to 10, wherein a combination of the condenser lens array (12) and the plurality of converging lenses (26) preferably completely covers an optically active input side of the display to an extent of at least 90% and the plurality of converging lenses (26) is configured to completely direct the light incident on the plurality of converging lenses (26) onto the non-imaging region (34) within a tolerance range of at most 10%.

12. Display according to one of the preceding claims, wherein a contour of the condenser lenses (14) of the condenser lens array (12) corresponds to at least a partial area of ​​the image to be displayed by means of the display.

13. Display according to one of the preceding claims, wherein at least one of the condenser lenses (14) of the condenser lens array (12) comprises a decentered lens segment.

14. Display according to one of the preceding claims, in which the condenser lens array (12) and the converging lenses on the one hand and the projection lens array (16) on the other hand are arranged on opposite sides of a lens substrate (38).

15. A display according to any one of the preceding claims, wherein the condenser lens array (12) comprises an array of irregularly branded lenses.

16. A display according to any one of the preceding claims, wherein the plurality of optical channels (22) comprises a first subset for displaying the image as a first image (54i) and a second subset for displaying a second image (542).

17. A display according to claim 16, which is designed to display the first image (54i) with a first color and the second image (542) in a second color.

18. Display according to one of the preceding claims, which is formed as a projection display and / or as a light field display.

19. Display according to one of the preceding claims, which is arranged to display at least parts of the image (24) with a three-dimensional effect.

20. Display according to one of the preceding claims, wherein the condenser lens array (12) is formed as a microlens array and the projection lens array (16) is formed as a microlens array.

21. A display according to any one of the preceding claims, wherein each optical channel (22) of the plurality of optical channels is configured to display an elementary image of a plurality of corresponding elementary images; wherein the plurality of optical channels (22) are configured to superimpose the plurality of elementary images in a projection plane.

22. Display according to one of the preceding claims, wherein each of the plurality of condenser lenses (14) is configured to image a light source (32) illuminating the condenser lens (14) into the projection lens (18) associated with the condenser lens (14).

23. Display according to one of the preceding claims, in which at least a subset of the projection lenses (18) are formed as a decentered lens segment.

24. Display according to one of the preceding claims, in which at least one condenser lens (14) of the condenser lens array (12) is designed to project a first subset of a light incident on the condenser lens onto the associated projection lens (18) and to direct a second subset of the incoming light onto at least one non-imaging region (34) arranged adjacent to the associated projection lens 25. Display according to claim 24, wherein the at least one condenser lens of the condenser lens array (12) comprises at least one of • a diffuser; • a freeform lens; and • a plurality of condenser lens sub-regions; to separate the first subset from the second subset.

26. A display according to any one of the preceding claims, comprising a light source (32) configured to provide collimated light to the condenser lens array (12) as the incident light (28).

27. Display according to one of the preceding claims, wherein an arrangement of the condenser lenses (14) and / or an arrangement of the projection lenses (18) comprises at least 6 lenses in an arrangement with at least three columns and at least two rows.

28. System (50) with a display according to one of the preceding claims.

29. System according to claim 28, comprising a plurality of displays or a display with a plurality of sub-areas which are designed to project different sub-areas (54) of an overall image (28) to be displayed.

30. A system according to claim 28 or 29, comprising a contactless keyboard, wherein the image to be displayed comprises keys of the keyboard.

31. The system of claim 30, configured to present the touchless keyboard as a floating structure.

32. System according to claim 28 or 29, comprising an automotive light, in particular a tail light or brake light, and the image is a three-dimensional character in a region of the automotive light.

33. System according to claim 28 or 29, which is designed as a vehicle light and is designed to dynamically display the image for communication with another road user.

34. A method (600) for projecting an image comprising the following steps: Illuminating (610) a condenser lens array having a plurality of condenser lenses, wherein at least one respective condenser lens forms part of an optical channel with a respective projection lens of a projection lens array, and the projection lenses are configured to project the image to be displayed by means of the display; Directing (620) light from spaces between adjacent condenser lenses to areas away from the optical channels.

35. Method (700) for producing a display comprising the following steps: Producing (710) a condenser lens array having a plurality of condenser lenses and a projection lens array having a plurality of projection lenses; such that a plurality of optical channels each comprise at least one condenser lens and one projection lens and are configured to project the image to be presented by means of the display; such that a plurality of converging lenses are arranged between beam paths of adjacent condenser lenses; and such that a respective converging lens collects incoming light and directs it to regions away from the projection lenses.

36. The method of claim 35, wherein the manufacturing comprises an injection molding process.

37. A method according to claim 35 or 36, comprising: Producing at least one non-imaging region (34) as a target region of the converging lenses by carrying out a coating process on a region (48) of a projection lens substrate that is raised relative to projection lenses.

Images