EP4334772A1

EP4334772A1 - Display device

Info

Publication number: EP4334772A1
Application number: EP22726015.5A
Authority: EP
Inventors: Markus Schwab
Original assignee: Tooz Technologies GmbH
Current assignee: Tooz Technologies GmbH
Priority date: 2021-05-04
Filing date: 2022-04-27
Publication date: 2024-03-13
Also published as: WO2022233656A1; US20240231107A1; CN117242391A; DE102021111515A1

Abstract

The invention relates to a display device comprising: a holding device (2) which can be placed onto the head of a user; an imager (6) secured to the holding device (2) for generating an image; a control unit (15) for controlling the imager (6); and a spectacle lens (3, 4) that is secured to the holding device (2) and has a coupling-in portion (9) and a coupling-out portion (12) spaced therefrom in a first direction. The coupling-out portion (12) has a deflecting structure (13) having a predetermined extension in the first direction, and the generated image is coupled into the spectacle lens (3, 4) via the coupling-in portion (9), is guided in the spectacle lens (3, 4) by at least one reflection as far as the coupling-out portion (12), and coupled out into an exit pupil (16) via the coupling-out portion (12) by deflecting on the deflecting structure (13) in a coupling-out direction. As a result, when the holding device (2) is placed on the user's head, the user can perceive the coupled-out image as a virtual image. The coupling-in portion (9) has an entry surface (10) which is wider in the first direction than the image of the imager (6), and it is possible to adjust the entry surface (10) coupling-in position at which the image is coupled in via the entry surface (10) in the first direction. The coupling-in position determines the coupling-out direction of the coupling-out portion (12) and therefore the position of the exit pupil (16) in the first direction such that the distance between the exit pupil (16) and the coupling-in portion in the first direction can be adjusted. Irrespective of the coupling-in position, when the deflecting structure (13) causes a deflection, the deflecting structure (13) is always utilised across the entire predetermined extension in the first direction.

Description

display device

The present invention relates to a display device that can be placed on a user's head and offers him a virtual image through a spectacle lens.

The problem with such display devices is that different users have different temple-to-eye distances, so that in relation to the user's temple the position for the virtual image can differ in the lateral direction from user to user.

Proceeding from this, it is therefore the object of the invention to provide a display device with which simple adjustment to different temple-to-eye distances is possible.

The invention is defined in independent claim 1. Advantageous developments are specified in the dependent claims.

Since, according to the invention, the position of the exit pupil in the first direction is defined via the position of the coupling point of the generated image, an adjustment to different temple-to-eye distances can easily be carried out in this way.

Furthermore, according to the invention, the deflection structure along the first direction is always used over the entire predetermined extent, independently of the coupling point during the deflection by means of the deflection structure. As a result, the deflection structure can be made very compact in the first direction.

If there is an intermediate image of the image within the spectacle lens between the coupling-in section and the coupling-out section, the spectacle lens can be made very compact. It is also possible, due to the then present larger optical

To introduce path length, for example, one or two additional correction mirrors. This allows the system to be corrected more easily and flexibly, with better distortion and spot size being able to be achieved. The spectacle lens according to the invention alone (or with additional optics, which can be arranged between the image generator and the entry surface of the spectacle lens) implements imaging optics that depict the image generated by the image generator in such a way that the user can perceive it as a virtual image. The imaging optics are designed in such a way that the in-coupling point of the entry surface, at which the generated image is in-coupled, defines the out-coupling direction of the out-coupling section and thus the position of the exit pupil in the first direction.

Furthermore, the imaging optics can be implemented telecentrically, for example, on the imager side. The virtual position can then also be shifted in the z-direction by means of a z-shift of the imager (or changing the distance between the imager and the spectacle lens), without the field of view being changed.

The spectacle lens can be made of plastic or glass. In particular, the spectacle lens can be designed in one or more parts.

The deflection structure can be designed as a single continuous mirror surface. The mirror surface can be partially reflective. However, it is also possible for it to have the highest possible reflectivity of almost 100%.

Furthermore, the deflection structure can have a plurality of mirror surfaces that are offset relative to one another and can be designed in particular as a reflective or partially reflective Fresnel structure.

It goes without saying that the features mentioned above and those still to be explained below can be used not only in the specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention.

The invention is explained in more detail below on the basis of exemplary embodiments with reference to the accompanying drawings, which also disclose features that are essential to the invention. These embodiments are provided for illustration only and are not to be construed as limiting. For example, a description of an embodiment having a plurality of elements or components should not be construed as implying that all of those elements or components are necessary for implementation. Rather, other embodiments may include alternative elements and components, fewer elements or components, or additional elements or components. Elements or components of different exemplary embodiments can be combined with one another unless otherwise stated. Modifications and variations, which are described for one of the embodiments, can also apply to others Embodiments may be applicable. To avoid repetition, the same or corresponding elements in different figures are denoted by the same reference symbols and are not explained more than once. From the figures show:

1 shows a schematic perspective illustration of an embodiment of the display device according to the invention;

FIG. 2 shows an enlarged partial sectional view of the first spectacle lens including a schematic representation of the image generation module; FIG.

FIG. 3 shows a representation according to FIG. 2;

FIG. 4 shows a representation according to FIG. 2;

FIG. 5 shows a representation according to FIG. 2 of a further embodiment

FIG. 6 shows a representation according to FIG. 2 of a further embodiment, and

FIG. 7 shows a representation according to FIG. 2 of a further embodiment.

In the embodiment shown in Fig. 1, the display device 1 according to the invention comprises a folding device 2 that can be placed on the head of a user, which can be designed in the manner of a conventional spectacle frame, for example, and a first and a second spectacle lens 3, 4, which are attached to the folding device 2 are attached. The holding device 2 with the lenses 3, 4 can e.g. as sports glasses, sunglasses and/or glasses for correcting a

Be formed ametropia, wherein the user on the first lens 3, a virtual image can be reflected in his field of vision, as will be described below.

For this purpose, the display device 1 comprises an image generation module 5, which can be arranged in the area of the right side piece of the spectacles of the holding device 2, as is shown schematically in FIG. The image generation module 5 can have a flat image generation element 6 (FIG. 2), such as an OLED, an LCD or an LCoS chip or a tilting mirror matrix, with a large number of pixels arranged in rows and columns, for example. As can best be seen from the enlarged, schematic partial sectional view in FIG. 2 , the first spectacle lens 3 has a rear side 7 and a front side 8 . The back 7 and the front 8 are shown here as flat surfaces. However, it is also possible that the Back 7 and / or the front 8 are curved. For example, there can be a spherical curvature or an aspheric curvature.

On the side, the spectacle lens 3 has a coupling section 9 with an entry surface 10, which can be flat or curved, and a deflection surface 11, which can also be flat or curved. The deflection surface 11 can in particular be designed as a reflective surface. However, the deflection can also be brought about by total internal reflection.

Furthermore, the first spectacle lens 3 has a decoupling section 12 with a deflection structure 13 . The decoupling section 12 is spaced apart from the incoupling section 9 along a first direction (here the y-direction). The deflection structure 13 can be embodied as a mirror surface 13 which has a predetermined extent along the first direction. The mirror surface 13 can be flat. Depending on the application, it can be partially transparent. In this case, the user can perceive the created virtual image in superimposition with the environment. However, it is also possible for the mirror surface 13 to have the highest possible reflectivity. This is particularly advantageous for applications in which the user should only perceive the virtual image and not the environment.

A light beam 14 can emanate from each pixel of the imaging device 6 . The desired image can be generated by correspondingly driving the pixels of the image generator 6 by means of a control unit 15 which has a processor 19 and which can be part of the image generation module 5 . The beam path of a light bundle 14 is shown in FIG. 2 as a representative of the light bundle 14 .

The light beam 14 emanating from the image generator 6 enters the spectacle lens 3 via the entry surface 10 and is deflected by the deflection surface 11 in such a way that reflection takes place on the rear side 7 (e.g. total internal reflection) and the light beam 14 thus strikes the mirror surface 13. which causes a deflection towards the rear 7 in such a way that the light beam 14 exits the first spectacle lens 3 via the rear 7 . The deflection is effected in such a way that the decoupling direction, along which the light beam 14 emerges via the rear side 7, corresponds to the −z direction.

As is also indicated in the schematic representation in FIG. 2 , the first spectacle lens 3 is designed here such that an intermediate image of the image generated by the imaging device 6 is present within the spectacle lens 3 between the coupling-in section 9 and the coupling-out section 12 . However, such an intermediate mapping is not absolutely necessary. As shown in FIG. 2, the extent of the imager 6 in the first direction (y-direction) is smaller than the corresponding extent of the entry surface 10 and the imager 6 is arranged centrally in front of the entry surface 10 in relation to the first direction. In this case, the exit pupil 16 of the display device 1 is at the position indicated by the arrow P1, so that a user who wears the display device on his head and has his eye A positioned at this position P1 perceives a virtual image in front of the front face 8 can, as shown in Fig. 2 schematically. The corresponding field of view is indicated by the double arrow K1. A user can thus perceive the virtual image 17 in the eye position according to FIG. 2 and looking straight ahead (viewing direction 18 in FIG. 2).

In the display device according to the invention, the image generator 6 can be displaced along the first direction (y direction) by means of a positioning unit 20 under the control of the control unit 15, so that different coupling points can be set. The coupling point can relate to a predetermined point of the imager 6 (for example the center of the imager 6 or the upper or lower edge in the y-direction).

When the imaging device 6 is positioned as shown in FIG. 3, the imaging of the display device means that the decoupling direction no longer runs along the −z direction, but is inclined thereto. This leads to a lateral (in the y-direction) displacement of the exit pupil 16, so that the user's eye A must be positioned at position P2 in order to be able to perceive the virtual image (double arrow K2). The user's line of sight 18 is also tilted compared to Figure 2.

In the position of the imaging device 6 according to FIG. 4 , the decoupling direction changes again, so that the exit pupil 16 is shifted laterally. The user's eye A must be positioned at the appropriate point (arrow P3) in order to be able to perceive the virtual image (double arrow K3). The user's line of sight 18 is also tilted compared to Fig.

2.

As can be seen from FIGS. 2 to 4, the lateral position of the exit pupil 16 (along the y-direction) can be adjusted by selecting the coupling point of the image generator 6 in front of the entrance surface 10, so that the display device 1 can be adjusted to different temple-to-eye distances easily adjustable by the individual user.

The range 21 of the possible pupil positions leads to an angular range 22 of the associated viewing direction 18. As can also be seen from FIGS. 2 to 4, the deflection structure 13 is always used along the first direction over the entire predetermined extent, regardless of the coupling point when deflecting by means of the deflection structure 13 .

In a modification (FIG. 5), the extent of the imager 6 in the first direction (y-direction) is just as large or larger than the corresponding extent of the entry surface 10, so that the imager 6 itself does not have to be shifted to different coupling points for the generated image. Only the corresponding area on the image generator 6 is controlled in order to generate the image, so that the coupling point for the generated image can vary in the y-direction. In this case, the positioning unit 20 can be omitted.

In the described embodiments, the spectacle lens 3 for the image of the imager 6 is designed as imaging optics, which images the image generated by the imager 6 in such a way that the user can perceive it as a virtual image. As already mentioned, the imaging optics can be designed in such a way that there is an intermediate image and thus an intermediate image within the spectacle lens 3 . As a result, the cross section of the spectacle lens 3 can be reduced, so that a compact construction can be implemented. Furthermore, the intermediate image increases the optical path length into which, for example, one or two additional correction mirrors can then be introduced. This allows the imaging optics to be corrected more easily and flexibly, and better distortion and spot size can be achieved.

As is shown in the exemplary embodiment in FIG. 6 , further optics (shown here schematically as a lens 23 ) can be provided between the imaging device 6 and the entry surface 10 . This in turn allows for easier and more flexible correction with better distortion and spot size. The embodiment of Fig. 6 is a modification of the embodiment of Fig. 5. Of course, this modification described in connection with Fig. 6 can also be provided in the embodiment according to Figs. 2 to 4.

In Fig. 7 a modification of the embodiment of FIG. 2 is shown.

On the one hand, in this embodiment, the imaging device 6 is at a distance from the entry surface 10 . In this case, in particular, no further optical element can be present between the imaging device 6 and the entry surface 10 . Such a spacing of the imaging device 6 from the entry surface can also be provided in the embodiments according to FIGS. 2 to 5. On the other hand, the deflection surface 11 is designed to be tiltable in such a way that there is an air space between the spectacle lens 3 and the deflection surface 11 . The light beam 14 therefore emerges from the spectacle lens 3 via the surface 11', impinges on the deflection surface 11, is reflected on it and again enters the spectacle lens 3 via the surface 11'. The selection of the tilting angle of the deflection surface 11 can be used in addition to the position of the imaging device 6 along the y-direction in order to bring about the described displacement of the exit pupil 16 in the y-direction. Alternatively, it is possible to design the display device according to the invention in such a way that the described displacement of the exit pupil 16 along the y-direction only takes place via the selection of the tilt angle of the deflection surface 11 .

The two described features of the distance between the imaging device 6 and the entry surface 10 as well as the tiltable arrangement of the deflection surface 11 can be provided individually or together in all of the described embodiments.

Furthermore, the spectacle lens according to the invention is easy to manufacture, since the entry surface 10 and adjacent surfaces are located in relatively similar positions in the z-direction, although they are at a sufficient distance from one another. These are preferably optically used surfaces, such as the entry surface 10, the deflection surface 11 and the front and rear sides 8, 7. This makes it possible to provide an injection molding tool for producing the spectacle lens 3 with a transition between the surfaces that can be easily removed from the mold.

The imaging optics can be implemented telecentrically on the imager side. This achieves the advantage that a z-displacement of the image generator 6 leads to a displacement of the virtual image position along the z-direction without affecting the field of view for the user and thus the position of the exit pupil 16, which can also be referred to as the eyebox , is changed. For example, the positioning unit 20 can be designed accordingly for the displacement of the imaging device 6 along the z-direction and can then be controlled via the control unit 15 .

The representation in FIGS. 2 to 6 is very schematic. Preferably, after the deflection at the deflection surface 11, there is a reflection at the front side 8, followed by a reflection at the back and the deflection at the mirror surface 13.

In the display device 1 according to the invention, the virtual image is reflected into the field of vision of the user via the first spectacle lens 3. Of course, reflection via the second spectacle lens 4 is also possible. Furthermore, the display device 1 can be designed in such a way that information or virtual images about both Eyeglass lenses 3, 4 are reflected. The reflection can take place in such a way that a three-dimensional image impression is created. However, this is not absolutely necessary.

The spectacle lenses 3, 4 can have a refractive power of zero or a non-zero refractive power (in particular to correct ametropia). In particular, both the front side 8 and the back side 7 can be curved. In particular, the front side is spherically curved. If the spectacle lens 3, 4 has a non-zero refractive power in order to correct an ametropia, the curvature of the rear side 7 is usually selected accordingly in order to achieve the corresponding correction. The back 7 can have a curvature that deviates from the spherical shape.

The holding device 2 does not have to be in the form of a spectacle-like holding device. Any other type of holding device is also possible, with which the display device 1 can be placed and carried on the head.

Claims

patent claims

1. Display device with a holding device (2) that can be placed on the head of a user, an imager (6) attached to the holding device (2) for generating an image, a control unit (15) for controlling the imager (6) and one on the holding device (2) fixed spectacle lens (3, 4), which has a coupling-in section (9) and a coupling-out section (12) spaced therefrom along a first direction, the coupling-out section (12) having a deflection structure (13) with a predetermined extension in the first direction and wherein the generated image is coupled into the spectacle lens (3, 4) via the coupling section (9), guided in the spectacle lens (3, 4) by at least one reflection to the decoupling section (12) and via the decoupling section (12) by deflection the deflection structure (13) is coupled out along a coupling-out direction into an exit pupil (16), so that when the holding device ( 2) being able to perceive the coupled-out image as a virtual image, the coupling-in section (9) having an entry surface (10) which is wider in the first direction than the image of the imager (6), and it being adjustable on which

coupling point of the entry surface (10) the image is coupled in via the entry surface (10) in the first direction, with the coupling point determining the decoupling direction of the decoupling section (12) and thus the position of the exit pupil (16) in the first direction, so that the distance the exit pupil (16) can be adjusted by the coupling-in section along the first direction, and wherein the deflection structure (13) along the first direction is always used over the entire predetermined extent, regardless of the coupling-in point during the deflection by means of the deflection structure (13).

2. Display device according to claim 1, wherein the display device is designed in such a way that there is an intermediate image of the image between the coupling-in section (9) and the coupling-out section (12).

3. Display device according to one of the above claims, wherein the spectacle lens (3) has a front (8) and a rear (7) and the coupling-in section (9) has a deflection surface (11) arranged downstream of the entry surface (10), on which the image coupled in via the entry surface (10) to the front (8) is reflected, so that on the front (8) there is a reflection in the direction of the back (7), where the image is reflected and hits the deflection structure (13) directly.

4. Display device according to one of the above claims, wherein the deflection structure (13) is designed as a single continuous mirror surface.

5. Display device according to one of the above claims, wherein a positioning unit (20) is provided, which moves the imager (6) along the first direction to adjust the coupling point.

6. Display device according to one of the above claims, wherein the imager (6) generates the image such that it has a smaller extent in the first direction than the extent of the imager (6) in the first direction and by selecting the position of the generated Image on the imager (6) the setting of the coupling point is carried out.

7. Display device according to claim 6, wherein the extent of the imaging device (6) in the first direction corresponds at least to the extent of the entry surface (10) in the first direction.

8. Display device according to one of the above claims, wherein additional optics (23) are arranged between the image generator (6) and the entry surface (10), which, together with the spectacle lens (3, 4), reproduce the generated image as a virtual image (17 ) causes.