DE102014107938A1 - display device - Google Patents

Abstract

The invention relates to a display device with a holding device (2) which can be placed on the head of a user and a first imaging optical unit (15) attached to the holding device (2), which is designed to image a picture generated in an image plane (E) as a virtual image in that the user can perceive it in the head-mounted state of the holding device (2) with a first eye (LA, RA), the first imaging optical system (15) having a first lens (16) with negative refractive power and one of the first lens (16) having a second lens (17) with positive refractive power, wherein the first lens (16) is positioned closer to the image plane (E) than the second lens (17).

Description

The present invention relates to a display device with a holding device which can be placed on the head of a user and a first imaging optical system attached to the holding device, which is designed to image an image generated in an image plane as a virtual image in such a way that the user places it in an inverted manner State of the holding device can perceive with a first eye.

In such displays, there is a desire to present the largest possible image produced to the user in a large field of view. This is difficult because of the limited space since the display device is to be worn on the head. The imaging optics on the one hand should therefore be as light as possible and have a small space. This leads to imaging optics, with few optical elements and small dimensions. On the other hand, it should also present larger images produced in a sufficiently large field of view as a virtual image. For this purpose, larger and more optical elements are usually necessary.

Proceeding from this, it is therefore an object of the invention to provide a display device of the type mentioned in such a way that the aforementioned difficulties can be overcome as completely as possible.

According to the invention, the object is achieved with a display device of the type mentioned above in that the first imaging optics has a first lens with negative refractive power and a second lens with positive refractive power spaced from the first lens, wherein the first lens is positioned closer to the image plane than the second lens.

With this structure of the first imaging optics is advantageously achieved that all four interfaces of the two lenses can be designed differently and thereby the desired high imaging quality can be realized with low space requirement.

In particular, the first imaging optics is free of deflecting elements for beam path folding. This leads to a compact design of the first imaging optics.

The first lens has first and second interfaces and the second lens has first and second interfaces, wherein preferably all four interfaces of the two lenses are each formed as aspheres. In particular, they are designed as rotationally symmetric aspheres. Preferably, the aspheres or the rotationally symmetric aspheres are different for all four interfaces. This can be provided in a simple manner excellent image quality.

The first imaging optics performs the image purely refractive. In particular, the first imaging optics does not contain any diffractive and / or reflective elements.

The first lens may be formed as a concave-concave lens or as a convex-concave lens whose concave side faces the image plane. The second lens may be formed as a convex-convex lens.

In the display device according to the invention, the image plane in the mounted on the head state of the holding device can be substantially perpendicular to the straight-ahead direction. This simplifies the structure of the first imaging optics. By substantially vertical is meant here in particular that the angle is preferably 90 ° or nearly 90 °.

In particular, the first imaging optics may consist of the first and second lenses. In this case, the imaging optics contains no further optical elements.

The two lenses can be made of plastic. Thus, the weight of the first imaging optics can be kept low. It is also possible that at least one of the two lenses or both lenses are formed from a glass material.

The two lenses may be formed of different materials. In particular, it is preferred that the first lens has a first Abbe number and the second lens has a second Abbe number, wherein the second Abbe number is greater than the first Abbe number.

The first imaging optics may have an exit pupil which is, for example, circular or round (eg oval). Furthermore, the exit pupil can also be referred to as an eyebox, the eyebox in particular being the area which is provided by the first imaging optics and in which the user's eye can move and he can still see the generated image as a virtual image.

The display device may be configured such that the distance between the exit pupil and the image plane is less than 100 mm. In particular, the distance may be less than 90 mm, 80 mm, 70 mm or 60 mm and / or greater than 20 mm, 30 mm or 40 mm.

In particular, the distance between the exit pupil and the second lens (or the exit pupil-facing side of the second lens) may be at least 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm or 20 mm. At values of 15 mm and in particular at values of at least 18 mm, it is possible for a user to continue to wear his spectacles, if he needs one, when using the display device according to the invention. Thus, an ametropia correction can be made by the corresponding glasses of the user and the user can still use the display device in the intended manner.

In particular, the distance between the side of the first lens facing the image plane and the image plane may be less than or equal to 25 mm, 24 mm, 23 mm, 21 mm, 20 mm or 18 mm. The distance is determined here along the optical axis. For a compact design of the display device according to the invention is possible.

The exit pupil may have a diameter or a maximum extension of greater than or equal to 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm. In particular, the diameter or maximum extension may be 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm or 15 mm.

The first imaging optics can be designed such that an image generated in the image plane with a diagonal of at least 45 mm or 50 mm is completely formed as a virtual image. In particular, the diagonal can be 60 mm and the first imaging optics can completely image this image as a virtual image. The generated image is in particular square or rectangular. In particular, an aspect ratio of 4: 3 or even 16: 9 or other aspect ratios may be present.

In particular, the first imaging optic is designed in such a way that the generated image is displayed vignetting-free for a pupil of the eye positioned centrally in the exit pupil.

Furthermore, the first imaging optics can be designed such that it images the generated image so that the user is provided with a field of view with a diagonal of greater than 60 ° and in particular greater than 70 °. The diagonal may e.g. less than or equal to 90 °, 85 °, 80 ° or 75 °.

In the case of the display device according to the invention, the first imaging optical unit is designed to image an image generated in an image plane as a virtual image so that the user can perceive it with a first eye in the state of the holding device mounted on the head. Thus, the property of the first imaging optics is described in detail, without the display device according to the invention must contain an element for generating the generated image. The display device according to the invention thus preferably comprises only the holding device and the first imaging optics.

In the display device according to the invention can be arranged in the image plane, an imager which generates the image, which is imaged by means of the first imaging optics. The imager may in particular be a self-luminous display. Furthermore, the imager can have an LCD module, an LCoS module or an OLED module. The imager may comprise a plurality of pixels (e.g., arranged in rows and columns), each of which may emit a beam of light to produce the desired image.

The imager may also be part of another device or a device. For example, a mobile phone or other portable electronic device can be used with a corresponding display. It is also possible to use a display for such a device as such.

Preferably, the imager can be interchangeably arranged in the image plane. Thus, e.g. be provided a holder for the imager. For example, the holder may be adapted for a particular mobile phone so that the user can insert and use his mobile phone in the display device.

The first imaging optics can in particular be designed so that the distance between the two lenses is not changeable. However, it is also possible to support the two lenses so that they are displaceable along the optical axis. The holder may be formed so that the first lens and / or the second lens is displaceable along the optical axis. This displacement can be used eg for a diopter compensation for a user.

Additionally or alternatively, the holder of the two lenses may be formed so that an adjustment or displacement transversely or perpendicular to the optical axis is possible. Thus, an adjustment of the position of the first imaging optics to the position of the eye can be performed. In particular, an adaptation to the pupillary distance of the user can take place.

The lenses of the first imaging optics are preferably arranged coaxially and thus have a common optical axis.

In particular, the first imaging optics can be designed so that the Strehl ratio for each field angle is greater than or equal to 0.3 and in particular greater than or equal to 0.4.

In particular, the first imaging optics can be designed so that the amount of the focal length of the first lens corresponds approximately to the amount of the focal length of the second lens. In particular, the difference between the amounts of the focal lengths can not be more than 30% and in particular not more than 20%. The amount of the focal length of the second lens may be larger or smaller than the amount of the focal length of the first lens. In particular, the amount of the focal length of the second lens may be 0.9 to 1.2 times the amount of the focal length of the first lens.

In the display device according to the invention, the first lens may be formed as a convex-concave lens whose concave side faces the image plane. This allows very good imaging properties to be realized. In particular, the provision of a large exit pupil is possible.

The concave side of the first lens may, in particular, have a substantially conical shape, the conical shape having a rounded tip (in the region of the optical axis). In particular, the conical design may correspond to a straight circular cone whose tip is rounded.

The display device according to the invention may have, in addition to the first imaging optics, a second imaging optic which is designed in the same way as the first imaging optic, wherein the second imaging optic is designed to provide a generated second image to a second eye of the user as a virtual image, if the latter holds the holding device wearing on the head.

The second imaging optics may in particular be designed so that the distance between the two lenses is not changeable. However, it is also possible to support the two lenses so that they are displaceable along the optical axis. The holder can be designed so that the first lens and / or the second lens of the second imaging optical system is displaceable along the optical axis. This displaceability can e.g. be used for a diopter compensation for a user. Additionally or alternatively, the holder may be formed so that the two lenses of the second imaging optics can be positioned transversely or perpendicular to the optical axis. Thus, an adaptation to the available pupil distance of each user is easily possible.

For both imaging optics, a separate imager can be arranged in the display device. However, it is also possible that a common imager is provided which has a section for the first imaging optics and a section for the second imaging optics. The two sections are preferably separated from each other. This can be realized, for example, if, when the user uses his mobile phone as an imager, a part of the screen of the mobile phone for the first imaging optics generates the image and another part of the screen of the mobile phone generates the image for the second imaging optics.

The imager may be configured to produce a monochromatic or a multicolor image.

The holding device may be formed like a spectacle. In particular, it may have a nose pad. However, it is also possible any other type of holding device that allows wearing of the display device on the head of the user.

The display device according to the invention may have further, known in the art elements that are necessary for their operation.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the specified combinations but also in other combinations or alone, without departing from the scope of the present invention.

The invention will be explained in more detail for example with reference to the accompanying drawings, which also disclose characteristics essential to the invention. Show it:

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

2 a schematic plan view of the embodiment of 1 ;

3 a sectional view through the first image unit 11 the display device according to the invention;

4 a representation for explaining the provided field of view;

5 a representation for explaining the occurring during the imaging by means of the first imaging optics distortion;

6 a representation of the modulation transfer function of the first image unit 11 ;

7 - 9 Representations of the dot image function of the first image unit 11 for different field angles;

10 a sectional view according to 3 by a further embodiment of the first image unit 11 ;

11 a sectional view according to 10 a further embodiment of the first image unit 11 ;

12 a representation according to 2 a further embodiment of the display device according to the invention, and

13 a perspective schematic representation of another embodiment of the display device according to the invention.

In 1 is a first embodiment of the display device according to the invention 1 shown schematically in a perspective view. The display device 1 has a glasses-like holding device 2 with a front part 3 that a nose pad 4 includes, as well as two with the front part 3 connected straps 5 on.

The display device 1 Can be placed like a conventional glasses on the head of a user, in which case the nose pad 4 on the nose of the user and those of the front part 3 groundbreaking ends of the temples 5 resting on the ears of the user.

The display device 1 can optional earphone 6 each having a connecting portion 7 with the front part 3 are connected. The connecting sections 7 are designed so that the earphones 6 in the mounted on the head state of the holding device 2 So the user's ears can be positioned over the earphones 6 can perceive emitted signals. The earphones 6 may be designed in particular as in-ear listeners or on-ear listeners.

The display device according to the invention 1 may also optionally have a connecting line K, here in the right bracket 5 empties. About this line K can be a power supply and / or Data can be transmitted. However, it is also possible to omit the line K. In this case, for example, a battery or a battery may be provided to ensure the power supply, if necessary. Data, if they need to be transmitted, can be transmitted via radio, for example.

The display device 1 In particular, it is designed so that it fits every eye of the user in the attached state of the holding device 2 provides a virtual image so that the user can perceive only the virtual image and not the environment. In this case, the display device 1 also be referred to as HMD (Head Mounted Display) device. Thus, a user can perceive only displayed images and not the environment with attached display device.

In 2 is in a schematic plan view essentially one in the front part 3 arranged image module 10 represented, which is a first image unit 11 for a left eye LA of the user and a second imaging unit 12 for a right eye RA of the user. Because the two image units 11 . 12 are basically the same design, like elements are denoted by the same reference numerals and is below essentially only the first image unit 11 described in detail. In the presentation of 2 is the front part 3 as shown above, so that the image module 10 is visible. However, it is preferred that the front part 3 is formed closed.

The first picture unit 11 comprises a planar imager 13 , a control unit 14 for the imager 13 as well as an imaging optics 15 with two spaced apart lenses 16 and 17 ,

The planar imager, which may be a self-luminous display and may include, for example, an LCD module, an LCoS module or an OLED module, generates under the control of the control unit 14 an image by means of the imaging optics 15 So it will picture a user when he is holding the fixture 2 wearing on his head, with his left eye can perceive LA as a virtual image.

The planar imager 13 extends in the y and x directions and thus perpendicular to the plane according to 2 , The imager 13 is thus in an image plane E, which is spanned by the y and x direction. The imager 13 For example, it may produce an image that is quadrangular or rectangular, with the corresponding sides of the square or rectangular image preferably extending in the x and y directions. For rectangular images, the longer side preferably extends in the y direction. In the embodiment described here, the aspect ratio of the generated image is 4: 3, with the diagonal being 62.5 mm.

In the 3 shown enlarged sectional view of some elements of the first imaging unit 11 is along the diagonal of the imager 13 provided image field or the image generated, wherein the beam path for one half of the diagonal is shown schematically.

As in particular the representation in 3 it can be seen, is the first lens 16 the imaging optics 15 is designed as a lens with negative refractive power and is the second lens 17 that from the first lens 16 is formed as a lens with positive refractive power.

The first lens 16 has a first and a second interface 18 . 19 and the second lens 16 has a first and second interface 20 and 21 on. All four interfaces 18 - 21 are designed as aspheric surfaces. In particular, they can be designed as rotationally symmetric aspheres, which are rotationally symmetrical with respect to the optical axis OA. The optical axis OA is perpendicular to the image plane.

The four interfaces can be described by the following surface equation, where r is the radial height on the surface.

The aspheric constants for the areas are shown below Table 1 given. Table 1 area c k A B C D e F 21 0.02458985 -34.37620747 0 0 0 0 0 0 20 -0.08089100 -1.20132548 -1.02404E-06 0 0 0 0 0 19 -0.05245461 -0.82014849 2.70981E-05 -4.48079E-09 0 0 0 0 18 0.03588622 -7.51958853 -1.60900E-06 8.73574E-09 0 0 0 0

The distances along the optical axis OA are given in Table 2 below. Table 2 Surface area Distance [mm] 22 - 21 16.0 21 - 20 13.9 20 - 19 8.83 19 - 18 3.0 18 -E 16.27

The first lens 16 is made of polycarbonate with a refractive index n1 of 1.585 and an Abbe number ν1 of 30.0. The second lens 17 is formed of PMMA with a second refractive index n2 of 1.492 and a second Abbe number v2 of 57.2. The refractive indices and Abbe numbers are given here for the wavelength of 589 nm.

Because the two lenses 16 and 17 spaced apart and not formed as a cemented member, all four interfaces 18 - 21 used to achieve the desired image. This makes it possible to view the image of the imager 13 as a virtual image, the exit pupil 22 has a diameter of 6 mm. The exit pupil 22 is from the image plane E and thus from the imager 13 spaced by a distance d of 58 mm. Thus, there is an extremely compact structure which, as shown below, provides excellent optical imaging characteristics.

The focal length of the first lens in the embodiment described here is -18.7 mm and the focal length of the second lens 17 here is +21.02 mm. Thus, a good color aberration compensation is possible, although the two lenses 16 . 17 not formed as a cemented element. In particular, the focal lengths can be chosen such that the amount of the focal length of the second lens 17 is greater than the amount of the focal length of the first lens 16 , Preferably, the amount of the focal length of the second lens is in a range extending from the amount of the focal length of the first lens to 1.2 times the amount of the focal length of the first lens. In other words, the ratio of the amount of the focal length of the first lens is 16 to the amount of the focal length of the second lens 1: 1 to 1: 1.2.

Thus, the virtual image is given to the user with a field of view S with α1 = 60 ° in the y-direction and α2 = 45 ° in the x-direction ( 4 ) so that the field of view S in the diagonal is 75 °.

The occurring distortions within this field of view α1 and α2 are in 5 shown schematically, being the ideal case with the rectangles 23 and the actual picture with the easily listed rectangles 24 is shown. Overall, the presentation shows that there is very little distortion. It is in the range of <4%.

In 6 For example, the polychromatic modulation transfer function is shown for an eye pupil of an eye of a user with a diameter of 3 mm, along the ordinate the modulation from 0 to 1 and along the abscissa the line pairs per millimeter are plotted.

The curve K1 shows the theoretical ideal case and the remaining curves show the modulation transfer function for different field angles in the field of view, with the solid lines Modulation transfer function for the y-direction and dashed lines for the x-direction are shown. Furthermore, wavelengths 643 nm, 546 nm and 480 nm with the weights 5: 10: 3 are taken into account for each field angle.

The curve K2 relates to a field angle of 0 ° and thus the point of the virtual image on the optical axis OA. Here the modulation transfer functions for the x-direction and the y-direction coincide. From the curve K2 to the curves K3 and K4, the field angles increase. The curve K3 relates to a field angle of 37.5 ° for the y-direction and the curve K4 relates to a field angle of 37.5 ° for the x-direction. The curves K3 and K4 thus affect the diagonal corners of the virtual image. Essential to the presentation in 6 is that the modulation transfer function for all field angles of the virtual image lies between the curve K2 and the curve K3 or K4.

From the presentation of 6 can be seen that the imaging optics 15 has excellent imaging properties.

In 7 is the point image function for a point on the optical axis OA shown, along the direction of the double arrow P1, the expansion in the x direction in mm, along the direction of the double arrow P2, the expansion in the y direction in mm and along the ordinate the intensity is plotted in percent. In this illustration, the same wavelength weighting was performed as in the illustration of FIG 6 , As the illustration in 7 can be seen, have excellent imaging properties.

In the presentation according to 7 the Strehl ratio is 0.756. The Strehl ratio is the ratio of the observed maximum intensity in the imaging plane to the theoretical maximum intensity of a perfect optical system.

The same representation as in 7 is in 8th and 9 shown, where 8th a diagonal field angle of 18.7 ° and 9 refer to a diagonal field angle of 37.5 °. These representations also show the excellent imaging property that Strehl ratio here is 0.419 (for 8th ) and 0.650 (for 9 ).

Furthermore, the imaging optics 15 a vignette-free mapping available so that overall excellent imaging qualities despite the large field of view and the very short space available.

In 10 is in a sectional view in the same way as in 3 a further embodiment of the first image unit and in particular of the imaging optics 15 shown.

The imaging optics 15 again comprises the two spaced-apart lenses 16 and 17 , where the lens 16 , which is closer to the image plane E, as a negative lens and the lens 17 is designed as a positive lens.

While in the embodiments described so far, the first lens 16 is designed as a concave-concave lens is in accordance with the embodiment described here 10 the first lens 16 formed as a convex-concave lens, the concave side of the image plane E faces. This makes it possible to have a larger exit pupil 22 provide. The exit pupil 22 here has a diameter of 8 mm. The diameter of the exit pupil 22 is here thus one third larger compared to the previously described embodiments. Here is the first lens 16 in the same way as in the previously described embodiments of polycarbonate and the second lens 17 made of PMMA.

The four interfaces 18 - 21 the first and second lenses 16 . 17 are in turn formed as rotationally symmetric aspheres, which are rotationally symmetrical with respect to the optical axis OA. They are described by the area equation given above, with the aspheric constants for the areas 18 - 21 in the following Tables 3, 4 are given. Table 3 area c k A B 21 0.02755029 -1.19257843 -4.02478E-05 6.53210E-08 20 -0.13372702 -3.43219655 -7.94677E-05 2.61207E-07 19 0.04566567 -47.19842611 -1.01677E-04 6.67058E-07 18 0.18275401 -3.65018645 -2.25585E-05 2.97105E-07 Table 4 area C D e F 21 0 0 0 0 20 -6.57144E-10 8.27311E-13 0 0 19 -2.78498E-09 7.08411E-12 -9.16515E-15 4.10729E-18 18 -1.72556E-09 5.06512E-12 -7.20390E-15 3.88235E-18

The distances along the optical axis OA are given in Table 5 below. Table 5 Surface area Distance [mm] 22 - 21 18.0 21 - 20 19.34 20 - 19 0.39 19 - 18 4.0 18 -E 20.27

In addition to the large diameter of the exit pupil 22 is in the embodiment described here still advantageous that the distance between the exit pupil 22 and the area 21 (and thus the distance to the second lens 17 ) Is 18 mm. This also allows spectacle wearers to wear the display device according to the invention as intended along with their glasses on their heads. Thus, a possibly necessary diopter compensation is ensured by the user's glasses and the user is provided an excellent viewing experience.

In 11 is in a sectional view in the same way as in 10 a modification of the embodiment of the first image unit 11 and in particular the imaging optics 15 according to 10 shown.

In this modification, the imaging optics includes 15 again two spaced-apart lenses 16 and 17 , where the first lens 16 , which is closer to the image plane E, as a negative lens and the second lens 17 is designed as a positive lens. Further, the first one

lens 16 formed as a convex-concave lens, the concave side of the image plane E faces. The second lens 17 is designed as a convex-convex lens. Furthermore, the first lens 16 formed in the same manner as in the previously described embodiments of polycarbonate and the second lens of PMMA. The same materials were used as in the previously described embodiments.

The four interfaces 18 - 21 the first and second lenses 16 . 17 are formed as rotationally symmetric aspheres, which are rotationally symmetrical with respect to the optical axis OA. They can be described by the area equation given above, with the aspheric constants of the areas 18 - 21 in Tables 6 and 7 below. Table 6 area c k A B 21 0.03033007 -1.60209948 -4.30003E-05 6.46580E-08 20 -0.12496804 -3.35679383 -8.06124E-05 2.67804E-07 19 0.04115641 -43.59420143 -8.60171E-05 5.94804E-07 18 0.16131129 -3.81629776 5.94271E-06 1.79555E-07 Table 7 area C D e F 21 0 0 0 0 20 -6.80472E-10 8.06005E-13 0 0 19 -2.59066E-09 6.83841E-12 -9.37934E-15 4.79164E-18 18 -1.58643E-09 5.55020E-12 -9.00686E-15 5.57075E-18

The distances along the optical axis OA are given in Table 8 below. Table 8 Surface area Distance [mm] 22 - 21 18.0 21 - 20 19.92 20 - 19 0.40 19 - 18 4.15 18 -E 18.05

In this embodiment, the round exit pupil 22 a diameter of 8 mm. Again, the distance between the exit pupil is 22 and the area 21 18 mm so that wearer glasses the display device according to the invention 1 intended to wear together with their glasses on their heads. Furthermore, the distortion in this embodiment is very small. It is less than or equal to 1%.

Unlike the embodiment according to 10 In the present embodiment, the distance d is from the exit pupil 22 to the image level a little smaller. In the embodiment according to 11 the distance is 60.52 mm whereas in the embodiment according to FIG 10 62 mm.

In the previous description, it was assumed that each image unit 11 . 12 a separate planar imager 13 having. Of course it is also possible (as shown schematically in 12 is shown), a continuous area imager 13 provide, with a part of the imager 13 by means of the imaging optics 15 for the left eye LA and an area of the imager spaced apart or directly adjacent thereto 13 by means of the imaging optics 15 is imaged for the right eye RA. In particular, a mobile telephone, for example a so-called smartphone, or another device with a corresponding display (such as, for example, the so-called iPod touch from Apple Inc., California, USA) can be used as a planar imager 13 be used. In this case, the front part 3 For example, a recording (not shown), in which the mobile phone or other device can be used. It is also possible to use only one display used in a mobile phone or similar devices as such.

A further embodiment of the display device according to the invention 1 is in 13 shown schematically.

The front part 3 is essentially box-shaped and has a nose pad 4 on, wherein the user-facing side of the front part 3 is open. The contour of the open side is such that when wearing the holding device 2 the edge of the open side abuts the head, this concern is preferably light-tight.

Instead of the temple 5 the previous embodiments is an elastic band 25 or a band 25 with adjustable length (which can also be elastic) with both ends on the front side 3 attached, so that the tape 25 can lead over the back of the head and thus there is a contact pressure, the front part 3 presses against the head in an ergonomically pleasing manner.

Furthermore, schematically the first and second imaging optics 15 shown. When the user the display device 1 on the head, he can thus perceive an image generated in the image plane E with his left and right eye in the manner described.

The display device according to 13 is in particular designed so that a conventional mobile phone or other device with a corresponding display can be used interchangeably and in the inserted state of the screen of the mobile phone or the display of the device is in the image plane E.

Claims (18)

Display device with a holding device which can be placed on the head of a user ( 2 ) and one on the holding device ( 2 ) attached first imaging optics ( 15 ) which is designed to image an image generated in an image plane (E) as a virtual image so that the user in the upside down state of the holding device ( 2 ) with a first eye (LA, RA) can perceive, wherein the first imaging optics ( 15 ) a first lens ( 16 ) with negative refractive power and one of the first lens ( 16 ) spaced second lens ( 17 ) with positive refractive power, the first lens ( 16 ) is positioned closer to the image plane (E) than the second lens ( 17 ). Display device according to Claim 1, in which the first imaging optics ( 15 ) is free of deflecting elements for beam path folding. Display device according to Claim 1 or 2, in which the first lens ( 16 ) a first and second interface ( 18 . 19 ) and the second lens ( 17 ) a first and second interface ( 20 . 21 ) and all four interfaces ( 18 - 21 ) of the two lenses ( 16 . 17 ) are each formed as rotationally symmetric aspheres.  Display device according to claim 3, in which all four rotationally symmetric aspheres are different. Display device according to one of the preceding claims, wherein the image plane (E) in the upside down state of the holding device ( 2 ) is substantially perpendicular to the straight-ahead direction. Display device according to one of the above claims, wherein the first imaging optics ( 15 ) from the first and second lenses ( 16 . 17 ) consists. Display device according to one of the preceding claims, in which the two lenses ( 16 . 17 ) are formed of plastic. Display device according to one of the preceding claims, in which the two lenses ( 16 . 17 ) are formed of different materials. Display device according to one of the preceding claims, in which the first lens ( 16 ) a first Abbe number and the second lens ( 17 ) has a second Abbe number, the second Abbe number being greater than the first Abbe number. Display device according to one of the above claims, wherein the first imaging optics ( 15 ) an exit pupil ( 22 ), wherein the distance (d) between the exit pupil ( 22 ) and the image plane (E) is less than 100 mm and preferably less than 65 mm. Display device according to one of the above claims, wherein the first imaging optics ( 15 ) an exit pupil ( 22 ), which has a maximum extension of greater than or equal to 5 mm. Display device according to one of the above claims, wherein the first imaging optics ( 15 ) images in the image plane (E) generated image with a diagonal of at least 45 mm completely as a virtual image. Display device according to one of the above claims, wherein the first imaging optics ( 15 ) images the generated image centrally without vignetting. Display device according to one of the above claims, wherein the first imaging optics ( 15 ) images the generated image such that the user is provided with a field of view with a diagonal of greater than 60 ° and in particular greater than 70 °. Display device according to one of the preceding claims, in which in the image plane (E) an imager ( 13 ), which generates the image which is produced by means of the first imaging optics ( 15 ) is shown. Display device according to Claim 15, in which the imager ( 13 ) is arranged interchangeable in the image plane (E). Display device according to one of the preceding claims, in which the amount of the focal length of the second lens ( 17 ) is within a range of the amount of the focal length of the first lens ( 16 ) up to 1.2 times the amount of the focal length of the first lens ( 16 ). Display device according to one of the preceding claims, in which the first lens ( 16 ) is formed as a convex-concave lens, wherein the concave side ( 18 ) of the first lens ( 16 ) faces the image plane (E).

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