Optical system for a virtual retinal display (retinal scan display)

Abstract

The invention relates to an optical system (1) for a virtual retinal display (retinal scan display). The optical system (1) has an illumination unit (10), which in turn has at least one light source for emitting a light beam (15a, 15b). Furthermore, the optical system (1) has a controllable deflection unit (20) for the light beam (15a, 15b) for the scanning projection of an image content. In addition, the optical system (1) has a focusing unit (30) and a scattering unit (40). The focusing unit (30) serves to focus the scanning light beam (16a, 16b) onto the scattering unit (40), and the scattering unit (40) is designed to expand the scanning light beam (17a, 17b) in the direction of a deflection unit (90). The deflection unit (90) of the optical system (1) is designed to deflect the expanded light beam (18a, 18b) in the direction of a pupil (60) of a user of the retinal display.

Description

[0001] The invention relates to an optical system for a virtual retinal display (retinal scan display). Furthermore, the invention relates to data glasses with the optical system. State of the art

[0002] Data glasses (smartglasses) with retinal scan displays are already known.

[0003] The invention is based on the object of developing an optical system for a virtual retinal display (retinal scan display) that offers the user a large eyebox with a comparatively large field of view. Disclosure of the invention

[0004] To achieve this object, an optical system for a virtual retinal display (retinal scan display) according to claim 1 is proposed. Furthermore, data glasses according to claim 12 are proposed.

[0005] The optical system for a virtual retinal display (retinal scan display) comprises an illumination unit. The illumination unit, in turn, comprises at least one light source, in particular a laser diode or an LED or a superluminescent SL-LED, for emitting a light beam. The light beam in particular comprises light in a red, blue, or green wavelength range. Furthermore, the optical system comprises a controllable deflection unit for the light beam for the scanning projection of an image content. The controllable deflection unit in particular comprises at least one micromirror, which is in particular rotatably mounted. Furthermore, the optical system comprises a focusing unit and a scattering unit.The focusing unit is designed to focus the scanning light beam onto the scattering unit, and the scattering unit serves to expand the scanning, in particular focused, light beam toward a deflection unit. Furthermore, the deflection unit of the optical system is designed to redirect the expanded light beam toward the pupil of a user of the retinal display. The optical system enables an enlarged eyebox without compromising the field of view. Furthermore, the projected image content reaches the user's pupil with the highest possible resolution.

[0006] The optical system preferably additionally comprises an alignment unit for aligning the light beam expanded by the diffusion screen in the direction of the deflection unit. The alignment unit is preferably designed as an optical exit window for the expanded light beam arranged on the temple of the spectacle. The alignment unit serves, particularly in combination with the deflection unit, to correct image aberrations such as astigmatism or image field tilt. The alignment unit is preferably designed as an optical lens. In this context, the optical lens is preferably designed as a spherical, cylindrical, aspherical, and / or freeform lens.

[0007] Preferably, the focusing unit is configured to focus the scanning light beam onto the scattering unit in such a way that the image content is displayed on the scattering unit. The scattering unit, in turn, enlarges the numerical aperture, which allows the image content displayed on the scattering unit to be projected onto an enlarged eyebox of the user.

[0008] The controllable deflection unit is preferably designed to deflect the scanning light beam at a first point in time, in particular in a first position of the deflection unit, at a first angle in the direction of the focusing unit. The diffusion plate, in turn, is designed to expand the first light beam at the first point in time, in particular at the first position of the deflection unit, at a second angle in the direction of the deflection unit. The second angle is greater than the first angle. Thus, the image content is expanded at a larger angle in the direction of the deflection unit compared to the image content coming from the deflection unit. The result is a larger eyebox for the user.

[0009] Preferably, the scattering unit is designed to be at least partially reflective of the light beam. Alternatively, the scattering unit is designed to be at least partially, in particular completely, transmissive of the light beam. The scattering unit is preferably designed as a scattering disk, in particular as a mirror element. Furthermore, the scattering unit has a planar or, alternatively, a curved outer surface.

[0010] The deflection unit is preferably designed as a holographic optical element. The focusing unit is preferably designed as a focus lens.

[0011] Preferably, the scattering unit is spatially arranged between the focusing unit and the deflection unit. This arrangement enables the most compact, space-saving design of the optical system possible.

[0012] A further subject of the present invention is data glasses with the optical system. Preferably, the illumination unit, the controllable deflection unit, the focusing unit, the scattering unit, and the alignment unit are arranged in a temple of the data glasses. The deflection unit is integrated into a lens of the data glasses. Description of the drawings Fig. 1 shows an optical system for a virtual retinal display (retinal scan display). Fig. 2 shows data glasses with the optical system. Description of the embodiments

[0013] The Fig. 1 schematically shows an optical system 1 for a virtual retinal display (retinal scan display). The optical system 1 has an illumination unit 10, which in turn has a light source (not shown here for simplification) for emitting at least one light beam 15a and 15b. Furthermore, the optical system 1 has a controllable deflection unit 20 for the light beam 15a and 15b for the scanning projection of an image content. In this embodiment, the controllable deflection unit 20 is designed as a two-dimensionally rotatably mounted micromirror. In addition, the optical system 1 has a focusing unit 30 and a scattering unit. The focusing unit 30 serves to focus the scanning light beam 16a and 16b onto the scattering unit 40, and the scattering unit 40 is designed to expand the scanning, in particular focused, light beam 17a and 17b in the direction of a deflection unit 90.The deflection unit 90 of the optical system 1 is designed to deflect the expanded light beam 18a and 18b toward a pupil 60 of a user of the retinal display. In this embodiment, the deflection unit 90 is designed as a holographic optical element.

[0014] Optionally, the optical system 1 additionally has an alignment unit 50 for aligning the light beam 18a and 18b expanded by the diffuser 40 in the direction of the deflection unit 90. In this case, the alignment unit 50 is designed as an optical lens.

[0015] Furthermore, in the illustrated embodiment, the focusing unit 30 is designed to focus the scanning light beam 16a and 16b onto the scattering unit 40 such that the image content is displayed on the scattering unit 40. Furthermore, the focusing unit 30 is designed as a focus lens.

[0016] In this embodiment of the optical system 1, the controllable deflection unit 20 is designed to deflect the scanning light beam 16a and 16b at a first point in time, in particular in a first position of the deflection unit 20, at a first angle (here 0°) in the direction of the focusing unit 30. The diffusion plate 40 is in turn designed to expand the first light beam 18a and 18b at the first point in time, in particular at the first position of the deflection unit 20, at a second angle 21 in the direction of the deflection unit 90. The second angle 21 is greater than the first angle.

[0017] The scattering unit 40, which in this case is a scattering disk, is designed to be transmissive to the light beams 17a and 17b. Furthermore, in this embodiment, the scattering unit 40 has a planar outer surface.

[0018] In the illustrated embodiment of the optical system 1, the scattering unit 40 is spatially arranged between the focusing unit 30 and the deflection unit 90.

[0019] Fig. Figure 2 schematically shows a pair of data glasses 2 with the previously described optical system 1. The illumination unit 10, the controllable deflection unit 20, the focusing unit 30, the scattering unit 40, and the alignment unit 50 are arranged in a temple 80 of the data glasses. The deflection unit 90, which is designed as a holographic optical element, is integrated into a lens 100 of the data glasses 2. The holographic optical element 90 serves to deflect the expanded and, in this case, aligned light beam 19c toward the pupil 60 of a user of the retinal display.

Claims

[1] Optical system (1) for a virtual retinal display (retinal scan display), comprising at least - an illumination unit (10) of the optical system (1), wherein the illumination unit (10) has at least one light source for emitting a light beam (15a, 15b), and - a controllable deflection unit (20), in particular comprising at least one micromirror, for the light beam (15a, 15b) for scanning projection of an image content, and - a focusing unit (30) and a scattering unit (40), wherein the focusing unit (30) is designed to focus the scanning light beam (16a, 16b) onto the scattering unit (40) and the scattering unit (40) is designed to widen the scanning, in particular focused, light beam (17a, 17b) in the direction of a deflection unit (90), and - the deflection unit (90), wherein the deflection unit (90) is designed to deflect the expanded light beam (18a, 18b) in the direction of a pupil (60) of a user of the retinal display. [2] Optical system (1) according to claim 1, characterized by that the optical system (1) additionally has an alignment unit (50) for aligning the light beam (18a, 18b) expanded by the diffusing disc (40) in the direction of the deflection unit (90). [3] Optical system (1) according to claim 2, characterized by that the alignment unit (50) is designed as an optical lens. [4] Optical system (1) according to one of claims 1 to 3, characterized by that the focusing unit (30) is designed to focus the scanning light beam (16a, 16b) onto the scattering unit (40) in such a way that the image content is displayed on the scattering unit (40). [5] Optical system (1) according to one of claims 1 to 4, characterized byin that the controllable deflection unit (20) is designed to deflect the scanning light beam (16a, 16b) at a first point in time, in particular in a first position of the deflection unit (20), at a first angle in the direction of the focusing unit (30), wherein the diffusion plate (40) is designed to widen the first light beam (18a, 18b) at the first point in time, in particular in the first position of the deflection unit (20), at a second angle (21) in the direction of the deflection unit (90), wherein the second angle (21) is greater than the first angle. [6] Optical system (1) according to one of claims 1 to 5, characterized by that the scattering unit (40) is at least partially reflective or transmissive for the light beam (17a, 17b). [7] Optical system (1) according to one of claims 1 to 6, characterized by that the scattering unit (40) is designed as a scattering disc. [8] Optical system (1) according to one of claims 1 to 7, characterized by that the scattering unit (40) has a planar or a curved outer surface. [9] Optical system (1) according to one of claims 1 to 8, characterized by that the deflection unit (90) is designed as a holographic optical element. [10] Optical system (1) according to one of claims 1 to 9, characterized by that the focusing unit (30) is designed as a focus lens. [11] Optical system (1) according to one of claims 1 to 10, characterized by that the scattering unit (40) is spatially arranged between the focusing unit (30) and the deflection unit (90). [12] Data glasses (2) with an optical system (1) according to one of claims 1 to 11. [13] Data glasses (2) according to claim 12, characterized bythat the lighting unit (10), the controllable deflection unit (20), the focusing unit (30), the scattering unit (40) and the alignment unit (50) are arranged in a temple piece (80) of the data glasses (2), wherein the deflection unit (90) is integrated into a spectacle lens (100) of the data glasses (2).

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