smart glasses

Abstract

The invention relates to smart glasses (1a) designed for a virtual retinal scan display for a user of the smart glasses (1a). The smart glasses (1a) comprise a projector unit (14) with a time-modulated light source (2) for generating at least one first light beam (8, 11) and with a controllable deflection device (16) for the at least one first light beam (8, 11) for scanning and projecting an image content. The smart glasses (1a) also comprise a first deflection unit (10) onto which the image content is projected and which directs the projected image content onto one eye (9) of a user. Furthermore, the smart glasses (1a) comprise at least one laser feedback interferometry sensor (5) arranged in or on the smart glasses (1a), which is configured to emit a second modulated light beam (12), in particular an infrared beam. Furthermore, the data glasses (1a) have a computing unit (13).The laser feedback interferometry sensor (5) serves to detect a second light beam reflected from an object (7) located between the controllable deflection device (16) and the first deflection unit (10), or on a side of the first deflection unit (10) facing away from the eye (9) of the user of the data glasses (1a). The processing unit (13) serves to detect the object (7) depending on the reflected second light beam.

Description

[0001] The invention relates to data glasses. Furthermore, the invention relates to a method for detecting an object arranged between a controllable deflection device and a first deflection unit of data glasses or on a side of the first deflection unit facing away from the eye of the data glasses wearer. State of the art

[0002] Data glasses for a virtual retinal display (retinal scan display) are known.

[0003] The invention is based on the object of developing data glasses which ensure that when the data glasses are operated, no external objects are introduced into the beam path which could lead to a deflection of the laser light towards the user's eye. Disclosure of the invention

[0004] To achieve the object, data glasses according to claim 1 are proposed. Furthermore, a method according to claim 8 is proposed for detecting an object arranged between a controllable deflection device and a first deflection unit of data glasses or on a side of the first deflection unit facing away from the eye of the user of the data glasses.

[0005] The data glasses are designed for a virtual retinal display (retinal scan display) of a user of the data glasses. The data glasses comprise a projector unit with a temporally modulatable light source for generating at least one first light beam, in particular one visible to the user, and with a controllable deflection device for the at least one first light beam for scanning projection of an image content. The data glasses further comprise a first deflection unit onto which the image content is projected and which directs the projected image content onto an eye of a user. The first deflection unit is in particular a first holographic optical element. The first deflection unit is in particular integrated into a spectacle lens of the data glasses. Furthermore, the data glasses have at least one laser feedback interferometry sensor arranged in or on the data glasses.The laser feedback interferometry sensor is designed to emit a second modulated light beam, in particular an infrared one. The data glasses further comprise a computing unit. The laser feedback interferometry sensor is designed to detect a second light beam reflected back from an object, in particular an external one, arranged between the controllable deflection device and the first deflection unit. Alternatively, the laser feedback interferometry sensor is designed to detect a second light beam reflected back from an object, in particular an external one, arranged on a side of the first deflection unit facing away from the eye of the data glasses user. In this context, the computing unit serves to detect the object depending on the reflected second light beam.

[0006] The controllable deflection device is preferably formed from a first micromirror mounted so as to be rotatable about a first axis of rotation and from a second micromirror mounted so as to be rotatable about a second axis of rotation. The first axis of rotation is arranged substantially perpendicular to the second axis of rotation. The first micromirror is designed to be rotated about the first axis of rotation at a first frequency, in particular a first rotational frequency. The second micromirror is in turn designed to be rotated about the second axis of rotation at a second frequency, in particular a second rotational frequency. The first frequency is higher, in particular significantly higher, than the second frequency. The image content is thus projected in rows or columns, in particular in a raster format. The laser feedback interferometry sensor is designed to emit the second light beam, in particular directly, onto the second micromirror.The second micromirror, in turn, serves to deflect the second light beam onto the object arranged between the controllable deflection device and the first deflection unit. Due to the direct coupling between the laser feedback interferometry sensor and the second micromirror, the object can be scanned in several lines by the second light beam and thus detected. Therefore, no separate, particularly optical, component is required to detect the object; instead, a component is used that is already used for image projection. The laser feedback interferometry sensor is preferably arranged in a spectacle arm, particularly adjacent to the second micromirror. Alternatively, the data glasses have a second deflection unit, which is particularly designed as a second holographic optical element. The second holographic optical element is particularly integrated into a spectacle lens of the data glasses.The first and second holographic optical elements are in particular stacked. In this context, the laser feedback interferometry sensor is designed to emit the second light beam, in particular directly, onto the second deflection unit. The second deflection unit, in turn, serves to expand the second light beam in the direction of the object arranged on the side of the first deflection unit facing away from the eye of the data glasses user. This also allows objects on the world side of the data glasses to be detected, which could also lead to disruptive reflections in the direction of the user's eye. The laser feedback interferometry sensor is preferably arranged in a temple or in a frame. The second deflection unit is preferably designed to linearly expand the second light beam in the direction of the object arranged on the side of the first deflection unit facing away from the eye of the data glasses user.Alternatively, the second deflection unit serves to expand the second light beam in the form of discrete points toward the object located on the side of the first deflection unit facing away from the eye of the data glasses user. This allows a larger area to be searched for the object and also allows the type of object to be assessed.

[0007] The computing unit is preferably designed to switch off the projection unit, in particular the temporally modulatable light source, depending on the detected object. Such a temporally modulatable light source is designed as a laser source in a laser projector as a projector unit. To compensate for a potentially low efficiency of a first holographic optical element as the first deflection unit, the light source has a comparatively high laser power. Objects, in particular external objects, located between the controllable deflection device and the first deflection unit or on the side of the first deflection unit facing away from the eye of the data glasses user can lead to reflections of the laser light in the direction of the eye. Switching off the projection unit thus serves to increase the eye safety of the data glasses user.

[0008] Preferably, the computing unit is designed to determine distance values ​​depending on the at least one reflected second light beam. The distance values ​​are, in particular, distance values ​​of the object relative to the laser feedback interferometry sensor. In the case of the laser feedback interferometry sensor coupled to the second micromirror, the distance values ​​are determined in particular as a function of the scanning angle of the second micromirror. This also makes it possible to determine the type of object and thus assess whether it is a light-reflecting and thus potentially critical object. In the case of the laser feedback interferometry sensor, which is oriented in the direction of the first deflection unit, the distance values ​​are determined in particular as a function of the signal strength.

[0009] The data glasses preferably have at least one additional second sensor. This is, in particular, a further laser feedback interferometry sensor. The second sensor is designed to detect contact of the data glasses with the skin, in particular the scalp, of the user. Alternatively or additionally, the second sensor serves to detect a distance of the second sensor from the user's head. In this context, the computing unit is designed to determine a, in particular current, wearing state of the data glasses from the sensor data recorded by the second sensor. A detected object can only have an impact on the eye safety of the data glasses user if the user is currently wearing the data glasses. This means that, for example, switching off the projector unit is not necessary despite the detection of a potentially critical object.

[0010] A further subject matter of the present invention is a method for detecting an object arranged between a controllable deflection device and a first deflection unit of data glasses or on a side of the first deflection unit facing away from the eye of the user of the data glasses. The data glasses are, in particular, the data glasses described above. In the method, a first light beam, which is in particular visible to the user of the data glasses, is first emitted by means of a time-modulatable light source of a projector unit of the data glasses. Furthermore, the first light beam, in particular in the form of image content, is projected in a scanning manner onto the first deflection unit by means of the controllable deflection device of the projector unit of the data glasses. The first deflection unit is, in particular, a first holographic optical element of the data glasses.Furthermore, the projected image content is deflected onto one eye of the user by means of the first deflection unit. In a further method step, a second modulated light beam, in particular an infrared one, is emitted by means of a laser feedback interferometry sensor of the data glasses. Furthermore, the second light beam reflected back by the object, in particular an external object, arranged between the controllable deflection device and the first deflection unit is detected by means of the laser feedback interferometry sensor. Alternatively, the second light beam reflected back by the object, in particular an external object, arranged on the side of the first deflection unit facing away from the user's eye of the data glasses is detected by means of the laser feedback interferometry sensor. In a further method step, the object is detected by means of a processing unit of the data glasses as a function of the reflected second light beam.

[0011] Depending on the detected object, the projector unit, in particular the temporally modulatable light source, is preferably switched off by means of the computing unit. In a laser projector, such a temporally modulatable light source is designed as a laser source as a projector unit. In order to compensate for a potentially low efficiency of a first holographic optical element as the first deflection unit, the light source has a comparatively high laser power. Objects, in particular external objects, located between the controllable deflection device and the first deflection unit or on the side of the first deflection unit facing away from the eye of the data glasses user can lead to reflections of the laser light in the direction of the eye. Switching off the projector unit thus serves to increase the eye safety of the data glasses user.

[0012] Preferably, distance values ​​to objects relative to the laser feedback interferometry sensor are determined by means of the computing unit as a function of the at least one reflected second light beam. The objects are in particular external objects. In this context, first distance values ​​of components of the data glasses or of an eye of the user relative to the laser feedback interferometry sensor are preferably determined by means of the computing unit at a first point in time. This method step serves in particular for an initial calibration of the data glasses. Furthermore, second distance values ​​determined by means of the computing unit at a second point in time following the first point in time are compared with the first distance values. In a further method step, the object is detected by means of the computing unit as a function of the comparison carried out.The initial calibration step enables a comparison of a disturbance-free system with a system that has a potentially disturbing external object.

[0013] Preferably, the detected object is a prism, a lens, or a spectacle lens. Such optical objects have an increased risk of reflecting the first light rays toward the user's eye. Description of the drawings Fig. 1 shows a section of a first embodiment of data glasses. Fig. 2 shows distance values ​​of objects relative to the laser feedback interferometry sensor detected by the first embodiment of the data glasses. Fig. 3 shows a detail of a second embodiment of data glasses. Fig. 4 shows distance values ​​of an object relative to the laser feedback interferometry sensor detected by means of the second embodiment of the data glasses. Fig. 5 shows a method for detecting an object arranged between a controllable deflection device and a first deflection unit of data glasses or on a side of the first deflection unit facing away from the eye of the user of the data glasses. Description of the embodiments

[0014] The Fig. 1 schematically shows a section of a pair of data glasses 1a designed for a virtual retinal display (retinal scan display) of a user of the data glasses 1a. The data glasses 1a comprise a projector unit 14 with a temporally modulatable light source 2 for generating at least one first light beam 11, which is in particular visible to the user. The projector unit 14 further comprises a controllable deflection device 16 for the first light beam 11 for the scanning projection of an image content. The data glasses 1a further comprises a first deflection unit 10, which in this embodiment is designed as a first holographic optical element and onto which the image content is projected and which directs the projected image content onto an eye 9 of a user.Furthermore, the data glasses 1a have a laser feedback interferometry sensor 5, which is designed to emit a second modulated light beam 12, in particular an infrared one. The laser feedback interferometry sensor 5 is integrated into a temple 15 of the data glasses 1a. In this exemplary embodiment, the projector unit 14 is also integrated into the temple 15. The data glasses 1a also have a computing unit 13. The laser feedback interferometry sensor 5 is designed to detect a second light beam reflected back from an external object 7 arranged between the controllable deflection device 16 and the first deflection unit 10. The computing unit 13 is designed to detect the object 7 as a function of the reflected second light beam.

[0015] In the illustrated embodiment, the controllable deflection device 16 is formed from a first micromirror 3 mounted so as to be rotatable about a first axis of rotation and from a second micromirror 4 mounted so as to be rotatable about a second axis of rotation. The first axis of rotation is arranged substantially perpendicular to the second axis of rotation. The first micromirror 3 is designed to be rotated about the first axis of rotation at a first frequency, in particular a first rotational frequency. The second micromirror 4, in turn, is designed to be rotated about the second axis of rotation at a second frequency, in particular a second rotational frequency. The first frequency is significantly greater than the second frequency. The laser feedback interferometry sensor 5 is designed to emit the second light beam 12, in particular directly, onto the second micromirror 4.In this context, the laser feedback interferometry sensor 5 is arranged directly adjacent to the second micromirror 4. The second micromirror 4, in turn, is designed to deflect the second light beam 12 onto the object 7 arranged between the controllable deflection device 16 and the first deflection unit 10.

[0016] As on Fig. 1, first light rays 8 are reflected by the external object 7 in the direction of the eye 9. This direct reflection in the direction of the eye can have negative health consequences for the eye 9. In this exemplary embodiment, the computing unit 13 is designed to deactivate the project unit 14 depending on the detected object. In particular, the computing unit 13 is designed to deactivate the time-modulatable light source 2.

[0017] In this case, the data glasses 1a further comprise an additional second sensor 17, which is embodied as a further laser feedback interferometry sensor. The second sensor 17 is designed to detect contact of the data glasses 1a with the skin, in particular the scalp, of the user and / or a distance of the second sensor 17 from the user's head. The computing unit 13 is in turn designed to determine a, in particular current, wearing state of the data glasses 1a from the sensor data acquired by the second sensor 17.

[0018] Furthermore, the data glasses 1a optionally have an exit window 6 for the exit of the first 11 and / or second light beam 12 from the temple 15. The exit window 6 can be designed as a glass window, in particular a transparent one. Alternatively, the exit window 6 is designed as a segmented lens.

[0019] Furthermore, in this exemplary embodiment, the computing unit 13 serves to determine distance values ​​of the object 7 relative to the laser feedback interferometry sensor 5 as a function of the at least one reflected second light beam. Fig. In this context, Figure 2 shows the objects detected by the laser feedback interferometry sensor 5. The distance relative to the laser feedback interferometry sensor 5 is plotted on the X-axis 21 of the diagram shown. The scanning angle of the second micromirror 4 is plotted on the Y-axis 20. First, first distance values ​​22 to the external object 7 are detected. In this case, the external object 25 is a mirror. Furthermore, the first deflection unit 10 is detected at a more distant second distance 23. The eye 9 is then detected at an even more distant third distance 25. The area 24 is intended to represent an example of a shadow in the distance detection that occurs if a detected object absorbs light and thus objects behind it cannot be detected or can only be partially detected.

[0020] Fig. 3 shows a detail of a second embodiment of data glasses 1b. In contrast to the first embodiment, the external object 31 is arranged on a side of a first deflection unit 34 facing away from the eye of the user of the data glasses 1b (not shown here for simplicity). Such an object 31 can also impair the user's eye safety by reflecting a laser beam back to the user's eye. Such an object 31 can also disrupt the beam path for image projection. In this context, the data glasses 1b have a second deflection unit 33 in the form of a second holographic optical element. The laser feedback interferometry sensor 30 is designed in this context to emit the second light beam 35 directly onto the second deflection unit 33.The second deflection unit 33 is designed to expand the second light beam 32 behind the second deflection unit 33 in the direction of the object 31 arranged on the side of the first deflection unit 34 facing away from the eye of the user of the data glasses 1b. In this exemplary embodiment, the second deflection unit 33 is designed to expand the second light beam 32 in the direction of the object 31 in the form of discrete points.

[0021] In this exemplary embodiment, too, a computing unit of the data glasses 1b (not shown here for the sake of simplicity) is designed to determine distance values ​​of the object 31 relative to the laser feedback interferometry sensor 30 as a function of at least one reflected second light beam. Fig. In this context, Figure 4 uses a diagram to show the objects detected by the laser feedback interferometry sensor 5. The signal strength is plotted on the Y-axis 40. The distance relative to the laser feedback interferometry sensor 30 is plotted on the X-axis 41 of the diagram shown. The distance values ​​42 represent glass reflections at the second holographic optical element as the second deflection unit 33. The distance values ​​43 represent the detected distance values ​​to the external object 31.

[0022] Fig. Figure 5 shows, using a flowchart, a method for detecting an object arranged between a controllable deflection device and a first deflection unit of data glasses on a side of the first deflection unit facing away from the eye of the user of the data glasses. The data glasses are, in particular, data glasses as shown in Fig. 1 or Fig.3. In a method step 100, a first light beam, in particular visible to the user of the data glasses, is emitted by means of a temporally modulated light source of a projector unit of the data glasses. In a subsequent method step 110, the first light beam, in particular in the form of an image content, is projected onto the first deflection unit, in particular a first holographic optical element, of the data glasses, by means of the controllable deflection device of the projector unit of the data glasses. In a further method step 120, the projected image content is deflected onto one eye of the user by means of the first deflection unit. In a subsequent method step 130, a second modulated light beam, in particular an infrared one, is emitted by means of a laser feedback interferometry sensor of the data glasses.In a subsequent method step 140, the second light beam reflected back by the object, in particular an external one, arranged between the controllable deflection device and the first deflection unit is detected by the laser feedback interferometry sensor. Optionally, in method step 140, the second light beam reflected back by the object, in particular an external one, arranged on the side of the first deflection unit facing away from the eye of the data glasses user is detected by the laser feedback interferometry sensor. In a subsequent method step 180, the object is then detected by a computing unit of the data glasses based on the reflected second light beam. The method is then terminated.

[0023] Optionally, distance values ​​to objects, in particular external objects, relative to the laser feedback interferometry sensor are further determined by means of the computing unit as a function of the at least one reflected second light beam. In this context, in a method step 150 following method step 140, first distance values ​​of components of the data glasses, in particular the first deflection unit, or of an eye of the user relative to the laser feedback interferometry sensor are optionally determined by means of the computing unit at a first point in time. This method step corresponds to a first calibration step of the data glasses. In a subsequent method step 160, second distance values ​​are determined by means of the computing unit at a second point in time following the first point in time. In a subsequent method step 170, the first distance values ​​are compared with the second distance values.If no differences are detected that could indicate an external object, the process starts again. However, if a difference is detected during the comparison that could indicate an external object, the process continues with step 180.

[0024] In an optional method step 190 following method step 180, the projector unit, in particular the temporally modulatable light source, is switched off by the computing unit if an external object has been detected. The object is, in particular, a prism, a lens, or a spectacle lens.

Claims

[1] Data glasses (1a, 1b) designed for a virtual retinal display (retinal scan display) of a user of the data glasses (1a, 1b), the data glasses (1a, 1b) comprising - a projector unit (14) with a time-modulatable light source (2) for generating at least one first light beam (8, 11), in particular visible to the user, and with a controllable deflection device (16) for the at least one first light beam (8, 11) for scanning projection of an image content, - a first deflection unit (10, 34), in particular a first holographic optical element, onto which the image content is projected and which directs the projected image content onto an eye (9) of a user, - at least one laser feedback interferometry sensor (5, 30) arranged in or on the data glasses (1a, 1b), wherein the laser feedback interferometry sensor (5, 30) is designed to emit a second modulated light beam (12, 32, 35), in particular an infrared one, and - a computing unit (13) characterized by that the laser feedback interferometry sensor (5, 30) is designed to receive a - between the controllable deflection device (16) and the first deflection unit (10), or - to detect a second light beam reflected back from an object (7, 31) arranged on a side of the first deflection unit (10) facing away from the eye (9) of the user of the data glasses (1a, 1b), in particular an external one, and the computing unit (13) is designed to detect the object (7) as a function of the reflected back second light beam. [2] Data glasses (1a, 1b) according to claim 1, characterized byin that the controllable deflection device (16) is formed from a first micromirror (3) mounted so as to be rotatable about a first axis of rotation and from a second micromirror (4) mounted so as to be rotatable about a second axis of rotation, wherein the first axis of rotation is arranged substantially perpendicular to the second axis of rotation, wherein the first micromirror (3) is designed to be rotated about the first axis of rotation at a first frequency, in particular a first rotational frequency, wherein the second micromirror (4) is designed to be rotated about the second axis of rotation at a second frequency, in particular a second rotational frequency, wherein the first frequency is greater, in particular significantly greater, than the second frequency, wherein the laser feedback interferometry sensor (5, 30) is designed to emit the second light beam, in particular directly, onto the second micromirror (4), wherein the second micromirror (4) is designed to direct the second light beam (12, 32,35) onto the object (7) arranged between the controllable deflection device (16) and the first deflection unit (10). [3] Data glasses (1a, 1b) according to claim 1, characterized by in that the data glasses (1a, 1b) have a second deflection unit (33), in particular a second holographic optical element, wherein the laser feedback interferometry sensor (5, 30) is designed to emit the second light beam (12, 32, 35), in particular directly, onto the second deflection unit (33), wherein the second deflection unit (33) is designed to widen the second light beam (12, 32, 35) in the direction of the object (7, 31) arranged on the side of the first deflection unit (10) facing away from the eye (9) of the user of the data glasses (1a, 1b). [4] Data glasses (1a, 1b) according to claim 3, characterized byin that the second deflection unit (33) is designed to widen the second light beam (12, 32, 35) in a line shape or in the form of discrete points in the direction of the object (7, 31) arranged on the side of the first deflection unit (10, 34) facing away from the eye (9) of the user of the data glasses (1a, 1b). [5] Data glasses (1a, 1b) according to one of claims 1 to 4, characterized by that the computing unit (13) is designed to switch off the project unit (14), in particular the time-modulatable light source (2), depending on the detected object (7, 31). [6] Data glasses (1a, 1b) according to one of claims 1 to 5, characterized by in that the computing unit (13) is designed to determine distance values (22, 23, 25, 42, 43), in particular of the object (7, 31) relative to the laser feedback interferometry sensor (5, 30), as a function of the at least one reflected second light beam. [7] Data glasses (1a, 1b) according to one of claims 1 to 6, characterized by in that the data glasses (1a, 1b) have at least one additional second sensor (17), in particular a further laser feedback interferometry sensor, wherein the second sensor (17) is designed to detect contact of the data glasses (1a, 1b) with the skin, in particular scalp, of the user and / or a distance of the second sensor (17) from the head of the user, wherein the computing unit (13) is designed to determine a, in particular current, wearing state of the data glasses (1a, 1b) from the detected sensor data of the second sensor (17). [8] Method for detecting an object (7, 31) arranged between a controllable deflection device (16) and a first deflection unit (10) of data glasses (1a, 1b), in particular data glasses (1a, 1b) according to one of claims 1 to 7, or on a side of the first deflection unit (10) facing away from the eye (9) of the user of the data glasses (1a, 1b), the method comprising the following method steps: - emitting (100) a first light beam (8, 11), which is particularly visible to the user of the data glasses (1a, 1b), by means of a time-modulatable light source (2) of a projector unit (14) of the data glasses (1a, 1b), and - scanning (110) projection of the first light beam (8, 11), in particular in the form of an image content, onto the first deflection unit (10), in particular a first holographic optical element, of the data glasses (1a, 1b), by means of the controllable deflection device (16) of the projector unit (14) of the data glasses (1a, 1b), and - redirecting (120) the projected image content to one eye (9) of the user by means of the first redirecting unit (10), and - emitting (130) a second modulated light beam (12, 32, 35), in particular an infrared one, by means of a laser feedback interferometry sensor (5, 30) of the data glasses (1a, 1b), - detecting (140) the second light beam reflected back from the object (7, 31) arranged between the controllable deflection device (16) and the first deflection unit (10), or on the side of the first deflection unit (10) facing away from the eye (9) of the user of the data glasses (1a, 1b), in particular an external object, by means of the laser feedback interferometry sensor (5, 30), and - Detection (180) of the object (7, 31) as a function of the reflected second light beam by means of a computing unit (13) of the data glasses (1a, 1b). [9] Method according to claim 8, characterized by that depending on the detected object (7, 31) the projector unit (14), in particular the time-modulatable light source (2), is switched off by means of the computing unit (13). [10] Method according to one of claims 8 or 9, characterized bythat, depending on the at least one reflected second light beam, distance values (22, 23, 25, 42, 43) to objects, in particular external objects, relative to the laser feedback interferometry sensor (5, 30) are determined by means of the computing unit (13). [11] Method according to claim 10, characterized by that the procedure comprises the following additional procedural steps: - determining (150) first distance values of components of the data glasses (1a, 1b), in particular of the first deflection unit (10), or of an eye (9) of the user relative to the laser feedback interferometry sensor (5, 30) by means of the computing unit (130) at a first time, and - comparing (170) second distance values determined (160) at a second time following the first time with the first distance values by means of the computing unit (13), and - Detection (180) of the object (7, 31) depending on the comparison carried out by means of the computing unit (13). [12] Method according to one of claims 8 to 11, characterized by that the detected object (7, 31) is a prism, a lens or a spectacle lens.

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