TWI622806B - Virtual reality display apparatus - Google Patents

Abstract

A virtual reality display device includes at least a display module, an image sensor, and an adjustment mechanism. The display module includes a display and an optical component. The display is used to provide an image beam to a user's eyes. The optical component is disposed on the transmission path of the image beam and includes at least one Fresnel lens, wherein the optical component has an optical center. The image sensor is used to measure an offset distance of the user's eyes from the optical center. The adjustment mechanism is connected to the display and the optical component to adjust the tilt angle of the display relative to the optical component. The display and the optical components are inclined relative to the eyes of the user.

Description

Virtual reality display device

The present invention relates to a display device, and more particularly to a virtual reality display device.

With the advancement of display technology, in order to pursue the immersive feeling, users are no longer satisfied with watching only flat images. In order to provide users with more realistic and three-dimensional visual entertainment, virtual reality (VR) ) Has become a new trend of current display technology. Virtual reality can use a virtual scene that simulates a three-dimensional space to provide users with visual and other sensory experiences. They can instantly view images in three-dimensional space and even interact with virtual images.

A common virtual reality display device includes a head mounted display (HMD), which can be worn on a user's head. However, in order to make head-mounted displays to be thin, light, and short, and to make head-mounted displays with larger viewing angles, stereoscopic imbalances in images tend to occur. For example, the sharpness of an image seen when the user's line of sight looks straight ahead may be lower than the sharpness of an image seen when the user's line of sight is squinted to both sides. Or, when the user's eyes turn to the left or right, the phenomenon that one eye sees a clearer image and the other eye sees a more blurred image may occur. These three-dimensional imbalances can make users feel uncomfortable or have poor visual effects when using a head-mounted display.

The invention provides a virtual reality display device, which can effectively achieve the stereoscopically balanced visual effect.

An embodiment of the present invention provides a virtual reality display device including at least one display module, an image sensor, and an adjustment mechanism. The display module includes a display and an optical component. The display is used to provide an image beam to a user's eyes. The optical component is disposed on the transmission path of the image beam and includes at least one Fresnel lens, wherein the optical component has an optical center. The image sensor is used to measure an offset distance of the user's eyes from the optical center. The adjustment mechanism is connected to the display and the optical component to adjust the tilt angle of the display relative to the optical component. The display and the optical components are inclined relative to the eyes of the user.

In the virtual reality display device according to the embodiment of the present invention, an image sensor can be used to measure an offset distance of the user's eyes from the optical center, and the adjustment mechanism can be used to adjust the display relative to the optical component. Therefore, the virtual reality display device according to the embodiment of the present invention can effectively achieve a stereoscopically balanced visual effect.

In order to make the above features and advantages of the present invention more comprehensible, embodiments are hereinafter described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of a virtual reality display device according to an embodiment of the present invention, and FIG. 2 illustrates a situation in which a user views the virtual reality display device of FIG. 1 at different viewing angles. Please refer to FIGS. 1 and 2. The virtual reality display device 100 of this embodiment includes at least one display module 200 (two display modules 200 a and 200 b are taken as an example in FIG. 1), an image sensor 110, and One adjustment mechanism 120. Each display module 200 includes a display 210 and an optical component 220. The display 210 is used to provide an image beam 212 to a user's eye 50. In this embodiment, the display 210 is, for example, a liquid crystal display, an organic light emitting diode display, a light emitting diode display, or other appropriate displays.

The optical component 220 is disposed on the transmission path of the image light beam 212 and includes at least one Fresnel lens 222 (in the figure, two Fresnel lenses 222 arranged in parallel are taken as an example). The optical component 220 has an optical center C, which is the intersection of the optical axis of the optical component 220 and the surface 221 of the optical component 220 facing the eye 50. In this embodiment, both Fresnel lenses 222 are flat plates, and have Fresnel surfaces 225 and 227 and planar surfaces 221 and 223.

The image sensor 110 is used to measure an offset distance D1 of the user's eye 50 relative to the optical center C. In this embodiment, the image sensor 110 is, for example, an eye tracker. In addition, in this embodiment, the offset distance D1 refers to the distance from the intersection point S of the front line of sight 50 of the eye 50 (see the line of sight when the line of sight angle is 0 degrees) and the surface 221 to the optical center C. In addition, the adjustment mechanism 120 is connected to the display 210 and the optical component 220 to adjust the inclination angle θ3 of the display 210 with respect to the optical component 220. Furthermore, the display 210 and the optical component 220 are inclined relative to the user's binocular connection L. For example, the display 210 is inclined by an inclination angle θ1 relative to the connection line L, the optical component 220 is inclined by an inclination angle θ2 relative to the connection line L, and θ3 = θ1-θ2. In this embodiment, the tilt angle θ1 is, for example, greater than 23 degrees and less than or equal to 29 degrees, the tilt angle θ2 is, for example, 23 degrees, and the tilt angle θ1 is greater than the tilt angle θ2. The direction of the line of sight when the line of sight angle is 0 degrees, that is, the direction perpendicular to the line L.

In this embodiment, the adjusting mechanism 120 may include a gear, a rack, a slide rail, a screw, a spring, other appropriate mechanical elements or a combination thereof. Any mechanical element or a combination thereof capable of adjusting the inclination angle θ3 may be used for adjustment. Components of the mechanism 120. In one embodiment, the user can manually adjust the tilt angle θ3 to an appropriate value according to the magnitude of the offset distance D1 measured by the image sensor 110. At this appropriate value, the sharpness of the image displayed by the display 210 seen by the user's eyes 50 looking straight ahead (that is, when the line of sight angle is 0 degrees in FIG. 2) is better than that of the user's eyes 50 on either side. The sharpness of the image displayed on the display 210 when viewed from one side (for example, when the sight angle is either 23 degrees or -23 degrees in FIG. 2).

FIG. 3A to FIG. 3C are modulation transfer functions (MTF) and tilts of the image when the offset distance D1 in FIG. 1 is 2 millimeters (mm), 3 mm, and 4 mm, respectively. The relationship curve of the angle θ3, and FIGS. 4A to 4C are the spot diagrams of the images seen at each viewing angle when the offset distance D1 of FIG. 1 is 2 mm, 3 mm, and 4 mm, respectively. 3A to 4C are simulated under the condition that the back focal length (BFL) of the optical component 220 is 38 mm. It can be seen from FIG. 3A and FIG. 4A that when the offset distance D1 is 2 mm, the user can adjust the tilt angle θ3 to about 3 degrees. At this time, the value of the modulation conversion function is the largest when the line of sight angle is 0 degrees ( (As shown in Figure 3A), and is greater than the modulation conversion function seen at other viewing angles (such as 23 degrees, -23 degrees, and -45 degrees), that is, the image seen when the viewing angle is 0 degrees is the clearest , And at this time (that is, the inclination angle θ3 is about 3 degrees), the light spot radius is also at a minimum value when the line-of-sight angle is 0 degrees (see FIG. 4A), which can verify that the image is clearest at this time. In addition, it can be seen from FIG. 3B and FIG. 4B that when the offset distance D1 is 3 mm, the user can adjust the tilt angle θ3 to about 4 degrees. At this time, the value of the modulation conversion function when the line of sight angle is 0 degrees is The largest (as shown in Figure 3B) and greater than the modulation conversion function seen at other viewing angles (such as 23 degrees, -23 degrees, and -45 degrees), that is, the image seen when the viewing angle is 0 degrees It is the clearest, and at this time (that is, the inclination angle θ3 is about 4 degrees), the light spot radius is also at a minimum value when the line-of-sight angle is 0 degrees (see FIG. 4B), which can verify that the image is the clearest at this time. On the other hand, it can be seen from FIGS. 3C and 4C that when the offset distance D1 is 4 mm, the user can adjust the tilt angle θ3 to about 4.5 degrees. At this time, the modulation conversion function of the line of sight angle is 0 degrees. The value is the largest (as shown in Figure 3C), and is greater than the modulation conversion function seen at other viewing angles (such as 23 degrees, -23 degrees, and -45 degrees), that is, when the viewing angle is 0 degrees The clearest image is the clearest. At this time (that is, the inclination angle θ3 is about 4.5 degrees), the radius of the light spot is also at a minimum value when the line-of-sight angle is 0 degrees (see Figure 4C). It can be verified that the image is the clearest at this time.

It can be known from the above-mentioned optical simulation that the larger the offset distance D1 is, the larger the user adjusts the tilt angle θ3 to a proper value.

In this embodiment, in order to make it more convenient for the user, the tilt angle θ3 can be adjusted by an automatic adjustment method. Specifically, in this embodiment, the virtual reality display device 100 further includes a controller 130, which is electrically connected to the image sensor 110 and the adjustment mechanism 120, and is configured to instruct the adjustment mechanism 120 to change the distance according to the offset distance D1. The inclination angle θ3 of the display 210 with respect to the optical component 220 is adjusted to an appropriate value. Under the appropriate value, the sharpness of the image displayed by the user's eyes 50 when looking directly at the front of the display 210 is better than the user's eyes 50. The sharpness of the image displayed on the display 210 when looking obliquely to either of the two sides, and this appropriate value may be the same as the appropriate value of the manual adjustment tilt angle θ3 described above. In this embodiment, the adjustment mechanism 120 includes an actuator 122 in addition to the above-mentioned mechanical elements, and the controller 130 is electrically connected to the image sensor 110 and the actuator 122, and is configured to be based on the offset distance. D1 controls the operation of the actuator 122. Specifically, the controller 130 may instruct the actuator 122 to operate according to the offset distance D1, so that the adjustment mechanism 120 adjusts the inclination angle θ3 to the above-mentioned appropriate value. In the present embodiment, the actuator 122 is, for example, a motor or other suitable actuator. In addition, in this embodiment, the controller 130 may also determine or calculate the offset distance D1 according to the image signal of the eye 50 transmitted from the image sensor 110.

In this embodiment, there are two display modules 200, that is, the display module 200a and the display module 200b, and the two displays 210 of the two display modules 200a and 200b provide two image light beams 212 to the left eye of the user, respectively. 50a and right eye 50b, and the adjustment mechanism 120 is adapted to adjust the distance D2 between the two display modules 200 to suit the different distance D3 of the pupils of the two eyes, that is, the pupil 52 of the left eye 50a to the right eye 50b The distance of the pupil 52. In this embodiment, the distance D3 of the pupils of the eyes of the user is smaller than the distance D4 of the two optical centers C of the two optical components 220 of the two display modules 200a and 200b.

In the virtual reality display device 100 of this embodiment, an image sensor 110 can be used to measure an offset distance D1 of the user's eye 50 from the optical center C, and the adjustment mechanism 120 can be used to adjust the display accordingly. The inclination angle θ3 of 210 with respect to the optical component 220. Therefore, the virtual reality display device 100 of this embodiment enables the user's eyes 50 to look directly at the display 210 seen in front of the display. The sharpness of the image displayed by the display 210 is better than that of the user's eyes. The sharpness of the image displayed on the display 210 when seen from one side to the other side 50 can effectively achieve the stereoscopically balanced visual effect.

In this embodiment, the controller 130 is used to instruct the adjusting mechanism 120 to adjust the two displays 210 of the two display modules 200a and 200b respectively according to the rotation positions of the left eye 50a and the right eye 50b detected by the image sensor 110. The two inclination angles θ3 of the two optical components 220 are adjusted to a first appropriate value and a second appropriate value, respectively. Under the first appropriate value and the second appropriate value, the left eye 50a and the right eye 50b are in this rotation position. The difference in sharpness of the images displayed by the two monitors 210 respectively seen is narrowed. For example, in this embodiment, at the first proper value and the second proper value, the modulation conversion functions of the images displayed by the two displays 210 seen by the left eye 50a and the right eye 50b at this rotation position are The gap is less than 0.1. That is, the controller 130 may find two values corresponding to the modulation conversion functions of the two eyes that are close to each other according to the sight angles of the left eye 50a and the right eye 50b according to the optical simulation data (such as the data shown in FIGS. 3A to 4C). The first appropriate value and the second appropriate value of the inclination angles θ3. In this way, no matter which direction the user's left eye 50a and right eye 50b turn, the two inclination angles θ3 will be adjusted correspondingly, so that both eyes can see a similarly sharp image, thereby achieving a better stereo Balance visual effects. In another embodiment, the controller 130 can also find the first proper value and the second proper value of the two tilt angles θ3 when the left eye 50a and the right eye 50b rotate to a certain angle by looking up a table. And the command adjustment mechanism 120 adjusts the two tilt angles θ3 to the first appropriate value and the second proper value, respectively. The value table used in this table lookup method can be completed by experimental settings before leaving the factory or calibrated before use. The value table can be stored in a data storage medium for the controller 130 to read. The numerical table may include the correspondence between the sight angles of the left eye 50a and the right eye 50b and the first appropriate value and the second appropriate value.

In one embodiment, the controller 130 is, for example, a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a programmable controller, and a programmable The present invention is not limited to a logic device (programmable logic device, PLD) or other similar devices or a combination of these devices. In addition, in one embodiment, each function of the controller 130 may be implemented as a plurality of codes. The codes are stored in a memory, and the controller 130 executes the codes. Alternatively, in one embodiment, the functions of the controller 130 may be implemented as one or more circuits. The present invention is not limited to implementing the functions of the controller 130 by means of software or hardware.

In summary, in the virtual reality display device according to the embodiment of the present invention, an image sensor can be used to measure an offset distance of the user's eyes from the optical center, and the adjustment mechanism can be used to adjust accordingly. The inclination angle of the display relative to the optical component, so the virtual reality display device of the embodiment of the present invention can effectively achieve the stereoscopically balanced visual effect.

Although the present invention has been disclosed as above with the examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some modifications and retouching without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be determined by the scope of the attached patent application.

50‧‧‧ eyes
50a‧‧‧left eye
50b‧‧‧right eye
52‧‧‧ Pupil
100‧‧‧Virtual Reality Display Device
110‧‧‧Image Sensor
120‧‧‧ adjustment agency
122‧‧‧Actuator
130‧‧‧controller
200, 200a, 200b‧‧‧ display module
210‧‧‧ Display
212‧‧‧Image Beam
220‧‧‧Optical components
221, 223‧‧‧ surface
222‧‧‧ Fresnel lens
225, 227‧‧‧ Fresnel surface
C‧‧‧Optical Center
D1‧‧‧Offset distance
D2, D3, D4‧‧‧ distance
L‧‧‧ Connect
S‧‧‧ meeting point θ1, θ2, θ3‧‧‧ tilt angle

FIG. 1 is a schematic cross-sectional view of a virtual reality display device according to an embodiment of the present invention. FIG. 2 illustrates a situation in which a user views the virtual reality display device of FIG. 1 at different viewing angles. FIG. 3A to FIG. 3C are graphs showing the relationship between the modulation conversion function and the tilt angle θ3 of the image when the offset distance D1 in FIG. 1 is 2 mm, 3 mm, and 4 mm, respectively. FIGS. 4A to 4C are graphs showing the relationship between the light spot radius and the inclination angle θ3 in the light spot image of the image when the offset distance D1 of FIG. 1 is 2 mm, 3 mm, and 4 mm, respectively. .

Claims (10)

A virtual reality display device includes: at least one display module including: a display for providing an image beam to a user's eyes; and an optical component disposed on a transmission path of the image beam and including At least one Fresnel lens, wherein the optical component has an optical center; an image sensor for measuring an offset distance of the eye of the user relative to the optical center; and an adjustment mechanism connected to The display and the optical component are used to adjust an inclination angle of the display with respect to the optical component, and both the display and the optical component are inclined relative to the eyes of the user. The virtual reality display device described in item 1 of the patent application scope further includes a controller, which is electrically connected to the image sensor and the adjustment mechanism, and is configured to instruct the adjustment mechanism to change the distance according to the offset distance. The tilt angle of the display with respect to the optical component is adjusted to an appropriate value, where the user ’s eyes look directly in front of the display and the sharpness of the image displayed by the display is better than the user ’s eyes The sharpness of the image displayed by the monitor when looking sideways at either side. The virtual reality display device according to item 2 of the scope of patent application, wherein the larger the offset distance is, the larger the appropriate value is. According to the virtual reality display device described in item 1 of the patent application scope, wherein the at least one display module is a two display module, and the two displays of the two display modules respectively provide two image beams to the left eye of the user and For the right eye, the virtual reality display device further includes a controller, which is electrically connected to the image sensor and the adjustment mechanism, and is configured to be based on the left eye and the right eye detected by the image sensor. The rotation position commands the adjustment mechanism to adjust the two tilt angles of the two displays of the two display modules with respect to the two optical components to a first appropriate value and a second appropriate value, respectively. With the second appropriate value, the difference between the sharpness of the images displayed by the two displays as seen by the left eye and the right eye at the rotation position is reduced. The virtual reality display device according to item 4 of the scope of patent application, wherein under the first appropriate value and the second appropriate value, the two displays that the left eye and the right eye respectively see in the rotation position The difference between the modulation transfer functions of the displayed image is less than 0.1. The virtual reality display device according to item 4 of the scope of patent application, wherein the controller finds the first and second eye positions based on the rotation positions of the left eye and the right eye detected by the image sensor by means of a table lookup. An appropriate value and the second appropriate value. According to the virtual reality display device described in item 1 of the patent application scope, wherein the at least one display module is a two display module, and the two displays of the two display modules respectively provide two image beams to the left eye of the user and For the right eye, the adjustment mechanism is adapted to adjust the distance between the two display modules to adapt to different binocular pupil distances of different users. The virtual reality display device according to item 1 of the scope of patent application, wherein the image sensor is an eye tracker. According to the virtual reality display device described in item 1 of the patent application scope, wherein the at least one display module is a two display module, and the two displays of the two display modules respectively provide two image beams to the left eye of the user and In the right eye, the distance between the pupils of the eyes of the user is smaller than the distance between the two optical centers of the two optical components of the two display modules. The virtual reality display device according to item 1 of the patent application scope, wherein the adjustment mechanism includes an actuator, and the virtual reality display device further includes a controller electrically connected to the image sensor and the actuation. And is used to control the operation of the actuator according to the offset distance.