Patent Publication Number: US-11657782-B2

Title: Display apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. application Ser. No. 16/136,268 filed on Sep. 20, 2018, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure is related to a display apparatus, and more particularly, to a display apparatus capable of displaying images showing different colors and/or light intensities at different viewing angles. 
     2. Description of the Prior Art 
     As the display apparatus being adopted in more and more applications, the requirement for better visual effects is also raised. For example, high dynamic range (HDR) displays have been developed to show high contrast images so the details in both the bright portion and the dark portion of an image can be seen. Although the HDR display is able to show images with greater brightness contrast and delivers better visual effects than the traditional display apparatus, the HDR display still has difficulty in showing the real light shining effects. 
     SUMMARY OF THE DISCLOSURE 
     One embodiment of the present disclosure discloses a display apparatus including a first pixel array, an optical modulator, a controller and at least one memory device. The optical modulator is disposed on the first pixel array and used to modulate light emitted from the first pixel array to corresponding angles. The controller is used to generate images of a scene with different lighting profiles corresponding to different viewing angles. The at least one memory device stores a frame memory including color information and material information of objects in the scene. The controller generates the images according to the frame memory. The display apparatus displays the images through the first pixel array at a same time. 
     Another embodiment of the present disclosure discloses a method for operating a display apparatus, the display apparatus comprising a first pixel array, an optical modulator, a controller, and at least one memory device. The method includes storing a frame memory to at least one memory device, the frame memory comprising color information and material information of objects in a scene; the controller generating images of the scene with different lighting profiles corresponding to different viewing angles according to at least information stored in the frame memory; the display apparatus displaying the images through the first pixel array at a same time; and the optical modulator modulating light emitted from the first pixel array to corresponding angles. 
     These and other objectives of the present disclosure will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a display apparatus according to one embodiment of the present disclosure. 
         FIG.  2    shows a viewing scenario of the display apparatus in  FIG.  1   . 
         FIG.  3    shows the specular light reflection on an object of the scene displayed by the display apparatus in  FIG.  1   . 
         FIG.  4    shows the specular light reflection profile corresponding to different materials. 
         FIG.  5    shows the data structure of the frame memory according to one embodiment of the present disclosure. 
         FIGS.  6 A- 6 E  shows the images of a static scene of the display apparatus of  FIG.  1    from five viewing angles according to one embodiment of the present disclosure. 
         FIG.  7    shows a display apparatus according to another embodiment of the present disclosure. 
         FIG.  8    shows the usage scenario of the scan system of  FIG.  7   . 
         FIG.  9    shows a scan system according to another embodiment of the present disclosure. 
         FIG.  10    shows a flow chart of a method for operating the display apparatus of  FIG.  1    in accordance with one embodiment of the present disclosure. 
         FIG.  11    shows a flow chart of a method  500  for operating the display apparatus of  FIG.  7    in accordance with one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The terms “about” and “substantially” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “substantially” can mean within one or more standard deviations, or within .+−0.20%, .+−0.15%, .+−0.10%, .+−0.5%, .+−0.3% of the stated value. It is noted that the term “same” may also refer to “about” because of the process deviation or the process fluctuation. 
     It should be noted that the elements or devices in the drawings of the present disclosure may be present in any form or configuration known to those skilled in the art. In addition, the expression “a layer is disposed above another layer”, “a layer is disposed on another layer” and “a layer is disposed over another layer” may indicate that the layer is in direct contact with the other layer, or that the layer is not in direct contact with the other layer, there being one or more intermediate layers disposed between the layer and the other layer. 
     One advantage of the display apparatus of the present disclosure is showing the real light shining effect in a static scene. To show the real light shining effects, people may see different lighting profiles on the same object when watching the display from different viewing positions. For example, some objects, such as the butterfly wings and the bubbles, can scatter the light and produce structural colors. In this case, people may see different colors and/or light intensities when looking at the object from different positions. However, the conventional display can only show unchanged reflection profile of a static scene corresponding to different viewing angles. 
       FIG.  1    shows a display apparatus  100  according to one embodiment of the present disclosure. The display apparatus  100  includes a public information display apparatus, an automobile display apparatus, a business exhibition display apparatus, or other suitable display apparatus. The display apparatus  100  includes a first pixel array  110 , an optical modulator  120 , and a controller  130 . 
     In some embodiments, the first pixel array  110  can generate different grey levels of colors to display images. The first pixel array  110  may include a display medium. For example, the display medium may include a liquid crystal, a light-emitting diode (LED), an organic light-emitting diode (OLED), a mini light-emitting diode, a micro light-emitting diode, a quantum dot, a fluorescence, a phosphor, a display medium of other kinds, or a combination thereof. However, the present disclosure is not limited thereto. In some other embodiments, the first pixel array  110  may use other types of pixel array to display the images according to the system requirement. 
     In some examples, the optical modulator  120  is disposed on the first pixel array  110 , and may be able to modulate the light emitted from the first pixel array  110  to corresponding angles. The optical modulator  120  can be, for example but not limited to, lenticular lens, liquid crystal (LC) grin lens, parallax barrier, LC parallax barrier, or other suitable optical components that can modulate the light. 
     With the optical modulator  120 , the light emitted by at least a portion of the pixels in the first pixel array  110  can be modulated to different viewing angles. For example,  FIG.  2    shows a viewing scenario of the display apparatus  100 . In  FIG.  2   , the light emitted by the pixels PA 1 , PA 2 , and PA 3  may be modulated to the same viewing region A while the light emitted by the pixels PB 1 , PB 2 , and PB 3  may be modulated to the same viewing region B. Therefore, when viewing the display apparatus  100 , the eyes of the viewer watching the display apparatus  100  at the viewing region A will see the image displayed by the pixels PA 1 , PA 2 , and PA 3 , and the eyes of the viewer watching the display apparatus  100  at the viewing region B will see the image displayed by the pixels PB 1 , PB 2 , and PB 3 . 
     The controller  130  can generate the images for the same scene with different lighting profiles (e.g. colors and/or light intensities) corresponding to different viewing angles, and the display apparatus  100  will display the images through the first pixel array  110  at the same time. That is, the images generated by the controller  130  can be corresponding to the same scene with the same objects but with different lighting profiles corresponding to different viewing angles, so the viewer will see the same objects with different lighting profiles in different viewing angles, simulating the real shining effects and improving the visual effects. 
     For example, in reality, the intensity of reflected light received by the viewer is varied with the viewing angles, and the variance of light intensity may have a sharper peak if the object has a smoother surface. That is, if the object is made by metal and has a smoother surface, the reflected light may only be seen from a narrow scope of viewing angles. With the display apparatus  100 , the viewer may only see the reflection when he/she enters that scope of viewing angles. Therefore, the realistic lighting effects can be simulated by the display apparatus  100 , providing the desired visual effect. 
     In  FIG.  1   , the display apparatus  100  may further include a second pixel array  140 . In this case, the optical modulator  120  can be disposed between the first pixel array  110  and the second pixel array  140 . The second pixel array  140  can further modulate the light passing through the optical modulator  120 ; therefore, the resolution of the image can be further improved. In some embodiments, some of the layers (e.g. polarizers) of the first pixel array  110  and some of the layers of the second pixel array  140  can be disposed in a crossing manner to reduce the Moiré effect. In some examples, the optical modulator  120  may be disposed in a slanting manner to the first pixel array  110  and/or the second pixel array  140 . 
     In some embodiments, one of the first pixel array  110  and the second pixel array  140  may include a color filter layer. For example, the first pixel array  110  can display the images with single-colored grey levels (e.g. monochrome), and the second pixel array  140  can display the images with multiple-colored grey levels. That is, the first pixel array  110  may be used to control the brightness distribution and the second pixel array  140  may be used to control the color distribution. However, in some other embodiments, the first pixel array  110  may display the images with multiple-colored grey levels, and the second pixel array  140  may display the images in monochrome. Furthermore, the display device  100  may also omit the second pixel array  140  in some other embodiments. 
     Also, to generate the images with different lighting profiles corresponding to different viewing angles, the display apparatus  100  also needs the information of the object(s) in the scene. Therefore, as shown in  FIG.  1   , in one embodiment, the display apparatus  100  may also include at least one memory device  135  to store the information of a light map  150 , a view map  160 , and a frame memory  170 . The controller  130  can generate the images according to the information of the light map  150 , the view map  160 , and the frame memory  170 . 
     The information of the light map  150  may include the intensities and locations of the light in the ambient environment for viewing the scene. In some embodiments, the light map  150  may be an image showing the existence of all surrounding light. In the light map  150 , the intensity of the light at each spatial location can be recorded in the corresponding pixel of the image. 
     In some embodiments, the light map can be designed by the computer graphic (CG) rendering software, and the light map  150  can be generated by the CG rendering software as well. However, in some other embodiments, the display apparatus  100  may further include a light capturing device  190  to generate the information to be stored in the light map  150  of the real viewing environment. For example, the light capturing device  190  can be a fisheye camera and can record the intensities and the locations of the light in the ambient environment for generating the light map. The light map  150  can be stored in a fisheye format, an equi-rectangular format, or a cubical format. 
     The information of the view map  160  may include the viewing vectors of at least a portion of pixels in the first pixel array  110 . In some examples, the viewing vector may include the information of the light path emitted from a pixel through the optical modulator  120 . For example, in  FIG.  2   , the light path may be denoted as a viewing direction, the viewing directions VA 1 , VA 2 , VA 3  of the pixels PA 1 , PA 2 , and PA 3  would be recorded in the view map  160 . In some embodiments, the viewing directions VA 1 , VA 2 , and VA 3  can be stored in forms of vectors or in forms of vector IDs. In some embodiments, if the lenticular lens is adopted as the optical modulator  120 , the viewing vector may be a 1 dimensional value representing the viewing angles on the same plane as the objects. In this case, the view map  160  can be corresponding to at least a portion of the pixels in the first pixel array  110 , and the value of the pixel in the view map  160  would be the 1 dimensional value of the viewing angle. In other examples, the viewing vector may be a 2 dimensional value and may be shown as (x, y). It may depend on the optical modulator used in the display apparatus. 
     Also, since the viewing vectors of the pixels are related to the modulation caused by the optical modulator  120 , the viewing vectors of the pixels may be known factors to the display apparatus  100  when the parameters of the optical modulator  120  are determined, and thus viewing vectors can be preliminarily saved in the memory during manufacturing. However, in some other embodiments, the viewing vectors can also be derived by measurement. In this case, the inaccuracy caused during manufacturing can be calibrated, thereby improving the accuracy. 
     The information of the frame memory  170  may include the color information, the material information and the position information of the objects in the scene. In examples, the frame memory  170  may include a format of the input video frame. The light map and the view map may be stored in one memory device, while the frame memory may be stored in another memory device. In some examples, other information may be added into the frame memory  170 . In one embodiment, to render the images into the scene may require the consideration of at least two different types of light, and the at least two different types of light may be the diffused light and the specular light. The diffused light can be seen as the ambient light and can help to show the intrinsic color of the object. In some examples, the diffused light may not be changed when changing the viewing angles. The specular light may be reflected light corresponding to different viewing angles, and the viewer may see different levels (and different colors) of reflected light according to the viewing angles. 
     Since the diffused light is rather straight forward for showing the intrinsic color of the objects, it can be seen as the color information of the object and may be stored in the frame memory  170 . 
     However, deriving the reflection of the specular light may be more complicated.  FIG.  3    shows the specular light reflection on an object O of the scene. In  FIG.  3   , the reflection vector RV can be derived according to the lighting vector LV of the light source and the surface normal vector NV of the object O. In some embodiments, the position information of the objects stored in the frame memory  170  can include the surface normal vector NV of the object O. Also, the lighting vector LV can be generated according to the information stored in the light map. Therefore, with the locations of the light stored in the light map  150  and the surface normal vectors stored in the frame memory  170 , the controller  130  would be able to derive the reflection vectors of specular light. 
     Since the intensities of the reflection can be seen by the viewer are also related to the viewing vector VV and the material of the object O as aforementioned, the controller  130  will further derive intensities of the specular light according to the viewing vectors stored in the view map  150 , the material information of the objects stored in the frame memory  170 , and the reflection vectors of the specular light derived previously. 
       FIG.  4    shows the specular light reflection profile corresponding to different materials. In  FIG.  4   , Y axis represents the intensity of the object O while X axis represents the angle between the reflection vector (e.g. the reflection vector RV) and the viewing vector (e.g. the viewing vector VV). 
     In  FIG.  4   , the material M 1  may have a smooth surface. For example, the material M 1  may be a polished metal. Therefore, the intensity of the reflected light on the surface of the material M 1  may be greater when the angle between the viewing vectors and the reflection vector is rather small, and the intensity distributions are centralized. 
     However, in  FIG.  4   , the material M 2  may have a surface capable of generating the structural light. For example, the material M 2  may be the compact disk (CD), or the butterfly wings. In this case, the intensities of the red reflected light, the green reflected light, and the blue reflected light on the surface of the material M 2  may have different distributions, and, thus, the viewer may see different colors when watching the display apparatus  100  from different position. The material M 3  may be different from the materials M 1  and M 2 . Therefore, the reflection profile is different from the reflection profiles of the materials M 1  and M 2 . 
     Since the calculation for the lighting profile for different materials can be complicated, the display apparatus  100  can store the reflection profiles for different materials in a lookup table in advance in some embodiments. Therefore, the reflection intensity can be derived with the lookup table by inputting the material type, and the angle between the viewing vector and the reflection vector. In some examples, the angle may be a function of the light map, the view map, and the position information. 
     In this case, the material information can be stored as the material ID. That is, different types of materials can correspond to different IDs. With the material ID and the angle between the reflection vector and the viewing vector, the corresponding reflection profile can be retrieved from the lookup table. 
     Consequently, the controller  130  would be able to generate the images of the scene by combining the diffused light effect and the specular light effect according to the color information of the objects and the intensities of the specular light. 
     Since the display apparatus  100  can use the lookup table to retrieve the required reflected lighting profile, the complicated computation can be reduced, thereby allowing the display apparatus  100  to generate the images of the scene for real time video. 
       FIG.  5    shows the data structure of the frame memory  170  according to one embodiment of the present disclosure. In  FIG.  5   , the information stored in the frame memory  170  can be stored by multiple frames F 1  to FM (M is a positive integer greater than 1), each frame corresponding to an image. In this case, the color information of the objects in frame F 1  can be stored with a plurality of pixels PR 1  to PR N  and a plurality of pixels PM 1  to PM N , wherein N is a positive integer greater than 1. At least one of the pixels PR 1  to PR N  includes the intensity of the red sub-pixel (R), the green sub-pixel (G), and the blue sub-pixel (B). Also, the position information and the material information of the objects can also be stored by the format of pixels PM 1  to PM N  in the same frame. In  FIG.  5   , one of the pixel PM 1  to PM N  is corresponding to a pixel of the pixels PR 1  to PR N , and includes the two dimensional normal vector (NX, NY) and the material ID MID. That is, in  FIG.  5   , at least one of the frames may be divided into at least two parts: one for the color information R, G, and B while another one for the normal vectors NX and NY and the material ID MID. However, the present disclosure is not limited by the storing order shown in  FIG.  5   . In some other embodiments, pixels PR 1  to PR N  and pixels PM 1  to PM N  can be stored in a different order, such as interleaving lines, according to the system requirement. 
     Although the reflection profile shown in  FIG.  4    is corresponding to one dimensional angle (along X axis), in some other embodiments, the lookup table can include at least two dimensional table for two dimensional angles. In this case, the anisotropic reflection effect produced by the objects such as the cat eye stone can also be presented by the display apparatus  100 . 
     Furthermore, although the frame memory  170  may store the material IDs and the surface normal vectors for deriving the reflected lighting profile, in some other embodiments, the frame memory  170  may store other types of information for deriving the reflected lighting profile according to the system requirement. 
     For example, in some other embodiments, the position information of the objects stored in the frame memory  170  can include the depth information of the objects, and the material information of the objects stored in the frame memory  170  can include the refractive indices and coarse parameters of the objects. In this case, the controller  130  may generate the images of the scene by calculation according to the information stored in the light map  150 , the view map  160 , and the frame memory  170 . Therefore, the lookup table may be omitted. 
     In addition, in some embodiments, the display apparatus  100  may generate multi-layered frame data for the object to simulate the transparency and interface reflection effects, thereby making the images of the scene look even more realistic. 
     Furthermore, in  FIG.  1   , the display apparatus  100  can further include an eye tracking device  180 . The eye tracking device  180  can track the position of the viewer. In this case, the controller  130  can generate the images according to the information stored in the light map, the view map, and the frame memory, and the position of the viewer. Since the position of the viewer can be detected, the display apparatus  100  can dedicatedly generate the images of the scene corresponding to the viewing directions that are within a region near to the position of the viewer. 
     In this case, the display apparatus  100  can provide adaptive viewing angles according to the tracked position of the viewer. Therefore, the range of the viewing angles can be wider, and the jumping issue (or the discontinuous images) caused by the fixed viewing angles may be decreased. Also, since the controller  130  may generate fewer images corresponding to the viewing angles within the position of the viewer, unnecessary computation for images outside of the region may be skipped, thereby saving the power consumption and the calculation resource. 
       FIGS.  6 A- 6 E  shows the images of a static scene of the display apparatus  100  from five viewing angles according to one embodiment of the present disclosure. In other word, when the display apparatus  100  shows a static scene, the viewer may see images with different colors and/or light intensities at different viewing angles. For example, when the viewer changes the viewing angle, the viewer may sequentially see  FIGS.  6 A to  6 E . 
       FIG.  7    shows a display apparatus  200  according to another embodiment of the present disclosure. The display apparatus  200  has a similar structure as the display apparatus  100 , and can be operated with similar principles as the display apparatus  100 . However, the display apparatus  200  further includes a scan system  290  for generating the information stored in the light map  150  and/or the frame memory  170  in a real scene. 
     The scan system  290  can include a light source  292  and a light capturing device  294  (e.g. a camera).  FIG.  8    shows the usage scenario of the scan system  290 . In  FIG.  8   , the light source  292  can revolve around the object OA to cast light on the object OA from different angles while the distance between the light source  292  and the object OA may remain constant. In some examples, the distance between the light source  292  and the object OA may be varied. In some embodiments, the light source  292  can be implemented by a spot light, a light bar or other different types of light sources. The light capturing device  294  can capture the images of the object OA in the scene with the light being casted from different locations. In some embodiments, the light source  292  can be disposed above or below the object OA so that the light source  292  may not appear in the images captured by the light capturing device  294 . In other examples, the light source  292  can be disposed in the same level as the object OA. 
     In some embodiments, the light source  292  may revolve around the object OA for a total of 180 degrees and shifting 1 degree at a time. In this case, the light capturing device  294  will capture an image whenever the light source  292  moves to the next position so a total of 180 different lighting profiles of the object OA can be derived. However, in some embodiments, the total revolving degree may be in a range from 30 degrees to 360 degrees, such as 60 degrees, 120 degrees, 150 degrees, or 270 degrees. The degree of one revolving step may be in a range from 0.1 degrees to 60 degrees. But the present disclosure is not limited thereto. Also, in one example, the total revolving degree and the degree of one revolving step can be determined according to the pitch of the optical modulator  120 . 
     Consequently, the scan system  290  can generate the information to be stored in the light map and/or frame memory  170  according to the images captured by the light capturing device  294  and/or the locations of the light source  292 . 
     In some embodiments, the scan system  290  can further include more light sources.  FIG.  9    shows a scan system  390  according to another embodiment of the present disclosure. The scan system  390  includes light sources  392 A 1  to  392 A N , and N is a positive integer greater than 1. The light sources  392 A 1  to  392 A N  disposed on the circumference of the circle with the object OA being at the center of the circle. Also, the central angles between two adjacent light sources of the light sources  392 A 1  to  392 A N  may be substantially equal. In some embodiments, the light sources  392 A 1  to  392 A N  are disposed above or below the object OA so that the light sources  392 A 1  to  392 A N  will not appear in the images captured by the light capturing device  394 . In other examples, the light sources  392 A 1  to  392 A N  may be disposed in the same level as the object OA. 
     In one embodiment, the light sources  392 A 1  to  392 A N  can revolve around the object OA within a predetermined range. For example, the light sources  392 A 1  may move from the current position to the position next to the light source  392 A 2  in  FIG.  9   , and for example but not limited to, 1 degree at a time. Also, the light sources  392 A 1  to  392 A N  can move and cast light sequentially, so the light capturing device  394  can capture the image of the object OA with different lighting profiles one at a time. 
     In  FIG.  8    and  FIG.  9   , the light sources can revolve around the object OA; however, in some other embodiments, the light sources can also be fixed at the same positions. For example, in some embodiments, if the number N of the light sources  392 A 1  to  392 A N  is large enough, the light sources  392 A 1  to  392 A N  may be fixed on the circumference of the circle with the object OA being at the center of the circle, and the light sources  392 A 1  to  392 A N  can cast the light on the object OA from the different locations sequentially. 
     Alternatively, in  FIG.  8   , if the light source  292  is fixed at the same position, the light capturing device  294  may revolve around the object OA as the object OA spins synchronously. Therefore, the light capturing device  292  will capture the images of the same side of the object OA with different lighting profiles, and the images can be used to generate the information required by the display apparatus  100 . 
       FIG.  10    shows a flow chart of a method  400  for operating the display apparatus  100  in accordance with one embodiment of the present disclosure. The method  400  includes steps S 410  to S 480 . Some of the steps may be omitted as another embodiment of the present disclosure. In one example, the step S 420  may be omitted. In one embodiment, the sequence of the steps S 410  to S 480  may be changed or integrated as one step. In one example, the step S 430  may be performed before the step S 410 . In other examples, the step S 420  may be performed after the step S 450  or the step S 480 . In some examples, the steps S 430 , S 440  and/or S 450  may be integrated as one step. But the present disclosure is not limited thereto. 
     S 410 : the light capturing device  190  records the intensities and the locations of the light in the ambient environment for generating the information that would be subsequently stored in the light map  150  and/or the frame memory  170 ; 
     S 420 : the eye tracking device  180  tracks the position of the viewer; 
     S 430 : store the intensities and locations of light in the ambient environment for viewing the scene as the light map  150  in at least one memory device  135 ; 
     S 440 : store the viewing vectors of the pixels in the first pixel array  110  in at least one memory device  135 ; 
     S 450 : store the color information, the material information and the position information of objects in the scene as the frame memory  170  in at least one memory device  135 ; 
     S 460 : the controller  130  generates the images of the scene with different lighting profiles corresponding to different viewing angles according to information stored in the light map  150 , the view map  160 , the frame memory  170  and the position of the viewer; 
     S 470 : the display apparatus  100  displays the images through the first pixel array  110  at the same time; 
     S 480 : the optical modulator  120  modulates the light emitted from the first pixel array  110  to corresponding angles. 
     In step S 410 , the light capturing device  190  can record the intensities and the locations of the light in the ambient environment for generating the information that would be stored in the light map  150  and/or the frame memory  170 . However, in some embodiments, the intensities and locations of light in the ambient environment that stored in the light map  150  may be generated by the computer graphic rendering software. In some examples, the light capturing device  190  may be omitted, and step S 410  can be skipped. 
     In addition, the display apparatus  100  can generate the images corresponding to the position of the viewer based on the tracking result of the eye tracking device  180  in step S 420 . However, in some embodiments, the display apparatus  100  may also omit the eye tracking device  180 . In this case, the controller  130  may generate the images corresponding to any possible viewing angles supported by the display apparatus  100  according to the information stored in the light map  150 , the view map  160 , and the frame memory  170 , without considering the position of the viewer. That is, step S 420  may be skipped. 
     In some embodiments, the position information of the objects in the scene stored in the frame memory  170  can include the surface normal vectors of the objects. In this case, in the step S 460 , the controller  130  may derive the reflection vectors of specular light according to the surface normal vectors stored in the frame memory  170  and the locations of the light stored in the light map  150  at first. Then, the controller  130  may derive the intensities of the specular light according to the reflection vectors of the specular light, the viewing vectors stored in the view map  160 , and the material information of the objects stored in the frame memory  170  with a lookup table. Finally, the controller  130  can generate the images to show the color information of the objects and the intensities of the specular light by combining the lighting effects caused by the diffused light and the specular light. 
     With the lookup table storing the reflected lighting profiles of different materials, the method  400  can save significant computation overhead and allow the display apparatus  100  to generate the images soon enough to present a real time video, providing even more astonishing visual effects. 
     However, in some other embodiments, the position information of the objects stored in the frame memory  170  may include the depth information of the objects, and the material information of the objects stored in the frame memory  170  may include the refractive indices and coarse parameters of the objects. In this case, the controller  130  may generate the images of the scene by calculation according to the information stored in the light map  150 , the view map  160 , and the frame memory  170 . Therefore, the lookup table may be omitted. 
     Furthermore, the method  400  is not limited by the order shown in  FIG.  10   . For example, in some embodiments, steps S 410  and S 420  may be performed in parallel, and steps S 430  to S 450  may be performed in parallel. 
       FIG.  11    shows a flow chart of a method  500  for operating the display apparatus  200 . The method  500  includes steps S 510  to S 530 . 
     S 510 : the light source  292  revolves around the object OA in the scene and cast light on the object OA from different angles; 
     S 520 : the light capturing device  294  captures the images of the object OA in the scene with light casted from different angles; and 
     S 530 : the scan system  290  generates the information to be stored in the light map  150  and/or the frame memory  170  according to the images captured by the light capturing device  294 . 
     With the method  500 , the scan system  290  would be able to generate the information to be stored in the light map  150  and/or the frame memory  170  so the display apparatus  100  can generate the images accordingly. In some embodiments, if the light source  292  is fixed at the same spot, then, instead of performing step S 510 , the light capturing device  294  may revolve around the object OA as the object OA spins synchronously to capture the images with the light from different angles. 
     Also, in some embodiments, for example, in the scan system  390 , a plurality of light sources  392 A 1  to  392 A N  can be disposed on the circumference of the circle with the object being at the center of the circle. In this case, the method  500  can also be applied and the light sources  392 A 1  to  392 A N  can revolve around the object OA within a predetermined angle to cast light on the object OA from different angles in step S 510 . Also, the light sources  392 A 1  to  392 A N  can move and cast light sequentially, so the light capturing device  394  can capture the image of the object OA with different lighting profiles. However, in some other embodiments, the light sources  392 A 1  to  392 A N  can be disposed in a fixed spot and cast the light on the object OA from different angles sequentially. 
     By moving the light sources  292 , and  392 A 1  to  392 A N  or moving the light capturing devices  294  and  394 , the different lighting profiles on the object OA can be captured, and the scan systems  290  and  390  can generate the information to be stored in the light map  150  and/or the frame memory  170  accordingly. 
     In summary, the display apparatus and the method for operating the display apparatus provided by the embodiments of the present disclosure can generate images for the same scene (e.g. astatic scene) with different lighting profiles corresponding to different viewing angles, so the viewer can see different lighting results (e.g. different light intensities and/or colors) of the scene when viewing the display apparatus from different angles. Therefore the display apparatus can simulate the light shining effect in reality and provides a better visual experience to the viewers. In addition, with the scan systems provided by the embodiments of the present disclosure, the information required by generating images of different viewing angles can be derived, allowing the display apparatus to be applied in even more fields. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the disclosure. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.