Abstract:
The present invention discloses a micro-optical phase film and a micro-lenticular lens. The optical phase film is integrally formed and includes an optical phase film base and a concave surface disposed on the optical phase film base. The concave surface has a plurality of concave and semi-cylinder like protrusions which are separated from each other in a constant pitch and have the same height. A lens layer covers the optical phase film to form a micro-lenticular lens. The optical phase film will exhibit different refractive index because of the incident light with different polarization angles, so as to achieve the object of 2D/3D image switching.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an integrally formed micro-optical phase film and the manufacturing method thereof, and more particularly to a micro-optical phase film applied to 2D/3D image switching. 
     BACKGROUND OF THE INVENTION 
     Stereoscopic display technology is considered as a new generation product target in display technology. From the point of view of the consumer, although the hardware of with glasses type stereoscopic display technology has developed maturely and can meet the demand for enabling stereoscopic images to be viewed by multiple viewers at the same time, it still suffers from a problem in which the viewers must wear special glasses to see the stereoscopic images. Therefore, multiple manufacturers invest in the development of the bare-eye type 3D stereoscopic display technology which does not need to wear special glasses. Thus, the bare-eye type stereoscopic display technology will be the major trend in the future. Actually, the bare-eye type stereoscopic display technology has currently developed into the multi-view display technology which enables multiple viewers to view the stereoscopic images at the same time. 
     However, text portions of stereoscopic images on the bare-eye type multi-view stereoscopic display may be blurred, which results in the reading problem. Therefore, there is a need for developing a new stereoscopic display system in the hardware technology, which can automatically detect the contents of texts and images and the ranges of the display regions thereof, can display the image portions on the screen in a 3D stereoscopic mode while still displaying the description portions, for example texts and so on, in a traditional 2D mode, and meanwhile can perform dynamic switching between 2D/3D modes in partial display regions. 
     Switchable stereoscopic image technology for the flat panel television may be principally divided into a parallax barrier technology as shown in  FIG. 1   a  and a lenticular lens technology as shown in  FIG. 1   b  in view of optical control technology. The basic theorem of both is to divide the pictures to be displayed into pixel  111  for the right eye and pixel  112  for the left eye; for the parallax barrier technology, a parallax barrier  120  is utilized to render the right eye  101  to be unable to see the pixel  111  for the left eye  102  and render the left eye  102  to be unable to view the pixel  112  for the right eye  101 . Therefore, the right eye  101  and the left eye  102  may see images with different optical phases, in order for the brain to combine them into stereoscopic images. For the lenticular lens technology, lenticular lenses  130  are utilized to refract and transmit the pixel  112  for the right eye  101  and the pixel  111  for the left eye  102  to the right eye  101  and the left eye  102  respectively. Based on the current levels of skill, the images formed by the lenticular lens have better brightness, but the steadiness of the manufacturing process and the technology maturity of the lenticular technology are lower than those of the parallax barrier technology, thereby the parallax barrier technology has the cost advantage relatively. However, both of the aforementioned two technologies are the method of statically presenting the 3D stereoscopic images and cannot perform dynamic switching between 2D/3D images. 
       FIGS. 2   a  and  2   b  illustrate a prior art which can perform dynamic switching between 2D/3D images. The prior art has a switching liquid crystal layer  220 , which can change the polarization phase angle of the light through the polarized voltage applied on the polarizing film  210  thereabove and therebelow; a liquid crystal layer  240  which can also change the refraction index thereof by controlling the voltage; a lens layer  250  with a fixed refraction index n. As shown in  FIG. 2   a , when the polarized voltage (Va)  271  is applied on the polarizing films  210  above and below the switching liquid crystal layer  220 , the liquid crystal molecules change the arrangement directions thereof to render the polarized light  280  of zero degree to pass the pixel  201 , enter the switching liquid crystal layer  220  and then be transformed into the polarized light  281  of 90 degrees. At this time, the refraction index of the liquid crystal layer  240  is controlled as N, which is different from the refraction index n of the lens layer  250 , such that the light changes the traveling direction thereof and the effect equivalent to lenticular lens is generated, which is referred to as the 3D mode. As shown in  FIG. 2   b , after the polarized voltage (Vb)  272  is applied on the polarizing films  210  above and below the switching liquid crystal layer  220 , the liquid crystal molecules change the arrangement directions thereof again to render the polarized light  280  of zero degree to pass the pixel  201 , enter the switching liquid crystal layer  220  and then remain as the polarized light  280  of zero degree. But, at this time, the refraction index of the liquid crystal layer  240  is controlled as n, which is the same as the refraction index n of the lens layer  250 , such that the light does not change the traveling direction thereof, which is referred to as the 2D mode. 
     However, the prior art still suffers from several shortcomings. For example, the liquid crystal layer  240  and the lens layer  250  must be made on a glass substrate  230 , and another glass substrate  260  is needed on the top of the liquid crystal layer  240  and the lens layer  250 . Further, the liquid crystal layer  240  must be controlled by utilizing voltages or other methods to change the refraction index thereof, so as to cooperate with the lens layer  250  to achieve the function of switching between 2D/3D modes. 
     In comparison with the prior art, the technology disclosed by the present invention can omit the glass substrate and does not need to control the liquid crystal lens to change the refraction index thereof and the lens film is integrally formed, thereby the present invention can significantly reduce the cost. 
     SUMMARY OF THE INVENTION 
     The present invention discloses an integrally formed micro-optical phase film and a micro-phase lenticular lens. The structure of the optical phase film includes: an optical phase film base having a thickness and being rectangular from a point of view from top thereof, wherein the optical phase film has two lateral edges with an equal length and two longitudinal edges with an equal length; a concave surface disposed on the optical phase film base; and wherein the concave surface has a plurality of parallel concave and semi-cylinder like protrusions, the plurality of concave and semi-cylinder like protrusions being separated from each other in a constant pitch, a cylinder height being formed between highest points of the concave and semi-cylinder like protrusions and points at which the concave and semi-cylinder like protrusions start to protrude upwards, an angle being formed between axis directions of the concave and semi-cylinder like protrusions and arrangement phases of material molecules of the optical phase film. 
     The material of the optical phase film may be a transparent material, which includes poly(vinyl chloride) (PVC), polycarbonate (PC), poly(vinyl acetate) (PVA), polyethylene terephthalate (PET), polyethylene (PE), tri-acetyl cellulose (TAC), or cellulose acetate propionate (CAP). The thickness of the optical phase film base is about 50 μm˜150 μm, and the constant pitch of the concave and semi-cylinder like protrusions is about 120 μm˜450 μm, preferably 150 μm˜200 μm. The cylinder height of the concave and semi-cylinder like protrusions is about 10 μm˜180 μm. The factor for changing the refraction index of the optical phase film includes the angle between axis directions of the concave and semi-cylinder like protrusions and arrangement phases of material molecules of the optical phase film, the cylinder height of the concave and semi-cylinder like protrusions, the constant pitch of the concave and semi-cylinder like protrusions, or a polarization angle of an incident light. 
     The present invention discloses a micro-phase lenticular lens, including a lens layer disposed on the concave surface of the aforementioned optical phase film, the lens layer having a refraction index n; and wherein an incident light with a polarization angle enters a planar bottom surface of the optical phase film base and passes through the optical phase film and the lens layer. When the polarization angle of the incident light is a first angle, a refraction index of the optical phase film is N. When the polarization angle of the incident light is a second angle, the refraction index of the optical phase film is n, wherein n is unequal to N. 
     In one embodiment, the first angle includes zero degree or 180 degrees, and the second angle includes 90 degrees or 270 degrees. In anther embodiment, the first angle includes 90 degrees or 270 degrees, and the second angle includes zero degree or 180 degrees. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may be understood by some preferred embodiments and detailed descriptions in the specification and the attached drawings below. The identical reference numbers in the drawings refer to the same components in the present invention. However, it should be appreciated that all the preferred embodiments of the invention are provided only for illustrating but not for limiting the scope of the Claims and wherein: 
         FIGS. 1   a  and  1   b  illustrate a prior art of 3D stereoscopic images; 
         FIGS. 2   a  and  2   b  illustrate a prior art of 2D/3D image switching; 
         FIGS. 3   a - 3   c  illustrate an exemplary integrally formed micro-optical phase film of the present invention; 
         FIG. 4  illustrates the theorem of refraction index variation of the optical phase film of the present invention; and 
         FIGS. 5   a  and  5   b  illustrate an exemplary application of the optical phase film of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The invention will now be described with the preferred embodiments and aspects and these descriptions interpret structure and procedures of the invention only for illustrating but not for limiting the Claims of the invention. Therefore, except the preferred embodiments in the specification, the present invention may also be widely used in other embodiments. 
     The present invention discloses an integrally formed micro-optical phase film and a micro-lenticular lens. In comparison with the prior art, the technology disclosed by the present invention can omit the glass substrate and does not need to control the liquid crystal lens to change the refraction index thereof and the phase film is integrally formed, thereby the present invention can significantly reduce the cost and may be utilized to manufacture the optical phase film which can switch 2D/3D images. 
       FIG. 3   a  illustrates a cross-sectional view of the exemplary integrally formed micro-optical phase film  310  made by the present invention. The optical phase film  310  is integrally formed, and the optical phase film  310  may be conceptually divided into an optical phase film base  311  and concave and semi-cylinder like protrusions  312  for convenience of explanation. The bottom surface of the optical phase film base  311  is a planar bottom surface  301 . In one embodiment, the thickness of the optical phase film base may be about 50 μm˜150 μm.  FIG. 3   b  illustrates a top view of the planar bottom surface  301  of the optical phase film  310 . The planar bottom surface  301  is rectangular as shown in  FIG. 3   b . The lengths of the longitudinal edge  302  and the lateral edge  303  of the planar bottom surface  301  may be designed according to the demand of panels which the optical phase film will cooperate with. The concave and semi-cylinder like protrusions  312  of the optical phase film  310  are separated from each other in a pitch P. In one embodiment, the pitch P may be about 150 μm˜200 μm. In another embodiment, the pitch P may be about 120 μm˜450 μm. It should be noted that the pitch P may change according to pixel pitches of the panel to be applied in practical application. The axis direction of the concave and semi-cylinder like protrusions  312  may be designed as parallel to the longitudinal edge  302  or the lateral edge  303 . 
     The thickness D of the optical phase film base  311  of the optical phase film  310  may change in accordance with different demands, such as light transmittance, yield of manufacturing processes, hardness, adhesive capacity, etc. The height h of the concave and semi-cylinder like protrusions  312  is from the point at which the concave and semi-cylinder like protrusions  312  start to protrude from the optical phase film base  311  to the highest point of the concave and semi-cylinder like protrusions  312 . In one embodiment, the height h may be, but be not limited to, about 10 μm˜180 μm. The height h of the concave and semi-cylinder like protrusions  312  affects the curvature of the concave and semi-cylinder like protrusions  312 . The height h may be controlled to change the refraction index of the concave and semi-cylinder like protrusions  312 . Therefore, the height h may be designed according to practical demands and may not be limited to fixed ranges. 
     In one embodiment, the material of the optical phase film  310  may be transparent materials, including poly(vinyl chloride) (PVC), polycarbonate (PC), poly(vinyl acetate) (PVA), polyethylene terephthalate (PET), polyethylene (PE), tri-acetyl cellulose (TAC), cellulose acetate propionate (CAP). 
     In one embodiment, as shown in  FIG. 3   c , a lens layer  320  may cover the surface of the concave and semi-cylinder like protrusions  312  of the optical phase film  310  to form a micro-phase lenticular lens  330 . The micro-phase lenticular lens  330  may be adhered onto the display panel through the planar bottom surface  301  of the optical phase film  310 . 
       FIG. 4  illustrates the theorem of refraction index variation of the optical phase film  310  of the present invention. As shown in  FIG. 4 , the material molecules  421  in the optical phase film  310  are regularly arranged along one direction. An angle θ is formed between the axis direction  410  of the concave and semi-cylinder like protrusions of the optical phase film and the phase axis  420  of the material molecules. The angle θ may be controlled to change the refraction index of the optical phase film  310 . In one embodiment, the refraction index of the optical phase film  310  may also be changed by adjusting the height h and the pitch P of the concave and semi-cylinder like protrusions  312  of the optical phase film  310 . 
     The following will describe the application of the micro-phase lenticular lens  330  of the present invention to the display panel to achieve the function of 2D/3D switching.  FIGS. 5   a  and  5   b  illustrate the application of the exemplary micro-phase lenticular lens  330  of the present invention. Similar to the prior art in  FIGS. 2   a  and  2   b , the micro-phase lenticular lens  330  of the present invention is applied on a display with switching liquid crystal layer  220 , and the planar bottom surface  301  of the optical phase film  310  is adhered onto the switching liquid crystal layer  220 . As shown in  FIG. 5   a , if the polarized voltage (Va)  271  is applied on the polarizing films  210  above and below the switching liquid crystal layer  220 , the liquid crystal molecules change the arrangement directions thereof to render the incident light  580  with the polarization direction of zero degree to pass the pixel  201 , enter the switching liquid crystal layer  220  and then be transformed into the incident light  581  with the polarization direction of 90 degrees or 270 degrees. At this time, the refraction index of the optical phase film  310  is N, which is different from the refraction index n of the lens layer  320 , such that the light changes the traveling direction  583  thereof and the effect equivalent to lenticular lens happens, which is the 3D mode. In another embodiment, when the polarized voltage (Va)  271  is applied on the polarizing films  210  above and below the switching liquid crystal layer  220 , the liquid crystal molecules change the arrangement directions thereof to render the incident light  580  with the polarization direction of zero degree to pass the pixel  201 , enter the switching liquid crystal layer  220  and then become the incident light (not shown) with the polarization direction of zero degree or 180 degrees. At this time, the refraction index of the optical phase film  310  is N, which is different from the refraction index n of the lens layer  320 , such that the light changes the traveling direction thereof and the effect equivalent to lenticular lens happens, which is the 3D mode. 
     Relatively, as shown in  FIG. 5   b , after the polarized voltage (Vb)  272  is applied on the polarizing films  210  above and below the switching liquid crystal layer  220 , the liquid crystal molecules change the arrangement directions thereof again to render the incident light  580  with polarization direction of zero degree to pass the pixel  201 , enter the switching liquid crystal layer  220  and then become the incident light  582  with polarization direction of zero degree or 180 degrees. At this time, the refraction index of the optical phase film  310  is n, which is the same as the refraction index n of the lens layer  320 , such that the light does not change the traveling direction  584  thereof, which is the 2D mode. In another embodiment, after the polarized voltage (Vb)  272  is applied on the polarizing films  210  above and below the switching liquid crystal layer  220 , the liquid crystal molecules change the arrangement directions thereof again to render the incident light  580  with polarization direction of zero degree to pass the pixel  201 , enter the switching liquid crystal layer  220  and then be transformed into the incident light (not shown) with polarization direction of 90 degrees or 270 degrees. At this time, the refraction index of the optical phase film  310  is n, which is the same as the refraction index n of the lens layer  320 , such that the light does not change the traveling direction thereof, which is the 2D mode. 
     The foregoing description is a preferred embodiment of the present invention. It should be appreciated that this embodiment is described for purposes of illustration only, not for limiting, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations are included insofar as they come within the scope of the invention as claimed or the equivalents thereof.