Patent Publication Number: US-2013242212-A1

Title: Mirror switchable organic light emitting display and mirror switchable display

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 101109091, filed on Mar. 16, 2012. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a display, and more particularly to a minor switchable display. 
     2. Description of Related Art 
     Among the displays, organic light emitting display is a self-illuminating screen, and has the greatest potential to become the major display product in the next generation, with the advantages including wide viewing angle, low power consumption, simple manufacturing process, low cost, a wide operating temperature range, a high response speed and full-color display. 
     In general, the ambient light is reflected by the surface of the organic light emitting display, and thus the organic light emitting display is not able to display a black image to the viewer in the general environment, especially in the bright light environment. This problem can be solved by disposing the circular polarizing plate which includes the liner polarizing plate and the λ/4 phase retardation plate. In detail, when the ambient light passes through the liner polarizing plate, half of the energy of the ambient light is absorbed and the remaining ambient light is then polarized by the liner polarizing plate. After that, the polarized ambient light is converted to a dextrorotary light when passing through the λ/4 phase retardation plate, and is further polarized when passing through the λ/4 phase retardation plate again. Therefore, a polarized angle between the converted ambient light and the ambient light only passing through the liner polarizing plate is 90 degrees, and the converted ambient light is blocked by the liner polarizing plate and can not be transmitted into the display. Accordingly, the reflection of the ambient light at the surface of the display is eliminated. 
     However, the circular polarizing plate in the current organic light emitting display can not be turned on or turned off selectively, that is, can not be switched between λ/4 phase retardation and zero phase retardation. Thus, the application of the organic light emitting display is limited. 
     SUMMARY OF THE INVENTION 
     The invention provides a mirror switchable organic light emitting display that is switchable between an image display mode and a mirror mode. 
     The invention further provides a mirror switchable display that is switchable between an image display mode and a mirror mode. 
     The invention is directed to a mirror switchable organic light emitting display including an organic light emitting display panel, a switchable quarter-wave phase retardation panel, a light transflective layer, and a polarizing plate. The organic light emitting display panel has a light output surface. The switchable quarter-wave phase retardation panel is disposed at the light output surface of the organic light emitting display panel, and has a first surface and a second surface, wherein the first surface faces the organic light emitting display panel. The light transflective layer is disposed at the first surface of the quarter-wave phase retardation panel and faces the organic light emitting display panel. The polarizing plate is disposed on the second surface of the quarter-wave phase retardation panel. 
     The invention is further directed to a mirror switchable display including an active light emitting display panel, a switchable quarter-wave phase retardation panel, a light transflective layer, and a polarizing plate. The active light emitting display panel has a light output surface. The switchable quarter-wave phase retardation panel has a first surface and a second surface, wherein the first surface faces the active light emitting display panel. The light transflective layer is disposed at the first surface of the quarter-wave phase retardation panel and faces the active light emitting display panel. The polarizing plate is disposed on the second surface of the quarter-wave phase retardation panel. 
     Based on the above, the mirror switchable organic light emitting display and the mirror switchable display of the invention have phase retardation panels which can be switched between λ/4 phase retardation and zero phase retardation. Thus, the display is switchable between an image display mode and a mirror mode, or simultaneously provides mirror area and image area at different regions therein. Furthermore, in the image display mode, since the phase retardation panel can reduce the interference of the incident light to the display, the display has superior display effect. On the other hand, in the mirror mode, the light transflective layer disposed at a side surface of the phase retardation panel is able to increase the reflection of the incident light, and thus the display also has superior mirror effect. In addition, since the light transflective layer is disposed at the first surface of the quarter-wave phase retardation panel, the reflection of the incident light is increased and the scattering of the incident light is reduced, and the display provides improved mirror effect when in the mirror mode. 
     In order to make the aforementioned properties and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings constituting a part of this specification are incorporated herein to provide a further understanding of the invention. Here, the drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a schematic cross-sectional view illustrating a mirror switchable organic light emitting display according to an embodiment of the invention. 
         FIG. 2  is a schematic cross-sectional view illustrating a mirror switchable organic light emitting display according to another embodiment of the invention. 
         FIG. 3A  is a schematic view illustrating λ/4 phase retardation effect generated by the switchable quarter-wave phase retardation panel of the mirror switchable organic light emitting display. 
         FIG. 3B  is a schematic view illustrating 0 phase retardation effect generated by the switchable quarter-wave phase retardation panel of the mirror switchable organic light emitting display. 
         FIG. 4A  is a schematic cross-sectional view illustrating a mirror switchable organic light emitting display according to an embodiment of the invention. 
         FIG. 4B  is a schematic top view illustrating a mirror switchable organic light emitting display according to an embodiment of the invention. 
         FIG. 5  is a schematic cross-sectional view illustrating a mirror switchable display according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1  is a schematic cross-sectional view illustrating a mirror switchable organic light emitting display according to an embodiment of the invention. The mirror switchable organic light emitting display  1000  includes an organic light emitting display panel  100 , a switchable quarter-wave (λ/4) phase retardation panel  200 , a light transflective layer  300 , and a polarizing plate  400 . 
     In the present embodiment, the organic light emitting display panel  100  includes a substrate  102 , a first electrode  104 , a second electrode  106 , and an organic light emitting layer  108 . The substrate  102  can be made of a light-transmissive material, a non-light-transmissive material, a reflective material (such as a conductive material, metal, wafer, ceramics, or the like), or other suitable materials. The light-transmissive material can be glass, quartz, an organic polymer, or other suitable materials. 
     The first electrode  104  is disposed on the substrate  102 , for instance. In the present embodiment, a material of the first electrode  104  can be a transparent conductive material, or a non-transparent conductive material. The transparent conductive material includes metal oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum tin oxide (ATO), aluminum zinc oxide (AZO), indium germanium zinc oxide, other suitable oxide, or a stacked layer having at least two of the above materials. The non-transparent conductive material includes metal. 
     The second electrode  106  is disposed above the first electrode  104 . In the present embodiment, the second electrode  106  can be a patterned electrode or an unpatterned electrode, and a material thereof can be a transparent conductive material or a non-transparent conductive material. The transparent conductive material includes metal oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum tin oxide (ATO), aluminum zinc oxide (AZO), indium germanium zinc oxide, other suitable oxide, or a stacked layer having at least two of the above materials. The non-transparent conductive material includes metal. 
     Generally, one of the first electrode  104  and the second electrode  106  is served as an anode of the organic light emitting display panel  100 , and the other one is served as a cathode of the organic light emitting display panel  100 . In the present embodiment, the first electrode  104  is an anode, for instance, and the second electrode  106  is a cathode, for instance. 
     The organic light emitting layer  108  is disposed between the first electrode  104  and the second electrode  106 . Here, the organic light emitting layer  108  may include a red organic light emitting pattern layer, a green organic light emitting pattern layer, a blue organic light emitting pattern layer, a light emitting pattern layer with other colors, or a combination of the aforesaid light emitting pattern layers. Besides, according to other embodiments, the organic light emitting layer  108  may further include an electron transmission layer, an electron injection layers, a hole transmission layer, a hole injection layer, or a combination of the aforesaid layers(not shown), which is well known to the one skilled in the art and the detailed description is omitted. 
     In the present embodiment, the organic light emitting display panel  100  may further include a thin film transistor T 1 , disposed on the substrate  102  and electrically connecting to the first electrode  104 . According to the present embodiment, the thin film transistor T 1  includes a gate electrode G, a channel layer C, a source electrode S, a drain electrode D, a dielectric layer P 1 , a passivation layer P 2 , and a planar layer P 3 , for instance. The gate electrode G is, for instance, disposed on the substrate  102 . The channel layer C is, for instance, disposed on the dielectric layer P 1  above the gate electrode G. The source electrode S and the drain electrode D are disposed on the relative sides of the channel layer C above the gate electrode G, for example. The passivation layer P 2  covers the source electrode S, the drain electrode D, and the dielectric layer P 1 , for instance. The planar layer P 3  covers the passivation layer P 2 . In the present embodiment, the first electrode  104  is, for instance, served as a pixel electrode of the thin film transistor T 1 . The first electrode  104  is formed on the planar layer P 3  and electrically connected to the drain electrode D through the openings in the planar layer P 3  and the passivation layer P 2 , so as to be electrically connected to the thin film transistor T 1 , for instance. 
     It is mentioned that although the bottom gate thin film transistor is exemplified herein for the thin film transistor T 1 , but the invention is not limited to this. In other words, according to other embodiments, the organic light emitting display panel  100  may include, for example, a top-gate thin film transistor. Moreover, although the thin film transistor T 1  is exemplified as shown in  FIG. 1  herein, but the thin film transistor T 1  may have other configurations. 
     In the present embodiment, the organic light emitting display panel  100  is exemplified as a top emission organic light emitting display, and thus a material of the second electrode  106  includes a transparent conductive material, and the second electrode  106  is disposed at the light output surface  110  of the organic light emitting layer  108 . That is to say, the transmission path of the light emitted by the organic light emitting layer  108  is from the first electrode  104  towards the second electrode  106 , and therefore the second electrode  106  is disposed at the light output surface  110  of the organic light emitting layer  108 . In another embodiment, as shown in  FIG. 2 , the organic light emitting display panel  100  may also be a bottom emission organic light emitting display, and thus the transmission path of the light emitted by the organic light emitting layer  108  is from the second electrode  106  towards the first electrode  104 . Hence, a material of the first electrode  104  includes a transparent conductive material, for example, and the first electrode  104  is disposed at the light output surface  110  of the organic light emitting layer  108 . Moreover, if the organic light emitting display panel  100  is a bottom emission organic light emitting display, the substrate  102  is required to apply a transparent material. 
     The switchable quarter-wave (λ/4) phase retardation panel  200  is disposed at the light output surface  110  of the organic light emitting display panel  100 , and has a first surface  200   a  and a second surface  200   b,  wherein the first surface  200   a  faces the organic light emitting display panel  100 . Based on the above, if the organic light emitting display panel  100  is a top emission organic light emitting display, the second electrode  106  is disposed at the light output surface  110  of the organic light emitting layer  108 . Therefore, the switchable quarter-wave phase retardation panel  200  is, for instance, disposed at a side of the second electrode  106 , which the side is corresponding to a side at which the organic light emitting layer  108  is disposed. In other words, the switchable quarter-wave phase retardation panel  200  and the organic light emitting layer  108  are disposed at two opposite sides of the second electrode  106 , respectively. On the contrary, if the organic light emitting display panel  100  is a bottom emission organic light emitting display, the first electrode  104  is disposed at the light output surface  110  of the organic light emitting layer  108 . Therefore, the switchable quarter-wave phase retardation panel  200  is, for instance, disposed at a side of the first electrode  104 , which is corresponding to a side at which the organic light emitting layer  108  is disposed. That is to say, the switchable quarter-wave phase retardation panel  200  and the organic light emitting layer  108  are disposed at two opposite sides of the first electrode  104 , respectively. 
     In the present embodiment, the switchable quarter-wave phase retardation panel  200  includes, for instance, a quarter-wave phase retardation unit U. The quarter-wave phase retardation unit U may include a first transparent substrate  202 , a second transparent substrate  204 , a liquid crystal layer  206 , a first conductive layer  208 , and a second conductive layer  210 . 
     The second transparent substrate  204  is disposed opposite to the first transparent substrate  202 , for instance. The first transparent substrate  202  and the second transparent substrate  204  can be made of glass, quartz, organic polymer, or any other appropriate material. A material of the first transparent substrate  202  and the second transparent substrate  204  can be the same or different, which is determined based on users&#39; preference or requirements and should not be construed as a limitation to this invention. 
     The liquid crystal layer  206  is disposed between the first transparent substrate  202  and the second transparent substrate  204 , for example. The liquid crystal layer  206  includes a plurality of liquid crystal molecules LC, wherein the liquid crystal molecules LC are optically anisotropic in the electrical field and optically isotropic when there is no electrical field. According to other embodiments, the liquid crystal layer  206  can also include spacers (not shown) which are used to maintain the thickness of the switchable quarter-wave phase retardation panel  200 , and a material of the spacers can be an organic transparent insulated material or inorganic transparent insulated material. 
     The first conductive layer  208  is, for example, disposed on the first transparent substrate  202  and between the first transparent substrate  202  and the liquid crystal layer  206 . The second conductive layer  210  is, for example, disposed on the second transparent substrate  204  and between the second transparent substrate  204  and the liquid crystal layer  206 . In the present embodiment, a material of the first conductive layer  208  and the second conductive layer  210  can include a transparent conductive material. The transparent conductive material is indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), the mixtures thereof or the stacked layers thereof, for example. 
     In the present embodiment, the switchable quarter-wave phase retardation panel  200  may further include an active device T 2 , disposed on the first transparent substrate  202  and electrically connected to the first conductive layer  208 . The active device T 2  is, for example, a thin film transistor, and includes a gate electrode G, a channel layer C, a source electrode S, a drain electrode D, dielectric layers P 1  and P 4 , and a passivation layer P 2 , for instance. The gate electrode G, the channel layer C, the source electrode S, the drain electrode D, the dielectric layers P 1  and P 4 , and the passivation layer P 2  may be referred to as those described in the previous embodiment and thus will not be reiterated herein. The dielectric layer P 4  is, for example, disposed on the first transparent substrate  202 , and the first conductive layer  208  is disposed on the dielectric layer P 4 , for instance. In the present embodiment, the first conductive layer  208  is electrically connected to the active device T 2  through the drain electrode D, for instance. Although a bottom gate thin film transistor is exemplified herein for the active device T 2 , but the present disclosure is not limited to this. In other words, according to other embodiments, the active device T 2  may also be a top-gate thin film transistor or other type thin film transistors. 
     The light transflective layer  300  is disposed at the first surface  200   a  of the quarter-wave phase retardation panel  200  and faces the organic light emitting display panel  100 . The light transflective layer  300  has both transmission and reflection properties to light. A material of the light transflective layer  300  can include aluminum, silver, platinum, copper, or gold, and thus mirror reflection is obtained when the incident light enters the light transflective layer  300 . That is to say, by disposing the light transflective layer  300  at the first surface  200   a  of the quarter-wave phase retardation panel  200 , the reflection of the incident light is increased and thus the display may provide superior mirror effect. In the present embodiment, a thickness of the light transflective layer  300  ranges from 1 to 1000 nm. Moreover, the light transflective layer  300  may also include a refractive index-matching layer (not shown), so as to increase the probability of reflection. Moreover, the light transflective layer  300  can also be made of a plurality of films, to achieve transflective effect by total reflection. Since the light transflective layer  300  is separately disposed, the light transflective layer  300  with superior transflective properties can be used to meet the requirements of mirror reflection. In addition, since the light transflective layer  300  is disposed at the first surface  200   a  of the quarter-wave phase retardation panel  200 , the reflection of the incident light is increased and the scattering of the incident light is reduced, and thus the display provides superior mirror effect when in the mirror mode. 
     The polarizing plate  400  is disposed on the second surface  200   b  of the quarter-wave phase retardation panel  200 . In the present embodiment, the polarizing plate  400  can include a liner polarizing plate. The polarizing plate  400  may polarize the incident light. 
     According to the present embodiment, the mirror switchable organic light emitting display  1000  further includes, for instance, a light-transmissive material layer  500  which is disposed between the light transflective layer  300  and the organic light emitting display panel  100 . Therefore, the transmitted light emitted from the organic light emitting display panel  100  can pass the light-transmissive material layer  500  and the light transflective layer  300 , so as to display an image. Accordingly, the light transflective layer  300  can be not entirely contact with the second electrode  106 . The light-transmissive material layer  500  may be an adhesive layer, a spacing layer, a package layer, other layers, or a combination thereof. The adhesive layer can be a transparent insulated material, the spacing layer may be photoresist spacers, and the package layer may be a transparent package material, sealant, sealing glass, sealing gas such as inert gas or residue gas after being vacuumed, or a combination thereof. For example, the photoresist spacers may be selectively disposed between the light transflective layer  300  and the organic light emitting display panel  100 , the sealant or sealing glass may surround the outer of the interface between the light transflective layer  300  and the organic light emitting display panel  100 , and the residue gas is left in the space between the light transflective layer  300  and the organic light emitting display panel  100  after the space being vacuumed. In addition, the adhesive layer may also be entirely adhered to the light transflective layer  300  and the organic light emitting display panel  100 , and so as to secure them. A low refractive material may be used to form the light-transmissive material layer  500 , so as to increase the mirror reflection effect of the light transflective layer  300 . The detail configuration of the light-transmissive material layer  500  is determined based on users&#39; preference or requirements and should not be construed as a limitation to this invention. 
     The mechanism of switching between λ/4 phase and 0 phase by the mirror switchable organic light emitting display  1000  is described below with reference to the figures.  FIGS. 3A and 3B  are respectively schematic views illustrating λ/4 phase retardation effect and 0 phase retardation effect generated by the switchable quarter-wave phase retardation panel  200  of the mirror switchable organic light emitting display  1000  in the image display mode and the mirror mode. Referring to  FIG. 3A , in the image display mode, when a voltage difference between the first conductive layer  208  and the second conductive layer  210  is zero or there is no voltage applied to the first conductive layer  208  and the second conductive layer  210 , the liquid crystal molecules LC in the liquid crystal layer  206  are in a horizontal state, and thus λ/4 phase retardation effect is generated. In detail, an incident light L is, for example, an ambient light, the incident light L is polarized by the polarizing plate  400  when the incident light L passes through the mirror switchable organic light emitting display  1000 , and then is converted to a levorotatory light by the switchable quarter-wave phase retardation panel  200 . After that, the levorotatory light is converted to a dextrorotary light (referred as a reflective light L′) by the light transflective layer  300 , and is further polarized when passing through the switchable quarter-wave phase retardation panel  200  again. Comparing the reflective light L′ and the incident light L, a polarized angle therebetween is  90  degrees, and the reflective light L′ is blocked by the polarizing plate  400  and can not be transmitted into the mirror switchable organic light emitting display  1000 . As a result, the reflective light L′ is eliminated, and the mirror switchable organic light emitting display  1000  displays a black image. At this time, a transmitted light T is emitted from organic light emitting display panel  100 , and passing through the light transflective layer  300  and the quarter-wave phase retardation panel  200 , thereby forming an image. 
     Referring to  FIG. 3B , in the mirror mode, when a voltage is applied to the first conductive layer  208  or the second conductive layer  210 , or the first conductive layer  208  and the second conductive layer  210  have a voltage difference, the liquid crystal molecules LC in the liquid crystal layer  206  are in a vertical state, and thus λ/4 phase retardation effect is turned off. Thus, 0 phase retardation is provided by the quarter-wave phase retardation panel  200 . In detail, after the ambient light L enters the mirror switchable organic light emitting display  1000 , the polarized incident light L directly passes through the quarter-wave phase retardation panel  200  and the polarized state thereof is not changed. Then, the polarized incident light L is reflected by the light transflective layer  300 , and a reflective light L′, which has the same polarized direction as the polarized incident light L, is formed. The reflective light L′ is able to directly pass through the switchable quarter-wave phase retardation panel  200  to the polarizing plate  400 , and is then further polarized and emitted. As a result, the mirror switchable organic light emitting display  1000  provides mirror reflection effect. 
     In the present embodiment, the mirror switchable organic light emitting display  1000  can be switched between λ/4 phase retardation and 0 phase retardation, and thus is switchable between an image display mode and a mirror mode. As a result, the interference to the display caused by the incident light is decreased, and thereby the display has favorable display effect. 
       FIGS. 4A and 4B  are respectively schematic cross-sectional view and schematic top view of illustrating a mirror switchable organic light emitting display according to an embodiment of the invention. Referring to  FIGS. 4A and 4B , according to the present embodiment, the configuration of the mirror switchable organic light emitting display  1000 ′ is similar to that of the mirror switchable organic light emitting display  1000 , while the difference therebetween lies in the switchable quarter-wave phase retardation panel  200 ′ has a plurality of switchable regions R. A switchable unit U is disposed in each switchable region R. Details about the switchable unit U can be referred to the switchable unit U in the aforementioned embodiment and are not reiterated herein. The switchable regions R are arranged in array, and thus the switchable units U are also arranged in array, for example. It should be noted that in  FIG. 4A , the switchable quarter-wave phase retardation panel  200 ′ is exemplified as having  2  switchable regions R 1  and R 2 , while the invention is not limited thereto. In other words, according to other embodiments, the switchable quarter-wave phase retardation panel  200 ′ can have more than 2 switchable regions R. 
     The switchable units U can be controlled by the same circuit or different circuits. Thus, each switchable unit U can respectively provide λ/4 phase retardation or 0 phase retardation. For example, a plurality of switchable units U simultaneously provides λ/4 phase retardation or 0 phase retardation, and thus an image is displayed or a mirror effect is provided. Certainly, in an embodiment, one or more of the switchable units U can provide λ/4 phase retardation and the others can provide 0 phase retardation, and thus the display simultaneously provides mirror area and image area at different regions corresponding to the switchable units U. 
     In the present embodiment, the mirror switchable organic light emitting display  1000 ′ has a plurality of switchable units U which are respectively switchable between λ/4 phase retardation and 0 phase retardation. Hence, the mirror switchable organic light emitting display  1000 ′ is switchable between an image display mode and a mirror mode, or simultaneously shows mirror area and image area at different regions. As a result, the application range of the mirror switchable organic light emitting display  1000 ′ is greatly extended, to satisfy the requirement of the customers for displays. 
       FIG. 5  is a schematic cross-sectional view illustrating a mirror switchable display according to an embodiment of the invention. The mirror switchable display  2000  includes an active light emitting display panel  1100 , a switchable quarter-wave (λ/4) phase retardation panel  1200 , a light transflective layer  1300 , a light-transmissive material layer  1500 , and a polarizing plate  1400 . 
     The active light emitting display panel  1100  has a light output surface  1100   a.  In the present embodiment, the active light emitting display panel  1100  can include an organic light emitting display panel, a field emission display panel, a plasma display panel, and a liquid crystal display panel. 
     The switchable quarter-wave phase retardation panel  1200  has a first surface  1200   a  and a second surface  1200   b,  wherein the first surface  1200   a  faces the active light emitting display panel  1100 . In the present embodiment, the switchable quarter-wave phase retardation panel  1200  is, for example, disposed at the light output surface  1100   a  of the active light emitting display panel  1100 . The light transflective layer  1300  is disposed at the first surface  1200   a  of the quarter-wave phase retardation panel  1200  and faces the active light emitting display panel  1100 . The light-transmissive material layer  1500  is disposed between the light transflective layer  1300  and the active light emitting display panel  1100 . The polarizing plate  1400  is disposed on the second surface  1200   b  of the quarter-wave phase retardation panel  1200 . The structures of the quarter-wave phase retardation panel  1200 , the light transflective layer  1300 , the light-transmissive material layer  1500 , and the polarizing plate  1400  are similar to the structures of the quarter-wave phase retardation panel  200 ,  200 ′, the light transflective layer  300 , the light-transmissive material layer  500 , and the polarizing plate  400  described above, and thus can referred to those mentioned above and will not be reiterated herein. 
     In the present embodiment, the mirror switchable organic light emitting display  2000  has switchable quarter-wave phase retardation panel  1200  which can be switched between λ/4 phase retardation and zero phase retardation. Hence, the mirror switchable organic light emitting display  2000  is switchable between an image display mode and a mirror mode, or simultaneously shows mirror area and image area at different regions. Furthermore, in the image display mode, since the phase retardation panel can reduce the interference of the incident light to the display, the display has superior display effect. On the other hand, in the mirror mode, the light transflective layer disposed at a side surface of the phase retardation panel is able to increase the reflection of the incident light, and thus the display also has superior mirror effect. As a result, the application range of the mirror switchable organic light emitting display is greatly extended, to satisfy the requirement of the customers for display. 
     To sum up, the mirror switchable organic light emitting display and the mirror switchable display of the invention includes the display panel, the switchable quarter-wave phase retardation panel, the light transflective layer, and the polarizing plate. The switchable quarter-wave phase retardation panel is switchable between λ/4 phase retardation and zero phase retardation. Therefore, by using the switchable quarter-wave phase retardation panel with the polarizing plate and the light transflective layer, in the image display mode, the interference of the incident light to the display can be reduced with eliminating the reflection of the incident light at the surface of the display, and the display shows superior displayed image. On the other hand, in the mirror mode, the reflection of the incident light is increased, and thus the display also shows superior mirror reflection effect. In addition, since the light transflective layer is disposed at the first surface of the quarter-wave phase retardation panel, the reflection of the incident light is increased and the scattering of the incident light is reduced, and thus the display has improved mirror effect when in the mirror mode. Furthermore, according to an embodiment, the mirror switchable organic light emitting display has a plurality of switchable units, which are respectively switched between λ/4 phase retardation and zero phase retardation. Hence, the mirror switchable organic light emitting display is not only switchable between the image display mode and the mirror mode, but also simultaneously shows mirror area and image area at different regions. As a result, the application range of the mirror switchable organic light emitting display and the mirror switchable display is greatly extended, to satisfy the requirement of the customers for display. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.