Abstract:
An integrated opto-electronic device, a portable reflective projection system and a method for in situ monitoring and adjusting light illumination are provided. The device includes a reflective polarizing composite film ( 150 ) configured to receive a source light ( 210 ) at a desired non-normal incident angle ( 221 ), polarizes and reflects a first portion ( 211 ) of said source light ( 210 ) as polarized illumination light ( 16 ) at a reciprocal angle ( 222 ) to said desired non-normal incident angle ( 221 ); and a photovoltaic cell ( 180 ), adhered to an opposite side of said reflective polarizing composite film ( 150 ) to said source light ( 210 ), configured to receive a second portion ( 212 ) of said source light ( 210 ) that passes through said reflective polarizing composite film ( 150 ) and transform said second portion ( 212 ) to photogenerated charge. Unused illumination can be collected in order to re-store and reuse recovered energy.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority of provisional application No. 61/039,291, filed on Mar. 25, 2008, entitled “A Solid State Reflective Polarizer with Photovoltaic Cell Backplane and Its Uses in Portable Projection System”, which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a image projecting field, particularly to an integrated opto-electronic device and a portable reflective projection system. 
       BACKGROUND 
       [0003]    A variety of optical-electrical systems exist for projecting images or information on a display screen sized tens to hundreds of inches, from a microdisplay imager in a size of sub inch. Such a microdisplay imager consists of a planar array of light modulation micro-scale pixels fabricated on a silicon substrate. The optical reflectance of each pixel is electrically modulated in situ by an underlying CMOS-based circuitry fabricated on the same silicon substrate. Most common of such reflective microdisplay imagers are liquid crystal on silicon (LCOS), deformable mirror device (DMD) and galvanic light valve (GLV). 
         [0004]    A variety of optical engine and projection lens assembles are employed and assembled, for adequately inducing light ray to such a reflective microdisplay imager and then optically projecting the image formed in differentiated gray scales of reflected light on the microdisplay imager to a display screen. Such an optical system, often called optical engine assembly, at least consists of a light source, a reflective microdisplay imager, a projection lens (or lens), and last but not least, an optical device, often called engine core, inducing the illumination light from the light source to the reflective microdisplay imager, in which a reflective microdisplay imager and the projection lens are mounted in parallel on the opposite sides of the engine core. Fixed in a tilted angle with the microdisplay imager and projection lens, the engine core consists of at least one optical surface, receiving and deflecting portion of illumination light from the light source towards the microdisplay imager. Portion of spatially modulated light reflected from the source light by the imager passes through the engine core and the projection lens and thus, is projected on a display screen forming an enlarged image. Prior art shown in the patents, such as U.S. Pat. No. 5,552,922, U.S. Pat. No. 5,604,624, U.S. Pat. No. 6,461,000, U.S. Pat. No. 6,490,087, EP 2000/0830425, and US 20080012805, by Magarill, Lambertini and Duncan well exemplifies the basic optical framework of such an optical engine assembly and projection system. More sophisticated projection systems employ an engine core combining two or more of such optical surfaces in crossing configuration for inducing light to multiple microdisplay imagers and constructing the images of different color or light spectrums to a single projection display. 
         [0005]    Such a projection system is miniaturized to a “micro” or “pico” system, with both optical engine and imager shrunk proportionally, for various portable and mobile handheld applications. In such applications, power consumption of a micro or pico projection system is often of serious concern. Meanwhile, optical efficiency of such a projection system is far from 100% and so is the net energy efficiency from electrically powered light source to projection illumination out of projection lens. Diffraction and deflection away from the main illumination beam paths by various surfaces, as well as light scattering by transparent medium, such as air, in such a projection system are among the main causes to such loss in optical efficiency and thus electrical energy. It is highly desirable to collect and convert such unused illumination in order to recover part, if not most of energy loss, preferably in situ within the projection system and to re-store it into a built-in energy storage device, particularly into a rechargeable battery, and to reuse recovered energy for partially powering the light source and/or microdisplay imager, as well as other electrically powered devices in such a handheld device. 
         [0006]    As photovoltaic device technology advances, more than 20% of photonic-electrical energy conversion efficiency could be achieved. Such micro or pico projection systems often require illumination in a fairly high intensity from its light source, but the overall optical efficiency is in low percentages. Loss due to light reflection and deflection by various surfaces as well as light scattering by transparent material enclosed in their optical system contributes substantially to efficiency reduction. Thus, potential and need for recovering such energy loss due to unavoidable optical artifacts and converting portion of unused illumination to reusable photogenerated charge is considerable for extending service time of the built-in rechargeable battery. 
         [0007]    However, in a portable reflective projection system employing a single-panel LCOS imager as a the reflective microdisplay imager  20  and a simple optical engine as shown in  FIG. 1 , considerable loss in optical efficiency still results from polarization of illumination light by a transmissive polarizing film  11  providing polarized source light  12  towards a light-redirecting mirror  14 . Second, a low cost transmissive polarizing film  11  is often made of polymeric materials so that its thermal stability and radiation aging are of concern under various adverse application environments. Further advance of the prior art from the system shown in  FIG. 1  is made by employing a reflective transmissive polarizing film  11   a , replacing both the transmissive polarizing film  11  and the light-redirecting mirror  14 , as shown in  FIG. 2 . Even though majority of the P-component of incident light is reflected for illumination eventually to the LCOS imager, the S-component is deflected and absorbed as waste energy by the reflective polarizing film  11   a . It is highly desired that such loss of energy could be partially recovered while the optical engine system is configured to have sufficient temperature stability and mechanical compactness at low cost without additional components. Such reflective polarizing film or panel can be fabricated as shown in U.S. Pat. No. 7,158,302 by Yu et al, or U.S. Pat. No. 6,970,213 by Kawahara, et al. 
       SUMMARY 
       [0008]    The subject of the present invention is to provide an integrated opto-electronic device and a portable reflective projection system. 
         [0009]    An embodiment of the present invention provides an opto-electronic device which may be in a plannar configuration. The opto-electronic device comprises a reflective polarizing composite film configured to receive a source light at a desired non-normal incident angle, polarize and reflect a first portion of the source light as polarized illumination light at a reciprocal angle to the desired non-normal incident angle; and a photovoltaic cell  180  which may be a plannar photovoltaic cell, adhered to an opposite side of the reflective polarizing composite film to the source light, configured to receive a second portion of the source light that passes through the reflective polarizing composite film and transform the second portion to photogenerated charge. 
         [0010]    Another embodiment of the present invention further provides a portable reflective projection system comprising:
       an electrically powered light source configured to provide a source light in a first direction;   an integrated opto-electronic device of the present invention;   a reflective microdisplay imager comprising a plurality of reflective pixel elements which are arranged in a common plane, wherein the reflective pixel elements are configured to individually modulate reflectivity to incident polarized light and project spatially modulated light in a third direction perpendicular to the common plane;   a lens having a principal plane parallel to the common plane and a principal axis aligned in the third direction;   an optical surface positioned between the lens and the reflective microdisplay imager and further positioned in a tilted angle with the common plane configured to receive the polarized illumination light, so that a portion of the polarized illumination light is deflected by the optical surface as the incident polarized light towards the reflective microdisplay imager, a portion of the spatially modulated light passes through the optical surface as projection light partially passes through the lens in the third direction;   a power management device;   an energy storage device configured to provide electrical power to one or both of the light source and the reflective microdisplay imager through the power management device; and   a voltage converter and battery charger configure to convert and charge the photogenerated charge transformed by the photovoltaic cell to the energy storage device.       
 
         [0019]    Another embodiment of the present invention further provides a method for in situ monitoring and adjusting light illumination from a light source in a portable reflective projection system of the present invention. The method comprises:
       measuring accumulated photogenerated charge converted from a second portion of a source light collected by a photovoltaic cell over defined time duration of an integrated opto-electronic device; and   in situ monitoring and adjusting the light illumination from the light source according to a measurement result.       
 
         [0022]    Specifically, the opto-electronic device according to one embodiment of the present invention can provide three optical and optical-electronic functions: 1 receiving source light from a light source in the first direction and polarizing a first portion of the received source light; 2 redirecting or reflecting such polarized illumination light towards an optical surface in a second direction; and 3 receiving a second portion of the received source light into its photovoltaic cell and transforming such second portion to photogenerated charge. 
         [0023]    Replacing both the transmissive polarizing filming and the light-redirecting mirror in prior art, the novel opto-electronic device of the present invention not only simplifies a portable reflective projection system but also provides an effective measure to recover portion of the unused optical energy and thus improves the overall energy efficiency of such a portable reflective projection system. 
         [0024]    Preferably the photovoltaic cell of the disclosed novel opto-electronic device may be first fabricated on a semiconductor substrate, such as single crystalline or polycrystalline silicon. The photovoltaic cell may comprise a backside electrical contact, a photon-to-electron converting photo diode and a top contact grid in an adherent plannar configuration and spatial stacking sequence. The reflective polarizing film may be later fabricated seamlessly adherent to the top surface of the photovoltaic cell, preferably also through semiconductor fabrication methods. 
         [0025]    In one embodiment of the present invention, the reflective polarizing film may comprise one or more of optical layer pairs each made of a top layer and a bottom layer. The top layer first receives the source light having higher refractive index (n) and the bottom layer having lower refractive index (n). Both top layer and bottom layer may be made of dielectric material, such as one or any combination of silicon dioxide, silicon oxy-nitride, silicon nitride, aluminum oxide, hafnium oxide, tantalum oxide and titanium oxide with extinctive coefficients (k) below 0.1 over the desired spectrum of visible light with the wavelength from 400 nm to 700 nm. 
         [0026]    Such optical layer pair receives incident source light in a desired non-normal incident angle, polarizes and reflects a first portion of the P-component of the source light as polarized illumination light in a desired reciprocal angle, to be re-directed to illuminate a reflective microdisplay imager. Meanwhile, a second portion, particularly majority of the S-component of source light, is deflected into the photovoltaic cell and thus partially converted by a photo-diode to photogenerated charge. Such photogenerated charge may be electrically drained out through a top contact grid externally to an energy storage device, managed by a voltage converter and battery charger. The opto-electrical energy thus received and restored into the energy storage device (rechargeable battery) may be reused for powering any electronic or opto-electrical component, including the reflective microdisplay imager, the voltage converter and battery charger and even the light source in a portable reflective projection system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  shows the overall construction of a conventional portable reflective projection system in prior art, using a transmissive polarizing film  11  and a light-redirecting mirror  14  for inducing polarized illumination light  16  eventually to a reflective microdisplay imager  20  by the means of modulation of polarized illumination. 
           [0028]      FIG. 2  shows the overall construction of another conventional portable reflective projection system in prior art, using a reflective polarizing film  11   a  for inducing polarized illumination light  16  eventually to a reflective microdisplay imager  20 . 
           [0029]      FIG. 3  shows the schematic of one embodiment of the portable reflective projection system with an integrated opto-electronic device incorporated in accordance with one embodiment of the present invention; 
           [0030]      FIG. 4   a  is a perspective view showing an integrated opto-electronic device in accordance with one embodiment of the present invention, in which the reflective polarizing composite film  150  is adhered on the top of a photovoltaic cell  180  in a plannar stacking configuration; 
           [0031]      FIG. 4   b  is a cross-section view of  FIG. 4   a;    
           [0032]      FIG. 5   a  is a perspective view showing another embodiment of the disclosed novel integrated opto-electronic device  134 , in which the reflective polarizing composite film  150  comprises an micro-structured layer  160  of dielectric material  162  containing regularly spaced, parallel reflective conductive strips  164  in a plannar configuration; 
           [0033]      FIG. 5   b  is a cross-section view of  FIG. 5   a;    
           [0034]      FIG. 6   a  is a perspective view showing another embodiment of the disclosed novel integrated opto-electronic device  134 , where on a semiconductor substrate, a plurality of reflective top electrical contact lines  184   a  at the top of the photovoltaic cell  180 , regularly spaced in parallel with a desired spacing and embedded in a dielectric material  162 , reflect the P-component of incident light while deflect the S-component into photo diode, generating photogenerated charge; 
           [0035]      FIG. 6   b  is a cross-section view of  FIG. 6   a;    
           [0036]      FIG. 6   c  shows a specific schematic of the reflective top electrical contact grid  184  in  FIG. 6   a  and  FIG. 6   b.    
       
    
    
     DETAILED DESCRIPTION 
       [0037]    The present invention is described in detail below through embodiments accompanied with drawings. 
         [0038]      FIG. 1  shows the overall construction of a reflective microdisplay projection system in one prior art, using a transmissive polarizing film  11  and a light-redirecting mirror  14  for inducing polarized illumination light  16  eventually to a reflective microdisplay imager  20  using polarized modulation. As shown in  FIG. 1 , source light  210  provided by an electrically powered light source  10  first confronts the transmissive polarizing film  11 , which blocks all the S-component and allows only portion of the P-component of the source light  210 , or polarized portion, passes through as the polarized source light  12  still in the first direction  138 . A light-redirecting mirror  14  receives and reflects the polarized source light  12  as the polarized illumination light  16  in the second direction  18 . An optical surface  40  then receives and reflects portion of the polarized illumination light  16 , as the incident polarized light  26  illuminating a reflective microdisplay imager  20  in the third direction  28 . The incident polarized light  26  is modulated spatially and timely in light intensity and reflected at each of the reflective pixel elements  22  on the reflective microdisplay imager  20  back forth in the third direction  28  as the spatially modulated light  27 . Portion of the spatially modulated light  27  then partially passes through the optical surface  40  as the projection light  68  towards a lens  30 , with the principal axis  38  of the lens  30  aligned parallel to the third direction  28 . The projection light  68  passes through the lens  30  and as a magnified image  100  originally generated by the reflective microdisplay imager  20 , is eventually projected onto the projection display screen  1  outside the projection engine chassis  65  on which all those components are assembled and mounted. 
         [0039]      FIG. 2  shows the overall construction of a reflective microdisplay projection system in another prior art, using a reflective polarizing film  11   a  for inducing the polarized light illumination eventually to the modulation microdisplay imager  20 , as one improvement and simplification of the first prior art shown in  FIG. 1 . The reflective polarizing film  11   a  receives the source light  210  and reflects only first portion  211  of the P-component of the source light  210  as the polarized illumination light  16 , eventually redirected towards the reflective microdisplay imager  20  by the optical surface  40 . However, the rest or second portion  212  of the source light  210  incident to the reflective polarizing film  11   a  is not used and thus wasted. 
         [0040]      FIG. 3  shows the schematic of one embodiment of the portable reflective projection system with a disclosed novel integrated opto-electronic device  134  incorporated in accordance with the present invention. The integrated opto-electronic device  134  comprises a reflective polarizing composite film  150  and a photovoltaic cell  180 , adherently stacked in a plannar configuration. The reflective polarizing composite film  150  may entirely or partially cover the photovoltaic cell  180 , and the photovoltaic cell  180  may entirely or partially cover the reflective polarizing composite film  150 . The reflective polarizing composite film  150  can be directly placed on the photovoltaic cell  180 , or there can be one or more layers, such as a transparent layer, between the reflective polarizing composite film  150  and the photovoltaic cell  180 , The reflective polarizing composite film  150  receives incident light, in particular, the source light  210 , at a desired non-normal incident angle  221 , and reflects only a portion  211  of the P-component of the received source light  210  at the reciprocal angle  222  to the desired non-normal incident angle  221 . The rest or the second portion  212 , including the S-portion, of the received incident light (the source light  210 ) is deflected into and received by the photovoltaic cell  180 . Illuminated by the received second portion  212 , the photo diode  186  photogenerates electron-hole pairs, in which photogenerated electrons are extracted as photogenerated charge (by the top electrical contact grid  184  and photogenerated holes by the backside electrical contact  188 , as shown in  FIGS. 4   a  and  4   b ). Such photogenerated charges can be restored as electrical energy in an energy storage device  80  such as a rechargeable battery though an appropriate electrical circuitry setting shown in  FIG. 3  as applied to a reflective microdisplay projection system. 
         [0041]      FIG. 4   a  is a perspective view showing one embodiment of the disclosed novel integrated opto-electronic device  134  in accordance with the present invention, in which the reflective polarizing composite film  150  is adhered on the top of a photovoltaic cell  180  in a plannar stacking configuration and  FIG. 4   b  is a cross-section view of  FIG. 4   a . Replacing the reflective polarizing film  11   a  in the reflective microdisplay projection system shown in  FIG. 2  by the novel integrated opto-electronic device  134 , only portion of the P-component of the source light  210  is reflected as the polarized illumination light  16  eventually for illuminating the reflective microdisplay imager  20 , while unused light not reflected but deflected by the reflective polarizing composite film  150  enters and illuminates the underneath photovoltaic cell  180 . 
         [0042]    In one embodiment of the disclosed invention, the reflective polarizing composite film  150  comprises a single or a plurality of optical layer pairs  152  made of two layers of dielectric material such as rubber. Within the optical layer pair  152 , the top layer  153   a  first receiving the source light  210  has relatively higher optical refractive index than the bottom layer  153   b , and the top layer  153   a  and bottom layer  153   b  have relatively low optical extinctive coefficients, preferably less than 0.1, to effectively reflect majority of the P-component of the source light  210  at the desired non-normal incident angle  221 . 
         [0043]    As shown in both  FIG. 3  and  FIGS. 4   a  and  4   b , by electrically grounding the backside electrical contact  188  made of metal (such as copper and aluminium) or other conductive material (such as conductive ceramics), photogenerated charge (electrons) by the photo diode  186  of the photovoltaic device  180  is extracted by the top electrical contact grid  184  made of metal (such as copper and aluminium) or other conductive material (such as conductive ceramics) and then wired to and temporarily stored in the reservoir capacitor  72  of a voltage converter and battery charger  70 . Besides collecting unused illumination by the reflective polarizing composite film  150  and converting to photogenerated charge, a side photovoltaic panel  50 , perpendicularly facing the polarized illumination light  16 , can be employed to collect not reflected but transmitting portion of the polarized illumination light  16  and deflected portion of spatially modulated light  27 , to convert to photogenerated charge also conducted to the reservoir capacitor  72 . 
         [0044]    The optical surface  40 , which deflects the polarized illumination light  16  from the integrated opto-electronic device  134  towards the reflective microdisplay imager  20  and let pass the spatially modulated light  27 , can be also a concaved cylinder with its axis parallel to the common plane  24  of the reflective microdisplay imager  20 , and its outer surface facing the incident polarized illumination light  16 . 
         [0045]    The voltage converter and battery charger  70  further comprises a voltage converter  74  and a battery interface  76 . By monitoring voltage of accumulated photogenerated charge on the reservoir capacitor  72 , the voltage converter  74  is turned on once voltage of the accumulated photogenerated charge is adequate. Moreover, the reservoir capacitor  72  supports full cycles of operation of the voltage converter  74  without allowing the input voltage of the voltage converter  74  in switching mode to drop below its operating voltage. When voltage of the reservoir capacitor  72  drops below a predetermined level (the minimum operating voltage of the voltage converter  74 , or higher), the voltage converter  74  shuts down until the reservoir capacitor  72  again charges above the minimum operating voltage. The battery interface  76  is employed and connected with the rechargeable battery  80 , to monitor the output voltage of the rechargeable battery  80  and to disable switching between the voltage converter  74  and the rechargeable battery  80  when the output voltage of the rechargeable battery  80  reaches a first limit and to enable the switching when the output voltage declines below a second limit. The reference IC application note by Maxim illustrates such a device and system of the voltage converter and battery charger  70  with the rechargeable battery  80 . 
         [0046]    By measuring accumulated photogenerated charge collected by the photovoltaic cell  180  of the integrated opto-electronic device  134  over defined time duration through the voltage converter and battery charger  70 , light illumination generated by the light source  10  can be in situ monitored and adjusted real time according to a measurement result. Thus, intensity of the polarized illumination light  16 , the incident polarized light  26  and the projection light  68  can be estimated and adjusted timely. 
         [0047]    Typically, the energy storage device  80  is a rechargeable battery in lead acid or NiCd, as widely used in common portable and handheld systems. In practical application of the portable microdisplay projection system of the disclosed invention shown in  FIGS. 4   a  and  4   b , the same rechargeable battery  80  as a single energy storage device is employed to power one or both of the light source  10  and the reflective microdisplay imager  20 , through the power management device  90 . Also through the power management device  90 , the rechargeable battery  80  could be regularly charged by an external electrical power source  95 , also optionally providing electrical power to other electric-mechanical, electronic or optical devices affiliated with the disclosed portable microdisplay projection system, including the voltage converter and battery charger  70 . This is applicable particularly as the disclosed portable microdisplay projection system is embedded into a handheld communication and computing device or a laptop computing device in which the number of device groups of the similar or same function is minimized. In modern integrated circuits, the power management device  90  could be readily integrated with the voltage converter and battery charger  70  into a single integrated circuit device. 
         [0048]      FIG. 5   a  is a perspective view showing another embodiment of the disclosed novel integrated opto-electronic device  134 , in which the reflective polarizing composite film  150  comprises an micro-structured layer  160  of dielectric material  162  containing regularly spaced, parallel reflective conductive strips  164  made of metal (such as copper and aluminium) or other conductive material (such as conductive ceramics) in a plannar configuration; and  FIG. 5   b  is a cross-section view of  FIG. 5   a . According to the desired non-normal incident angle  221  and reciprocal angle  222 , the desired effective wavelength spectrum for visible light, preferably from 400 nm to 700 nm, and dielectric material  162  used as well as refractive index of the metal used, those reflective conductive strips  164  are spaced regularly in parallel at certain predefined fraction of the average wavelength spectrum, continuously covering the whole illumination area on the reflective polarizing composite film  150  by the source light  210 . 
         [0049]      FIG. 6   a  is a perspective view showing another embodiment of the disclosed novel integrated opto-electronic device  134 , where on a semiconductor substrate, a plurality of reflective top electrical contact lines  184   a  at the top of the photovoltaic cell  180 , regularly spaced in parallel with a desired spacing and embedded in a dielectric material  162 , first portion  211  of the P-component of incident light (source light  210 ) while deflect the rest portion of P-component and all the second portion  212  into the photo diode  186 , which generates photogenerated charge on a semiconductor substrate  190 ; and  FIG. 6   b  is a cross-section view of  FIG. 6   a . This embodiment is a simplified hybrid plannar device which employs a plurality of reflective top electrical contact lines  184   a  on top of the photo diode  186  in a plannar configuration, as both electrical contact and wires for transporting photogenerated charge (electrons) and regularly spaced reflective conductive strips for reflecting majority of the first portion  211  of the P-component of incident light (source light  210 ) while deflecting the second portion  212  into the photo diode  186  to produce photogenerated charge. As they all transport photogenerated charge towards the edge of the integrated opto-electronic device  134 , the reflective top electrical contact grid  184  are merged with either single or a plurality of metal pads  185 , sized adequately for wiring with a ceramic or plastic circuit board or flex connected to the voltage converter and battery charger  70  as shown in  FIG. 6   c . The metal pads  185  sized in relatively large size are exposed, via photolithography and etching, at edges of the reflective polarizing composite film  150  where those reflective top electrical contact grid  184  end and merge with the metal pads  185 . 
         [0050]    An alternative configuration as additional embodiment of this invention employs a reflective polarizing composite film  150  which comprises a plurality of optical layers made of polymeric materials. Thus the integrated opto-electronic device  134  is assembled by seamlessly bonding the polymeric reflective polarizing composite film  150  to the photovoltaic cell  180  fabricated on a semiconductor substrate. 
         [0051]    In summary, as shown in the drawing and hereinbefore described, the disclosed invention provides an innovative design opto-electronic architecture for designing a compact, electrically efficient of portable micro to pico projection systems using a reflective microdisplay imager based on spatial modulation of polarized illumination, by the means of partially energy-recovering, self-powering, and desirable arrangement for image formation and photovoltaic conversion of portion of unused light illumination, with help of a novel opto-electronic device, a voltage converter and battery charger and a built-in energy storage device. Such a novel opto-electronic device incorporates a reflective polarizing film onto a photovoltaic cell, readily fabricated on one semiconductor substrate. Although the provided description is for addressing primarily on a portable projection system employing a single LCOS imager, extended embodiments could be reasonably derived as applicable to other reflective microdisplay projection systems based on a number of reflective microdisplay imagers using spatial modulation of polarized illumination. 
         [0052]    Although a specific embodiment of the disclosed invention has hereinbefore been described, the inventor will be appreciated by those skilled in the art that other embodiments may be conceived, without nevertheless departing from the scope of my invention as described in the appended claims. For example, the disclosed portable microdisplay projection system is readily applicable as the embedded projection display module into a handheld communication and computing or laptop computing device within which the rechargeable battery  80  sharing a single, main energy storage device also powers other electric-mechanical, electronic and optical devices. The integrated opto-electronic device according to the present invention can be applied to different types of portable reflective projection system, not limited to those described in the specification. 
         [0053]    Finally, it should be understood that the above embodiments are only used to explain, but not to limit the technical solution of the present invention. In despite of the detailed description of the present invention with referring to above preferred embodiments, it should be understood that various modifications, changes or equivalent replacements can be made by those skilled in the art without departing from the scope and spirit of the present invention and covered in the claims of the present invention.