Abstract: Optical MEMS scanning micro-mirror comprising: —a movable scanning micro-mirror (101), being pivotally connected to a MEMS body (102) substantially surrounding the lateral sides of the micro-mirror, —a transparent window (202) substantially covering the reflection side of the micro-mirror; —wherein a piezo-actuator assembly (500) and a layer of deformable transparent material (501) are provided on the outer portion of said window (202); —the piezo-actuator assembly (500) being arranged at the periphery of the layer of transparent material (501); —said piezo-actuator assembly (500) and transparent material (501) cooperating so that when actuated, the piezo-actuator assembly (500) causes micro-deformation of the transparent material (501), thereby providing an anti-speckle effect. The invention also provides the corresponding micro-projection system and method for reducing speckle.

Abstract: A light source apparatus includes a red light emitting device to emit red light; a green light emitting device to emit green light; a blue light emitting device to emit blue light, each of the red light emitting device, the green light emitting device, and the blue light emitting device disposed separately from any other. Among the red light emitting device, the green light emitting device and the blue light emitting device, at least two light emitting devices each includes a first light source and a second light source, the first light source emitting light having a wavelength of a light of a primary color, and the second light source emitting light having a wavelength deviated from the wavelength of the light of the primary color.

Abstract: A projector includes a light source apparatus, a light modulator that modulates light outputted from the light source apparatus in accordance with image information, and a projection system that projects light modulated by the light modulator. The light source apparatus outputs light formed of first light of a narrow wavelength band having a first wavelength where the optical intensity peaks and second light of a narrow wavelength band having a second wavelength where the optical intensity peaks, and the separation between the first and the second wavelength is set at a value greater than ¼ of one-cycle wavelength of a ripple among ripples contained in an optical spectrum of light that results from the light incident on the light modulator and is reflected off the light modulator, the ripple located in the wavelength regions of the first light and the second light, but smaller than ¾ of the one-cycle wavelength.

Abstract: A micromechanical component includes: at least one micromirror; and an integrated photodiode. The micromechanical component is part of a microprojector which further includes a light source. The integrated photodiode of the micromechanical component receives light from the light source.

Abstract: A light source unit may include a cooling device; a luminescent substance; an excitation radiation source having a laser source; and an optical element arranged between the radiation source and the substance; wherein the cooling device constitutes a heat sink, wherein the substance is linked thermally to the heat sink; and wherein the optical element is designed as an integrating optical element and is coupled between the radiation source and the substance in such a manner that a part of the radiation emitted by the radiation source, entering in an acceptance angle range of the integrating optical element, is subjected to an internal reflection in the optical element before it exits the optical element and strikes the substance, and that a part of the radiation emitted by the substance enters the optical element and exits the optical element as effective radiation.

Abstract: An exemplary video wall includes two display panels and a polygonal mullion elimination lens. Each of the display panels includes a main body and a bezel surrounding the main body. The polygonal mullion elimination lens includes a central first concave surface configured to reflect internal light incident thereon, two flat surfaces respectively attached to the main bodies of the display panels, a central second concave surface opposite to the first concave surface, and two lateral surfaces each connecting between a corresponding one of the flat surfaces and the second concave surface. Portions of light emitted by the main bodies of the display panels can enter the mullion elimination lens via the flat surfaces.

Abstract: A projector includes an illumination device having a light source device emitting light, and a polarization conversion element adapted to emit light from the light source device as polarized light, a light modulation device adapted to modulate the light from the illumination device in accordance with image information, and a projection optical system adapted to project the light from the light modulation device, and the illumination device further includes a light diffusing unit disposed in at least one of upstream and downstream of the polarization conversion element.

Abstract: A projector system that includes a first input device, a second input device, a control device, a sensor and a phase locked loop (PLL). A phase reference signal is created based on a signal rate of the first input device. A phase feedback signal is created based on the rotational speed of the second input device as it is measured by the sensor. The PLL compares the phase reference signal and the phase feedback signal to determine whether the first input device and the second input device are synchronized. A signal is sent to the control device for the second input device to change the rotational speed of the second input device in response to determining that the first input device and the second input device are not synchronized.

Abstract: A miniature projector is provided that comprises: a means for providing at least three different light beams of different color; and a means for scanning the light beams; wherein the scanning means is adapted to scan the light beams according to a pattern from a first edge to an ending edge in the screen to form an image, the pattern being a wave pattern of scan lines such that amplitudes oscillates along a first axis as the beams progressively scan along a second axis, the second axis being perpendicular to the first axis, and wherein the wave pattern is a composite of a vertical scan profile and horizontal scan profile and the vertical scan profile has a cyclic wobulation corresponding to the amplitudes.

Abstract: A micro-projection system for projecting light on a projection surface (104), comprising: —at least one coherent light source (101); —optical elements (102, 108, 109) in the optical path between said coherent light source and said projection surface; —said optical elements including at least one reflective member (102) actuated by a drive signal for deviating light from said light source so as to scan a projected image onto said projecting surface; —said optical elements including at least one pixel displacement unit (106) for providing a displacement signal synchronized with the image scanning signal so as to reduce speckle onto said projecting surface. The corresponding method for reducing speckle is also provided.

Abstract: A projector includes a solid-state light source that emits linearly polarized light, a birefringence element that converts the linearly polarized light emitted from the solid-state light source into circularly or elliptically polarized light, a diffusion element that diffuses the light having exited from the birefringence element, and a polarization conversion element that separates the diffused light having exited from the diffusion element into first polarized light polarized in a first polarization direction and second polarized light polarized in a second polarization direction, converts the polarization direction of the first polarized light into the second polarization direction, and outputs the resultant first and second polarized light.

Abstract: Assuming that a normal line of an image display surface of a DMD is a normal line Ax of the image display surface, that a direction in which a light beam specularly reflected by a mirror is outputted is a specular reflection direction R, and that an angle that the specular reflection direction R forms with respect to the normal line Ax of the image display surface is denoted by ?, an image projection apparatus satisfies the following conditional expression: ?(2·k?1)?2·???(2·k)??(2·k+1), where ?(2·k?1) and ?(2·k+1) represent a diffraction angle of an odd-order diffracted light, and ?(2·k) represents a diffraction angle of an even-order diffracted light.

Abstract: An apparatus and method for despeckling that includes a green laser diode assembly, a pulsed laser with a repetition rate of less than 100 kHz, and stimulated Raman scattering light formed in an optical fiber. The laser diode light and stimulated Raman scattering light are combined to form a projected digital image. The green laser diode assembly or the pulsed laser is switched to improve the bit depth of the projected digital image.

Abstract: A system and method for providing a fiber array light source with individually controlled multiple-wavelength outputs are disclosed. A single spatial light modulator (SLM) outputs an image light of a first wavelength and an image light of a second wavelength. An overlap image is produced based on the image light of the first and second wavelengths. A fiber array receives light associated with the overlap image so that each individual optical fiber in the fiber array corresponds to multiple pixels on the SLM.

Abstract: An illumination system including at least one laser source, at least one anisotropic light expanding element and a wavelength conversion element is provided. The at least one laser source emits a laser beam. The at least one anisotropic light expanding element is disposed on the transmission path of the laser beam and causes the laser beam to expand along a light expanding direction. The light expanding direction is substantially parallel to the slow axis of the laser beam. The wavelength conversion element is disposed on the transmission path of the laser beam. A projection apparatus is also provided.

Abstract: A system and method for multiplexing multiple images of different colors using only a single spatial light modulator (SLM) are disclosed. In the disclosed system, a first dichroic beam splitter receives an image light of first and second wavelengths from the SLM, and reflects the image light of the first wavelength towards a first mirror and an image light of the second wavelength towards a second mirror. The first mirror reflects the image light of the first wavelength at a first angle, and the second mirror reflects the image light of the second wavelength at a second angle. Further, the system includes a second dichroic beam splitter that receives the image light of the first wavelength from the first mirror and the image light of the second wavelength from the second mirror, and recombines the image light of the first and second wavelengths to produce an overlap image.

Abstract: Provided is a projector including: a control unit which controls amounts of laser light output by a plurality of light source units, based on color pixel values of each of plural pixels of an image which is projected onto a projection surface, the color pixel values corresponding to different colors of wavelengths of the laser light output by the plurality of light source units, wherein the control unit further compensates for the amounts of the laser light, based on a portion of the amounts of the laser light detected by an OEIC, so that for each of the different colors, proportion of the amount of the laser light of the color output by one of the light source units to the color pixel value of the color in each of the plural pixels of the image corresponds to predetermined proportion.

Abstract: A chart generation unit generates an adjustment chart, and a projection unit projects the adjustment chart onto a circular cylinder. A parameter acquiring unit acquires 12 parameters in total, relating to the positions of four corners and middle points of a top side and a bottom side of a chart and lateral expansion of the chart, the chart being input by a user through manipulations of an operation unit. A transform function determination unit calculates, from the total of 12 parameters, an accurate transform function for projecting an image onto the circular cylinder. An image conversion unit applies geometric transformation to the image based on the calculated transform function.

Abstract: A projection apparatus including a casing, a light source module, a fan, and a light engine module is provided. The casing has an inlet and an outlet. The light source module is disposed in the casing and is adjacent to the inlet. The fan is disposed in the casing and is adjacent to the outlet, and is configured to provide a heat dissipation airflow. The light engine module is disposed in the casing and is located between the fan and the light source module, and the heat dissipation airflow sequentially flows through the inlet, the light source module, the light engine module, the fan, and the outlet. The fan is disposed between the light engine module and the outlet.

Abstract: Various embodiments may relate to a method for irradiating an imaging optical system of a projector. The imaging optical system is irradiated with light of different colors from different semiconductor light sources sequentially, both with individual colors and superimposed as mixed light.

Abstract: A projection display is provided with an imager that is implemented to generate individual images in a distribution of sub-areas of an imaging plane of the imager. The projection display also includes a multi-channel optics, which is configured to map one allocated sub-area of the imager each per channel, such that the mappings of the individual images are combined to an overall image in a projection area. At least some channels of the multi-channel optics are arranged along at least one curve which is similar to at least one elongated image feature of the overall image, so that a two-dimension anisotropic out-of-focus behavior of each projected image point is obtained. In this way, a large depth of focus range can be combined with relatively high projection brightness without having to accept losses with respect to the focused illustration of image features that are to be projected with sufficient focus.

Abstract: A projector includes a light source module, a collimation element, a liquid crystal unit, and a combination element. The light source module includes a red light source, a green light source, and a blue light source. The collimation element includes an optical portion, the optical portion includes three collimation lenses aligned with the red light source, the green light source, and the blue light source respectively. The liquid crystal unit includes three information-loading areas aligned with the three collimation lenses respectively. The combination element includes three parallel reflecting surfaces, the three reflecting surfaces incline 45 degrees toward the liquid crystal unit, and are aligned the three information-loading areas respectively.

Abstract: A solid state illumination system is provided as a replacement for conventional arc light, metal halide and Xenon white-light sources for applications in life sciences including, microscopy, fluorescence microscopy, and endoscopy. The solid state illumination system generates high quality white light output from LED light sources. The white light output is continuous in the visible spectrum from 380 nm to 650 nm and is suitable for imaging all the most common fluorophores and fluorescent proteins. In embodiments, an LED light pipe engine is used to generate a portion of the spectral content of the white light output. In alternative embodiments the solid state illumination system produces light output of a selectable color.

Abstract: An image projection device includes a number-of-times measurement section that measures the number of passage times that the scanned laser light has passed through the light radiation members, a time measurement section that is triggered to measure an elapsed time when the number-of-times measurement section measures the number of passage times, an arithmetic section that calculates an initial timing at which the laser light source section starts outputting the laser light based on the measurement results of the number-of-times measurement section and the time measurement section, and a signal generation section that generates the switch signal at the initial timing calculated by the arithmetic section.

Abstract: A digital light processing projector includes a light emitting diode (LED), a laser, a rotatable optical element, a reflector, a first filter, a second filter, a digital micro-mirror device (DMD), and a projection lens. The LED and the laser respectively emit a first and second homogeneous lights. The rotatable optical element converts a first portion of the second homogeneous light to a third homogeneous light, reflects the third homogeneous light, and transmits a second portion of the second homogeneous light. The reflector reflects the third homogeneous light. The first filter transmits the first homogeneous light, and reflects the second portion to the second filter. The second filter transmits the second portion and the first homogeneous light, and reflects the third homogeneous light to the DMD. The DMD modulates the first, second and third homogeneous lights to obtain optical images. The projection lens projects the optical images on a screen.

Abstract: A system is provided for projecting a three-dimensional image. The system includes a first light source, emitting a light of a first color and a second light source emitting light of a second color. At least one polarizing beam splitter (PBS) is disposed adjacent the first light and the second light source, and at least one imaging device is disposed adjacent the at least one PBS.

Abstract: Optical element 10 according to the present invention comprises light guide body 11, surface plasmon excitation means 14 that is provided on the interface with light guide body 11 and that allows surface plasmon to be excited by a specific polarization component of light whose polarization direction is orthogonal to the first direction y in the surface of light guide body 11, from among light entering from light guide body 11, and a light generation means that includes metal layer 12 and cover layer 13, and that generates light having the same polarization component as the specific polarization component of light, from surface plasmon produced in the interface between metal layer 12 and cover layer 13 in response to surface plasmon excited by the specific polarization component in surface plasmon excitation means 14.

Abstract: An illumination system including a light source, a filtering module, a wavelength conversion unit, and a reflection unit is provided. The light source emits an illumination beam. The filtering module is disposed on a transmission path of the illumination beam and includes a plurality of filtering units having different colors. The filtering units move into the transmission path of the illumination beam in turn. Each filtering unit reflects a part of the illumination beam and allows another part of the illumination beam to pass through. The wavelength conversion unit is disposed on a transmission path of the part of the illumination beam reflected by at least one of the filtering units to convert the part of the illumination beam reflected by the at least one of the filtering units into a converted beam. The wavelength conversion unit is disposed on the reflection unit. A projection apparatus is also provided.

Abstract: A light source system for a stereoscopic projection apparatus is provided. The light source system has a light source module, a first lens unit, a light splitting element, a color wheel module and a light integration element. The light source module provides a light beam, which is transferred by the first lens unit to the light splitting element. Then, the light beam is split by the light splitting element into a first light beam with a first bandwidth and a second light beam with a second bandwidth. The first and the second light beams are then received and transformed by the color wheel into a third light beam and a fourth light beam which are then transmitted to the light integration element. With the above arrangement, the light source system can be applied on a projection apparatus to provide a stereoscopic image.

Abstract: The present invention is concerning an image projection apparatus comprising: a projecting unit that projects and displays on a projection surface each image in a time sharing manner for each of a plurality of color components, for an input image signal; a shooting unit that shoots a projected image on the projection surface; a shoot control unit that makes the shooting unit perform the shooting, when a detection mode of a irradiation point at which light is irradiated from an irradiation device on the projection surface is set, in timing shifted by a certain amount of time from a synchronized state to time sharing timing of each color component in the projecting unit; and an irradiation-point-position detecting unit that detects, from a projected image projected by the projecting unit, a position of the irradiation point on the image.

Abstract: A projector that projects a visible image as well as a non-visible image. The non-visible image might be used for any purpose, but an example is in order to provide depth information regarding physical item(s) interacting with the projected visible image. The projector includes multiple projecting units (e.g., one for each pixel to be displayed), each including light-emitting elements configured to emit light in the visible spectrum. Some or all of those projecting units might also include an emitting element for emitting light in the non-visible spectrum so as to collectively emit a non-visible image. Optics may be positioned to project the visible image and the non-visible image. A depth sensing module detects depth of surfaces within the scope of the non-visible image using a reflected portion of the non-visible image.

Abstract: A free-space dynamic diffractive projection apparatus comprises a laser light source element, a dynamic diffractive element, a control element, and a signal output element. Based on a pattern signal outputted from the signal output element, the control element controls the laser light source element to emit a color beam, and controls the dynamic diffractive element to perform real-time signal modulation so as to generate different dynamic diffractive grating distributions in a specific period. Accordingly, the color beam passes through the dynamic diffractive element to produce the pixels defined by the pattern signal in a specific space. The control element controls the dynamic diffracting element to be quickly switched to display each pixel, so that each pixel is projected on a corresponding position in a specific space to form a two-dimensional geometric image.

Abstract: A light source apparatus includes a light source unit and an output unit. The light source unit includes at least one solid-state light source capable of outputting light in a predetermined wavelength range as output light. The output unit includes a light emitter and a base unit. The light emitter is excited by the output light from the light source unit and emits visible light with a wavelength different from a wavelength of the output light. The base unit is rotatable about a predetermined rotation axis and contains a crystalline member having a crystal axis direction set to a direction different from a direction orthogonal to an optical axis direction of the output light, the light emitter being supported in the optical axis direction. The output unit is capable of outputting combined light containing the light in the predetermined wavelength range and the visible light emitted from the light emitter.

Abstract: Systems for and methods of creating a visual display associated with a mobile robot within a data storage library and libraries including such systems and utilizing such methods.

Abstract: A projection-type image display apparatus includes a color separation element including a color separation surface, a light modulation element configured to receive the light divided by the color separation element, a polarizing beam splitter disposed between the color separation element and a projection optical system to separate a light path of a light modulated by the light modulation element according to a polarization direction and guide the resulting light to the projection optical system, and a phase difference plate disposed between the color separation element and the light modulation element. An optic axis of the phase difference plate and the normal of the color separation surface are substantially parallel or perpendicular to each other, in a cross section parallel to a normal of the color separation surface and a normal of the light modulation element.

Abstract: An image display apparatus includes: a laser light source for outputting a laser beam; a diffusion optical element for diffusing the laser beam; a drive unit for oscillating the diffusion optical element; and an image conversion unit for converting the laser beam output from the diffusion optical element into an image. The diffusion optical element disposed in the drive unit is oscillated and operated in a state where an amplitude of the drive of the drive unit, which is, for example, an amplitude that is driven in a direction of the arrow X in a plane that is perpendicular to an optical axis, is not constant.

Abstract: A projector for displaying textual patterns includes a light emitting matrix and a controller for controlling the light emitting matrix. The light emitting matrix is selectively illuminated to project textual patterns on a surface.

Abstract: An optical fiber fixing structure for fixing a fiber bundle that covers a plurality of bundled optical fibers with a coating and the plurality of optical fibers that are exposed from an end of the coating of the fiber bundle at a predetermined position comprises a first holding section that holds the coating of the fiber bundle, and a second holding section that holds distal end portions of the plurality of optical fibers exposed from the end of the coating of the fiber bundle respectively. The first holding section and the second holding section are integrally formed.

Abstract: A method for projecting a three-dimensional image, that includes providing a first light source and a second light source. A polarizing beam splitter (PBS) is disposed adjacent the first light source and the second light source. An imaging device is adjacent the PBS. A polarization flipping element is disposed adjacent the PBS opposite the imaging device, and a mirror is disposed adjacent the polarization flipping element. A first light is emitted from the first light source. The first light is polarized such that it reflects through the PBS to a polarization flipping element. The first light passes through the polarization flipping element twice such that it will reach the surface of the imaging device. The second light is emitted from the second light source after the first light is emitted. The second light is polarized such that the light passes through the PBS to the imaging device.

Abstract: Provided is a light source unit that includes: one or more kinds of phosphor; a substrate, on which the one or more kinds of phosphor is applied; a plurality of semiconductor laser elements arrayed at a predetermined interval in a package, wherein each of the semiconductor laser elements emits a laser light beam through a light emission region; and a first optical system that comprises a first lens system, a multiplexing optical member having a light entering surface and a light exiting surface, and a second lens system, wherein the first optical system directs the laser light beams emitted from the respective semiconductor laser elements toward the substrate, the first lens system receives the laser light beams emitted from the respective semiconductor laser elements directly without substantial parallelization of the respective received laser light beams, and condenses the received laser light beams on the light entering surface of the multiplexing optical member, the multiplexing optical member multiplexes

Abstract: Provided is a projection apparatus that can enhance the efficiency of utilization of RGB laser lights, eliminate positional displacement in projection point caused by spaced-apart fiber cores emitting the laser lights, and detect additional information while projecting an image with the laser lights. The projection apparatus includes a laser light source emitting infrared and RGB laser lights, a fixing device fixing end portions of an infrared-light fiber and colored-light fibers used to transmit the infrared and RGB laser lights, a scanning unit projecting an image on a projection surface by scanning the projection surface with the RGB laser lights emitted from the end portions of the colored-light fibers, a detection unit detecting reflection of the infrared laser light emitted from the end portion of the infrared-light fiber, and a control unit controlling emission of the RGB laser lights from the light source, based on information detected by the detection unit.

Abstract: A light source unit, includes: a semiconductor laser device that emits laser light; a wheel substrate that has a light entering surface and a light exiting surface, and includes one or more phosphor-containing regions each contains one or more kinds of phosphor converts the laser light into light having a wavelength different from a wavelength of the laser light; a motor that faces the light entering surface of the wheel substrate, wherein the motor has a rotational shaft that supports a center of the wheel substrate, and is configured to rotate the wheel substrate; and a condensing optical system that faces the light exiting surface of the wheel substrate, and condenses light that has exited from the light exiting surface of the wheel substrate, the condensing optical system comprising a lens having an optical axis that substantially coincides with a reference axis of the light that has exited from the light exiting surface of the wheel substrate, wherein the lens is sized to cover the center of the wheel su

Abstract: There is disclosed a laser projector and a method of processing a signal thereof. The laser projector includes a plurality of laser sources configured to generate lasers, a controller configured to control each of the generated lasers to be incident on a specific region of a screen with a time difference, and a scanner configured to scan each of the lasers on the screen.

Abstract: A projector includes a light source, a light collection optical system adapted to collect light emitted from the light source, and a light modulation panel adapted to modulate the light collected by the light collection optical system, the light collection optical system includes a color separation optical system adapted to separate the light emitted from the light source into a plurality of types of colored light, and a reflecting curved surface is disposed in at least a light path of the colored light with the longest light path length between the light source and the light modulation panel out of the plurality of types of colored light.

Abstract: An image projection apparatus includes a light source; a projected image outputting unit having multiple mirrors arranged in a matrix, to which radiating light emitted from the light source while controlling an angle of a light reflection face of each of the mirrors; a control unit controls the angle of light reflection face of the mirrors using the a division half-toning control based on image data of a projected image, and settings of control parameters used for the time division half-toning control; and an image capturing device to capture the projected mage. When the control unit detects a false contour in a projected test pattern image based on image data of the projected test pattern image captured by the image capturing device, the control unit corrects the control parameters for the time division half-toning control based on detection of the false contour.

Abstract: A small light source unit is provided which emits lights of the primary colors which are highly bright and which have a high color reproducibility and excitation light, and the light source unit includes a light source module and a light source control module and the light source module has a first light source which emits light having a first wavelength which is used as excitation light which excites a luminescent material, and a second light source which emits light having a second wavelength which is different from the first wavelength but which falls within a range of wavelengths of light of a similar color to that of the light of the first light source, and the light source control module controls individually the illumination of the first light source and the second light source.

Abstract: A light source apparatus includes a light emitting device that has a first light emitting region outputting first excitation light and a second light emitting region outputting second excitation light, a phosphor layer that is so provided that the phosphor layer coincides with the first light emitting region in a plan view and emits fluorescence light, a reflector that is provided on the opposite side of the phosphor layer to the light emitting device, transmits the fluorescence light, and reflects the excitation light, and a light guide section that is disposed on an optical path between the phosphor layer and the reflector, and guides the second excitation light reflected off the reflector such that at least part of the reflected second excitation light enters the phosphor layer.

Abstract: An illuminator includes: a light source section including a laser light source; an optical element through which a laser beam from the laser light source passes; a driving section oscillating the optical element; and a control section controlling, in a driving operation performed by the driving section, the driving operation to allow an oscillating amplitude value of the optical element in a startup period of the optical element to be equal to or less than the oscillating amplitude value of a steady-state operation period of the optical element that is subsequent to the startup period.

Abstract: A projection system includes a laser light source module, at least one display module, and a projection lens. The laser light source module includes at least one light source, at least one wavelength conversion element, at least one light detecting unit, and a controller. The laser light source emits a first light beam with a first wavelength. The wavelength conversion element is used for converting the first light beam into a light beam with a wavelength different from the first wavelength. After an optical energy of the light beam outputted from the wavelength conversion element and higher than a systematic etendue is detected by an optical sensor of the laser light source module, at least one of a brightness and a light color of the laser light source module is adjusted or compensated by the controller according to the detecting result.

Abstract: A phosphor wheel includes a glass, a first phosphor agent and a first filter. The glass has a first region and the first phosphor agent is coated on the first region for converting a first color light into a second color light. The first filter is disposed next to the first region for filtering at least a portion of the first color light and a first light beam of the second color light, so that a second light beam of the second color light is transmitted through the first filter. The second color light is yellow light, the first phosphor agent is yellow phosphor agent, and the first filter is a red light filter. The present invention achieves the advantages of decreasing the fabricating cost, increasing the brightness of the red light with increasing of driving current and the whole brightness of the illumination system, and improving the image quality.