Embodiment
In the following description, in order to make the reader understand the application better many ins and outs have been proposed.But, persons of ordinary skill in the art may appreciate that even without these ins and outs with based on the many variations and the modification of following each embodiment, also can realize each claim of the application technical scheme required for protection.
For making the purpose of this utility model, technical scheme and advantage clearer, embodiment of the present utility model is described in further detail below in conjunction with accompanying drawing.
Can use technical solutions of the utility model a kind of light engine structure as shown in Figure 1, this light engine is a reflection-type, comprising: R light source (10R), G light source (10G), B light source (10B), dichronic mirror 50R, 40G, 50B, diffuser (20), beam shaping (Beam Shaper) (30), object lens (40-1,40-2), photomodulator (60), projection lens (70), polarization spectroscope (80), wherein R represents redness, and G represents green, and B represents blue.
The R/G/B light source shines R/G/B light successively, specifically, the time of a frame of irradiation is made as T, the time irradiation R light source of T/3, and the time irradiation G light source of the T/3 that follows, the T/3 time of following is again shone the B light source.Be appreciated that light source also can be according to other order irradiation successively, as B/G/R etc.
The light source that minitype projection machine is used also wants luminous many should volume for a short time, therefore needs to use LASER Light Source.Three light sources (10R, 10G, 10B) by separately dichronic mirror 50R, 50G, 50B reflection or be transmitted to diffuser (20).
The effect that dichronic mirror 50G plays reflection G light source (green laser that irradiates from 10G) and allows residual ray see through, dichronic mirror 50G also can use the general mirror that common visible rays all can be reflected.Dichronic mirror 50R plays the effect of reflection R light source (red laser that irradiates from 10R), the light by the residue wavelength coverage, and dichronic mirror 50B plays the effect of reflection R light source (blue laser that irradiates from 10B) by residue wavelength coverage light.
Diffuser (20) is perpendicular to the optical axis vibration, and in the time of therefore by diffuser (20), the randomness of light (Randomness) can obtain increasing.This diffuser is the device that is provided with in order to eliminate the distinctive laser speckle of laser (Speckle), reaches the purpose that reduces laser speckle in order to continuity (Coherence) feature that reduces laser beam.
Light by diffuser (20) can change beam shape by beam shaping (30).The reason that changes beam shape be the apperance of light beam to be shaped to be adapted to photomodulator (60) plane of incidence shape to improve optical efficiency.
The fly's-eye lens that beam shaping in the example among Fig. 1 (30) has used the two sides to be made of the micro objective body also can use 2 pieces of single face lens.On such two sides, or a plurality of micro objectives of assembling moulding above two pieces are separately known from experience each other one by one, and correspondence is shaped.
The micro objective body that is included in fly's-eye lens can be multiple shape: such as four jiaos of convex lens shape, hexagonal convex lens shape or circle etc., but preferably consistent with photomodulator shape (words are the effective coverage picture shapes with photomodulator more accurately).Such as the active area shape of photomodulator is when being dimetric, and the shape of micro objective body is also made quadrangle and can will be arrived light loss minimum.
The diameter of lenslet body is preferably 80-500um, the easier shaping of light beam under this size. this is because the diameter of micro objective is understood because the continuity of laser produce the grid lines in light beam less than the words of 80um, and under prior art, being difficult to make the lens arrangement of the shiny surface also littler than 80um. the effect of the words beam shaping that the diameter change is big can weaken, can not get the required uniform source of light of miniature optical engine, so following for well with 500um.
Each lenslet body is made up of the lenslet mixing of multiple different sizes, thereby laser speckle is reduced.
Object lens (40) are to utilize photomodulator (60) to carry out the lens of boundling the light through the beam shaping shaping, generally form by one to two.
Photomodulator (60) is meant that the light with incident carries out selectivity by, blocking-up or change the element that optical path forms the image picture.The representative instance of photomodulator (60) has Digital Micromirror Device (DigitalMicromirror Device, abbreviation " DMD "), liquid crystal display (Liquid Crystal Display, abbreviation " LCD ") element, liquid crystal on silicon (Liquid Crystal On Silicon is called for short " LCOS ") or the like.
DMD is used in digital light to handle (Digital Light Processing, abbreviation " DLP ") element of projector, it utilizes a type of drive of sequential (field sequential), uses the digital mirror of arranging with the as many matrix form of pixel quantity (DIGITAL MIRROR).DLP is meant that the light that goes out from light source irradiation regulates optical path with digital mirror, and reflects the projector that reaches gradual change (Gradation) or form image with dividing plate.
Liquid crystal display cells (LCD) is meant that optionally the ON/OFF liquid crystal forms visual element.Use in the projector of LCD element, direct viewing type (direct-view), porjection type and reflection-type are arranged.The direct viewing type projection is that the bias light of liquid crystal display cells back forms image and mode that can Direct observation by the LCD panel; The porjection type projection is to project screen after the image that will form by liquid crystal display cells utilizes projection lens to amplify, and observes from the mode of the image of screen reflection; The structure of reflection-type and porjection type is basic identical, and the difference part is that reflection-type is provided with reflectance coating on the substrate below LCD, and the light of reflection is exaggerated and projects on the screen.
LCOS belongs to reflective liquid crystal and shows, it in the past the lower substrate in the two sides substrate of liquid crystal display end change silicon substrate into by transparent glass, thereby operate with the reflection-type mode.
Polarization spectroscope (80) is to play the optical element that incident light is delivered to the effect of photomodulator (60), and in the hexahedron of its glass material, the polarisation diffusion barrier distributes with diagonal line, is the necessary optical element of reflection-type optical engine.
Incident light arrives on the polarisation diffusion barrier of polarization spectroscope (80), and the S polarisation can pass through, and the P polarisation then can be reflected to the reverse direction of projection lens and abandon.Therefore, the light from light source (10) comes out need a certain position conversion (Conversion) on light path become the form of linearly polarized light just can keep optical efficiency.But the polarization that comes from the light self of LASER Light Source compares up to hundreds of ratios one, so do not need the extra optical element that is used for forming linearly polarized light that adds.
So by the S polarisation of polarisation diffusion barrier, can form the P polarisation by photomodulator the time, the visual light that converts the P polarisation to incides in the polarization spectroscope (80) again, contacts with polarization separating film.At this moment visual light all is the P polarisation, therefore can all be reflected by the polarisation diffusion barrier, incides in the projection lens (70).
Projection lens (70) is made of a plurality of lens, will be gone up to screen (not identifying among the figure) by the image that photomodulator (60) form and amplify projection.
Above-described is the light engine of reflection-type, and the technical solution of the utility model also is applicable to the light engine of transmission-type.The structure of the light engine of transmission-type and reflection-type similar, difference mainly is not have polarization spectroscope (80), in addition, the light path of object lens (40), photomodulator (60) and projection lens (70) is same straight line.
Fig. 2 is the rough schematic of LASER Light Source structure.
The volume of LASER Light Source chip is very little, be difficult to processing, therefore can be made into the form of adhering to the LASER Light Source chip on the mount pad shown in Figure 2 (Mount). the convenience in order to illustrate in the utility model explains orally into C mount pad (C-Mount) type. and Fig. 2 is exactly the LASER Light Source of signal C mount pad type.
The mount pad body (100) that LASER Light Source chip (90) will be connected die bottom surface uses as anode (Anode).Place insulating bodies at the mount pad upper limb, on insulating bodies with the moulding of connecting line form negative electrode (120, Cathode), more above-mentioned connecting line and LASER Light Source chip are carried out line.
Above-mentioned light-source structure is C mount pad (C-Mount) type, is that the mount pad body construction promptly uses as anode (Anode) than the easier structure of general LASER Light Source chip manufacture.
The light engine of minitype projection machine is a kind of subminiature close packed structure, and therefore this mount pad metallic object itself plays the situation of the effect of anode (Anode), fracture easily in the assembling of light engine, thus produce the not high problem of processing procedure yields.
In embodiment of the present utility model, the works of LASER Light Source and high heat conduction is fixed, the contact site of this works and LASER Light Source will carry out mechanical buffing to be handled, other parts coating film treatment that insulate.
In an example, works can be made of the upper and lower side substrate, and LASER Light Source is formed a kind of " parcel ", and protection physically both was provided, and is convenient to again install.Certainly, works also can not be the form of upper and lower side substrate, and for example works can be combined or the like by three block elements.
Fig. 3 is one of example of the present utility model, is the synoptic diagram that LASER Light Source is fixed on the lower end substrate.
The LASER Light Source parallel surface is affixed on lower end substrate (130), is fixed with connector on the side of lower end substrate (130) simultaneously, plays the effect that links to each other with outside terminal.
Lower end substrate (130) is made by metal material, is coated with electron opaque material on the surface.Owing to be that metal material is made, so lower end substrate (130) also equals the area increase of heat radiator.Consider the weight and the thermal conductivity of light engine, in copper, aluminium, magnesium, zinc, select.On the thermal conductivity, copper and aluminium are better; Magnesium and zinc are then low weight.
Do not carry out coating film treatment with the surface of contact of LASER Light Source and the anode of connector (Anode), utilization contacts with LASER Light Source, and anode terminal and connector are coupled together.The bending of negative electrode (Cathode) connecting line is connected to connector.Owing to can link to each other with outside terminal by connector easily, so improved its working (machining) efficiency.
But, thermal resistance can take place when the face of LASER Light Source and lower end substrate (130) contacts, the heat that produces during LASER Light Source work can not in time distribute and can be stranded in mount pad.If heat can not be transmitted to lower end substrate (130) and be detained, not only the temperature of mount pad can rise, and the temperature of LASER Light Source chip also can rise, thereby causes migration (Shift) phenomenon of optical maser wavelength, and the amplitude of migration probably is 0.25nm/C °.Therefore, will change, have influence on color sensation, cause the problem of lasing fluorescence stability aspect if the temperature rising more than 20C °, constitutes white chromaticity coordinates.
The surface of contact that causes the reason lower end substrate (130) of the problems referred to above and LASER Light Source is smooth inadequately, and the coarse surface of contact area that causes reduces.Simultaneously, can use the outstanding thermal interface material of thermal conductivity (Thermal Interface Material) to carry out when adhering with lower end substrate (130), if the roughness of this face is too high, above-mentioned TI M just can not infiltrate equably, caused between the pore that should play conductive force and filled into air, reduced the validity of heat conduction.
In order to reduce above-mentioned thermal resistance, the upper surface of lower end substrate (130) and the lower surface of laser mount pad have been carried out mechanical buffing (Mechanical Polishing) processing in the utility model embodiment.By mechanical buffing, the contact area of two faces obtains increasing, and above-mentioned thermal interface material (TIM) also can infiltrate more equably, and the heat that can effectively LASER Light Source be taken place is transmitted on the lower end substrate (130).Surfaceness suggestion after the mechanical buffing maintains below the Rmax 6.3s.
As thermal interface material, heat-conducting silicone grease (Thermal greases) or phase transformation pad (Phase changepads) etc. are the main materials that uses, the particularly phase transformation pad expansion that meeting becomes liquid and produces volume from solid under the uniform temperature condition, drive away air, infiltrate in the pore, thereby realize better thermal conductivity.
Fig. 4 is the combination of LASER Light Source and lower end substrate (130), the synoptic diagram that combines with upper end substrate (140).Have the lens opening of lens devices on laser path above the upper end substrate (140), the laser of dispersing can be carried out light harvesting.
The same with lower end substrate (130), upper end substrate (140) also all is coated with megohmite insulant except that LASER Light Source portion, then is that face contacts with LASER Light Source.And also preferably the contact site is polished, and utilize thermal interface material (TIM) to adhere.
Upper end substrate (140) and lower end substrate (130) carry out soldering with soldering paste (Solder Cream), allow upper and lower side substrate (130) suitably be pressed in above the LASER Light Source, and heat conductivility is played good result.Substrate (140) and lower end substrate (130) also can otherwise be fixed on being appreciated that, for example fix or fix with securing member with mechanical bayonet socket, as long as can suitably be pressed on the LASER Light Source all right.
In the present embodiment, the upper and lower side substrate adopts metal material, and metal material not only can be put forward good altogether heat-conducting effect, also because of the high strength of metal the LASER Light Source chip is had the better protect effect.Certainly, also can use other highly heat-conductive material, as compound substance, high heat-conducting ceramic or the like.
Though used three LASER Light Source in the present embodiment, but the technical solution of the utility model is not limited to all use the light engine of LASER Light Source.Also can comprise one or more light emitting diodes (Light Emitting Diode is called for short " LED ") light source in a plurality of light sources of light engine.For example, a light engine has three light sources, and one is red LASER Light Source, and another is green LASER Light Source (being obtained through frequency multiplication by infrared laser light source), also has one to be blue led light source.Led light source also has bigger thermal value, also can use the technical solution of the utility model to obtain better radiating effect.
Around the said structure thing of LASER Light Source, play the heating radiator effect of the heat that distributes the LASER Light Source generation in the utility model embodiment, allowed the connection of LASER Light Source input power supply become easily simultaneously, improved the assembling convenience of light engine.Particularly the heat that takes place is dispersed into rapidly in the airborne situation using fan, has prevented that the wind that fan sends from directly contacting with the LASER Light Source chip, thereby reduced the damage possibility of LASER Light Source chip.
Though by reference some preferred implementation of the present utility model, the utility model is illustrated and describes, but those of ordinary skill in the art should be understood that and can do various changes to it in the form and details, and do not depart from spirit and scope of the present utility model.