CN101067666A - Optical member unit and image display device - Google Patents

Abstract

The invention provides an optical member unit including a light transmitting member guiding light emitted by a light source to an imaging optics system by folding the light. The light transmitting member has a refractive index that achieves total reflection of a part of light entering the imaging optics system, the incident angle of the part of light is within the maximum effective incident angle of the light to the imaging optics system. The maximum effective incident angle is determined by the imaging optics system and the refractive index of an incident-side medium that is a medium provided between the imaging optics system and the optical member unit.

Description

Optical member unit and image display device

Technical field

The present invention relates to a kind of special parts such as reflectance coating that do not need just can catoptrical optical member unit and image display device.

Background technology

In the optical system, the emitted light of light source incides in the various opticses at the state that its light path is changed.For example, in the projection type image display apparatus such as liquid crystal projection apparatus, the emitted light of light source incides in the dichroic element after optical modulation is implemented, if but the light path between light source and the dichroic element is a linearity, just then device all can maximize.Projection type image display apparatus in recent years, therefore having relatively high expectations of slimming miniaturization by the mechanism of the direct of travel that changes the emitted light of light source is set, satisfy the requirement of slimming miniaturization.

As the mechanism of the direct of travel that is used for changing light, it is effectively using prism (mainly being triangular prism).Inclined-plane at triangular prism is formed with reflecting surface, and incides this reflecting surface by light and make change in travel direction.The one example is disclosed in the spy and opens in the 2005-316446 communique.The spy opens in the 2005-316446 communique, is applicable to liquid crystal projection apparatus as optical system, and the emitted light of light source makes optical path change by reflecting surface (spy opens the diagonal plane of the 2005-316446 communique) reflection of prism.Thereby, in order to bring into play reflection function, on diagonal plane, be provided with reflectance coating or catoptron cover.

The spy opens in the 2005-316446 communique, used the catoptron cover, but because the catoptron cover need be installed on the prism, so according to its installation accuracy, thereby incident light can not import to the light from light source in the liquid crystal display device (image that the spy opens the 2005-316446 communique forms mechanism) towards given direction reflection sometimes.In addition, realizing there is the such problem of the corresponding increase of part count under the situation of reflection function by the catoptron cover.And then if the part count of catoptron cover increases, cost also can correspondingly increase.In addition, also has the method that forms reflectance coating rather than catoptron cover at the reflecting surface of prism.If the formation reflectance coating has then been avoided problems such as the problem of part count or installation accuracy, incident light can be reflected.But, exist metallic reflective coatings such as employed silver of reflectance coating or aluminium to produce light absorption etc. and make problem that reflectivity reduces, reduce such problem based on the weather resisteant of oxidation or sulfuration etc.

In the past, having the optics that is made of photopermeability material (for example glass) (below be called light guide member) and the optical member unit of the optics (triangular prism) that is made of photopermeability material (for example glass), generally is well-known.In addition, triangular prism is the direction (incident direction) that makes light incident and the different optics of direction (exit direction) of light outgoing.

Be provided for making the method for incident direction triangular prism different and light guide member like this with exit direction, can list method (" プ ロ ジ ェ Network Dou Zhi Knowledge ", [Online] of refractive index less than the air-gap of triangular prism and light guide member is set between triangular prism and light guide member, " retrieval on March 13rd, 2006 ", internet＜http://www.geocities.co.jp/Hollywood-Studio/7057/mame1/mame3.ht m 〉).

According to this method, between triangular prism and light guide member, air-gap is set, the part that can suppress light thus sees through the reduction of caused smooth utilization ratios such as triangular prism or the generation of irregular colour not by total reflection.

Here, the method for above-mentioned air-gap is set, considers to use the method for globule as spacer.Specifically, the bonding agent that utilization contains globule is glued together the part of the peripheral part of the light entrance face of the part of the peripheral part of the light-emitting face of light guide member and triangular prism, and between the light entrance face of the light-emitting face of light guide member and triangular prism, form air-gap (for example the spy opens flat 11-231256 communique) by globule.

On the other hand, all be under the situation of effective range at the light-emitting face of light guide member and the comprehensive of light entrance face of triangular prism, the globule that contains in the bonding agent makes light scattering, so the light utilization ratio of optical member unit reduces.

Therefore, the amount of bonding agent that preferably contains globule is less, if but reduce the amount of the bonding agent that contains globule, then the bond strength of light guide member and triangular prism will reduce.

Summary of the invention

A feature of the present invention is a kind of optical member unit, it is made of light transmission (light-transmission) parts that import to imaging optical system after the emitted light of light source is bent, wherein, above-mentioned transparent member, have make in the light that incides above-mentioned imaging optical system, to the maximum effectively refractive index of the light total reflection below the incident angle of above-mentioned imaging optical system; The effective incident angle of above-mentioned maximum is the refractive index and the decision of above-mentioned imaging optical system of light incident side medium by medium set between above-mentioned imaging optical system and above-mentioned optical member unit.

As preferably, in the above-mentioned feature of the present invention, above-mentioned transparent member has the reflecting surface that is used for the light reflection, and the exit facet that makes the light outgoing that above-mentioned reflecting surface reflects; Refractive index at above-mentioned transparent member is made as nt, the refractive index of the perimeter of above-mentioned transparent member is na, the refractive index of above-mentioned light incident side medium is ni, the effective incident angle of above-mentioned maximum is θ i, the incident angle that incides above-mentioned exit facet is θ r, above-mentioned reflecting surface and the formed angle of above-mentioned exit facet are β, and with the above-mentioned reflecting surface face vertical with above-mentioned exit facet both sides in, reflection angle in the above-mentioned reflecting surface is made as " negative sense " less than the direction that light reflected of angle delta, reflection angle is made as " forward " greater than the direction that light reflected of angle delta, when the normal direction of above-mentioned imaging optical system is made as " orthogonal directions ", wherein above-mentioned angle delta is that the normal direction of direction parallel with the optical axis center of the light that incides above-mentioned imaging optical system and above-mentioned reflecting surface is formed, the angle of composition in the above-mentioned vertical face in the reflection angle of above-mentioned reflecting surface, under the condition that satisfies " nt＞na " and " nt＞ni ", light from above-mentioned forward entrance to above-mentioned imaging optical system is when " θ r＜(90-β) ° ", satisfy the condition of " nt * sin (sin-1 ((ni/nt) * sin θ i)+β)/na 〉=sin90 ° ", incide light the above-mentioned imaging optical system when " nt * sin β/na 〉=sin90 ° " from above-mentioned orthogonal directions, incide light the above-mentioned imaging optical system when " θ r＜β ° " from above-mentioned negative sense, satisfy the condition of " nt * sin (sin-1 ((ni/nt) * sin θ i)-β)/na 〉=sin90 ° ".

As preferably, in the above-mentioned feature of the present invention, the refractive index n t of above-mentioned prism satisfies the condition of " 1.59597≤nt ".

As preferably, in the above-mentioned feature of the present invention, have: the 1st optics, it has the 1st light entrance face, the 1st light-emitting face and the 1st smooth mirrored sides, is made of translucent material; The 2nd optics, it has the 2nd light entrance face, the 2nd light-emitting face and the 2nd smooth mirrored sides, is made of translucent material; Region of low refractive index forms parts, the part of the part of the peripheral part of itself and above-mentioned the 1st light-emitting face and the peripheral part of above-mentioned the 2nd light entrance face is bonding, be used between above-mentioned the 1st light-emitting face and above-mentioned the 2nd light entrance face, form above-mentioned the 1st optics of refractive index ratio and the little region of low refractive index of above-mentioned the 2nd optics; And sprung parts, it has the bonding adhesive surface of a part with a part and above-mentioned the 2nd smooth mirrored sides of above-mentioned the 1st smooth mirrored sides, with above-mentioned the 1st optics and above-mentioned the 2nd optics suspension; At least one side in above-mentioned the 1st optics and above-mentioned the 2nd optics is the light incident direction parts different with the light exit direction; Above-mentioned sprung parts will reflect through the light after the part of above-mentioned the 1st smooth mirrored sides.

As preferably, in the above-mentioned feature of the present invention, above-mentioned sprung parts is made of glass or transparent resin.

As preferably, in the above-mentioned feature of the present invention, above-mentioned sprung parts is made of the material with above-mentioned the 1st optics and above-mentioned the 2nd optics identical type.

As preferably, in the above-mentioned feature of the present invention, the above-mentioned adhesive surface of above-mentioned sprung parts is the minute surface that the light that sees through the above-mentioned the 1st smooth mirrored sides and above-mentioned the 2nd smooth mirrored sides is reflected.

As preferably, in the above-mentioned feature of the present invention, above-mentioned the 1st optics is the light guide member with quadrangular shape; Above-mentioned the 2nd optics is the triangular prism with triangular prism shape.

As preferably, in the above-mentioned feature of the present invention, above-mentioned triangular prism has to be made from the going direction changing of the light of above-mentioned the 2nd light entrance face institute incident and will import to the light reflecting slant of above-mentioned the 2nd light-emitting face side from the light of above-mentioned the 2nd light entrance face institute incident, above-mentioned sprung parts has on the limit that is parallel on the projecting plane of above-mentioned adhesive surface along above-mentioned smooth reflecting slant.

As preferably, in the above-mentioned feature of the present invention, above-mentioned sprung parts has and is being parallel on the projecting plane of above-mentioned adhesive surface along the limit of the normal of above-mentioned smooth reflecting slant.

In the feature of the present invention, optical member unit has: the 1st optics, and it has the 1st light entrance face, the 1st light-emitting face and the 1st smooth mirrored sides, is made of translucent material; The 2nd optics, it has the 2nd light entrance face, the 2nd light-emitting face and the 2nd smooth mirrored sides, is made of translucent material; Region of low refractive index forms parts, the part of the part of the peripheral part of itself and above-mentioned the 1st light-emitting face and the peripheral part of above-mentioned the 2nd light entrance face is bonding, be used between above-mentioned the 1st light-emitting face and above-mentioned the 2nd light entrance face, form above-mentioned the 1st optics of refractive index ratio and the little region of low refractive index of above-mentioned the 2nd optics; And sprung parts, it has the bonding adhesive surface of a part with a part and above-mentioned the 2nd smooth mirrored sides of above-mentioned the 1st smooth mirrored sides, with above-mentioned the 1st optics and above-mentioned the 2nd optics suspension; At least one side in above-mentioned the 1st optics and above-mentioned the 2nd optics is the light incident direction parts different with the light exit direction; Above-mentioned sprung parts makes through the light after the part of above-mentioned the 1st smooth mirrored sides and reflects.

In the feature of the present invention, image display device possesses the relevant optical member unit of an above-mentioned feature.

Description of drawings

Fig. 1 is the summary structural drawing of liquid crystal projection apparatus.

Fig. 2 is the key diagram of prism and projection lens.

Fig. 3 is the table of the relation between expression F value and the refractive index.

Fig. 4 is the key diagram of sprung parts.

Fig. 5 is the relation that is used to obtain the prismatic refraction rate of maximum reflection efficient.

Fig. 6 is the summary structural drawing of the liquid crystal projection apparatus of use DMD.

Fig. 7 is the figure of the relevant image display device 100 of expression the 2nd embodiment of the present invention.

Fig. 8 is the figure of the formation of the relevant image display device 100 of expression the 2nd embodiment of the present invention.

Fig. 9 is the stereographic map of the relevant optical member unit of expression the 2nd embodiment of the present invention.

Figure 10 is the figure of an example of the relevant optical member unit of expression the 2nd embodiment of the present invention.

Figure 11 is the figure of an example of the relevant optical member unit of expression the 3rd embodiment of the present invention.

Figure 12 is the figure of the variation of the profile of the relevant sprung parts 160 of expression the 4th embodiment of the present invention.

Embodiment

The contrast accompanying drawing describes embodiments of the present invention below.In addition, in the following accompanying drawing record, to identical or the identical or similar symbol of similar portions mark.

But should be noted in the discussion above that accompanying drawing only illustrates that each dimensional ratios etc. are different with reality.Therefore, concrete size etc. need be considered the following description in light of actual conditions and judges.In addition, size relationship or the different part of ratio between also containing mutually in certain accompanying drawing.

[the 1st embodiment]

The contrast accompanying drawing describes the 1st embodiment below.The example of liquid crystal projection apparatus as projection type image display apparatus has been shown among Fig. 1.In addition, below " red with " expression be used for the optics of red light, " green with " expression is used for the optics of green light, " blue with " expression is used for the optics of blue light.The object lesson of each optics will describe in turn.The liquid crystal projection apparatus of example shown in Figure 1 has light source 10 (red with light source 10R, green with light source 10G and blue general name with light source 10B), light element 20 (red with light element 20R, green with light element 20G, blue general name with light element 20B), prism 40, liquid crystal display device 50 (red with liquid crystal display device 50R, green with liquid crystal display device 50G, blue general name with liquid crystal display device 50B), cross dichroic prism 60, imaging optical system 70 and screen 80.Light element 20 has leaded light angle control assembly 21 (red with leaded light angle control assembly 21R, green with leaded light angle control assembly 21G and blue general name with leaded light angle control assembly 21B) and light homogenization parts 22 (red with light homogenization parts 22R, green with light homogenization parts 22G and blue general name with light homogenization parts 22B).Red with light source 10R, green with light source 10G and bluely use light source 10B, be respectively the light source of the light (red light) that sends red wave band, the light source of light (green light) that sends green wave band and the light source that sends the light (blue light) of blue wave band.Situation as light source use LED (Light Emitting Diode) is described, but be not limited in this.

Red is the clavate parts of taper with leaded light angle control assembly 21G and blueness with leaded light angle control assembly 21B with leaded light angle control assembly 21R, green.Here the situation of using third rare resin, polycarbonate resin, glass and other transparent materials (hereinafter to be referred as making transparent material) as transparent member is described.Light source 10 each emitted coloured light incide leaded light angle control assembly 21.Leaded light angle control assembly 21 is taper, so the total reflection on the conical surface on one side of the light of institute's incident, advances being endowed under the state of angle Yi Bian follow into direction.Also promptly, while make light follow into direction by leaded light angle control assembly 21 to be endowed angle and to advance.Because leaded light angle control assembly 21 is transparent members, so light is advanced in transparent member inside.

Red is transparent member with light homogenization parts 22G and blueness with light homogenization parts 22B with light homogenization parts 22R, green, and it is shaped as the shape of rectangular parallelepiped.Light homogenization parts 22 are arranged on the exiting side of leaded light angle control assembly 21, incide in the light homogenization parts 22 through the light behind the leaded light angle control assembly 21.As shown in Figure 1, the cross section with the rectangular shape of light homogenization parts 22 forms identically with the outgoing end face of leaded light angle control assembly 21.If leaded light angle control assembly 21 uses transparent member, then the energy distribution of light becomes inhomogeneous.Therefore,, then can mix and eliminate inequality by the light of various angles if light homogenization parts 22 use the transparent member of rectangular shape, thus the homogenization of realization energy distribution.

Prism 40 is the prisms that are made of transparent material, and example shows triangular prism among Fig. 1.Here,, the light path with green light uses prism 40 for bending.Among Fig. 1, green light is advanced on parallel light path with blue light, and green light is opposite with the direct of travel of blue light, and red light is also advanced on parallel light path.Therefore, owing to can make the light path of three coloured light all parallel, therefore help all densifications of crystal projection instrument apparatus.On the other hand, for 3 light that side incident is of all kinds from cross dichroic prism 60, need be with the light path bending of the light of at least 1 look in three coloured light.Among Fig. 1,90 ° of the light path bendings by green light, and 3 coloured light are incided in the cross dichroic mirror 60.Below adopt the situation of 90 ° of the light path bendings of green light to be illustrated, but also can make the angles beyond 90 ° of the light path bendings.

See through the red green light that is bent by prism 40 with the red light behind the light homogenization parts 22R, light path and see through the blue blue light of using behind the light homogenization parts 22B, before inciding cross dichroic prism 60, incide red respectively with liquid crystal display device 50R, green with liquid crystal display device 50G and blue with among the liquid crystal display device 50B.50 pairs of each coloured light of each liquid crystal display device are implemented optical modulation, form image of all kinds.In addition, by red light, green light and the blue light after each liquid crystal display device 50 optical modulations, from 3 side incidents of cross dichroic prism 60.

Cross dichroic prism 60 is cubical prisms, and two multilayered mediuies (the 1st multilayered medium 61 and the 2nd multilayered medium 62) form crosswise.The 1st multilayered medium 61 is to have the light of reflection blue wave band only and the multilayer film that sees through the optical characteristics of other band of light.The 2nd multilayered medium 62 is to have the light of reflection Red wave band only and the multilayer film that sees through the optical characteristics of other band of light.Therefore, the blue light that incides in the cross dichroic prism 60 is reflected by the 1st multilayered medium 61, and red light is by 62 reflections of the 2nd multilayered medium.The green light that incides in the cross dichroic prism 60 directly sees through cross dichroic prism 60.

Like this, in the cross dichroic prism 60, the light of this 3 look of red light, green light and blue light is synthesized by look.Imaging optical system 70 is used for the optical projection after by cross dichroic prism 60 looks synthetic to screen 80.Here, imaging optical system 70 uses lens.The general projection lens that uses shows coloured image by this projection lens on screen 80.The lens that adopt imaging optical system 70 below are that the situation of projection lens 71 describes.But as described later, under the situations such as projection type image display apparatus of using DMD (DigitalMicromirror Device), adopting the relay lens group who makes light import to DMD etc. to be imaging optical system, is not projection lens.

As shown in Figure 2, prism 40 has the plane of incidence 41 of green light incident, the reflecting surface 42 of green light reflection and the exit facet 43 of green light outgoing.Among Fig. 1 and Fig. 2, illustration triangular prism, as long as but have the plane of incidence 41, reflecting surface 42 and exit facet 43, also can use the prism of arbitrary shape.As shown in Figure 2, green with being formed with gap area 44 between light homogenization 22G of portion and the prism 40.Gap area 44 is the zones that are made of the lower medium of refractive index, generally uses air layer.Under the situation of using air layer, green with being formed with clearance (air gap: air-gap) between light homogenization parts 22G and the prism 40.But so long as the less medium of refractive index also can use air layer arbitrary medium in addition.

The perimeter of prism 40 (is the exterior lateral area of the prism 40 on border with reflecting surface 42) 47, the same with gap area 44, the medium that the selective refraction rate is lower.Therefore the same with gap area 44, generally also use air layer in the perimeter 47, but be not limited in air layer.Use the situation of the medium (being generically and collectively referred to as region of low refractive index) of identical refractive index n a to describe gap area 44 with perimeter 47 below.But gap area 44 also can be different media with perimeter 47.In addition, the medium between prism 40 and the projection lens 17 is made as light incident side medium 48, and this light incident side medium 48 uses has the refractive index materials lower than the refractive index of prism 40 (material of refractive index n i).

Here, prism 40 is made of transparent materials such as glass, and its refractive index (below be called refractive index n t) is than the refractive index n a height of region of low refractive index.Therefore, has refringence between prism 40 and the region of low refractive index.In addition, as shown in Figure 2, the green light of advancing in prism 40 inside, relatively reflecting surface 42 has incident under the state of angle.If total reflection on this reflecting surface 42 then just becomes maximum for the light quantity that image forms employed light.But, therefore do not need to make all total reflections of light of any angle because the incident angle of the utilized light of imaging optical system 70 is limited.In a word, so long as make the light that is formed on available angle in the imaging optical system 70 for image promptly utilize light total reflection to get final product.Therefore, method as this reflection efficiency that is used for improving prism 40 has following two methods, promptly increase the refringence between prism 40 and the region of low refractive index, and the angle of light that incides the reflecting surface 42 of prism 40 in the total reflection angle scope inner control by prism 40 and the refractive index regulation of perimeter 47.

More than two methods that are used for improving reflection efficiency, control the incident angle of the reflecting surface 42 that incides prism 40 fully by the optical system of the prime of prism 40, be difficult, some light loss may take place.Thereby among the present invention, the refractive index n t by control prism 40 enlarges the reflection angle on reflecting surface 42.Specifically, the material of prism 40 uses the higher high-index material of refractive index.If prism 40 uses the material of highs index of refraction, then no matter incide the plane of incidence 41 green light incident angle how, can both enlarge the total reflection angle on reflecting surface 42.

Therefore, among the present invention, according to the F value of imaging optical system 70, the required refractive index (minimum refractive index Min) of regulation prism 40 minimums.Suitably control in the mode of " Min≤nt " by refractive index n t, can improve reflection efficiency, and do not need to use special parts such as reflectance coating or reflex housing prism 40.

By the green light of reflecting surface 42 reflection of prism 40, finally incide in the projection lens 71 after synthetic by cross dichroic prism 60 looks.In the emitted green light of light source 10G, by the maximum effectively light more than the incident angle of the F value defined of projection lens 71, to finally being projected in the not contribution of image on the screen 80.Therefore, will improve the reflection efficiency of the following green light of maximum effectively incident angle in the green light that incides in the prism 40, projection lens 71.

As shown in Figure 2, the incident angle that incides the exit facet 43 of prism 40 is made as θ r, and the effective incident angle of above-mentioned maximum of projection lens 71 is θ i.In addition, the plane of incidence 41 of establishing prism 40 is α with exit facet 43 formed angles, and reflecting surface 42 is β with exit facet 43 formed angles, and the plane of incidence 41 is γ with reflecting surface 42 formed angles.At this moment, the maximum effectively incident angle θ i of projection lens 71 equates with refraction angle from the green light of 43 outgoing of exit facet.In addition, the angle of establishing prism 40 is respectively α, β, γ (alpha+beta+γ=180 °), under the situation of the triangular prism that uses right angle equilateral triangle shape, and " α=90 ° ", " β=γ=45 ° ".

In this case, be used for allowing the total reflection condition of the green light total reflection on the reflecting surface 42 of prism 40 in the maximum effectively incident angle θ i scope, be with reflecting surface 42 face vertical with exit facet 43 both sides in, the reflection angle of reflecting surface 42 is made as " negative sense " less than the direction that light reflected of angle delta, reflection angle is made as " forward " greater than the direction that light reflected of angle delta, when being made as " orthogonal directions " with the direction of the plane of incidence quadrature of projection lens 71, the refractive index n t of control prism 40 makes it satisfy the situation of following conditional, wherein, above-mentioned angle delta is that the normal direction of direction parallel with the optical axis center of the light that incides projection lens 71 and reflecting surface 42 is formed, in the reflection angle of reflecting surface 42 with above-mentioned reflecting surface 42 face vertical with exit facet 43 both sides in the angle of composition.In addition, in the following conditional, suppose to possess " nt＞na " and " nt＞ni " these two conditions.

When " θ r＜(90-β) ° ", satisfy the condition of " nt * sin (sin-1 ((ni/nt) * sin θ i)+)/na 〉=sin90 ° " from the light of forward institute incident; When " nt * sin β/na 〉=sin90 ° ", when " θ r＜β ° ", satisfy the condition of " nt * sin (sin-1 ((ni/nt) * sin θ i)-β)/na 〉=sin90 ° " from the light of vertical direction institute incident from the light of negative sense institute incident.

In the above-mentioned formula, with the variable key element that decides refractive index n t is " na, ni, β, θ i ", na wherein and ni can select medium and light incident side medium arbitrarily in advance as region of low refractive index, also can select prism 40 to adopt any shape in advance about β.In general, the medium of region of low refractive index is selected air, and therefore " na=1.0 ", light incident side medium 48 is also selected the space, therefore " ni=1.0 ".And, because the shape of prism 40 adopts the shape of right angle equilateral triangle, therefore " β=45 ° ".So na, ni and β can be used in fact determine that the variable key element of refractive index n t just is θ i as fixed factors.Also promptly, decide the refractive index n t of prism 40 by the maximum effectively incident angle θ i of projection lens 71.Can learn from above-mentioned formula, need be according to increasing with the proportional mode of expansion of the angle amplitude of the effective incident angle θ i of maximum refractive index n t with prism 40.

The maximum effectively incident angle θ i of projection lens 71 is by the F value regulation of projection lens 71.Also promptly, the F value of projection lens 71 is more little, and the maximum effectively amplitude of incident angle θ i becomes big more.So, the F value of projection lens 71 is more little, just requires the refractive index n t of prism 40 high more, and the F value is big more, and then refractive index n t can be lower.In addition, the effective incident angle θ of above-mentioned maximum i, except the F value of projection lens 71, the refractive index n i of light incident side medium 48 also is variable key element.Here, because " ni=1.0 ", thereby by the maximum effectively incident angle θ i of the F value regulation of projection lens 71, but under the variable situation of ni, by the F value of projection lens 71 and the maximum effectively incident angle θ i of refractive index n i regulation of light incident side medium 48.

In addition, as shown in Figure 2,, use the direction of the optical axis center that is parallel to the light that incides projection lens 71 and the formed angle delta of normal direction of reflecting surface 42 in order to determine " forward " and " negative sense ".The shape that has the right angle equilateral triangle at prism 40 (also is α=90 °, β=γ=45 °), under the normal direction of projection lens 71 and the corresponding to situation of direction of optical axis center that incides the light in the projection lens 71, above-mentioned angle delta equates with reflection angle (also being 45 °) in the reflecting surface.Therefore, in this case, the reflection angle in the reflecting surface 42 is " forward " greater than 45 ° reflection of light direction, is " negative senses " less than 45 ° reflection of light directions.

By more than, under situation, can stipulate the minimum refractive index Min of essential prism 40 by the maximum effectively incident angle θ i of the F value defined of projection lens 71 by reflecting surface 42 total reflections.

But, though carry out the refractive index control of prism 40 according to the F value of projection lens 71, realize the raising of the reflection efficiency of the green light in the reflecting surface 42, but among the present invention, decide the refractive index n t of prism 40 by F value according to projection lens 71, thereby also have the green light reflection that helps image to form that only makes projection lens 71 required, and the function that unwanted green light is discharged.Also be, F value according to projection lens 71 makes the control of the refractive index n t of prism 40 near minimum refractive index Min, the function that not only has the light path of simple change green light thus also has optionally this filtering function of the light that helps image formation in the reflection institute screen that is projected in 80.

Have at 42 of the reflectings surface of prism 40 under the situation of simple catoptrical function (for example waiting catoptrical situation etc.), existed image originally and form light beyond the needed light and incide possibility in the projection lens 71 by forming reflectance coating.So, because unwanted only improper reflected light, therefore become the light (so-called parasitic light) harmful, bring contrast this bad influence that descends finally in the screen 80 formed image the imaging of projection lens 71.Among the present invention, select to have prism 40 with the refractive index n t of the approaching value of the pairing minimum refractive index Min of the F value of projection lens 71.Become the essential factor of parasitic light than the light of the maximum effectively angle that incident angle θ i is big of the F value defined of projection lens 71, therefore preferably do not reflect this light and make its reflecting surface that sees through prism 40 42.Therefore, select to have the prism 40 with the refractive index n t of the approaching value of the pairing minimum refractive index Min of the F value of projection lens 71, thereby can only improve the reflection of light efficient in the scope of maximum effectively incident angle θ i.Also promptly, to image form unwanted light according to actively not reflecting the mode of its eliminating (seeing through) is controlled.Therefore, the refractive index n t by selecting prism 40 is near the value of the pairing minimum refractive index Min of F value of projection lens 71, thereby can give play to reflection of light function and these two effects of filtering function.

Contrast Fig. 3 describes (establish β=45 °, ni=1.0, na=1.0 also promptly establishes the refractive index that ni and na are air) to prism 40 needed minimum refractive index Min.Among Fig. 3, when the F of projection lens 71 value was " 1.7 ", maximum effectively incident angle θ i was " 17.10 ° ".Also promptly, incide have only in the light in the projection lens 71 incident angle be " 17.10 ° " with interior light, the image that is projected in the screen 80 is formed with contribution, therefore only the light in this scope on the reflecting surface 42 of prism 40 by total reflection.At this moment, be " 1.73347 " by the minimum refractive index Min that aforementioned formula derived.Therefore, when the F of projection lens 71 value is " 1.7 ", for the refractive index n t of the necessary prism 40 of total reflection is " nt 〉=1.73347 " just.In addition, the reflecting surface incident angle in the table of Fig. 3, the incident angle of light of the reflecting surface 42 of prism 40 is incided in expression.

Equally, the F value be " 2.0 " if the time refractive index n t satisfy the condition of " nt 〉=1.68289 ", the F value be " 2.4 " if the time refractive index n t satisfy the condition of " nt 〉=1.63587 ", the F value be " 2.9 " if the time refractive index n t satisfy the condition of " nt 〉=1.59597 ", then carry out total reflection with interior light by maximum effective incident angle of the F value defined of projection lens 71.In addition, the maximal value of the refractive index n t of prism 40 can be used till 2.0017 the value.As concrete glass material, preferably use the system TAFD25 of HOYA Corp. (nt=1.90366) etc.

But according to the incident angle that incides reflecting surface 42, a catoptrical part also may be not towards exit facet 43 reflections and towards the plane of incidence 41 reflections.Among the present invention, as shown in Figure 2, form region of low refractive index by gap area 44.In case formed region of low refractive index,,, do not seen through the plane of incidence 41 but reflect towards exit facet 43 once more just because the refringence of the refractive index n t of prism 40 and the refractive index n a of region of low refractive index towards a part of green light of the plane of incidence 41 reflection.For this reason, though by the part of the green light of reflecting surface 42 reflection towards the plane of incidence 41 reflections, also make this a part of light turn back to exit facet 43, thereby can suppress the generation of light loss owing to having formed region of low refractive index.

Therefore, in order to form region of low refractive index, folder is established spacer 45 between green is with light homogenization parts 22G and prism 40.If folder is established spacer 45 and fill the medium (medium of refractive index n a) of low-refraction between green is with light homogenization parts 22G and prism 40, just can form region of low refractive index.Be under the situation of air layer in region of low refractive index particularly, even do not use special medium, only folder is established spacer 45 between green is with light homogenization parts 22G and prism 40, just can form region of low refractive index.Be that the situation of air layer describes to region of low refractive index below.

As previously mentioned, since green with light homogenization parts 22G use transparent member, therefore reflect because of refringence with the green light that light homogenization parts 22G shines region of low refractive index from green.In addition, because prism 40 also uses transparent member, therefore the green light that incides the prism 40 from region of low refractive index is refracted once more.So green is carried out with the gap managerial demand strictness between light homogenization parts 22G and the prism 40.This is because as previously mentioned, because green light reflects repeatedly, and advances between different media, if green is not carried out strict control with the gap of light homogenization parts 22G and prism 40, will reflect with predetermined angular.Here, the spacer 45 that is used for gap management is arranged on green four jiaos with the coupling part between light homogenization parts 22G and the prism 40 for spherical (for example globule etc.).It is green with the structure in two places of the end between light homogenization parts 22G and the prism 40 that spacer 45 can adopt for example elongated cylindrical parts to be arranged in addition.

In addition, green with the sealed space preferably of the region of low refractive index between homogenization parts 22G and the prism 40.In region of low refractive index is under the situation of air layer, because this region of low refractive index is the path of short wavelength's green light (blue light, red light are too), if therefore sneaked into other impurity such as dust, green light just might be subjected to the influence of impurity.Therefore, in order to allow green be in air-tight state, form seal member 46 with the region of low refractive index between light homogenization parts 22G and the prism 4.Seal member 46 forms according to the mode that the inboard with spacer 45 is surrounded, and forms the region of low refractive index of seal cavity in the inside of sealing parts 46.

Here, the mode of preferably establishing region of low refractive index according to folder links green with light homogenization parts 22G and prism 40.On spacer 45 and seal member 46, use bonding agent to make the green method that is glued together with light homogenization parts 22G and prism 40 though also have, use sprung parts 30 here.What be suitable for use as sprung parts 30 is the light transmission plate-shaped member, most preferably uses the transparent member of the same race with green usefulness light homogenization parts 22G and prism 40 (for example identical parts of refractive index as glass component of the same race etc.).Sprung parts 30 is bonding with light homogenization parts 22G and prism 40 by bonding agent etc. and green, is in the state that both are linked.Sprung parts 30 for the green state bonding with light homogenization parts 22G and prism 40 under both linked securely and be utilized, if but use different types of transparent member, then may when for example temperature rises,, differing from of thermal expansivity peel off because of causing adhesive surface.Therefore preferably use transparent member of the same race.

As shown in Figure 2, the major part in the sprung parts 30 becomes and green adhesive surface with light homogenization parts 22G and prism 40.1 sprung parts 30 has been shown among Fig. 2, but also has been bonded with same sprung parts 30 at its opposition side.Therefore, owing to from both direction green is coupled together with light homogenization parts 22G and prism 40, thereby strength of joint is further strengthened.

Here, in the green light that green is advanced in light homogenization parts 22G, it most incides in the region of low refractive index, but as shown in Figure 4, will consider that also a part of green light incides in the sprung parts 30.If a part of green light that incides in the sprung parts 30 leaks into the outside,, therefore become the essential factor of light loss just this part green light can be lost.But among the present invention,,, be high index of refraction because sprung parts 30 uses and the transparent member of prism 40 identical type even a part of green light incides in the sprung parts 30.So the refractive index and the refringence between the sprung parts 30 of low index ellipsoid are bigger, incide a part of green light in the sprung parts 30, reflected by opposing face with the adhesive surface of sprung parts 30.Therefore can not leak into the outside, but turn back to once more in the prism 40.

In addition, the liquid crystal projection apparatus to the bending of the light path of green light among Fig. 1 is illustrated, but also can adopt the liquid crystal projection apparatus of blue light or red light bending.In addition, can also be not the bending 1 coloured light light path but bend 2 looks and even the liquid crystal projection apparatus of the light path of 3 coloured light.In addition, light source is that prerequisite is illustrated with LED, but also can use for example discharge lamp, LASER Light Source, EL (electroluminescent device) etc.

But when constituting projection type image display apparatus, the perimeter 47 of prism 40 just not saying place situation under the particular surroundings, is arranged in the air usually.But green is the enclosure spaces that surrounded by spacer 45 with the gap area 44 between light homogenization parts 22G and the prism 40, therefore might not form air layer, also might enclose desired medium.For example, also may fill the parts that conducts such as optical adhesive are used for adjusting refractive index in inside.Therefore, with optical adhesive AC R220B (Wan Red ケ ミ Star Network ス Co., Ltd. system) be filled under the situation in the clearance space 44, being used in the F value of imaging optical system 70 obtain maximum reflection efficient prism 40 refractive index relation as shown in Figure 5.

Next, use Fig. 6, the projection type image display apparatus that uses DMD is described.Among Fig. 6, use the projection type video display device of DMD, have light source 91, leaded light angle control assembly 92, prism 93, light homogenization parts 94, imaging optical system 95, DMD96, projection lens 97 and screen 98.Wherein, leaded light angle control assembly 92, prism 93, light homogenization parts 94, projection lens 97 and screen 98 play and aforementioned person's identical functions.Light source 91 is the light sources that send this 3 coloured light of blue light, green light and red light.Imaging optical system 95 is to be used for making photoimaging of all kinds after 94 outgoing of light homogenization parts to the relay lens group of DMD96.DMD96 is the small mirror of corresponding 1 pixel, controls by the vergence direction to this small mirror, carries out optical modulation.

Use in the projection type image display apparatus of DMD, the refractive index by control prism 93 does not need to form reflectance coating etc., just can reflect necessary light.Also promptly, only the maximum effectively light below the incident angle by the F value defined of the relay lens group of the imaging optical system 95 that is used for being imaged onto DMD96 helps image to form, so allows prism 93 have the refractive index that optionally only makes this light total reflection.In addition, the refractive index with prism 93 is suppressed in the scope of light loss permission.By the refractive index of suitable control prism 93, need in prism 93, not form reflectance coating, just total reflection can be carried out, and light loss can be suppressed.In addition, projection type image display apparatus is not limited to use DMD, can also use projection type image display apparatus arbitrarily such as reflective type liquid crystal display device.

[the 2nd embodiment]

(image display device)

Contrast accompanying drawing below, the image display device relevant to the 2nd embodiment of the present invention describes.Fig. 7 is the figure of the associated picture display device 100 of expression the 2nd embodiment of the present invention.

As shown in Figure 7, image display device 100 has projection lens 180, and 180 enlarged images of projection lens are presented on the screen 200.

In addition, in the 2nd embodiment, image display device 100 is illustrated as 3 chip projector, but is not limited in this.For example image display device 100 can also be the projector of one chip, can also be the back projection type TV.In addition, image display device 100 can also be the employed display of finding a view in camera etc.

Contrast accompanying drawing below, the formation of image display device is described.Fig. 8 is the figure of the formation of the relevant image display device 100 of expression the 2nd embodiment of the present invention.In addition, only put down in writing the formation that the present invention is correlated with among Fig. 8, but image display device 100 also have other opticses (for example relay lens etc.) certainly.

As shown in Figure 8, image display device 100 has a plurality of light sources 110 (light source 110r, light source 110g, light source 110b), a plurality of tapered pole 120 (tapered pole 120r, tapered pole 120g, tapered pole 120b), a plurality of light guide member 130 (light guide member 130r, light guide member 130g, light guide member 130b), a plurality of liquid crystal panel 140 (liquid crystal panel 140r, liquid crystal panel 140g, liquid crystal panel 140b), triangular prism 150, dichroic prism 170 and projection lens 180.

Light source 110r is the light source that sends red light, has a plurality of red LED and arranges the red LED array 111r that forms.Equally, light source 110g is the light source that sends green light, has a plurality of green LED and arranges the green LED array 111g that forms.Light source 110b is the light source that sends blue light, has a plurality of blue leds and arranges the blue LED arrays 111b that forms.

Tapered pole 120r has the conical in shape of the area of light-emitting face greater than the area of light entrance face, and the optics that reflected by the side of tapered pole 120r of the red light sent of light source 110r.

Equally, tapered pole 120g has the conical in shape of the area of light-emitting face greater than the area of light entrance face, and the optics that reflected by the side of tapered pole 120g of the green light sent of light source 110g.

And then tapered pole 120b has the conical in shape of the area of light-emitting face greater than the area of light entrance face, and the optics that reflected by the side of tapered pole 120b of the blue light that sent of light source 110b.

Light guide member 130r is made of translucent material, is the solid optics with quadrangular shape.In addition, translucent material for example is transparent resins such as acrylic acid resin, polycarbonate resin, glass etc.In addition, the quadrangular shape comprises taper certainly.In addition, light guide member 130r is that the side (below be called the light mirrored sides) by light guide member 130r is reflected the red light from the light-emitting face institute outgoing of tapered pole 120r, and imports to the optics of liquid crystal panel 140r side.

Equally, light guide member 130g is made of translucent material, is the solid optics with quadrangular shape.Be that side (below be called the light mirrored sides) by light guide member 130g is reflected the green light from the light-emitting face institute outgoing of tapered pole 120g, and import to the optics of liquid crystal panel 140g (triangular prism 150) side.In addition, the quadrangular shape comprises taper certainly.

In addition, light guide member 130b is made of translucent material, is the solid optics with quadrangular shape.Be that side (below be called the light mirrored sides) by light guide member 130b is reflected the blue light from the light-emitting face institute outgoing of tapered pole 120b, and import to the optics of liquid crystal panel 140b side.In addition, the quadrangular shape comprises taper certainly.

In addition, light guide member 130r, light guide member 130g and light guide member 130b have same formation, therefore as required it are generically and collectively referred to as light guide member 130.

Liquid crystal panel 140r according to the vision signal from driving circuit (not shown), modulates red light and shine dichroic prism 170.Equally, liquid crystal panel 140g, according to vision signal from driving circuit (not shown), green light is modulated and is shone dichroic prism 170, liquid crystal panel 140b, according to vision signal, blue light is modulated and is shone dichroic prism 170 from driving circuit (not shown).

Triangular prism 150 is made of translucent material, is the solid optics with triangular prism shape, will and import to liquid crystal panel 140g side from the going direction changing of the green light of the light-emitting face institute outgoing of light guide member 130g.In addition, triangular prism 150 is to realize that for the going direction changing by green light that light source 110g is sent the miniaturization of image display device 100 is provided with.

In addition, between the light entrance face of the light-emitting face of light guide member 130g and triangular prism 150, be provided with air-gap 161 according to the mode of the total reflection that does not hinder green light.

In addition, the part of the part of the light mirrored sides of light guide member 130g and the light mirrored sides of triangular prism 150, bonding with sprung parts 160.In addition, sprung parts 160 has the plate-like shape that is made of translucent material, and light guide member 130g and triangular prism 150 suspensions are got up.

In addition, sprung parts 160 is made of the material with light guide member 130 and triangular prism 150 identical type.

In addition, in the 2nd embodiment, the kind of " identical type " expression material is identical.For example, under the situation that light guide member 130 and triangular prism 150 are made of transparent resin, sprung parts 160 also is made of transparent resin, and under the situation that light guide member 130 and triangular prism 150 are made of glass, sprung parts 160 also is made of glass.In addition, the refractive index of light guide member 130 and triangular prism 150 can be different with the refractive index of sprung parts 160.

In addition, the peripheral construction (also being optical member unit) about air-gap 161 will describe (with reference to Fig. 9 and Figure 10) in the back in detail.

Dichroic prism 170 is to from the red light of liquid crystal panel 140r, synthesize from the green light of liquid crystal panel 140g and from the blue light of liquid crystal panel 140b.Specifically, dichroic prism 170 will reflect to projection lens 180 sides from the red light of liquid crystal panel 140r and blue light from liquid crystal panel 140b.In addition, dichroic prism 170 allows the green light from liquid crystal panel 140g see through.

Projection lens 180 makes liquid crystal panel 140r, liquid crystal panel 140g and the shown image of liquid crystal panel 140b amplify back demonstration on screen 200.Specifically, the light after projection lens 180 synthesizes dichroic prism 170 projects on the screen 200.

(optical member unit)

Contrast accompanying drawing below, the optical member unit relevant to the 2nd embodiment of the present invention describes.Fig. 9 is the stereographic map of the relevant optical member unit of expression the 2nd embodiment of the present invention.In addition, in the 2nd embodiment, optical member unit is meant the unit that is made of light guide member 130 and triangular prism 150 and suspension 160.

As shown in Figure 9, and meanwhile light guide member 130 have the light entrance face 131 that is used for light incident, the light-emitting face 132 that is used for the light outgoing and from the periphery of light entrance face 131 continuously to the set a plurality of smooth mirrored sides 133 (light mirrored sides 133a～light mirrored sides 133d) of the periphery of light-emitting face 132.In addition, light mirrored sides 133 will import to light-emitting face 132 behind the light total reflection of 131 incidents of light entrance face.

Triangular prism 150 have the light entrance face 151 that is used for light incident, the light-emitting face 152 that is used for the light outgoing and from one side of the periphery of light entrance face 151 continuously to the set a plurality of smooth mirrored sides 153 (light mirrored sides 153a～light mirrored sides 153d) in one side of the periphery of light-emitting face 152.

Here, the face direction of light entrance face 151 is different with the face direction of light-emitting face 152.Also promptly, the direction of triangular prism 150 smooth incidents (light incident direction) is different with the direction (light exit direction) of light outgoing.

In addition, light mirrored sides 153 will import to light-emitting face 152 behind the light total reflection of 151 incidents of light entrance face.Particularly, light mirrored sides 153b is the light total reflection of being imported from light entrance face 151, and makes the light incident direction light reflecting slant different with the light exit direction.

Sprung parts 160 has the bonding adhesive surface 160a of a part with a part and the light mirrored sides 153 of light mirrored sides 133, thus sprung parts 130g and triangular prism 150 suspensions is got up.

In addition, in the 2nd embodiment, sprung parts 160 by with the part of light mirrored sides 133a and the 1st bonding sprung parts of a part of light mirrored sides 153a, and constitute with bonding the 2nd sprung parts of the part of the part of light mirrored sides 133c and light mirrored sides 153c.

Here, between the light entrance face 151 of the light-emitting face 132 of light guide member 130 and triangular prism 150, be provided with the low zone of refractive index of refractive index ratio light guide member 130 and triangular prism 150, promptly air-gap 161.

Specifically, in the part of the peripheral part of the part of the peripheral part of light-emitting face 132 and light entrance face 151,, be bonded with globule 162 by bonding agent 163 in order to ensure the width of air-gap 161.Like this, globule 162 is the parts that are used for forming air-gap 161.

In addition, globule 162 for example has the spherical form that constitutes by Pyrex, has the diameter of about 20 μ m degree.In addition, bonding agent 163 is the bonding agents that just harden by ultraviolet ray (UV) irradiation, and the refractive index after the sclerosis is about about 1.4～1.5 (25 ℃).And globule 162 is included in the bonding agent 163 in advance.

In addition, contain the bonding agent 163 of globule 162, preferably be arranged in four jiaos of light-emitting face 132 peripheral parts and light entrance face 151 peripheral parts four jiaos.

Like this, by between the light entrance face 151 of the light-emitting face 132 of light guide member 130 and triangular prism 150, air-gap 161 being set, prevented from the light utilization ratio to be reduced from the part of the light of 132 outgoing of light-emitting face of light guide member 130.For example, under the situation that air-gap 161 is not set, sometimes the part of the light that is reflected by the light mirrored sides 153b of triangular prism 150 after light-emitting face 132 outgoing of light guide member 130 can incide the light mirrored sides 133 of light guide member 130 with very big incident angle.In this case, owing to do not satisfy total reflection condition, therefore, see through the light mirrored sides 133 of light guide member 130, thereby cause the light utilization ratio to reduce from the part of the light of 132 outgoing of light-emitting face of light guide member 130.

Figure 10 is the figure of an example of the relevant optical member unit of expression the 2nd embodiment of the present invention.In addition, Figure 10 is the resulting figure of viewing optics component unit from the side.

As shown in figure 10, sprung parts 160 gets up light guide member 130 and triangular prism 150 suspensions.In addition, sprung parts 160 has the tabular shape that is made of translucent material as mentioned above.

Here, the part of the light mirrored sides 153a of the part of the light mirrored sides 133a of sprung parts 160 and light guide member 130 and triangular prism 150 is bonding.In addition, sprung parts 160 has the refractive index greater than air, also promptly has the refractive index with light guide member 130 and triangular prism 150 same degree.

Therefore, as shown in figure 10, in the part of the bonding light mirrored sides 133a of sprung parts 160, not by total reflection, and see through the part of light mirrored sides 133a from the light of 131 incidents of light entrance face.In addition, through the reflecting surface 160b institute total reflection of the light after the part of light mirrored sides 133a by sprung parts 160.And then in the part of the bonding light mirrored sides 153a of sprung parts 160, the light that is reflected by the reflecting surface 160b of sprung parts 160 is by total reflection, and sees through the part of light mirrored sides 153a.

(effect and effect)

In the optical member unit that the 2nd embodiment of the present invention is correlated with, the part of the part of the light mirrored sides 133 of sprung parts 160 and light guide member 130 and the light mirrored sides 153 of triangular prism 150 is bonding, thus light guide member 130 and triangular prism 150 suspensions is got up.

Therefore, because sprung parts 160 has improved the bond strength of light guide member 130 with triangular prism 150, even, also can fully guarantee the bond strength of light guide member 130 and triangular prism 150 so it is less that the area of the bonding agent 163 that contains globule is set in light-emitting face 132 and the light entrance face 151.

Like this, owing to can dwindle in light mirrored sides 133a and light mirrored sides 153a the area that the bonding agent 163 that contains globule 162 is set, therefore can suppress the reduction of the globule 162 caused smooth utilization ratios that contain in the bonding agent 163.

In addition,, see through the light of the part of the bonding light mirrored sides 133a of sprung parts 160 thus, reflected by the reflecting surface 160b of sprung parts 160 by allowing sprung parts 160 constitute by translucent material (transparent resin or glass).

Therefore, in order to improve the bond strength of light guide member 130 and triangular prism 150, and be provided with under the situation of sprung parts 160, also can suppress the reduction of the light utilization ratio that sprung parts 160 produced.

In addition, the optical member unit that the 2nd embodiment of the present invention is relevant, by allowing sprung parts 160 constitute by material with light guide member 130 and triangular prism 150 identical type, improve the part of light mirrored sides 133a of light guide member 130 and the bond strength of sprung parts 160, and improved the part of light mirrored sides 153a of triangular prism 150 and the bond strength of sprung parts 160.

Therefore, sprung parts 160 has further improved the bond strength of light guide member 130 with triangular prism 150, so can further dwindle the area that the bonding agent 163 that contains globule 162 is set in light mirrored sides 133a and light mirrored sides 153a.

[the 3rd embodiment]

Contrast accompanying drawing below, the 3rd embodiment of the present invention is described.In addition, main difference to above-mentioned the 2nd embodiment and the 3rd embodiment below describes.

Specifically, the sprung parts 160 that above-mentioned the 2nd embodiment is relevant is made of translucent material, therefore through the light behind the light mirrored sides 133a of light guide member 130, by the reflecting surface 160b institute total reflection of sprung parts 160.

Relative therewith, in the sprung parts 160 that the 3rd embodiment is correlated with, adhesive surface 160a is the minute surface that is used for the light reflection.In addition, in the 3rd embodiment, because adhesive surface 160a is minute surface, so sprung parts 160 do not need specially to constitute by translucent material, can no matter which type of material be made of.

Figure 11 is the figure of an example of the relevant optical member unit of expression the 3rd embodiment of the present invention.In addition, Figure 11 is the resulting figure of viewing optics component unit from the side.

As shown in figure 11, sprung parts 160 gets up light guide member 130g and triangular prism 150 suspensions.In addition, the adhesive surface 160a of sprung parts 160 is the minute surfaces that are used for the light reflection.

Here, sprung parts 160 is the same with above-mentioned the 2nd embodiment, and is bonding with the part of the light mirrored sides 153a of the part of the light mirrored sides 133a of light guide member 130 and triangular prism 150.Therefore, suppose that at adhesive surface 160a be not under the situation of minute surface, the part of the light mirrored sides 133a by light guide member 130 can not be carried out the light reflection.

In addition, as shown in figure 11, in the 3rd embodiment, because the adhesive surface 160a of sprung parts 160 is minute surfaces, therefore the part of the light mirrored sides 133a by light guide member 130 also can be carried out the light reflection.

(effect and effect)

The optical member unit that the 3rd embodiment of the present invention is relevant, the adhesive surface 160a by sprung parts 160 is made of minute surface, thereby with the part of the light mirrored sides 133a of the bonding light guide member 130 of sprung parts 160, also can carry out the light reflection.

Therefore, be provided with under the situation of sprung parts 160 with the bond strength of triangular prism 150, also can suppressing the reduction of the light utilization ratio that produced because of sprung parts 160 in order to improve light guide member 130.

[the 4th embodiment]

Contrast accompanying drawing below, the 4th embodiment of the present invention is described.In addition, main difference to above-mentioned the 2nd embodiment and the 4th embodiment below describes.

Specifically, in above-mentioned the 2nd embodiment, do not touch the profile of sprung parts 160 especially, and in the 4th embodiment, will the profile of sprung parts 160 be described.

(profile of sprung parts)

Contrast accompanying drawing below, the profile of the relevant sprung parts of the 4th embodiment of the present invention is described.Figure 12 is the figure of the variation of the profile of the relevant sprung parts 160 of expression the 4th embodiment of the present invention.In addition, Figure 12 is the figure that is illustrated in the shape of the optical member unit on the projecting plane parallel with the adhesive surface 160a of sprung parts 160.

In addition, the same among Figure 12 with above-mentioned the 2nd embodiment, the sprung parts 160 that optical member unit has light guide member 130, triangular prism 150 and is used to make light guide member 130 and triangular prism 150 suspensions.In addition, between the light entrance face 151 of the light-emitting face 132 of light guide member 130 and triangular prism 150, be provided with air-gap 161.

Shown in Figure 12 (a), sprung parts 160 has rectangular shape on the projecting plane of the adhesive surface 160a that is parallel to sprung parts 160, and the part of sprung parts 160 reaches the outside of triangular prism 150 from the light mirrored sides 153b of triangular prism 150.

Like this, because the part of sprung parts 160 reaches the outside of triangular prism 150, therefore fully guaranteed area with the bonding adhesive surface 160a of triangular prism 150.In addition, optical member unit is being assembled in the operation of image display device 100, the part of sprung parts 160 hinders this operation sometimes.In addition, sprung parts 160 also might be damaged.

Shown in Figure 12 (b), sprung parts 160, on the projecting plane of the adhesive surface 160a that is parallel to sprung parts 160, have rectangular shape, and sprung parts 160 is set to not reach from the light mirrored sides 153b of triangular prism 150 outside of triangular prism 150.

Like this, because sprung parts 160 is set to not reach from the light mirrored sides 153b of triangular prism 150 outside of triangular prism 150, therefore the operation that optical member unit is assembled into image display device 100 becomes easily, has also reduced the possibility of sprung parts 160 breakages.In addition, owing to diminish with the area of the bonding adhesive surface 160a of triangular prism 150, so the bond strength of triangular prism 150 and sprung parts 160 reduces.

Shown in Figure 12 (c), sprung parts 160 has along the limit 160m of the light mirrored sides 153b (light reflecting slant) of triangular prism 150 on the projecting plane of the adhesive surface 160a that is parallel to sprung parts 160.

Like this, because sprung parts 160 has along the limit 160m of the light mirrored sides 153b (light reflecting slant) of triangular prism 150, therefore fully guaranteed area with the bonding adhesive surface 160a of triangular prism 150.In addition, the operation that optical member unit is assembled in the image display device 100 becomes easily, has also reduced the possibility of sprung parts 160 breakages.

Shown in Figure 12 (d), sprung parts 160, on the projecting plane of the adhesive surface 160a that is parallel to sprung parts 160, have along the limit 160m of the light mirrored sides 153b (light reflecting slant) of triangular prism 150 with along the limit 160n of the normal a of the light mirrored sides 153b (light reflecting slant) of triangular prism 150.

Therefore, shown in Figure 12 (d), light entrance face 151 sides and light-emitting face 152 sides at triangular prism 150 are respectively arranged with under the situation of a plurality of light guide members 130 across air-gap 161, and a plurality of sprung parts 160 that are respectively applied for each light guide member 130 of suspension and triangular prism 150 can not disturb yet.In addition, also fully guaranteed area with the bonding adhesive surface 160a of triangular prism 150.

In addition, as long as limit 160n is along normal a, also can not overlap with the same line of normal a on.In addition, limit 160n also can be not parallel to normal a.

And then the part that limit 160m and limit 160n intersect can have arc.In addition, suspended portion 160 also can be near the shape of having removed the angle that limit 160m and limit 160n intersect.

In addition, normal a is preferably on the projecting plane of the adhesive surface 160a that is parallel to sprung parts 160, by the summary central portion from the light mirrored sides 153b (light reflecting slant) of triangular prism 150.

As mentioned above, from triangular prism 150 and the bond strength of sprung parts 160 and the viewpoints such as easiness of the operation that optical member unit is assembled image display device 100, the shape that sprung parts 160 has shown in Figure 12 (c) and Figure 12 (d) is more effective.Particularly be provided with under the situation of a plurality of light guide members 130 in light entrance face 151 sides of triangular prism 150 and light-emitting face 152 sides, it is very effective that sprung parts 160 has the shape shown in Figure 12 (d).

[other embodiments]

Describe the present invention by above-mentioned embodiment, but a part disclosed herein discusses and accompanying drawing, and should not be construed the present invention is limited.According to the disclosure, those skilled in the art can clear and definite various replacement embodiments, embodiment and application technology.

For example, in the above-mentioned embodiment, set low index ellipsoid between the light-emitting face 132 of light guide member 130 and the light entrance face 151 of triangular prism 150 is the air-gap 161 that air constitutes, but is not limited in this.

Specifically, can be filled in the air-gap 161 by refractive index ratio light guide member 130 and triangular prism 150 little translucent materials and constitute region of low refractive index.

In addition, the translucent material that refractive index ratio light guide member 130 and triangular prism 150 are little can list transparent resins such as acrylic acid resin, polycarbonate resin, low-refraction bonding agent etc.

Like this, by refractive index ratio light guide member 130 and triangular prism 150 little translucent materials are filled in the air-gap 161, constitute region of low refractive index, can prevent that impurity such as dust from entering between the light entrance face 151 of the light-emitting face 132 of light guide member 130 and triangular prism 150.

In addition, if use the low-refraction bonding agent, can also further improve the bond strength of light guide member 130 and triangular prism 150 as refractive index ratio light guide member 130 and triangular prism 150 little translucent materials.

And then in the above-mentioned embodiment, air-gap 161 is arranged between the light entrance face 151 of the light-emitting face 132 of light guide member 130 and triangular prism 150, but is not limited in this.Specifically, air-gap can be arranged between the light entrance face of the light-emitting face of triangular prism and light guide member.

In addition, in the above-mentioned embodiment, optical member unit is made of light guide member 130 and triangular prism 150, but is not limited in this.Specifically, optical member unit can be made of triangular prism and triangular prism.

In addition, in the above-mentioned embodiment, optical member unit has the optics of the direct of travel change that is used for green light that light source 110g is sent, but be not limited in this, can also have the optics of the direct of travel of the red light that change light source 110r sent, or have the optics of the direct of travel of the blue light that change light source 110b sent.And then optical member unit can also have the optics of the direct of travel change that makes the mixed light of polychromatic light, or has the optics of the direct of travel change that makes complementary color (for example yellow) light.

In addition, in the above-mentioned embodiment, use liquid crystal panel 140 as optical modulation device, but be not limited in this, can also use DMD (Digital Micro Mirror Device) or reflective liquid crystal panel as optical modulation device.

And then in the above-mentioned embodiment, light guide member 130 is quadrangular shapes, but is not limited in this, can also be cylindrical shape or polygon prism shape etc.Equally, in the above-mentioned embodiment, light guide member 130 is triangular prism shapes, but is not limited in this, can also be cylindrical shape or polygon prism shape etc.

In addition, in above-mentioned the 2nd embodiment, sprung parts 160 is by constituting with light guide member 130 and triangular prism 150 identical materials, but is not limited in this, can also be by constituting with light guide member 130 and triangular prism 150 kinds of materials.

And then in the above-mentioned embodiment, each light source 110 has led array of all kinds, but is not limited in this, can also have LED monomer of all kinds.

In addition, in the above-mentioned embodiment, can implement chamfered edge processing to the crest line of opticses such as tapered pole 120, light guide member 130, triangular prism 150 and sprung parts 160.

And then in the above-mentioned embodiment, triangular prism 150 changes the direct of travel of light, but is not limited in this by by light mirrored sides 153b light being carried out total reflection.For example, for example triangular prism 150 can have the aluminium of institute's evaporation on the light mirrored sides 153b formation as minute surface.

Claims (13)

1. an optical member unit is made of the transparent member that imports to imaging optical system after the emitted light of light source is bent,

Above-mentioned transparent member, have make in the light that incides above-mentioned imaging optical system, to the maximum effectively refractive index of the light total reflection below the incident angle of above-mentioned imaging optical system,

The effective incident angle of above-mentioned maximum is that the refractive index and the above-mentioned imaging optical system of light incident side medium decides by medium set between above-mentioned imaging optical system and above-mentioned optical member unit.

2. optical member unit as claimed in claim 1 is characterized in that:

Above-mentioned transparent member has: be used for the reflecting surface of light reflection, and the exit facet that makes the light outgoing that above-mentioned reflecting surface reflects;

Refractive index at above-mentioned transparent member is made as nt, the refractive index of the perimeter of above-mentioned transparent member is na, the refractive index of above-mentioned light incident side medium is ni, the effective incident angle of above-mentioned maximum is θ i, the incident angle that incides above-mentioned exit facet is θ r, above-mentioned reflecting surface and the formed angle of above-mentioned exit facet are β, and with the above-mentioned reflecting surface face vertical with above-mentioned exit facet both sides in, reflection angle in the above-mentioned reflecting surface is made as " negative sense " less than the direction that light reflected of angle delta, reflection angle is made as " forward " greater than the direction that light reflected of angle delta, when the normal direction of above-mentioned imaging optical system is made as " orthogonal directions ", wherein above-mentioned angle delta is that the normal direction of direction parallel with the optical axis center of the light that incides above-mentioned imaging optical system and above-mentioned reflecting surface is formed, the angle of composition in the above-mentioned vertical face in the reflection angle in the above-mentioned reflecting surface

Under the condition that satisfies " nt＞na " and " nt＞ni ", light from above-mentioned forward entrance to above-mentioned imaging optical system satisfies the condition of " nt * sin (sin-1 ((ni/nt) * sin θ i)+β)/na 〉=sin90 ° " when " θ r＜(90-β) ° "; The light that incides above-mentioned imaging optical system from above-mentioned orthogonal directions is when " nt * sin β/na 〉=sin90 ° ", incide light the above-mentioned imaging optical system when " θ r＜β ° " from above-mentioned negative sense, satisfy the condition of " nt * sin (sin-1 ((ni/nt) * sin θ i)-β)/na 〉=sin90 ° ".

3. optical member unit as claimed in claim 2 is characterized in that:

The refractive index n t of above-mentioned transparent member, the condition of satisfied " 1.59597≤nt ".

4. optical member unit as claimed in claim 1 is characterized in that,

Have:

The 1st optics, it has the 1st light entrance face, the 1st light-emitting face and the 1st smooth mirrored sides, is made of translucent material;

The 2nd optics, it has the 2nd light entrance face, the 2nd light-emitting face and the 2nd smooth mirrored sides, is made of translucent material;

Region of low refractive index forms parts, the part of the part of the peripheral part of itself and above-mentioned the 1st light-emitting face and the peripheral part of above-mentioned the 2nd light entrance face is bonding, be used between above-mentioned the 1st light-emitting face and above-mentioned the 2nd light entrance face, form above-mentioned the 1st optics of refractive index ratio and the little region of low refractive index of above-mentioned the 2nd optics; And

Sprung parts, it has the bonding adhesive surface of a part with a part and above-mentioned the 2nd smooth mirrored sides of above-mentioned the 1st smooth mirrored sides, with above-mentioned the 1st optics and above-mentioned the 2nd optics suspension;

At least one side in above-mentioned the 1st optics and above-mentioned the 2nd optics is the light incident direction parts different with the light exit direction;

Above-mentioned sprung parts will reflect through the light after the part of above-mentioned the 1st smooth mirrored sides.

5. optical member unit as claimed in claim 4 is characterized in that:

Above-mentioned sprung parts is made of glass or transparent resin.

6. optical member unit as claimed in claim 5 is characterized in that:

Above-mentioned sprung parts is made of the material with above-mentioned the 1st optics and above-mentioned the 2nd optics identical type.

7. optical member unit as claimed in claim 4 is characterized in that:

The above-mentioned adhesive surface of above-mentioned sprung parts is to make the minute surface that reflects through the light after the above-mentioned the 1st smooth mirrored sides and the above-mentioned the 2nd smooth mirrored sides.

8. optical member unit as claimed in claim 4 is characterized in that:

Above-mentioned the 1st optics is the light guide member with quadrangular shape;

Above-mentioned the 2nd optics is the triangular prism with triangular prism shape.

9. optical member unit as claimed in claim 8 is characterized in that:

Above-mentioned triangular prism has and makes from the going direction changing of the light of above-mentioned the 2nd light entrance face institute incident and will import to the light reflecting slant of above-mentioned the 2nd light-emitting face side from the light of above-mentioned the 2nd light entrance face institute incident,

Above-mentioned sprung parts has on the limit that is parallel on the projecting plane of above-mentioned adhesive surface along above-mentioned smooth reflecting slant.

10. optical member unit as claimed in claim 9 is characterized in that:

Above-mentioned sprung parts has and is being parallel on the above-mentioned projecting plane of above-mentioned adhesive surface along the limit of the normal of above-mentioned smooth reflecting slant.

11. an optical member unit is characterized in that having:

The 1st optics, it has the 1st light entrance face, the 1st light-emitting face and the 1st smooth mirrored sides, is made of translucent material;

The 2nd optics, it has the 2nd light entrance face, the 2nd light-emitting face and the 2nd smooth mirrored sides, is made of translucent material;

Region of low refractive index forms parts, the part of the part of the peripheral part of itself and above-mentioned the 1st light-emitting face and the peripheral part of above-mentioned the 2nd light entrance face is bonding, be used between above-mentioned the 1st light-emitting face and above-mentioned the 2nd light entrance face, form above-mentioned the 1st optics of refractive index ratio and the little region of low refractive index of above-mentioned the 2nd optics; And

Sprung parts, it has the bonding adhesive surface of a part with a part and above-mentioned the 2nd smooth mirrored sides of above-mentioned the 1st smooth mirrored sides, with above-mentioned the 1st optics and above-mentioned the 2nd optics suspension;

At least one side in above-mentioned the 1st optics and above-mentioned the 2nd optics is the light incident direction parts different with the light exit direction;

Above-mentioned sprung parts makes through the light after the part of above-mentioned the 1st smooth mirrored sides and reflects.

12. an image display device has the described optical member unit of claim 1.

13. an image display device has the described optical member unit of claim 11.

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