CN1725058A - Projection-type display device - Google Patents
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- CN1725058A CN1725058A CN 200510091097 CN200510091097A CN1725058A CN 1725058 A CN1725058 A CN 1725058A CN 200510091097 CN200510091097 CN 200510091097 CN 200510091097 A CN200510091097 A CN 200510091097A CN 1725058 A CN1725058 A CN 1725058A
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Abstract
The present invention provides a projection-type display device which is used in a projector device for projecting optical images spatially modulated by reflection-type liquid crystal panels onto a screen to display an image, wherein a wavelength separation mirror is arranged so that an angle exhibited by an optical axis of light incident on the wavelength separation mirror and the optical axis of reflected light becomes smaller than 90 degrees or polarization filters or polarization separation elements are arranged on an incident facet side or an emission facet side of optical separation elements.
Description
The application is that application number is 99122473.6, the applying date is on September 29th, 1999, denomination of invention is divided an application for the application for a patent for invention of " projection display device ".
The present invention relates to a kind of projection display device, this device for example can be used in optical image with the reflection liquid crystal spatial modulation and project in the projector on the screen.
In relevant prior art, advised a kind of projection display device, the formation of this device produces the optical image of a spatial modulation with a reflection liquid crystal, then this optical image is incident upon on the screen, so that form a desirable color image.
Fig. 1 is the formation view of such projection display device
In this projection display device 1, a light source is made of this light emitted white illumination light for example a discharge lamp 3 and a reverberator 4.Convex lens 5 convert the illumination light by light source 2 emissions to substantially parallel luminous flux and this luminous flux are launched.
Dichronic mirror 6 reflections on the optical path of illuminating light of these convex lens 5 emissions have the illumination light of a predetermined wavelength and make remaining transmittance.Dichronic mirror 7 reflections on the optical path of illuminating light of reflection on this dichronic mirror 6 have the light of predetermined wavelength and make remaining illumination light transmission.Therefore projection display device is divided into red, blue and green illumination light to the illumination light by light source 2 emissions.
Lens 8, catoptron 9 and lens 10 make transmission cross the optical path of illuminating light bending of dichronic mirror 6, so that this light is directed on the polarising beam splitter 11.Polarising beam splitter 11 is transmitted in from lens 10 has a predetermined plane polarized illumination light to the illumination light of reflection liquid crystal 12 irradiation, and transmission have one with the described predetermined vertical plane polarized illumination light of plane polarization.In addition, the predetermined polarisation component in the optical image that polarising beam splitter 11 transmissions are undertaken launching after the spatial modulation by 12 pairs of these illumination light of reflection liquid crystal is transmitted into it colored synthetic prisms 13 then.
Polarising beam splitter 14 similarly is transmitted in the illumination light that has a predetermined plane polarization in the illumination light that reflects in the dichronic mirror 7 to reflection liquid crystal 15, and transmission has the plane polarized illumination light vertical with above-mentioned plane polarization.In addition, polarising beam splitter 14 transmissions are carried out the predetermined polarisation component in the optical image after the spatial modulation to this illumination light in reflection liquid crystal 15 and the polarized component that will be scheduled to is transmitted into colored synthetic prisms 13.
Polarising beam splitter 16 is similarly towards the irradiates light that has a predetermined plane polarization during reflective liquid crystal plate 17 is transmitted in the illumination light of dichronic mirror 7 reflection, and transmission has the plane polarized illumination light vertical with above-mentioned plane polarization.In addition, the predetermined polarisation component in the optical image that 17 pairs of these illumination light of polarising beam splitter 16 transflective liquid crystal boards carry out launching after the spatial modulation, and this polarized component is transmitted into colored synthetic prisms 13.
Reflection liquid crystal 12,15 and 17 is according to the colour signal spatial modulation illumination light corresponding to the incident illumination optical wavelength, by driving LCD panel, and the optical image that rotates with respect to this illumination light invested polarising beam splitter 11,14 and 16 in plane polarization separately by not shown driving circuit.
Colored synthetic prisms 13 synthetic optical images from these polarising beam splitters 11,14 and 16 incidents are launched synthetic optical image then, and projection lens 19 projects the synthesizing optical image of colored synthetic prisms 13 emissions on the screen 20.
Therefore, projection display device 1 is amplified in the image that forms on reflection liquid crystal 12,15 and 17 and also this image is projected on the screen 20, so that show the color image that needs.
Yet, the polarising beam splitter 11,14 and 16 that is used for projection display device 1 also reflects and launches a few percent of the incident light quantity of plane polarization component that must transmission, therefore in projection display device 1, make the unwanted plane polarization component that makes in this way through polarising beam splitter 11,14 and 16 reflections turn back to polarising beam splitter 11,14 and 16, and project on the screen 20 through colored synthetic prisms 13 from reflection liquid crystal 12,15 and 17.
In addition, some never being polarized but the non-modulation component that is reflected are also contained in the light via the modulation of reflective liquid crystal plate 12,15 and 17 reflections.In projection display device 1, some such components also project on the screen 20 via colored synthetic prisms 13.
Therefore, projection display device 1 has the defective of blooming, therefore wherein should be shown as black part originally and but be shown as whitely, and exist the contrast of a displayed image still not reach the problem of the quantity of practical application, thereby make the quality of displayed image become bad.
Further consider this blooming below from the viewpoint of the structure of polarising beam splitter.
When a black part is shown as white and shows this blooming, can not guarantee fully that contrast is the quantity in the image that is presented on the screen.
Polarising beam splitter is to constitute by the surface of the inclination of right-angle prism is sticked together mutually.This incident light is to be detected by the lamination at the thin dielectric film at inclined surface place, so, in the transmitted light and reflected light of polarized light beam splitting mirror, must emission detect resulting linearly polarized light thus at first.
Yet the glass material that constitutes this class right-angle prism has birefringence, therefore will launch with elliptically polarized light now with the reflected light and the transmitted light of linear polarization emission originally.
That is, this reflected light and transmitted light begin just to comprise and have the vertical plane polarized light of that linearly polarized light with original appointment.Light owing to linear polarization incident begins to be detected by ellipse in addition, thus wanted the part of light transmission or reflection to reflect or transmission originally by above-mentioned amount, and reversibly be transmitted to the former.
When from by reflection liquid crystal when this phenomenon is observed at the foothold of the optical image of polarising beam splitter emission, these reflection liquid crystal spatial modulation have the light of predetermined plane polarization and the catoptrics image synthetic light as P polarized component and S polarized component.Optical images of these original by this way emissions must be split up into P polarized component and S polarized component by the polarized light beam splitting mirror, and only the optical image of P polarized component are projected on the screen.
Yet, owing to the birefringent characteristic of polarization beam apparatus makes optical image become elliptically polarized light.The part S polarized component that the result is not subjected to spatial modulation at all also will project on the screen.
In addition, when the illumination light of observing from polarising beam splitter directive reflection liquid crystal, and to bleed through the component reflective liquid crystal plate spatial modulation, that have the vertical plane polarized light of predetermined plane polarized illumination light.The illumination light of bleeding so in statu quo projects on the screen.
It is pointed out that if above-mentioned blooming occurs inhomogeneously, the image of the demonstration on reflective display 1 will be subjected to uneven infringement.
The purpose of this invention is to provide a kind of energy by improving the projection display device that contrast shows a high-quality display image.
According to a first aspect of the present invention, a kind of projection display device is provided, this device comprises: at least one is used for first illumination light of spatial modulation and reflection incident so that launch the first reflective imaging unit of first optical image; Second illumination light that is used for spatial modulation and reflection incident is so that launch the second reflective imaging unit of second optical image; A measuring spectroscope, this spectroscope is used for being reflected in the illumination light of a predetermined wavelength of incident light, then it is transmitted into the first reflective imaging unit and remaining illumination light of transmission as first illumination light, then it is transmitted into the second reflective imaging unit as second illumination light, so that reflect first optical image and transmission second optical image, and launch first and second optical images, so that reversibly follow the tracks of the light path of incident light; A projection optics system that is used to throw first and second optical images; One is used for the light source that is transmitted into measuring spectroscope as the predetermined light of incident light; An and spectrophotometric unit, this unit is used for the incident light from light emitted is transmitted into measuring spectroscope and first and second optical images from measuring spectroscope incident are transmitted into the projection optics pattern system, set the inclination angle of this measuring spectroscope, the angle of optical axis that makes the optical axis that is incident on the light on the measuring spectroscope and first optical image is less than 90 °.
According to a second aspect of the present invention, provide a kind of projection display device, this device comprises: at least one is used for first illumination light of spatial modulation and reflection incident so that launch the first reflective imaging unit of first optical image; One is used to modulate and reflects second illumination light of incident so that launch the second reflective imaging unit of second optical image; The 3rd illumination light that is used for spatial modulation and reflection incident is so that launch the three-mirror reflective imaging unit of the 3rd optical image; First measuring spectroscope, the illumination light that this spectroscope is used for being reflected in a predetermined wavelength of incident light is transmitted into the first reflective imaging unit to it as first illumination light then, and transmission and remaining illumination light of emission, so that reflect first optical image and transmission second and the 3rd optical image, and launch first, second and the 3rd optical image so that reversibly follow the tracks of the light path of incident light; One second measuring spectroscope, this spectroscope is used for being reflected in the illumination light of the predetermined wavelength of the light that sees through first measuring spectroscope, and instead it is transmitted into the second reflective imaging unit as second illumination light, and remaining illumination light of transmission and it is transmitted into three-mirror reflective imaging unit as the 3rd illumination light, so that reflect second optical image, transmission the 3rd optical image and towards first measuring spectroscope emission the second and the 3rd optical image; A projection optics system that is used to throw first, second and the 3rd optical image; One is used for the light source that is transmitted into first measuring spectroscope as the predetermined light of incident light; And one be used for being transmitted into first measuring spectroscope from the incident light of light emitted and from first of the first measuring spectroscope incident, the second and the 3rd optical image is transmitted into the spectrophotometric unit of projection optics system, set the inclination angle of first measuring spectroscope, so that make angle between the optical axis of the optical axis that is incident on the light on first measuring spectroscope and first optical image less than 90 °, set the inclination angle of second measuring spectroscope, so as to make be incident on second spectroscope and then the angle between the optical axis of the optical axis of the light by first measuring spectroscope and second optical image less than 90 °.
Preferably, the emission of the first reflective imaging unit has plane polarized first optical image of a relative incident light rotation, polarized light filter is configured between light source and the spectrophotometric unit, the corresponding illumination light of plane polarization of the light on this polarized light filter is used for the selective transmission plane polarization and is incident on the first reflective imaging unit.
In addition, preferably, the emission of the first reflective imaging unit has plane polarized first optical image of a relative incident light rotation, it is first optical image of a relative incident light rotation, and polarized light filter is configured between projection optics system and the spectrophotometric unit, this polarized light filter is used for the selective transmission plane polarization incident light corresponding with the plane polarization of first optical image.
In addition, preferably, the emission of the first reflective imaging unit has plane polarized first optical image of a relative incident light rotation, first polarized light filter is configured between light source and the spectrophotometric unit, the corresponding illumination light of plane polarization of the light on this first polarized light filter is used for the selective transmission plane polarization and is incident on the first reflective imaging unit, and second polarized light filter is configured between projection optics system and the spectrophotometric unit, this second polarized light filter is used for the selective transmission plane polarization incident light corresponding with the plane polarization of first optical image.
According to a third aspect of the present invention, a kind of projection display device is provided, and this device comprises: one is used for spatial modulation and reflects the illumination light of predetermined flat polarization so that emission has a plane polarized reflective imaging unit that contrasts the plane polarization rotation of Mingguang City; A projection optics system that is used for the projection optics image; A light source that is used for emissive lighting light; And a spectrophotometric unit, this spectrophotometric unit is used for the illumination light that light source sends is transmitted into reflective imaging unit and the optical image of reflective imaging unit emission is transmitted into projection optical system; A polarization spectro element that is configured between light source and the spectrophotometric unit, the corresponding illumination light of plane polarization of the light on being used for the selective transmission plane polarization and being incident on the first reflective imaging unit, and the vertical plane polarization component of plane polarization of the light on selecting reflection and being incident on the first reflective imaging unit.
Preferably, the polarization spectro element is formed on the plane of incidence of illumination light of spectrophotometric unit.
According to a fourth aspect of the present invention, a kind of projection display device is provided, this device comprises: a reflective imaging unit is used for spatial modulation and the predetermined plane polarized illumination light of reflection so that emission has a plane polarized optical image that contrasts the plane polarization rotation of Mingguang City; A projection optics system that is used for the projection optics image; A light source that is applicable to emissive lighting light; And a spectrophotometric unit, this unit is used for being transmitted into the illumination light that light source sends on the reflective imaging unit and the optical image that reflective imaging unit is launched is transmitted into projection optics system; Also comprise a polarization spectro element that is configured between projection optics system and the spectrophotometric unit, this element is used for the incident light of the selective transmission predetermined plane polarization corresponding with the plane polarization of optical image and selects the reflection plane polarized component vertical with the plane polarization of optical image.
Preferably, the polarization spectro element is formed on the surface of emission of optical image of spectrophotometric unit.
According to a fifth aspect of the present invention, a kind of projection display device is provided, this device is equipped with a reflective imaging unit, and this unit is used for spatial modulation and reflection has a predetermined plane polarized illumination light so that emission has a plane polarized optical image that contrasts the plane polarization rotation of Mingguang City.This device also provides: a projection optics system that is used for the projection optics image; A light source that is used for emissive lighting light; A spectrophotometric unit, this unit is transmitted into reflective imaging unit to the illumination light from light emitted also being transmitted into projection optics system from reflective imaging unit transmitting optics image; One is configured in the first polarization spectro element between light source and the spectrophotometric unit, and the illumination light that the plane polarization of the light on being used for the selective transmission plane polarization and being incident on reflective imaging unit is corresponding is also selected the reflection plane polarized component vertical with the plane polarization of first optical image; A second polarization spectro element that is configured between projection optics system and the spectrophotometric unit is used for the incident light of the selective transmission predetermined plane polarization corresponding with the plane polarization of optical image and selects the reflection plane polarized component vertical with the plane polarization of optical image.
Preferably, the first polarization spectro element is formed on the plane of incidence of illumination light of spectrophotometric unit.
Preferably, the second polarization spectro element is formed on the plane of departure of optical image of spectrophotometric unit.
According to a sixth aspect of the present invention, a kind of projection display device is provided, this device is equipped with: a reflective imaging unit, and this unit is used for the illumination light of spatial modulation predetermined plane polarization, so that emission has a plane polarized optical image that contrasts the plane polarization rotation of Mingguang City; A projection optics system that is used for the projection optics image; A light source that is used for emissive lighting light; And polarising beam splitter, this beam splitter is used for the illumination light that light source sends is transmitted into reflective imaging unit and the predetermined polarized component from the light of the incident of reflective imaging unit is transmitted into the projection projection optics system, and this polarising beam splitter is made up of an element that satisfies following relational expression:
In the formula, K: the photoelastic constant (nm/mmmm of element
2/ N),
α: the linear expansion coefficient (10 of element
-6K),
E: the Young modulus (10 of element
3N/mm),
λ: illumination light wavelength (nm),
T: in the intrinsic transmissivity of af at wavelength lambda element,
ρ: the proportion (g/cm of element
3), and
Cp: the specific heat of element (J/gk),
Limit of integration in equation is the scope of the light absorption wavelength band of element.
According to a seventh aspect of the present invention, a kind of projection display device is provided, this device is equipped with: several reflective imaging unit, and each all is used for the incident light of spatial modulation predetermined wavelength and the plane polarized optical image of the plane polarization rotation that emission has relative incident light; A light source that is used for emissive lighting light; A colour splitting prism, this colour splitting prism according to wavelength change the illumination light of light emitted be transmitted into some reflective imaging unit and emission from the optical image of several reflective imaging unit incidents so that reversibly transmit along lighting optical axis; A projection optics system that is used for projection optics system; And polarising beam splitter, this beam splitter is transmitted into the illumination light from light emitted colour splitting prism and the component of the predetermined polarisation from the optical image of colour splitting prism incident is transmitted into projection optics system, and this polarization beam apparatus and colour splitting prism are made of the element that satisfies following relational expression:
In the formula, K: the photoelastic constant (nm/mmmm of element
2/ N),
α: the linear expansion coefficient (10 of element
-6/ K),
E: the Young modulus (10 of element
3N/mm),
λ: illumination light wavelength (nm),
T: in the intrinsic transmissivity of af at wavelength lambda element,
ρ: the proportion (g/cm of element
3), and
Cp: the specific heat of element (J/gk),
Limit of integration in equation is the scope of the light absorption wavelength band of element.
The scope of the light absorption wavelength band of element is preferably in the scope of 420nm to 500nm.
In addition, preferably the polarization spectro arrangements of components between light source and polarising beam splitter, the corresponding plane polarized illumination light of the plane polarization of the light on the polarization spectro element is used for transmission selectively and is incident on reflective imaging unit and reflect selectively be incident on reflective imaging unit on the vertical plane polarized component of plane polarization of light.
Preferably the polarization spectro element is formed on the plane of incidence of illumination light of polarising beam splitter.
Preferably the polarization spectro arrangements of components between projection optics system and polarising beam splitter, the polarization spectro element is used for the incident light of the predetermined plane polarization corresponding with the plane polarization of optical image of transmission selectively and the reflection plane polarized component vertical with the plane polarization of this optical image selectively.
Preferably the polarization spectro element is formed on the surface of emission of optical image of polarising beam splitter.
According to the present invention, if set the inclination angle of measuring spectroscope, make between the optical axis of the optical axis of the incident light on the measuring spectroscope and first optical image angle less than 90 °, then can reduce the wavelength difference of p polarized component and s polarized component in measuring spectroscope.Thereby, can show high-quality image by the utilization ratio that this numerical value improves illumination light.
In addition, if set the inclination angle of first measuring spectroscope, the angle of optical axis that makes the optical axis of the incident light on first measuring spectroscope and first optical image is less than 90 degree, if and the inclination angle of setting second measuring spectroscope, the angle of optical axis that makes the optical axis of light on second measuring spectroscope incident and that see through first measuring spectroscope and second optical image is less than 90 °, then can in measuring spectroscope, reduce the wavelength difference of catoptrical p polarized component and s polarized component with so-called three-chip type structure, thereby, can show high-quality image by the utilization ratio that this numerical value improves illumination light.
If between light source and spectrophotometric unit, the component that the formula imaging cells modulate that then never is reflected is crossed is stopped the polarization spectro arrangements of components, and this component can turn back to light source side, prevented from whereby to cause that owing to the projection of this component contrast reduces.Thereby can show high-quality image.In addition, can improve the utilization ratio of illumination light by utilizing this component once more, and can also prevent temperature rise by above-mentioned light quantity.
In addition, if the polarization spectro arrangements of components between projection optics system and spectrophotometric unit, the component that contrast in the projected image is reduced is stopped, and this component can turn back to light source side, prevented that whereby the projection owing to this component from causing the reduction of contrast, thereby can show high-quality image.In addition, can improve the utilization ratio of illumination light by utilizing this component once more, and can also prevent temperature rise by above-mentioned light quantity.
In addition, according to the present invention, even because of make birefringent increase because of temperature rise causes the stress increase in the element that satisfies the above-mentioned relation formula, birefraction is remained on to be enough to satisfy in the scope of practical application, thereby can reduce because the blooming that birefringence causes.In addition, can improve the utilization ratio of illumination light by utilizing this component once more, and can also prevent temperature rise by above-mentioned light quantity.
By following description of preferred embodiments with reference to the accompanying drawings, will make these and other characteristics of the present invention become clearer.
Fig. 1 is the pie graph of the projection display device in the related art.
Fig. 2 is the pie graph of one first embodiment of projection display device of the present invention.
Fig. 3 is a spectroscopical family curve.
Fig. 4 is the pie graph of second embodiment of projection display device of the present invention.
Fig. 5 is the figure of the polarization spectro element function in the key drawing 4.
Fig. 6 is the pie graph of the 3rd embodiment of projection display device of the present invention.
Fig. 7 is the pie graph of the 4th embodiment of projection display device of the present invention.
Fig. 8 is the pie graph of the 5th embodiment of projection display device of the present invention.
Fig. 9 is the curve that is used for the projection apparatus operation of key diagram 8.
Figure 10 is the pie graph of the 6th embodiment of projection display device of the present invention.
Figure 11 is the pie graph of the 7th embodiment of projection display device of the present invention.
Figure 12 is the figure of function that is used for illustrating the polarization spectro element of Figure 11.
The description of preferred embodiment
Describe embodiments of the invention below with reference to accompanying drawings in detail.
First embodiment
Fig. 2 is the pie graph of first embodiment of projection display device of the present invention.
In the display device 30 of the projection-type of Fig. 2, light source 31 is formed reverberator 33 by near xenon lamps 32 that are configured in the reverberator 33 and is roughly become paraboloidal cylindrical mirror to form by one, and the white illumination light that this light source 31 is launched xenon lamp 32 is from the opening ejaculation of reverberator 33.
A pair of fly lens 34A and the 34B that is configured on the optical path of illuminating light of light source 31 equipments whereby, becomes evenly the Flux Distribution of illumination light.
Linearly polarized light conversion sheet 35 is optical elements, it is mainly in the display device selective transmission S of this projection-type polarized component and will become the S polarized component with the vertical P component transformation of S polarized component, and described S polarized component is the polarized light of useful space modulation in reflection liquid crystal 36A, 36B and 36C just.
Thus, light source 31 can be increased in from having of xenon lamp 32 emission and the various plane polarized illumination light image be shown effective polarized component, and minimizing shows the illumination light that vertical polarized component of effective polarized component and emission are synthesized at last with described to image.The result to improve the utilization ratio of illumination light, from and make the contrast of displayed image obtain to improve.
The illumination light on the optical path of illuminating light that fly lens 34B penetrates is assembled and be transmitted in to convex lens 37.
From the illumination light irradiation catoptron 38 of this convex lens 37 emissions, level crossing 38 these illumination light of reflection and its directive being become with input path on 90 ℃ the direction then.
The light that convex lens 39 are assembled and emission is reflected via this level crossing 38.
Polarized light filter 40 selective transmissions show effective S polarized component to image be transmitted into 40 illumination light on one's body of light filter from convex lens 39, and the absorption P component vertical with the S polarized component.Therefore polarized light filter 40 selects emission to the effective S component of displayed image from light source side towards 41 of polarising beam splitters.
The angle that makes the optical axis of spectroscope 42B and incident light is 45 °, so that the angle theta 1 of the optical axis that makes incident light and the optical axis of the optical image that obtains from reflection liquid crystal 36B is less than 90 °.
Dispose spectroscopical the reasons are as follows like this:
Promptly, on the spectroscope 42B of the incident light that has required wavelength for a selection reflection, the transmission of selecting and the cutoff wavelength of reflection are different between P polarized component and S component, these two polarized components each with one as the angle ejaculation represented with the reverse rate of the reflectivity of P polarized component and S polarized component among Fig. 3, wherein represent the reflectivity of P polarized component with symbol RP, RS represents the reflectivity of S polarized component.In contrast, this class transmission-type display device 30 reflects the incident light of the S polarized component of using for reflection liquid crystal 36B, reflects from the optical image of the P polarized component of this reflection liquid crystal 36B incident, and makes its directive polarising beam splitter 41.Therefore, when being used for that there is difference in the cutoff wavelength of selective transmission light between P polarized component and S polarized component by this way, the utilization factor of light is also reduced by above-mentioned amount.
, exist such feature: if the incident angle of incident light diminishes, then the difference in the catoptrical cutoff wavelength of P polarized component and S polarized component is also reduced by above-mentioned amount.
Therefore, the display device of projection-type 30 equipment spectroscope 42B, disposing this spectroscope 42B, to make the inclination angle of the optical axis of its relative incident light be 45 °, thus the angle of the optical axis that makes incident light and the optical axis of the optical image that obtains from reflection liquid crystal 36B is less than 90 °.
In addition, with close polarising beam splitter 41 sides of reflection liquid crystal 36B, so that can reduce the profile scope of whole projection display device 30.
Beam split camera lens 42R reflects by this way by the light modulated of reflection liquid crystal 36R incident and its directive spectroscope 42B, and transmission simultaneously is from the light modulated of reflection liquid crystal 36G incident and make its directive spectroscope 42B.
Also also launch among the spectroscope 42R of the light that is synthesized synthetic green by this way with light modulated redness, if between the reflected light of the reflected light of P polarized component and S polarized component wavelength dissimilate and the incident angle of incident light little, then the difference of wavelength is also along with this quantitative change is smaller.Therefore, make spectroscope 42R and spectroscope 42B configured in parallel and make inclined light shaft 45 degree of its relative incident light, so that the angle θ 2 of the optical axis that makes incident light and the optical axis of the optical image of reflection liquid crystal 36R acquisition is less than 90 °.
In addition, make reflection liquid crystal 36R near polarising beam splitter 41 sides, so that can diminish projection display device 30 as a whole.
The P polarized component of polarized light filter 44 selective transmissions on the light path of the light modulated that penetrates from this polarising beam splitter 41, and select to absorb the S polarized component.Projection optics system 45 also projects the amplification of these polarized light filter 44 transmissions on the screen 46 then.
The following describes the operation that is suitable for this formation.
-in projection display device 30, projection-type liquid crystal board 36B, 36R and 36G are excited by blue, red and green, are formed on reflection liquid crystal 36B so that make corresponding to image blue, red and green signal, on 36R and the 36G.In projection display device 30, the illumination light that penetrates from light source 31 is resolved into the light of orchid, red and green wavelength, offer reflective liquid crystal plate 36B, 36R and 36G then.Therefore, the plane polarization of blue, red and green illumination light along with corresponding to blue, red and green rotation so that produce optical image.P polarized component in these optical images selectively projects on the screen 36, so that throw a colored displayed image by projection optics system 45.
That is, make the illumination light of launching shine polarising beam splitter 41 through catoptron 38 from light source 31.There, after reflecting via reflection liquid crystal 36B, 36R and 36G, the effective S polarized component of optical image becomes orchid, red and green illumination light by spectroscope 42B and 42R for forming in succession.Blue, red and green illumination light is through reflective liquid crystal plate 36B, 36R and 36G polarization and reflection, so that produce blue, red and green optical image by the synthetic light of P polarized light and S polarized light.These optical images shine on the polarising beam splitter 41 by spectroscope 42B and 42R.The P polarized component of these light modulated selects to see through polarising beam splitter 41 directive projection optics systems 45, projects on the screen 46 through this projection optical system 45 then.
At this moment, illumination light is with the angle tilt directive spectroscope 42B and the 42R of predetermined S polarized light, and the light of modulation is as the synthetic light of P polarized light and S polarized light directive spectroscope 42B and 42R obliquely.In contrast, because the spectroscope 42B and the 42 pairs of P polarized lights have different reflection characteristics with wavelength between the S polarized light, make the reflection characteristic in the light of the reflection characteristic that contrasts the wavelength in Mingguang City and modulation relatively become different (Fig. 3).
Yet in this embodiment, spectroscope 42B and 42R tilted configuration, so that make angle with respect to the optical axis of the illumination light of spectroscope 42B and 42R and the optical axis of the light modulated that is injected into spectroscope 42B and 42R, thereby the difference in the catoptrical cutoff wavelength of the reflected light of P polarized light and S polarization is diminished less than 90 °.Promptly, with from the orchid of spectroscope 42B and 42R directive reflection liquid crystal 36B, 36R and 36G, redly compare with green illumination light, make to have no lavishly to penetrate to become possibility corresponding to the orchid of illumination light, red and green polarized light towards projection optics system, and utilization factor that therefore can be by this amount raising illumination light and form the image of a bright high-quality display.
As above illustrated like that projection display device 30 spatial modulation are in the illumination light of the S of reflection liquid crystal 36B, 36R and 36G polarized light, and penetrate the light modulated of P polarized lights and S polarized light towards polarising beam splitter 41 by spectroscope 42B and 42R.
The P polarized component of polarising beam splitter 41 transmissions in the optical image of P polarized light and S polarized light, it is penetrated towards screen, at this moment, the component of the optical image that causes by the S polarized light should with separate by the optical image that on P polarising beam splitter 41, causes, and forbidden to project on the screen 46, but part sees through polarising beam splitter 41.
If the component of the optical image that is produced by the S polarized light is incident upon on the screen 46, then the contrast of displayed image will reduce, but in this embodiment, layout polarized light filter 44 between polarising beam splitter 41 and projection optics system 45.Therefore, the S polarized light component of transmission-polarizing beam splitter 41 is absorbed by this polarized light filter 44.Therefore, compare with relevant prior art, for the S polarized light component that contrast is reduced, the quantity of light reduces widely.So the contrast of displayed image is along with this light quantity increases on screen 46, thereby can show a high-quality image.
For the illumination light that offers reflection liquid crystal 36B, 36R and 36G, the S polarized component in the illumination light that is provided by light source 31 is polarized beam splitter 41 reflection back transmission, and the part of P polarized component is penetrated the back transmission by branch.
If this P polarized component is not subjected to any modulation ground reflection on reflection liquid crystal 36B, 36R and 36G, and with optical image (P optical component) without any difference project on the screen, then this component also can make the contrast of displayed image reduce, but in this is implemented, because between light source 31 and polarising beam splitter 41, arrange polarized light filter 40, so the P polarized component is absorbed by this polarized light wave filter 40.Therefore, offering reflective liquid crystal puts the quantity of illumination light of the P polarized light of formula plate 36B, 36R and 36G and reduces widely.So the contrast of displayed image increases along with the minimizing of the quantity of this polarized light, thereby can show a high-quality displayed image.
In addition, can prevent the uneven brightness of displayed image by means of so uniform illumination light, thereby also can show a high-quality displayed image by being configured in the illumination light that fly lens 34A on the light source 31 and 34B provide an even quantity.
Make and be polarized that optical filter 40 absorbs or partly convert the S component to and penetrate by being configured in linearly polarized light conversion sheet 35 between these two fly lens 34A and the 34B by polarization Light splitter toy 41 backs and to the absolutely void P polarized component of the demonstration of image, the utilization ratio of illumination light is increased because of such light quantity, the intensity level of displayed image obtains to improve, thereby can also show a high-quality image.In addition, by such light quantity the quantity of the P polarized component that is incident on the polarized light filter 40 is reduced in this way, the temperature rise of polarized light filter 40 is reduced, thereby prevented to become bad because of temperature rise causes characteristic.
As mentioned above, according to this first embodiment, spectroscope tilts to place, so that the angle of optic angle of light of putting the optical axis of the illumination light on the spectroscope that has been incident on the effect of wavelength spectroscope and modulation is less than 90 °, therefore be used for producing the light modulated of P polarized light and S polarized light and this light modulated projected the formation on the screen this from the illumination light of S polarized light, can reduce the wavelength difference between the P polarized component and S polarized component in reflected light, can improve the utilization ratio of illumination light by such light quantity, finally can show a high-quality image.
By being configured in polarizing filter between light source and the polarising beam splitter respectively and between polarising beam splitter and the projection optics system, and make these light filters absorb P polarized component and S polarized component respectively, can prevent the fuzzy existing image of above-mentioned displayed image, and can increase contrast, thereby can show a higher-quality image by such light quantity.
Second embodiment
Fig. 4 is the pie graph of second embodiment of projection display device of the present invention.
The projection display device 50 of the second embodiment of the present invention is with the difference of the projection display device of above-mentioned first embodiment of the invention: polarized light beam splitter 51 and 52 is arranged as shown in Figure 4 and is replaced polarized light filter.
It is to be noted, replace the polarized light wave filters to constitute this projection apparatus 50 because remove polarized light beam splitter 51 above-mentioned and 52, so identical formation parts represent and save the explanation of repetition with identical label to sentence the mode identical with projection display device 30.
As shown in Figure 5, polarized light beam splitter 51 and 52 has the more optically anisotropic pellicular cascades of having of predetermined thickness to form by handle, their selective transmissions have the incident light of predetermined plane polarization, and select to reflect the plane polarized incident light that has with above-mentioned predetermined plane polarization orthogonal.
Polarized light beam splitter 51 is configured between convex lens 39 and the polarized light beam splitting mirror 41, and selective transmission is in the S polarized component from the illumination light of light source 31 incidents, and selects the reflected P polarized component.
Therefore, polarized light beam splitter 51 and 52 has improved the contrast of displayed image.
In addition, different with the polarized light wave filter at this, polarized light beam splitter 51 and 52 does not absorb P polarized component and S polarized component, but reflects this two fens components, thereby can reduce temperature rise by this light quantity.
It is to be noted, in this manner, the plane of polarization variation takes place owing to waiting in the first-class repeatedly reflection of light source 31 in the light that turns back on light source side 31 or the polarising beam splitter 41, and the light of this backspace is also as shining on polarised light splitter 51 and 52 by the component of polarized light beam splitter 51 and 52.Therefore, by effectively utilizing this projection display device 50 of illumination light can improve the intensity level of displayed image.
Polarized light beam splitter 51 and 52 is fixed respectively and is bonded on the plane of incidence and reflecting surface of polarising beam splitter 41 by the optics adhesives.
For such projection display device, owing to got rid of, prevented because the light loss that these air cause at air layer between polarized light subelement 51 and the polarising beam splitter 41 and the air layer between polarized light beam splitter 52 and polarising beam splitter 41.In addition, compare with the situation of utilizing polarized light filter light device to absorb predetermined polarized component, the heat that these projection display device 50 radiation produce on polarization spectro element 51 and 52, thus more effectively reduced temperature rise.
It is to be noted, in a formation of also using polarized light filter, can consider the polarized light beam splitter is bonded on the polarized beam splitting device, but it is high on ratio polarization light beam splitter in the temperature rise on the polarized light device light device, probably produce birefringence because of polarising beam splitter temperature rise causing polarising beam splitter own, contrast is reduced, and make unevenness more serious.
According to this second embodiment, because the polarized light beam splitter 51 of selective transmission S component and selection reflecting part component is configured between light source and the polarising beam splitter 41, so improved the contrast of displayed image and can form high-quality displayed image.
Because selective transmission P polarized component and the polarized light beam splitting element of selecting to reflect the S polarized component 52 are configured between projection light system 45 and the polarising beam splitter 41, thus the contrast of displayed image improved, and form high-quality displayed image.
Because polarized light beam splitter 51 and 52 fixed bondings are on polarising beam splitter 41, so prevented because the light loss that air layer causes can show a bright high-quality displayed image.In addition, owing to can reduce temperature rise,, can prevent that optical element is aging, can also simplify the work of this configuration requirement so can improve reliability by above-mentioned light quantity.
The 3rd embodiment
Fig. 6 is the pie graph of the 3rd embodiment of projection display device of the present invention.
In the projection display device of third embodiment of the invention, dispose a polarising beam splitter 61 different with the polarising beam splitter 41 of the projection display device 50 of above-mentioned second embodiment, the difference of these two beam splitters is to have the plane of polarization of different transmission and reflection.The corresponding above-mentioned difference of the layout of optical system changes.
It is pointed out that in projection display device 60, represent identical part and save its repeat specification with the above-mentioned corresponding reference symbol of projection display device 50 usefulness.
That is, in this projection display device 60, polarising beam splitter 61 transmission S polarized components and reflected P polarized component are corresponding, and spectroscope 42R etc. is configured on the optical path of illuminating light through polarising beam splitter 61.
As shown in Figure 6, even under the situation of using different polarising beam splitters that constitute, also can obtain with second embodiment in identical effect.
The 4th embodiment
Fig. 7 is the pie graph of the 4th embodiment of transmission-type display device of the present invention.
In this projection display device 70, by replacing the spectroscope 42R in the projection display device 30, the Amici prism 72 of 43B makes illumination light resolve into red, orchid and green illumination light, synthetic red then, blue and green optical image.
As shown in Figure 7, synthetic red, blue and green optical image again by replacing spectroscope 42R and 42B and 42G Amici prism 72 will make illumination light resolve into red, blue and green illumination light, also can obtain effect same as the previously described embodiments.
It is pointed out that in this 4th embodiment,, the invention is not restricted to these situations though explanation is the projection optics system side that is configured in light source side and polarising beam splitter at polarized light filter or polarized light beam splitter.As long as be enough to satisfy under the situation of application request obtaining, the polarized light beam splitter can be disposed on any side.
In addition, though in third and fourth embodiment, just illustrate polarized light beam splitter fixed bonding on polarising beam splitter, the invention is not restricted to this, as long as satisfy under the situation of practicality requirement obtaining to be enough to, the polarized light beam splitter can be configured to insert air layer therebetween.
In addition, though the three the and the 4th embodiment in, explanation is just to be undertaken by having predetermined thickness and having under the situation that optically anisotropic pellicular cascade constitutes the polarized light beam splitter.But the invention is not restricted to this, as long as by being layered on the glass sheet for example the just passable of predetermined thickness having anisotropic Transparent Parts on the optics.
In addition, though in third and fourth embodiment, illustrate that the present invention does not limit this with regard to what carry out under the situation of polarized light beam splitter simple-arranged, also can the polarized light beam splitter be set by the AR coating.
The 5th embodiment
Fig. 8 is the pie graph of the 5th embodiment of projection display device of the present invention.
To concrete formation and the operation that the 5th projection-type of implementing is put view apparatus be described in proper order with regard to Fig. 8 and Fig. 9 below.
In the projection display device 80 of Fig. 8, light source 81 by one be configured in by one roughly near the xenon lamps 2 the reverberator formed of elliptical cylinder-shape mirror 83 constitute, this light source 81 shoots out white illumination light from xenon lamp 82 from the opening of reverberator 83.
In addition, light source 81 devices have a pair of fly lens 84A and the 84B that is configured on this optical path of illuminating light, so that make being evenly distributed of illumination light quantity.
In addition, light source 81 is equipped with one and is configured in plane polarization conversion sheet 85 is arranged between fly lens 84A and the 84B.
Plane polarization conversion sheet 85 is optical elements of main selective transmission S polarized component, this S polarized component is can be effectively via the polarized light of reflection liquid crystal 86A, 86B in this projection display device and 86C modulation, and 85 P polarized components vertical with the S polarized component of this converter plate are transformed into the S polarized component.
Thus, light source 81 can be increased in from having of xenon lamp 82 emission and the various plane polarized illumination light image be shown effective polarized component, and minimizing shows the illumination light that vertical polarized component of effective polarized component and emission are synthesized at last with described to image.The result to improve the utilization ratio of illumination light, from and make the contrast of displayed image obtain to improve.
The illumination light on the optical path of illuminating light that fly lens 84B penetrates is assembled and be transmitted in to convex lens 87.
The light of these level crossing 88 reflections is assembled and launched to convex lens 89.
In polarising beam splitter 90, the length of the bottom surface of each right-angle prism is 50mm, therefore makes one one cube shaped that the length of side is 50mm of the whole formation of polarising beam splitter.
The square prism that polarising beam splitter 90 is made by a glass material constitutes, this glass material have one by following equation pointed 3.71 * 10
2Parameter A, thereby reduce because the double refractive inde that thermal stress causes, this formula is:
In the formula, K: the photoelastic constant (nm/mmmm of glass material
2/ N),
α: the linear expansion coefficient (10 of glass material
-6/ K),
E: the Young modulus (10 of glass material
3N/mm),
λ: illumination light wavelength (nm),
T: in the intrinsic transmissivity of af at wavelength lambda glass material,
ρ: the proportion (g/cm of glass material
3), and
Cp: the specific heat of glass material (J/gK),
Limit of integration in equation (1) is the scope (420nm (λ 1) is to 500nm (λ 2)) of the light absorption wavelength band of glass material.
Making spectroscope 91B is 45 ° with respect to the angle of the optical axis of incident light, so that the angle theta 1 of the optical axis that makes incident light and the optic angle of the optical image that obtains from reflection liquid crystal 86B is less than 90 °.
Dispose spectroscopical the reasons are as follows like this:
That is, in order only to select reflection to have among the spectroscope 91B of incident light of required wavelength, the transmission of selection and the cutoff wavelength of reflection are different between P polarized component and S component, and these two polarized components penetrate at an angle.In contrast, this class transmission-type display device 80 reflects the incident light of the S polarized component of using for reflection liquid crystal 86B, reflects from the optical image of the P polarized component of this reflection liquid crystal 86B incident, and makes its directive light beam device 90.Therefore, when being used for that there is difference in the cutoff wavelength of selective transmission light between P polarized component and S polarized component by this way, the utilization factor of light is also reduced by above-mentioned amount.
, have such feature: if the incident angle of incident light diminishes, then the difference of the cutoff wavelength in the reflected light of P polarized component and S polarized component is reduced by above-mentioned amount.
Therefore, the display device of projection-type 80 equipment dichronic mirror 91B, disposing this spectroscope 91B, to make the inclination angle of the optical axis of its relative incident light be 45 °, thus the angle of the optical axis that makes incident light and the optical axis of the optical image that obtains from reflection liquid crystal 86B is less than 90 °.
In addition, with close polarising beam splitter 90 sides of reflection liquid crystal 86B, so that can reduce the profile of whole projection display device 80.
Also also launch among the spectroscope 91R of the light that is synthesized synthetic green by this way with light modulated redness, if between the reflected light of the reflected light of P polarized component and S polarized component wavelength dissimilate and the incident angle of incident light little, then the difference of wavelength is also along with this quantitative change is smaller.Therefore, make spectroscope 91R and spectroscope 91B configured in parallel and make inclined light shaft 45 degree of its relative incident light, so that the angle θ 2 of the optical axis that makes incident light and the optical axis of the optical image of reflection liquid crystal 86R acquisition is less than 90 °.
In addition, make reflection liquid crystal 86R near polarising beam splitter 90 sides, so that can diminish projection display device 80 as a whole.
The following describes the operation that is suitable for this formation.
One in projection display device 80, and projection-type liquid crystal board 86B, 96R and 86G are excited by blue, red and green, is formed on reflection liquid crystal 86B so that make corresponding to image blue, red and green signal, on 86R and the 86G.In projection display device 80, the illumination light that penetrates from light source 81 is resolved into the light of orchid, red and green wavelength, offer reflective liquid crystal plate 86B, 86R and 86G then.Therefore, the plane polarization of blue, red and green illumination light along with corresponding to blue, red and green rotation so that produce optical image.P polarized component in these optical images selectively projects on the screen 93, so that throw a colored displayed image by projection optics system 92.
That is, make the illumination light of launching shine polarising beam splitter 90 through catoptron 38 from light source 81.There, after reflecting via reflection liquid crystal 86B, 86R and 86G, the effective S polarized component of optical image becomes orchid, red and green illumination light by spectroscope 91B and 91R for forming in succession.Blue, red and green illumination light is through reflective liquid crystal plate 86B, 86R and 86G polarization and reflection, so that produce blue, red and green optical image by the synthetic light of P polarized light and S polarized light.These optical images shine on the polarising beam splitter 90 by spectroscope 91B and 92R.The P polarized component of these light modulated selects to see through polarising beam splitter 90 directive projection optics systems 45, projects on the screen 93 through this projection optical system 92 then.
At this moment, illumination light is with the angle tilt directive spectroscope 91B and the 91R of predetermined S polarized light, and the light of modulation is as the synthetic light of P polarized light and S polarized light directive spectroscope 91B and 91R obliquely.On the other hand because the relative S polarized light with 91R of spectroscope 91B has different reflection characteristics with the P polarized light, so that just the reflection characteristic in illumination light is different with reflection characteristic in light modulated.
Yet in this embodiment, spectroscope 91B and 42R tilted configuration, so that make angle with respect to the illumination light optical axis of spectroscope 91B and 92R and the optical axis of the light modulated that is injected into spectroscope 91B and 91R less than 90 °, diminish thereby can make at the reflected light of P polarized light and the catoptrical cut-off wave difference difference of S polarization.Promptly, with compare with the orchid of 91R directive reflection liquid crystal 86B, 86R and 86G, red and green illumination light from spectroscope 91B, make to have no lavishly to penetrate to become possibility corresponding to the orchid of illumination light, red and green polarized light towards projection optics system, and utilization factor that therefore can be by this amount raising illumination light and form the image of a bright high-quality display.
As above illustrated like that, in projection display device 80, the illumination light of the S polarized light of spatial modulation on reflection liquid crystal 86B, 86R and 86G, and penetrate the light modulated of P polarized lights and S polarized light by spectroscope 91B and 91R towards polarising beam splitter 90.
In polarising beam splitter 90, the P polarized component of transmission in the optical image of P polarization and S polarization, and directive screen.At this moment, the S polarized component in the optical image begins from optical image to separate with P polarization in polarising beam splitter 90, and is forbidden to be incident upon on the screen 93.
Yet when the P polarized component saw through the right-angle prism that constitutes polarising beam splitter 90, the plane of polarization of S polarized component was owing to birefringence changes, and the component with the incident of S polarization is detected as the P polarized component on the inspection side thus.Therefore in projection display device 80, part S polarized component will project on the screen 93 then through polarising beam splitter 90, because the minimizing of S component will make the contrast of displayed image reduce.
In addition, in the illumination light of light source 86 emissions, by the inspection on the detection faces of polarising beam splitter 90 then with P polarized component directive reflection liquid crystal 86B, 86R and 86G, but at this moment, be mixed in the P polarized component S polarized component and ejaculation owing to constitute the birefringence of the right-angle prism of polarising beam splitter 90.This S polarized component will and see through after 90s the projecting of polarising beam splitter by reflection liquid crystal 86B, 86R and 86G reflection and shield on 93.Reduce with regard to the contrast that makes displayed image owing to sneaking into of above-mentioned P component like this.
Yet in this embodiment, because right-angle prism by have by equation (1) have point out 3.71 * 10
2The glass material of parameter A make, so because birefringence can make the increase of P polarized component and S polarized component stop at the scope that is enough to satisfy practical application.Thereby birefringently stop to increase and can prevent because the above-mentioned fuzzy existing contrast that causes descends by above-mentioned.
That is,, then can reduce fuzzy existing image by reducing birefringence if the birefringent degree one that can reduce in the right-angle prism that constitutes polarising beam splitter 90 produces above-mentioned fuzzy existing visual reason.This birefringence is because stress in glass material inside causes that it can be normal by optical length * photoelasticity * indicate the strain of the strain value of glass material to measure as a standard value.
Wherein, the photoelastic constant amount depends on the constant of glass material, it is believed that therefore the existing image of this class can reduce by this photoelastic constant of control.Even photoelastic constant significantly reduces then, if also be difficult to reduce birefringent degree by the way but glass material has big stress.
Therefore when this strain of check, in this glass material, represent this stress with thermal strain+initial strain+contacting strain.At this, thermal stress is the stress that moves along with the temperature rise of glass material.In projection display device 80, it is because in device inner thermal convection, heat conduction, the loss of illumination light etc. causes what temperature rise produced.In addition, unrelieved stress when initial strain is polarising beam splitter 90 manufacturings, it be because unrelieved stress when the glass material hardening, the unrelieved stress that produces during to the cutting of glass material and polishing, also be because when the processing detection plane, heat the overstrain power that causes, adhesives contraction etc. produces when bonding, in addition, contact stress is the stress that is added to when polarising beam splitter 90 is set on the polarising beam splitter 90.
When the power supply of projection display device 80 is in on-state and sufficiently low and when observing show visual at internal temperature, can limit above-mentioned fuzzy existing image on the degree that allows in actual applications in the moment of power connection as shown in Figure 9, but in contrast, As time goes on above-mentioned fuzzy existing image increases, this shows that in the stress of being represented by this mode of thermal strain+primary stress+fixed stress birefringence being had the stress of maximum effect is thermal stress, also show if control because the strain quantity that thermal stress causes then can effectively reduce fuzzy existing image.
When further considering this thermal stress, can represent this thermal stress with some physical constants of determining this glass material, therefore represent the size of this stress with temperature difference * linear expansion coefficient * yang type modulus.In addition, temperature difference can be used specific heat, and proportion and transmission are recently represented.
After considering this point, just can judge because the fuzzy existing image that birefringence causes according to the parameter A in the equation (1).
In fact, if what study first embodiment is 3.71 * 10 by the value with a parameter A
2The polarising beam splitter 90 made of glass material and one be 5.44 * 10 by value with a parameter A
2The comparative result of the polarising beam splitter made of glass material the time, as shown in Figure 9, be 5.44 * 10 in the value of parameter A
2That polarising beam splitter 90 on, fuzzy existing image increased in several hours, and can perceive because the minimizing of the contrast that this fuzzy existing image causes.In contrast, be 3.71 * 10 at parameter value A
2That polarized light beam splitting mirror on, even used long-time after, also being difficult to find is to show a high-quality image effectively because the contrast that this fuzzy existing image causes reduces so use in reality.
When judging all these evaluation results, because reducing, the contrast that the birefringence of polarising beam splitter causes can not surpass the scope that is enough to satisfy practical application in order to make, actually, if the value of operation parameter A is 5.00 * 10
2Or littler glass material, then can obtain one and have contrast and homogeneity reduction projection display device seldom.
In this way, in projection display device 80, can prevent the reduction of contrast, can evenly supply with illumination light, can prevent the unevenness of the illumination of displayed image by such fader control by fly lens 84A and the 84B that is configured on the light source 81.Thereby can show a high-quality displayed image equally.
Make through polarising beam splitter 90 and be not used for P polarized component that image shows and partly be transformed into the S polarized component and penetrate owing to being configured in the flat polarisation transformation sheet 85 that shakes between fly lens 84A and the 84B, thereby improved the utilization ratio of illumination light by the increase of S component, improved the intensity level of displayed image, because same reason can show a high-quality image.
As mentioned above, according to the fifth embodiment of the present invention, be 3.71 * 10 because polarising beam splitter is a value with a kind of parameter A
2Glass material make, parameter A shows because the birefringence intensity that the thermal stress shown in the equation (1) causes, and the value of this parameter A is less than 5.00 * 10
2So, can stop the scope that keeps practical application to allow that is reduced to of contrast that above-mentioned fuzzy existing image causes, can show a high-quality image from face.
Particularly, because because the variation of the contrast that heat causes is little, so, also can obtain a stable contrast and evenly illumination even work is long-time.In addition with regard to the increase of the brightness that attends by displayed image and for the increase of illumination light, the thermal stress property of material has obtained improvement, therefore increases brightness easily.
According to this 5th embodiment, because make spectroscope tilt to place, so that make the angle that is incident on as the optical axis of the optical axis of the illumination light on the spectroscope of measuring spectroscope and light modulated less than 90 °, so can reduce P polarized component in the reflected light in an optical arrangement and the wavelength difference between the S polarized component, described optical arrangement is used for producing from the illumination light of S polarization the light modulated of P polarization and S polarization, and this light modulated is incident upon on the screen, can improve the utilization factor of illumination light by the useful light quantity of such increase, the result can show a high-quality image.
The 6th embodiment
Figure 10 is the pie graph of the 6th embodiment of projection display device of the present invention.
In this projection display device 100, spectroscope 91B and 91R with Amici prism 101 replaces in projection display device 80 resolve into orchid, red and green illumination light with illumination light, and orchid, red and green optical image are combined.
In addition, in projection display device 100, except polarising beam splitter 90, it is 3.71 * 10 that Amici prism is also used the pointed numerical value that has of equation (1)
2The glass material manufacturing of parameter A.
As shown in figure 10, be 3.71 * 10 as long as utilize the value of parameter A
2The glass material of parameter A make Amici prism, just can obtain the effect identical with the 5th embodiment, wherein parameter A is represented the dijection degree that causes owing to thermal stress.
The 7th embodiment
Figure 11 is the pie graph of the 7th embodiment of projection display device of the present invention.
In the projection display device 110 of the 7th embodiment, dispose a transmission polarising beam splitter 111 different with plane of reflection polarization that has with the polarising beam splitter 90 of the projection display device 80 of the 5th embodiment, the layout of its optical system changes corresponding to the 7th embodiment.
It is to be noted that in this projection display device 110 every and projection display device 80 identical parts all use corresponding reference number to represent, and save its repeat specification.
That is, in this projection display device 110, polarising beam splitter 111 utilizations have an expression and cause that by thermal stress the numerical value of birefringence level is 3.71 * 10
2The glass material of parameter A make, this polarising beam splitter transmission S polarized light, and the reflected P polarized light is corresponding, optical splitter 91B etc. are configured on the optical path of illuminating light by polarising beam splitter 111.
In addition, in this projection display device 110, polarized light beam splitter 112 and 113 is configured on the light source side and projection light system side of polarising beam splitter 111.
Polarized light beam splitter 112 and 113 is pre-thickness and has optically anisotropic pellicular cascade and form, the incident light of the predetermined plane polarization that polarisation beam splitter 112 and 113 selective transmissions are shown in Figure 12 selects reflection to have the plane polarized incident light that hangs down mutually with above-mentioned plane polarization simultaneously.
Polarized light beam splitter 112 is configured between convex lens 89 and the polarising beam splitter 111, and selective transmission is selected the reflected P polarized component simultaneously in the S polarized component from the illumination light of light source 81 incidents.
Polarized light beam splitter 113 is configured between projection optics system 92 and the polarising beam splitter 111, and selective transmission is from the P polarized component of polarising beam splitter 111 incidents, and selects reflection S polarized component.
Therefore, polarized light beam splitter 112 and 113 causes above-mentioned fuzzy existing image and can utilize those plane polarization components once more towards the light source side reflection, thereby improved the contrast of displayed image, and effectively utilized illumination light simultaneously, thereby the brightness that improves displayed image.
In addition, polarized light beam splitting element 112 and 113 fixed bondings are on the plane of incidence and the surface of emission of polarising beam splitter 111.
Therefore, projection display device 110 has been eliminated at air layer between polarized light beam splitter 112 and the polarized light beam splitting element 111 and the air layer between polarized light beam splitting element 113 and polarising beam splitter 111, thereby has prevented the light loss that caused by these air.
According to this 7th embodiment, except that according to the 5th embodiment, because polarized light beam splitter 12 and 113 also is configured between light source 81 and the polarising beam splitter 111 respectively and between projection optics system 92 and polarising beam splitter 111, can further prevent above-mentioned fuzzy existing image, contrast is improved, can form a high-quality displayed image.
In addition, because these two polarized light beam splitters 112 and 113 fixed bondings are on polarising beam splitter 111, thus prevented because the light loss that air layer causes, thus a bright high-quality displayed image can be shown.In addition, owing to can reduce temperature rise, and can improve reliability by the utilization factor of the useful light quantity of above-mentioned raising, can prevent above-mentioned optical element generation crackle, and further simplify the step of arranging that these elements are required.
It is to be noted, in an embodiment, though what describe is the situation that the present invention is suitable for utilizing the projection display device of a polarising beam splitter, but the present invention is not limited by this, and can also be widely used in disposing the situation of polarising beam splitter of each color and other certain situation.
Though the special embodiment that has selected with reference to purpose for example is illustrated invention above, in the present technique field the those of ordinary skill without prejudice to key concept of the present invention with not exceed to come in the scope of invention its various changes of making be conspicuous.
Claims (9)
1, a kind of projection display device is characterized in that comprising:
One is used for spatial modulation and the predetermined plane polarized illumination light of reflection so that emission has the reflective imaging unit of the plane polarized optical image of a plane polarization rotation that contrasts Mingguang City;
A projection optics system that is used to throw described optical image;
A light source that is used for emissive lighting light;
A polarising beam splitter, this polarising beam splitter are used for the illumination light that light source sends is transmitted into reflective imaging unit and the optical image of reflective imaging unit emission is transmitted into described projection optical system; And
A polarization spectro element that is configured between described light source and the described polarising beam splitter, the corresponding illumination light of plane polarization of the light on this beam splitter is used for the selective transmission plane polarization and is incident on described reflective imaging unit, and select the reflection plane polarization component vertical with described plane polarization.
2, projection display device as claimed in claim 1 is characterized in that, described projection display device also comprises:
The plane polarization converting unit is used for the corresponding illumination light of plane polarization of the light on converting its plane polarization to and be incident on described reflective imaging unit from the emission light of light source.
3, projection display device as claimed in claim 1 is characterized in that:
Described polarization spectro element is formed on the plane of incidence of illumination light of described polarising beam splitter.
4, a kind of projection display device is characterized in that comprising:
A reflective imaging unit, described imaging unit are used for spatial modulation and the predetermined plane polarized illumination light of reflection has a plane polarized optical image that contrasts the plane polarization rotation of Mingguang City so that launch;
A projection optics system that is used for the projection optics image;
A light source that is used for emissive lighting light; And
A polarising beam splitter, this polarising beam splitter are used for the reflective imaging of the illumination light directive unit that light source is sent and the optical image that reflective imaging unit is launched is transmitted into projection optics system;
A polarization spectro element that is configured between projection optics system and the polarising beam splitter, this beam splitter are used for the incident light of the selective transmission predetermined plane polarization corresponding with the plane polarization of optical image and select the reflection plane polarized component vertical with the plane polarization of optical image.
5, projection display device as claimed in claim 4 is characterized in that:
Described polarization spectro element is formed on the surface of emission of optical image of described polarising beam splitter.
6, a kind of projection display device is characterized in that this display device comprises:
A reflective imaging unit, this unit are used for spatial modulation and reflection has a predetermined plane polarized illumination light so that emission has a plane polarized optical image that contrasts the plane polarization rotation of Mingguang City;
A projection optics system that is used to throw described optical image;
A light source that is used to launch described illumination light; And
A polarising beam splitter, this polarising beam splitter is being transmitted into projection optics system from the reflective imaging of the illumination light directive unit of light emitted and the described optical image that sends from described reflective imaging unit;
One is configured in the first polarization spectro element between described light source and the described polarising beam splitter, and the illumination light that the plane polarization of the light on this beam splitter is used for the selective transmission plane polarization and is incident on reflective imaging unit is corresponding is also selected the reflection plane polarization component vertical with described plane polarization;
A second polarization spectro element that is configured between described projection optics system and the described polarising beam splitter is used for the incident light of the selective transmission predetermined plane polarization corresponding with the plane polarization of described optical image and selects the reflection plane polarization component vertical with the plane polarization of described optical image.
7, projection display device as claimed in claim 6 is characterized in that, the described first polarization spectro element is formed on the plane of incidence of illumination light of described polarising beam splitter.
8, projection display device as claimed in claim 6, its feature exists, and is formed in the described second polarization spectro element on the plane of departure of optical image of described polarising beam splitter.
9, projection display device as claimed in claim 6 is characterized in that:
The described first polarization spectro element is formed on the plane of incidence of illumination light of described polarising beam splitter;
The described second polarization spectro element is formed on the plane of departure of optical image of described polarising beam splitter.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10275370A JP2000105360A (en) | 1998-09-29 | 1998-09-29 | Projection type display device |
| JP275370/98 | 1998-09-29 | ||
| JP276974/98 | 1998-09-30 | ||
| JP301953/98 | 1998-10-23 |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB991224736A Division CN1236625C (en) | 1998-09-29 | 1999-09-29 | Projection type display equipment |
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| Publication Number | Publication Date |
|---|---|
| CN1725058A true CN1725058A (en) | 2006-01-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200510091097 Pending CN1725058A (en) | 1998-09-29 | 1999-09-29 | Projection-type display device |
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| Country | Link |
|---|---|
| JP (1) | JP2000105360A (en) |
| CN (1) | CN1725058A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101995745A (en) * | 2009-08-10 | 2011-03-30 | 佳能株式会社 | Color splitter and combiner system and projection display apparatus |
| CN111881719A (en) * | 2020-06-09 | 2020-11-03 | 青岛奥美克生物信息科技有限公司 | Non-contact biometric guiding device, method and biometric system |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002277850A (en) * | 2001-03-19 | 2002-09-25 | Nikon Corp | Optical device for projection display device, and the projection display device |
-
1998
- 1998-09-29 JP JP10275370A patent/JP2000105360A/en active Pending
-
1999
- 1999-09-29 CN CN 200510091097 patent/CN1725058A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101995745A (en) * | 2009-08-10 | 2011-03-30 | 佳能株式会社 | Color splitter and combiner system and projection display apparatus |
| CN111881719A (en) * | 2020-06-09 | 2020-11-03 | 青岛奥美克生物信息科技有限公司 | Non-contact biometric guiding device, method and biometric system |
| CN111881719B (en) * | 2020-06-09 | 2024-04-16 | 青岛奥美克生物信息科技有限公司 | Non-contact type biological recognition guiding device, method and biological feature recognition system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2000105360A (en) | 2000-04-11 |
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