CN101738666A - Optical sheet - Google Patents

Optical sheet Download PDF

Info

Publication number
CN101738666A
CN101738666A CN200810174073A CN200810174073A CN101738666A CN 101738666 A CN101738666 A CN 101738666A CN 200810174073 A CN200810174073 A CN 200810174073A CN 200810174073 A CN200810174073 A CN 200810174073A CN 101738666 A CN101738666 A CN 101738666A
Authority
CN
China
Prior art keywords
anisotropic film
optical
optical anisotropic
pitch
refractive index
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN200810174073A
Other languages
Chinese (zh)
Inventor
郑至成
林晖雄
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Industrial Technology Research Institute ITRI
Original Assignee
Industrial Technology Research Institute ITRI
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Industrial Technology Research Institute ITRI filed Critical Industrial Technology Research Institute ITRI
Priority to CN200810174073A priority Critical patent/CN101738666A/en
Publication of CN101738666A publication Critical patent/CN101738666A/en
Pending legal-status Critical Current

Links

Images

Abstract

The invention relates to an optical sheet which comprises a plurality of optical anisotropy films stacked mutually, wherein each optical anisotropy film has a plurality of main axis refractive indexes nx, ny and nz, wherein nx and ny are main refractive indexes of a plane surface, and nz is the refractive index in the thickness direction. In addition, the main axis refractive index nx of each optical anisotropy film is the maximum value or minimum value in the main axis refractive indexes nx, ny and nz. Each optical anisotropy film has an optical axis of which the direction is the direction of the main axis of the main axis refractive index nx. The optical axes of the optical anisotropy films in the optical sheet rotate sequentially along preset directions in the thickness direction of the optical anisotropy films, and the sum of the rotation angles of the optical axes is larger than or equal to 360 degrees.

Description

Optical sheet
Technical field
The present invention relates to a kind of optical sheet, and particularly relate to a kind of reflective functions and reflection function optical sheet of having concurrently.
Background technology
Along with showing being showing improvement or progress day by day of science and technology, people can make life convenient more by the auxiliary of display device, wherein flat-panel screens (Flat Panel Display, FPD) and characteristic that volume thin in light weight with it and become the main flow of present display.In many flat-panel screens, (LiquidCrystal Display LCD) has advantageous characteristic such as high spatial utilization ratio, low consumpting power, radiationless and low electromagnetic interference (EMI), and therefore, LCD is very popular because LCD.
Fig. 1 illustrates the diagrammatic cross-section of known a kind of LCD.Please refer to Fig. 1, LCD 100 comprises display panels 110 and backlight 120, and wherein backlight 120 is incident to display panels 110 in order to light L to be provided.More specifically, display panels 110 generally includes upper polarizer 110a, upper substrate 110b, liquid crystal layer 110c, infrabasal plate 110d and following polaroid 110e.After light L that backlight 120 is provided was incident to display panels 110, following polaroid 110d was with polarization of light that backlight 120 sent and transfer polarized light L to T, the rotation in various degree via liquid crystal molecule among the liquid crystal layer 110c can change polarized light L TIn the penetrance of zones of different, and again from upper polarizer 110a outgoing.So, display panels 110 produces display effect.
Though upper polarizer 110a and following polaroid 110e can be so that light L generation polarizations, and then the optical effect of auxiliary LCD 100 shown images.Yet, following polaroid 110e and upper polarizer 110a can make light L produce loss in by the process of upper and lower polaroid 110a, 110e, and the situation of energy dissipation takes place in the light L that causes backlight 120 to be sent in LCD 100, and then influences the brightness performance of LCD 100.Generally speaking, upper polarizer 110a is a kind of application of optical sheet with following polaroid 110e.Therefore, how properly to design the structure of optical sheet, make LCD 100 have higher light utilization, real be applied to demand urgently on the flat-panel screens problem that overcomes for present optical sheet.
Summary of the invention
The invention provides a kind of optical sheet, make light have higher polarized light separation efficiency and higher light utilization by this optical sheet.
The invention provides another kind of optical sheet, this optical sheet can reduce the energy loss of incident light.
For specifically describing content of the present invention, at this a kind of optical sheet (optical sheet) is proposed, this optical sheet comprises the optical anisotropic film (optical anisotropic film) that multilayer is piled up mutually.Wherein, each optical anisotropic film has a plurality of main shaft refractive index n x, ny and nz, wherein nx, ny are plane principal refractive index (in-plane main refractive index), and nz is thickness direction refractive index (thickness-wise refractive index).In addition, the main shaft refractive index n x of each optical anisotropic film is maximal value or the minimum value among these main shaft refractive index ns x, ny and the nz, and each optical anisotropic film has optical axis, and the direction of optical axis is the major axes orientation of main shaft refractive index n x.Each optical axis of multilayer optical anisotropic membrane rotates along preset direction in regular turn at the thickness direction of optical anisotropic film in the optical sheet, and total anglec of rotation of these optical axises is more than or equal to 360 degree.
For specifically describing content of the present invention, at this another kind of optical sheet is proposed, this optical sheet comprises optical anisotropic film and the λ/4 phase differential diaphragms that multilayer is piled up mutually, wherein λ/4 phase differential diaphragms are disposed on these optical anisotropic films.Each optical anisotropic film has a plurality of main shaft refractive index n x, ny and nz, wherein nx, ny are plane principal refractive index (in-plane main refractive index), and nz is thickness direction refractive index (thickness-wise refractive index).In addition, the main shaft refractive index n x of each optical anisotropic film is maximal value or the minimum value among these main shaft refractive index ns x, ny and the nz, and each optical anisotropic film has optical axis, and the direction of optical axis is the major axes orientation of main shaft refractive index n x.Each optical axis of aforesaid optical anisotropic film rotates along preset direction in regular turn at the thickness direction of optical anisotropic film, and total anglec of rotation of these optical axises is more than or equal to 360 degree.
Optical sheet of the present invention has the optical anisotropic film that multilayer is piled up mutually and optical axis rotates along preset direction in regular turn at thickness direction, and total anglec of rotation of these optical axises is more than or equal to 360 degree, become the different polarized light in twice polarization direction after making incident light by this optical sheet, wherein the polarization direction polarized light identical with preset direction utilized by the optical sheet reflection again, and another polarized light then penetrates optical sheet.Therefore, optical sheet of the present invention can reduce the energy loss of incident light.
For above-mentioned feature and advantage of the present invention can be become apparent, preferred embodiment cited below particularly, and cooperation institute accompanying drawing are described in detail below.
Description of drawings
Fig. 1 illustrates the diagrammatic cross-section of known a kind of display panels.
Fig. 2 A illustrates the diagrammatic cross-section of a kind of optical sheet of embodiments of the invention.
Fig. 2 B is the sectional perspective synoptic diagram according to one of them optical anisotropic film illustrated among Fig. 2 A.
Fig. 2 C is the schematic perspective view that optical sheet illustrated according to Fig. 2 A.
Fig. 2 D illustrates the schematic perspective view of the another kind of optical sheet of embodiments of the invention.
Fig. 2 E and Fig. 2 F illustrate the diagrammatic cross-section of six kinds of optical sheets in addition of the first embodiment of the present invention.
Fig. 3 A illustrates the diagrammatic cross-section of a kind of optical sheet of the second embodiment of the present invention.
Fig. 3 B illustrates the diagrammatic cross-section of the another kind of optical sheet of the second embodiment of the present invention.
The polarized light reflectivity of the second embodiment of the present invention that Fig. 3 C illustrates and the graph of a relation of polarized light wavelength.
Fig. 3 D illustrates the diagrammatic cross-section of another optical sheet of the second embodiment of the present invention.
Fig. 4 illustrates the diagrammatic cross-section of a kind of optical sheet of the third embodiment of the present invention.
Fig. 5 illustrates the diagrammatic cross-section of a kind of optical sheet of the fourth embodiment of the present invention.
Description of reference numerals
100: LCD
110: display panels
120: backlight
110a: go up polaroid
110b: upper substrate
110c: liquid crystal layer
110d: infrabasal plate
110e: following polaroid
200,200A, 200R, 200G, 200B, 200R ', 200G ', 200B ', 300,300A, 300B, 400,500: optical sheet
202,204,206,208,210,212,302R, 304R, 306R, 308R, 310R, 312R, 302G, 304G, 306G, 308G, 310G, 312G, 302B, 304B, 306B, 308B, 310B, 312B: optical anisotropic film
510: λ/4 phase differential diaphragms
A, A 202, A 204, A 206, A 208, A 210, A 212: optical axis
D, d R1, d G1, d B1, d R1～d R6, d G1～d G6, d B1～d B6, d R1'～d R6', d G1'～d G6', d B1'～d B6': thickness
d T, d R, d G, d B, d R', d R', d R': pitch
D1: thickness direction
D2: preset direction
L: light
L RR, L TR: ruddiness
L RG, L TG: green glow
L RB, L TB: blue light
L R, L T: polarized light
Nx, ny, nz: main shaft refractive index
θ: total anglec of rotation
θ 1, θ 2, θ 3, θ 4, θ 5: angle
Embodiment
Optical sheet of the present invention has special construction, the optical effect that light can obtain to expect by optical sheet the time by this special construction.Particularly, light can become polarization light after by optical sheet, and wherein partial polarization light can penetrate optical sheet, all the other partly polarization lights then can be reflected again and utilize by optical sheet.In following examples, will describe at the structure of optical sheet and light mechanism by optical sheet.
[first embodiment]
Fig. 2 A illustrates the diagrammatic cross-section of a kind of optical sheet of embodiments of the invention, and Fig. 2 B is the sectional perspective synoptic diagram according to one of them optical anisotropic film illustrated among Fig. 2 A.Please be simultaneously with reference to Fig. 2 A and Fig. 2 B, the optical sheet 200 of present embodiment comprises multilayer optical anisotropic membrane (opticalanisotropic film) 202,204,206,208,210,212, and wherein multilayer optical anisotropic membrane 202,204,206,208,210,212 piles up mutually.It should be noted that at this present embodiment illustrates six layers of optical anisotropic film 202,204,206,208,210,212 only in order to explanation, and the structure of unrestricted optical sheet of the present invention 200.In addition, in other embodiments, optical sheet 200 also can be further between two adjacent optical anisotropic films (for example 202,204 or 204,206... etc.) configuration optical isotropy film (optical isotropic film).
Hold above-mentioned, each optical anisotropic film 202～212 has a plurality of main shaft refractive index n x, ny and nz, wherein nx, ny are plane principal refractive index (in-plane main refractive index), and nz is thickness direction refractive index (thickness-wise refractive index), in other words, the travel rate of light in optical anisotropic film has different performances according to the different directions of rete.In addition, the main shaft refractive index n x of each optical anisotropic film 202～212 is maximal value or the minimum value among main shaft refractive index n x, ny and the nz.
Furthermore, the main shaft refractive index n x of each optical anisotropic film 202～212 is to be example with the maximal value in these main shaft refractive index ns x, ny and nz, in other words, in the present embodiment, each optical anisotropic film 202～212 belongs to the material of positive refracting power anisotropy (positive refractiveindex anisotropy), i.e. Δ n＞0.Certainly, the main shaft refractive index n x of each optical anisotropic film 202～212 also can be the minimum value among these main shaft refractive index ns x, ny and the nz, and each optical anisotropic film 202～212 belongs to the material of negative index anisotropy (negative refractiveindex anisotropy), i.e. Δ n＜0.In addition, each optical anisotropic film 202～212 has optical axis A, and the direction of optical axis A is the major axes orientation of main shaft refractive index n x.In other words, the refractive index of each optical anisotropic film 202～212 on the direction of its optical axis A is main shaft refractive index n x.
In the present embodiment, main shaft refractive index n x, the ny of each optical anisotropic film 202～212 and the nz relational expression that satisfies ny=nz ≠ nx.That is to say, in each optical anisotropic film 202～212, the refractive index n x of optical axis A constitutes extraordinary ray refractive index (Extraordinary refractiveindex) ne, and refractive index n y, the nz of vertical optical axis A direction constitute ordinary refraction index (Ordinaryrefractive index) no.Therefore, in part embodiment of the present invention, the relation of main shaft refractive index n x, ny and nz and extraordinary ray refractive index n e and ordinary refraction index no satisfies the relational expression of ne=nx and no=ny=nz, has optically uniaxial birefringence (birefringence) material and make each optical anisotropic film can be considered.In brief, the optical sheet 200 of present embodiment has birefringent characteristic, and becomes twice polarized light L after can making light L by arbitrary optical anisotropic film 202～208 or 210 TAnd L R(will be specified in the back).Yet in other embodiments, each optical anisotropic film also can be to have optically biaxial birefringent material, the relational expression that main shaft refractive index n x, the ny of optical anisotropic film and nz satisfy nx ≠ ny ≠ nz.
Hold above-mentionedly, each optical anisotropic film 202～212nd in the optical sheet 200 serves as preferred to have identical main shaft refractive index n x, ny and nz.Yet when the main shaft refractive index n x of optical anisotropic film adjacent in the optical sheet 200 (for example 202,204 etc.) had in fact smaller or equal to 0.05 difference, optical sheet still had the good optical performance.In like manner can know by inference, the main shaft refractive index n y of adjacent optical anisotropic film or main shaft refractive index n z also can have in fact the difference smaller or equal to 0.05.In other words, the present invention also allows few part to have difference slightly because of technological factor or other factors cause main shaft refractive index n x, ny or the nz of optical anisotropic film adjacent in the optical sheet 200 (for example 202,204 etc.).
In the present embodiment, each optical anisotropic film 202～212 has surperficial S.In theory, in each optical anisotropic film 202～212, the major axes orientation of main shaft refractive index n x and the angle between the surperficial S be with 0 the degree serve as preferred.Yet, in optical sheet 200 of the present invention, even the major axes orientation of the main shaft refractive index n x of optical anisotropic film and the angle between the surperficial S are roughly to equal 10 when spending, optical sheet 200 of the present invention also can reach the penetrating component polarization light and reflect another partly effect of polarization light.In other words, to allow few part be not the situation of 0 degree because of technological factor or other factors cause the major axes orientation of main shaft refractive index n x, ny or nz and the angle between the surperficial S in the present invention.
Fig. 2 C is the schematic perspective view according to the optical sheet of Fig. 2 A.Please refer to Fig. 2 C, in the optical sheet 200 of present embodiment, the optical axis A of each optical anisotropic film 202～212 rotates along preset direction D2 in regular turn at the thickness direction D1 of optical anisotropic film 202～212.What deserves to be explained is that preset direction D2 can be counter clockwise direction, clockwise direction or other proper orientation, is to be that example describes with the counter clockwise direction in the present embodiment.Total anglec of rotation θ of these optical axises A equals 360 degree.So, light L beam incident optical sheet 200 backs are divided into the opposite polarized light L in twice polarization direction according to the sense of rotation of those optical axises in the optical anisotropic film 202～212 TAnd L RIn the present embodiment, polarized light L TBe left circularly polarized light, and polarized light L TCan penetrate optical sheet 200 against the sense of rotation (being preset direction D2) of optical axis A.On the other hand, the polarization direction part identical with the sense of rotation (being preset direction D2) of optical axis A can be reflected by optical sheet 200 and make polarized light L and among the light L RBecome right-circularly polarized light.Certainly, in other embodiments, preset direction D2 can also look the range of application of product and selectivity is designed to clockwise direction, and so optical sheet 200 just can reflect left circularly polarized light, and right-circularly polarized light is penetrated, and decides on application demand.
Need to prove at this, total anglec of rotation θ is to be principle with essence more than or equal to the formed optical sheet 200 of 360 degree, meaning promptly allows between each optical anisotropic film 202～212 fewly partly to cause total anglec of rotation θ to be not equal to the situations of 360 degree because of technological factor or other factors.
Please be simultaneously with reference to Fig. 2 A and Fig. 2 C, when total anglec of rotation equals 360 in fact when spending, the thickness d summation of optical anisotropic film 202～212 can constitute pitch d T(pitch).For instance, the optical sheet 200 of present embodiment for example is to be made of 202～212 of six layers of optical anisotropic films, and the optical axis of the optical anisotropic film 202,204,206,208,210,212 that order is piled up in regular turn is A 202, A 204, A 206, A 208, A 210, A 212, and angle theta 1～θ 5Be A in regular turn 202With A 204Between, A 204With A 206Between, A 206With A 208Between, A 208With A 210, A 210With A 212Between angle.Shown in Fig. 2 C, A 202, A 204, A 206, A 208, A 210, A 212Along rotation in regular turn counterclockwise, and the angle theta between the optical axis of two adjacent optical anisotropic films 1～θ 5Be essentially 72 degree.So, just, can analogize other combinations.
Special one carry be, shown in Fig. 2 D, in other embodiments, when optical sheet 200A for example be constitute by 202～210 of five layers of optical anisotropic films and the optical axis of two adjacent optical anisotropic films between angle theta 1～θ 4Be all 90 when spending, optical sheet 200A can be reflection optical filter.
The optical sheet 200 of present embodiment provides a kind of structure that light is divided into the different polarized light in polarization direction, make the light of a part of polarization from the surperficial outgoing of optical sheet 200, and another partly the light of polarization utilize again from former incidence surface reflection, and optical sheet of the present invention 200 is separated into light the separation efficiency height of above-mentioned outgoing polarized light and above-mentioned polarization by reflection light.In detail, in the present embodiment, light L is separated into twice polarized light L TAnd polarized light L RSeparation rate can be defined as the polarized light L that left-hand polarization light is penetrating TIn ratio, perhaps be defined as right-handed polarized light the reflection polarized light L RIn ratio.When to it should be noted that based on penetrance and reflectivity summation be 100% consider, when optical sheet 200 is piled up when forming with more optical anisotropic film, optical sheet 200 can make the polarized light L that penetrates in the light TIn the polarization direction and the polarized light L of reflection RThe polarization direction reach unanimity.The polarized light L that for example penetrates TIn only have left-hand polarization light, and the reflection polarized light L RIn only have right-handed polarized light.At this moment, optical sheet 200 can make light L have preferred separation efficiency.
Angle between the optical axis A of the number of plies of the optical anisotropic film 202～212 that piles up from the above, and two adjacent optical anisotropic films (for example 202,204) (θ for example 1) have dependence relation, so that optical sheet 200 obtains preferred total anglec of rotation θ.Yet in the optical sheet of other embodiment, the optical axis of two adjacent optical anisotropic films also can have different angles, for example θ 1Be not equal to θ 2That is to say that in total anglec of rotation θ, the optical axis A that the present invention does not limit two adjacent optical anisotropic films must have identical angle, is decided by actual process or design requirement.
What deserves to be mentioned is that above-mentioned have a pitch d TOptical sheet 200 can reflect the polarization light of specific wavelength.Specifically, so-called herein specific wavelength is meant the wave band that is made of central wavelength lambda and frequency range W, wherein pitch d TSatisfy λ=(ne+no)/2 * d respectively with central wavelength lambda, frequency range W TAnd W=| (ne-no) * d T| relational expression.From another perspective, this has pitch d TOptical sheet 200 polarization light of specific wavelength is penetrated.For example, shown in Fig. 2 E, in the present embodiment, when light L by having pitch d ROptical sheet 200R the time, and when the preset direction D2 of optical sheet 200R such as above-mentioned counter clockwise direction, optical sheet 200R is suitable for reflecting that to have the polarization direction be the inclined to one side ruddiness L of dextrorotation circle RR, be the inclined to one side ruddiness L of left-handed circle and have the polarization direction TRThen can penetrate optical sheet 200R.In like manner, when light L respectively by having pitch d GOr pitch d BOptical sheet 200G or during 200B, optical sheet 200G and 200B can reflect respectively then that to have the polarization direction be the inclined to one side green glow L of dextrorotation circle RGAnd blue light L RB, be the inclined to one side green glow L of left-handed circle and have the polarization direction TGAnd blue light L TBThen can penetrate optical sheet 200G and 200B respectively.
In the present embodiment, the thickness of each optical anisotropic film 202～212 for example is to have identical thickness in the optical sheet 200.Shown in Fig. 2 E, pitch d R, d GWith d BFor example be respectively by six layers of identical thickness d R1, d G1With d B1Constitute.Yet in other embodiments, the thickness of each optical anisotropic film also can have different thickness in the optical sheet.With Fig. 2 F is example, the pitch d of optical sheet 200R ', 200G ' and 200B ' R', d G' and d B' for example be respectively by different thickness d R1'～d R6', d G1'～d G6' and d B1'～d B6' constitute.In brief, in each pitch, the thickness that the present invention does not limit each optical anisotropic film is essential identical.
From the above, in the present embodiment, optical sheet 200,200R, 200G, 200B, 200R ', 200G ' and 200B ' can see through respectively and adjust pitch d T, d R, d G, d B, d R', d G' and d B' size to obtain the specific polarization light of specific wavelength, wherein the light of part particular polarization can penetrate optical sheet, the light of the particular polarization of another part then can be reflected.
Traditionally, the part light penetration that polaroid in the LCD can make light source send, remaining light then can lose in the process by polaroid, and the situation of energy dissipation takes place in the light that causes light source to send in LCD, makes can't effectively be utilized by the light that light source sent.The present invention is different from known, when being applied to optical sheet of the present invention in the LCD, then by light that optical sheet reflected can be again material by having reflection characteristic or device and once more in the beam incident optical sheet, light in the LCD can be utilized maturely, and then promote the brightness performance of LCD.
[second embodiment]
Fig. 3 A illustrates the diagrammatic cross-section of a kind of optical sheet of the second embodiment of the present invention.Please refer to Fig. 3 A, the present embodiment and first embodiment are similar, and the two main difference is: the optical sheet 300 of present embodiment has a plurality of pitch d R, d GWith d B, and constitute pitch d GOne group of optical anisotropic film 302G～312G be positioned at and constitute pitch d ROne group of optical anisotropic film 302R～312R and constitute pitch d BOne group of optical anisotropic film 302B～312B between.
In the present embodiment, each pitch d R, d GOr d BOptical anisotropic film 302R～312R, 302G～312G or the combination of the 302B～312B polarization light that is suitable for reflecting different specific wavelengths.Wherein, the polarization direction of polarization light can be decided by the sense of rotation of each optical axis among optical anisotropic film 302R～312R, 302G～312G or the 302B～312B, and the present invention is not limited.For instance, in the present embodiment, constitute pitch d RThe combination of optical anisotropic film 302R～312R be suitable for reflecting the ruddiness of particular polarization, constitute pitch d GThe combination of optical anisotropic film 302G～312G be suitable for reflecting the green glow of particular polarization, and constitute pitch d BThe combination of optical anisotropic film 302B～312B be suitable for reflecting the blue light of particular polarization.Therefore, the optical sheet 300 of present embodiment is applied in the LCD, then helps to reduce the energy loss of light source, to promote the overall brightness performance of LCD.
In the present embodiment, the optical anisotropic film of above-mentioned formation pitch has identical thickness.Particularly, constitute pitch d ROptical anisotropic film 302R～312R have identical thickness d R1, constitute pitch d GOptical anisotropic film 302G～312G have identical thickness d G1, constitute pitch d BOptical anisotropic film 302B～312B have identical thickness d B1Yet in other embodiments, the optical anisotropic film that constitutes pitch also can have different thickness.
More specifically, in the optical sheet of present embodiment each layer optical anisotropic film also can adopt the cumulative or thickness of thickness decrescence mode and arrange, wherein each angle of total anglec of rotation of optical sheet also can be cumulative thereupon or decrescence.For instance, Fig. 3 B illustrates the diagrammatic cross-section of the another kind of optical sheet of the second embodiment of the present invention.Please refer to Fig. 3 B, optical sheet 300A is by constituting pitch d ROne group of optical anisotropic film 302R～312R, constitute pitch d GOne group of optical anisotropic film 302G～312G with constitute pitch d BOne group of optical anisotropic film 302B～312B form.By Fig. 3 B as can be known, constitute pitch d respectively R, d GWith d BEach layer optical anisotropic film 302R～312R, 302G～312G and each thickness d of 302B～312B R1～d R6, d G1～d G6With d B1～d B6For example be to reduce gradually.Certainly, in other embodiments, above-mentioned thickness d R1～d R6, d G1～d G6With d B1～d B6Also can be for increasing gradually.
Because optical sheet 300A makes incident ray L be separated into twice polarized light L TAnd polarized light L R, when the thickness of each layer optical anisotropic film in the same pitch is when arranging in the mode of above-mentioned decrescence (or cumulative), polarized light L RCan have bigger frequency range.In a preferred embodiment, polarized light L RFrequency range be the frequency range of visible light (being white light), the polarized light reflectivity that is illustrated as Fig. 3 C and the graph of a relation of polarized light wavelength.
What deserves to be mentioned is that optical anisotropic film 302R～312R, 302G～312G, 302B～312B also can further be stacked into has a plurality of pitch d R, a plurality of pitch d GOr a plurality of pitch d B Optical sheet 300 '.For instance, shown in Fig. 3 D, optical sheet 300 ' comprises that two groups have pitch d ROptical anisotropic film 302R～312R, two groups have pitch d GOptical anisotropic film 302G～312G and two groups have pitch d BOptical anisotropic film 302B～312B.Wherein, the thickness in each pitch is decided on actual product, and the present invention is not limited.Because the optical anisotropic film of optical sheet 300 ' with a plurality of identical pitch, therefore, incident light can obtain preferred separating effect after by optical sheet 200.
[the 3rd embodiment]
Fig. 4 illustrates the diagrammatic cross-section of a kind of optical sheet of the third embodiment of the present invention.Please refer to Fig. 4, the present embodiment and second embodiment are similar, and the two main difference is: constitute pitch d R, d GWith d BOptical anisotropic film 302G～312G, 302R～312R and the configuration relation of 302G～312G.Particularly, in the optical sheet 400 of present embodiment, constitute pitch d GEach optical anisotropic film 302G～312G be positioned to constitute pitch d REach optical anisotropic film 302R～312R and constitute pitch d BEach optical anisotropic film 302B～312B between.
Yet, in other embodiments, constitute pitch d R, d GOr d GArbitrary optical anisotropic film 302R～312R, 302G～312G or 302B～312B also can adopt the arbitrarily staggered pattern of piling up.For instance, constitute pitch d GOne of them optical anisotropic film 302G be positioned at and constitute pitch d RWherein two optical anisotropic film 302R and 304R between, constitute pitch d GOne of them optical anisotropic film 304G be positioned at and constitute pitch d BWherein two optical anisotropic film 302B and 304B between ... etc. pattern, but the present invention is not limited to this.In addition, each optical anisotropic film with same pitch can have identical thickness, also can have different thickness.
[the 4th embodiment]
Fig. 5 illustrates the diagrammatic cross-section of a kind of optical sheet of the fourth embodiment of the present invention.Please refer to Fig. 5, present embodiment and first embodiment to the, three embodiment are similar, and compared to previous embodiment, the optical sheet 500 of present embodiment further comprises λ/4 phase differential diaphragms 510, and make the optical sheet 500 of present embodiment constitute linear polarizer.Wherein, multilayer optical anisotropic membrane 202～212 piles up mutually, and λ/4 phase differential diaphragms 510 for example are to be disposed on the optical anisotropic film.
From the above, the optical sheet 500 of present embodiment has birefringent characteristic, so light L can become the different polarized light L in twice polarization direction after by optical sheet 500 TAnd polarized light L RAnd see through the setting of λ/4 phase differential diaphragms 510, can be so that the polarized light L of present embodiment TAnd L RTransfer linearly polarized light to.
Therefore, the optical sheet 500 of present embodiment has the advantage of the foregoing description, and optical sheet 500 is applied in the LCD, then can reduce the energy loss of the light source of LCD.In addition, the optical sheet 500 of present embodiment can adopt the project organization of the various kenels of the foregoing description, with the demand in response to various products.
In sum, optical sheet of the present invention utilizes the suitable configuration of the optical axis of each optical anisotropic film, so that utilize after the polarized light of particular polarization is reflected in the light again.Optical sheet of the present invention is applied in the LCD, then can effectively reduces the energy loss of the light source of LCD, and then promote the brightness performance of LCD.
Though the present invention discloses as above with preferred embodiment; right its is not in order to limit the present invention; those of ordinary skill in the technical field under any; without departing from the spirit and scope of the present invention; when can doing a little change and retouching, so protection scope of the present invention is as the criterion when looking the claim person of defining.

Claims (17)

1. optical sheet comprises:
The multilayer optical anisotropic membrane, described optical anisotropic film piles up mutually, each described optical anisotropic film has a plurality of main shaft refractive index n x, ny and nz, nx wherein, ny is the plane principal refractive index, nz is the thickness direction refractive index, and the main shaft refractive index n x of each described optical anisotropic film is described main shaft refractive index n x, maximal value among ny and the nz or minimum value, each described optical anisotropic film has optical axis, and the direction of described optical axis is the major axes orientation of described main shaft refractive index n x, the described optical axis of wherein said optical anisotropic film rotates along preset direction in regular turn at the thickness direction of described optical anisotropic film, and total anglec of rotation essence of described optical axis is more than or equal to 360 degree.
2. optical sheet as claimed in claim 1, wherein described main shaft refractive index n x, the ny of each described optical anisotropic film and the nz relational expression that satisfies ny=nz ≠ nx or nx ≠ ny ≠ nz.
3. optical sheet as claimed in claim 1, wherein the described main shaft refractive index n x of each described optical anisotropic film is the maximal value among described main shaft refractive index n x, ny and the nz, each described optical anisotropic film is the positive refracting power anisotropy.
4. optical sheet as claimed in claim 1, wherein said preset direction comprise clockwise direction or counter clockwise direction.
5. optical sheet as claimed in claim 1, wherein said optical axis equals 360 when spending according to total anglec of rotation of the thickness direction of described optical anisotropic film, the thickness summation of described optical anisotropic film constitutes pitch, and the described optical anisotropic film with described pitch is suitable for reflecting the polarization light of specific wavelength.
6. optical sheet as claimed in claim 5, wherein said optical anisotropic film has a plurality of pitch, and the combination of the described optical anisotropic film of each pitch is suitable for reflecting the polarization light of different specific wavelengths.
7. optical sheet as claimed in claim 6, wherein said optical anisotropic film has first pitch, second pitch and the 3rd pitch, and the one group of described optical anisotropic film that constitutes described second pitch is at the one group of described optical anisotropic film that constitutes described first pitch and constitute between one group of described optical anisotropic film of described the 3rd pitch.
8. optical sheet as claimed in claim 6, wherein said optical anisotropic film has first pitch, second pitch and the 3rd pitch, and each optical anisotropic film that constitutes described second pitch is at each optical anisotropic film that constitutes described first pitch and constitute between each optical anisotropic film of described the 3rd pitch.
9. optical sheet as claimed in claim 6, the described optical anisotropic film that wherein has same pitch has identical thickness.
10. optical sheet as claimed in claim 6, the described optical anisotropic film that wherein has same pitch has different thickness.
11. optical sheet as claimed in claim 1, wherein the described optical axis of two adjacent described optical anisotropic films has identical angle.
12. optical sheet as claimed in claim 1, wherein the described optical axis of two adjacent described optical anisotropic films has the angle smaller or equal to 90 degree.
13. optical sheet as claimed in claim 1, wherein each optical anisotropic film has the surface, and in each optical anisotropic film, the major axes orientation of described main shaft refractive index n x and the angle between the described surface are smaller or equal to 10 degree.
14. optical sheet as claimed in claim 1, described optical sheet are circular polarizing disk.
15. optical sheet as claimed in claim 1 also comprises the optical isotropy film, is disposed between the two adjacent described optical anisotropic films.
16. an optical sheet comprises:
The multilayer optical anisotropic membrane, described optical anisotropic film piles up mutually, each described optical anisotropic film has a plurality of main shaft refractive index n x, ny and nz, nx wherein, ny is the plane principal refractive index, nz is the thickness direction refractive index, and the main shaft refractive index n x of each described optical anisotropic film is described main shaft refractive index n x, maximal value among ny and the nz or minimum value, each described optical anisotropic film has optical axis, and the direction of described optical axis is the major axes orientation of described main shaft refractive index n x, the described optical axis of wherein said optical anisotropic film rotates along preset direction in regular turn at the thickness direction of described optical anisotropic film, and total anglec of rotation essence of described optical axis is more than or equal to 360 degree; And
λ/4 phase differential diaphragms is disposed on the described optical anisotropic film.
17. optical sheet as claimed in claim 16, described optical sheet are linear polarizer.
CN200810174073A 2008-11-13 2008-11-13 Optical sheet Pending CN101738666A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN200810174073A CN101738666A (en) 2008-11-13 2008-11-13 Optical sheet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN200810174073A CN101738666A (en) 2008-11-13 2008-11-13 Optical sheet

Publications (1)

Publication Number Publication Date
CN101738666A true CN101738666A (en) 2010-06-16

Family

ID=42462377

Family Applications (1)

Application Number Title Priority Date Filing Date
CN200810174073A Pending CN101738666A (en) 2008-11-13 2008-11-13 Optical sheet

Country Status (1)

Country Link
CN (1) CN101738666A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020087624A1 (en) * 2018-10-30 2020-05-07 惠科股份有限公司 Optical composite film, display panel and display device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020087624A1 (en) * 2018-10-30 2020-05-07 惠科股份有限公司 Optical composite film, display panel and display device
US11435612B2 (en) 2018-10-30 2022-09-06 HKC Corporation Limited Optical composite film, display panel and display device

Similar Documents

Publication Publication Date Title
US10539729B2 (en) Multilayer reflective polarizer
CN102016659B (en) Low layer count reflective polarizer with optimized gain
US5096520A (en) Method for producing high efficiency polarizing filters
JPH1090521A (en) Laminated phase difference plate which rotates polarization axis and projection type liquid crystal display device using the same
TWI637198B (en) Polymeric multilayer optical film
JP2000508081A (en) Non-polarizing beam splitter
JP2001357979A (en) El element
US6952245B2 (en) Polarizing plate having polarizer sides covered with low moisture permeable layers with permeability different than protective films covering the polarizer surfaces
JP2002303723A (en) Optical film, polarizing plate and display device
JP2006338005A5 (en)
KR100645664B1 (en) Circularly polarizing plate and liquid-crystal display device
JP6738829B2 (en) Optical laminate including reflective polarizer and compensation film
EP2128666A2 (en) Optical element and optical apparatus
JP2004258623A (en) Optical element consisting of liquid crystal layer and liquid crystal display device using the same
CN101738666A (en) Optical sheet
KR102062828B1 (en) Optical film, optical element and display device
WO2017193444A1 (en) Liquid crystal display device
US8369016B2 (en) Optical sheet
JP2695671B2 (en) Liquid crystal display
KR100893831B1 (en) Reflective polarizing element and the fabrication apparatus thereof
JPH02285304A (en) Phase difference plate and liquid crystal panel
JP6027199B2 (en) Phase difference element and manufacturing method thereof
KR100319103B1 (en) Reflex type LCD
CN1707328A (en) Liquid crystal display device
JP2000221507A (en) Liquid crystal display device

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C02 Deemed withdrawal of patent application after publication (patent law 2001)
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20100616