TWI313363B - Multi-focus objective lens - Google Patents

Description

1313363 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to a multifocal objective lens, and more particularly to a multifocal objective lens that is relatively easy to manufacture. [Prior Art] A conventional multi-focal objective lens, as disclosed in U.S. Patent Publication No. 2006/0201250, is an objective lens composed of a double lens, the objective lens of which is heavy, and the cost of assembly adjustment is high. Moreover, since a lens is required to be fabricated using a semiconductor process, the cost is high and the problem of stray light is likely to occur. US Patent Publication No. 2005/0281172 discloses a single-lens multi-focus objective lens having a diffraction structure, a first surface and a second surface, the first surface being opposite to the second surface A diffractive structure is formed over the first surface. The diffraction fringe of the diffraction structure of US Patent Publication No. 2005/0281172 needs to be less than 3/m, and the depth of the diffraction fringe is about 2.24/m. The diffraction structure needs to be fabricated by high-precision processing, * Its manufacturing cost and manufacturing difficulty are high. SUMMARY OF THE INVENTION The present invention provides a multifocal objective lens for solving the problems of the prior art, including a first surface and a second surface. The first surface includes a first aspherical surface, a second aspherical surface, a first diffractive structure, and a second diffractive structure. The first aspherical surface and the first diffractive structure are located in a first region, and the second aspherical surface and the second diffractive structure are located in a second region. The second zone 0949-A21811 TWF(N2); P51950098TW; the Lemon 6 乜13363 domain surrounds the first zone. The second surface includes: a spherical surface: a third diffraction structure and - a second: = = and a second diffraction structure is located in the - third region, the fourth aspheric surface and the first radiation structure are located in the - fourth region. The first

area. The second surface is the back surface of the first surface. "..." Two Q can invent the multi-focus objective lens, the retardation order of each diffraction structure is matched with the temperature variation and the aberration caused by the drift of the center wavelength of the light source. The first surface and the second surface of the objective lens of the same structure have a diffraction of 1 卩 to increase the interval of the diffraction fringes, thereby reducing the manufacturing difficulty. The present invention can be applied to the first beam (hd_dvd laser ά The diffraction efficiency of the light beam (DVD f light) and the third light beam (CD laser light) is all greater than -, and the amount of snagging is low; 1 [Embodiment] The first figure shows the present invention. a focal lens (10) for reading the disc 200, the multi-focus objective lens 100 includes a first surface S1 and a second surface S2. Referring to the second & second embodiment, the first surface S1 includes a first surface 11 a second aspherical surface 12, a first-diffraction structure 21 and a second, radiation structure 22. The first aspheric surface n and the first diffraction structure 2 "stand on, the area A1, the second aspheric surface 12 and the second The second structure A2 surrounds the first region Ai. The second surface A2 includes a third aspheric surface 13, a fourth aspheric surface 14, and a second surface. The diffraction structure 23 and the fourth diffraction structure 24. The second aspheric surface 13 and the third diffraction structure 23 are located in a third area A3. 0949-Α2Ί 811 TWF(N2); P51950098TW; Lemon 7 I313363, = aspherical surface 14 and fourth diffraction structure 24 are located in a fourth area A4. ^The first area A4 surrounds the third area A3. The second surface S2 is In the upper surface of the surface S1, the first region A1 corresponds to the third region A3, and the region A2 corresponds to the fourth region A4. The multifocal objective lens of the present invention is used for a first light beam (HD). a DVD laser light second beam (DVD laser light) and a third light beam (CD laser field light), wherein the first light beam comprises a first wavelength λι and the second light beam comprises a second wavelength λ2 ′ The third light beam includes a third wavelength λ3. Hereinafter, the design relationship between the first diffraction structure and the third diffraction structure will be first described. [Design of the first diffraction structure and the third diffraction structure Relationship] The first diffraction structure and the third diffraction structure include a first design wavelength λ", the first design wavelength and the first wavelength ^, the second wavelength χ 2 (; Λ 0< ΙΝΤ φ-φ Λ Λ <0.4 ΙΝΤ 9 Λ·ι ν ^ y % between 390 and 420 nm; 〇<Room; 0 < ζνΓ (Αΐ) - (Αί)

<0.4 INT /lr\ ιηΊ & between 600 and 698 nm

<0.4 INT ^ J^z ^ is between 700 and 890 nm, and 0949-A21811TWF(N2); P51950098TW; Lemon 8 1313363 Λ.1 = noun (Λ'-1), W where dl is the first - the Z-degree 1N between the diffraction structure and the third diffraction structure is the first-relay structure and the refractive index of the third diffraction structure 1 side beam includes a -th-diffraction order" 7&quot The second light beam includes 7 second windings, the number of the third light beams, the third light beam includes a third diffraction order, the δHai-, the second two, and the third diffraction order (Ύ3) are selected as follows: 2;1;0' ;(2;U) ' ' ^3,2,2) ^ (4,3,0). 8,5,Γ) I , (5,3,3), (M,G ), (6,4,3), and '(10 8'5'4), (9,6,0), (9,6,5), (10,6,0) (,6,5 ) The group of monarchs is composed. The series provided above is a sequence that can converge when designing. The first aspheric surface forms a first pupil with the third aspheric surface, and the diffraction structure includes a first winding. The baby is privately c, and the focal length fD], the first focal length f] and the % shot and the distance fD satisfy the following relationship: ~03<-~~<0.3

Jm on the same day, the younger brother of a divergence f -Μ- 〇 and 耵...from fD] satisfies the following relationship: j D\ =7~~--^___

(-2x/>xW;x^J , where n=; I, 2 or 3, representing the whistle coefficient. '^ brother—, the second-order phase of the light-emitting structure is the same as the third diffraction structure package 〜 _ the focal length f, and the third diffraction % focal length b, the -0.3 < A < 0.3 distance ^ satisfies the following relation ·· j 03 , and at the same time 'the third diffraction focal length satisfies the following relationship : 0949 A21811TWF(N2); p51g5〇〇98TW:Lern〇n 1313363 fm :7----- (~2χΡ3χ,77η xAj , where ϊι=1, 2 or 3, Ρ3 矣兮窜 _ coefficient. The second-order phase of the D-Hale two diffraction structure, the first diffraction structure and all the phase coefficients of the third body, and the '° structure (for example, the order phase money, the three-dimensional coffee absolute value is less than 0! The first, second, and third diffraction orders (W) of the first-diffraction structure and the third diffraction structure may be (five) or different. '』 The values provided above and the limit system Through the computing software (for example, the software c〇de V provided by Titans Technology), the cough diffraction structure, the third diffraction structure, the ^ ΛΑ ^ and the aspheric surface, and the third aspheric surface can be obtained. The design data, wherein the first signal ^ / θ ^ 5 is calculated by the wavelength λ,] is taken in a trial and error manner, which may be, for example, 3264 fine. a two-diffraction structure and the fourth diffraction junction [the first and the fourth diffraction structure] the second diffraction structure and the fourth diffraction structure comprise a second design wavelength λ,, 2 ' The second design wavelength X, '...'... and the Le-wavelength, and the first wavelength λ2, satisfy the following relationship: 〇<between;0<鲜(-)-(&) 乞0.4 1ΝΤ λ m, ' 11 between 390 and 420 nm < 0.4 INT 5 〇 949~A21811TWF(N2): P5l95〇〇98TW; Lern〇n Λ, ' 4 between 600 and 698 nm 10 I313363; and Λ·2 = Χ (Λ^ - 1), wherein 4 is the depth between the second diffraction structure and the fourth diffraction structure, and N is the refractive index of the second diffraction structure and the fourth diffraction structure, A light beam includes a first diffraction order m, the second light beam includes a -first diffraction order number, and the first and second diffraction orders are a number of columns (5'〇), (5, 3) , (6,0), (6,4) The group consisting of (8, 〇), (, (9, 〇), (θ9, 6), 〇〇, 〇) and (1〇, 6). The series provided above are the series of (4) at design time. = The second aspherical surface is formed with the fourth aspherical surface - the second focal length 4,, ::::: comprises a second diffraction focal length. The second focal length ^-% of the focal length fD2 satisfies the following relationship: · human -3-3 <-^<0.3 JD2 , and the second diffraction pitch fp (-2xJ}2xm/1xA „ ), 4 Fancho ',,, and tD2 satisfy the following relationship: where 11 = 1, 2, or 3, P / h ± phase focal length coefficient. 2 (d) The fourth diffraction structure of the second diffraction structure includes - the fourth chain 6 and the fourth diffraction pitch f # $ distance 圮 4, the first _ - .. 3 < fifty two meet the following relationship:

1DA (~2xP4xm/lxAll) The following relationship: Μ 0949-A2l81iTWF(N2); P51950098TW; Lemon 1313363 where number. 2 or 3, P4 represents the first-order phase of the fourth diffraction junction, and the absolute value of the second retardation structure and the fourth diffraction of the second diffraction junction _f is less than 〇. 筮 - Μ k / The first and the first, the first and the second, and the second and second radiant structures of n Haidi may be the same or different. And (the case should be on the value provided and the 11 just 1 series, through the softness of the soft (such as 'software Cc> de V provided by Titanic Technology), can be the diffraction structure, the fourth diffraction structure , ) = field to the design data of the two spheres of the brother, in which the spherical surface and the fourth non-method are calculated, which can be::: butterfly length, 2 series to try the wrong method, J Μ horse, for example, 2〇 4〇nm. The multi-focus objective lens can be made of a material such as plastic or broken glass. Temperature: 2: 2: In the example, 'Using aspherical surface can eliminate the spherical aberration caused by the main aberration and the degree of refractive index change, and the residual aberration and temperature change yield the ball produced by the shift of =, , and σ difference. Non-domain aberrations and pre-source center wavelength drift, absolutely silly #: Produce a positive spherical aberration. The diffraction structure produces a negative sphere. The image can be balanced to achieve the same 〇 aberration. Using the combination of aspheric coefficient and diffraction coefficient and diffraction order: to achieve disc tilt optical compensation design, disc thickness error optical compensation design, objective lens tilt optical compensation design, temperature variation optical compensation design, light source center wavelength The objective of drifting optical compensation design, objective lens optical compensation design in assembly error, and high diffraction efficiency optical design of diffraction structure. The use of the multi-focus objective lens of the Ming Dynasty, the diffraction order of each diffraction structure can compensate for the aberration caused by the temperature change and the drift of the center wavelength of the light source. Same as 0949-Α2 彳 S mWF_:P5 〗 950 〇 98 TW; Lemon 12 1313363 The invention of the invention is a sinister thing. 社雄.. ..., the surface of the objective lens and the second surface have diffraction. Same as: the spacing between the large diffraction stripes of the shore, which can reduce the difficulty of manufacturing), "'-'::, the diffraction of the first-light __ laser" and the diffraction of the third beam_laser light) The efficiency is all greater than 9 〇〇 / n LV μ π m ^ core; 得以 can reduce the loss of optical energy. Including another embodiment of the invention, the multi-focus objective lens - a second surface S2. Surface-surface S1 Including a brother aspherical surface π, a second aspherical surface 12, and a second diffractive structure 22, a second surface, a dih-different structure, a diffraction structure η, a diffraction structure 21, and a structure surrounding the first β% red structure 21 Formed on the first aspheric surface u „ two, the k-ray structure 22 is formed on the second aspheric surface 12. The second surface S2 includes a rear surface of the first surface S1, and the second surface S2 includes a spherical surface 13 and a third diffraction structure. The key structure 23 is formed on the third aspheric surface 13, wherein Third, the clock structure 23 corresponds to the first diffraction structure 21. A %, , , and port include the further embodiment of the present invention, the multi-focus objective lens "- surface 81 and a second surface illusion. a first surface-dipole-aspherical surface U, a second non-spherical surface = and a second diffraction structure 22, the second diffraction structure 2: upper, the second diffraction grating is formed on the second aspherical surface d The surface S2 is the back surface of the first surface S1, the second surface Μ includes a fourth aspherical surface 14 and a fourth diffraction structure Μ, and the structure 24 is formed in the fourth aspherical surface M: The four-diffraction junction 0949-A21811TWF(N2); P51950098TW; the Lemon 13 1313363 structure 24 corresponds to the second diffraction structure 22. Although the present invention has been described above in terms of the preferred embodiments thereof, it is not intended to limit the invention, and those skilled in the art can make some modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

0949-A21811TWF(N2); P51950098TW; Lemon 1313363 [Simplified description of the drawings] Fig. 1 shows the multifocal objective lens of the present invention; Fig. 2a shows the first surface of the multifocal objective lens of the present invention; Fig. 2b The second surface of the multifocal objective lens of the present invention is fully shown; Fig. 3 is a view showing another embodiment of the present invention; and Fig. 4 is a view showing still another embodiment of the present invention. [Description of main component symbols] Lu 11 to first aspherical surface 12 to second aspherical surface 13 to third aspherical surface 14 to fourth aspherical surface 21 to first diffraction structure 22 to second diffraction structure 23 to third winding The radiation structure 24 to the fourth diffraction structure® 100 to the multi-focus objective lens 200 to the disc A1 to the first area A2 to the second area A3 to the third area A4 to the fourth area S1 to the first surface S2 to the second surface 0949 -A21811TWF(N2); P51950098TW; Lemon 15

Claims (1)

1313363 X. Patent application scope: l - a multi-focus objective lens, comprising: a taste surface comprising a first diffraction structure and a first έ 构 structure surrounding the first-diffraction structure; A masked north one wild one shows the lunar surface of the dress, the second surface includes the brother - 'nine shot structure and a fourth implant 0 Μ hh' a music, 凡射 '纟σ结构, Biandi The four-diffraction structure surrounds the two diffractive structures. The multi-focus objective lens of claim 1, wherein the Guhai "focus lens pair - the first beam, the second beam, and the third beam enter: : focus: the first beam includes - the - wavelength In ninth, the second light beam includes a second wavelength λ_2, and the third light beam includes a third wavelength h. The multi-focus objective lens of claim 2, wherein the first radiation structure and the third diffraction structure comprise a first design wavelength, the first design wavelength λ, . Between the first wavelength λ], the second wavelength, and the third wavelength λ3, the following relationship is satisfied: 游令)_令: ^0.4 ΙΝΤ Λ (41)-(参) 幺0.4 ΙΝΤ ίΛ,) /^ 2 5 v > mn <0.4 ΙΝΤ 4 between 600 and 698 nm Λ between 700 and 890 nm 〇 < A between 390 and 420 nm; 0< between, 0<between; and Κχ (Λ, - 1), 0949-A21811TWF(N2); P51950098TW; Lemon 16 1313363 n L dl is the first-diffraction structure and the /wood degree between the third diffraction structure 'N is the first-around Qin+ & Shishi, ^•古=...the structure of the shot and the refraction of the Le three-diffraction structure: the first beam includes the -th-diffraction order w" the second beam includes a wrap! order 'the third beam includes— The third diffraction order is %, ^ brother - and the second diffraction order (Ύ,) is selected by the number 4/, 2), (5, 3, Q), tangent), '5, 〇) , (8,5,4), (9,6 , 〇), (9,6,5), (10 6 0, and (10,6,5) consisting of the group. ') The second circumstance described in item 3 of the multi-focus objective, wherein the aspheric surface Nowadays: the aspherical surface 'the second surface further comprises a third non-fourth (four)-diffraction structure formed on the first aspheric surface, and the light-emitting structure is formed on the (four) three aspherical surface. In the case of the multi-focal objective described in the fourth aspect of the patent, the present-aspherical surface and the third aspherical surface form a first,: -0.3 <-^-<0 3 J〇 The radiation structure includes - the first diffraction focal length W, the first focal length fD] satisfies the following relationship: /罘'. Light system: At the same time, the first diffraction focal length fDI satisfies the following (-2xAxw"x times) , where 'n=I, 2 or 3, p丨 surrogate from the 相位 phase coefficient. ^1. A second-order mirror of the %-shooting structure. Among them, the multi-focal 〇--A2wmWF(N2) as described in item 5 of the patent application scope: P5W5m ΐβ_η !313363 = er1 her dragon is less than 〇1 . The first item—where, the shot structure includes;::Γ formation—the first focus~, the first focus distance k satisfies the following relationship: 4 focal length W, the third ~°-3<-^-<0.3 system : The same diffractive focal length fD3 satisfies the following winding wm λ.. (-2χΡ3Χ/^χΛ), where η=1, phase coefficient. Or 3, Pa represents the multi-focus objective lens described in item 7 of the second-order patent range of the third diffraction junction, wherein the absolute value of all phase coefficients of the 兮%-shot structure is less than G1/, Μ 9 The fourth diffraction structure described in claim 2 includes - between the second set =, satisfying the following _ Ϊ length 1 and the second wavelength ^ 〇 < m, 0< INT(~) ~ (-^-) < 0.4 ΙΝΤ τη.Ί; and Λ·2 ~ Χ ~ ΐ) ^ between 390 and 420nm & between 600 and 698nm where 'd2 is (four) two diffraction structure and the first Between four diffraction structures °949-A21811TWF(N2); P51950098TW; Lemon 18 1313363 = iceiness 'N is the second diffraction structure and the refraction of the fourth diffraction structure=, the first beam includes a first The diffraction order is %, the second beam includes the second dipole order - the first and the second diffraction order (V) are selected from the t series (2, .), (1)), (10), (10), (4,0), (1), (5,〇), (5,3), (μ), (Μ), (M), the group. , (9, G), (9, 6), (_ and (the composition of the 10. As described in the scope of the patent application, the first surface is more succinct, a '5 Hai non-wiping ^ An aspherical surface, the second surface further includes a fourth \, the second diffraction structure is formed on the second aspherical surface, and the fourth diffraction structure is formed on the fourth aspherical surface. In the multi-focus objective lens of the 1G item, in the 1:, the aspherical surface and the fourth aspherical surface form a second focal length &,; the shot structure comprises a first 妓 妓 乐 乐 绕 绕 绕 f , , , The second focal length f2 and the second '03<-^<0.3 J D2 ', and the distance fD2 satisfy the following relationship: System: Λ: At the same time 'the second diffraction focal length ^ satisfies the following relationship. ~2xP2xmnxA„), a second order/, medium 1, 2 or 3, p2 represents the second diffraction phase coefficient of the second diffraction. 1 multi-focus objective lens according to item 11 of the patent application scope, The absolute value of all the phase coefficients of the two-shot structure is smaller than 〇i , the mirror, wherein, the multi-joule 0949-A218mwP(N2): P5195〇〇98Tw:L as described in the scope of claim 1G e 1313363 wherein, the 非_古—节 第 第 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二 二The first-------------------------------------------------- & satisfies the following λ, . f, M . — t 丄 (-2xP4xw” X/lJ, phase (four), 2 or 3, P4 represents the fourth, diffractive structure - second-order U as claimed in the 13th In the multi-focal objective lens described in the above, the absolute value of all the phase coefficients of the radiant structure is less than that of the first embodiment of the present invention, wherein the second wavelength λ2 satisfies the following Relational formula: J 〇16. The multi-focus objective lens described in claim 2, wherein the 兮-wave and the third wavelength satisfy the following: a multi-focus objective lens, including: - one: !"surface' includes a first aspherical surface, a second aspherical surface, a :::::Γ(10)-second diffraction structure, the second diffraction structure ring a fluorescing structure formed on the first aspheric surface, the second diffraction structure being formed on the second aspheric surface, and a second surface constituting the first surface On the back side, the second surface comprises 0949-A2181lTWF(N2): P51950098TW; Lemon 20 Ϊ 313363 2: J non: face and a third diffraction structure 'The third diffraction structure forms a shot above the aspheric surface 'where' The third diffraction structure corresponds to the first-to-around multi-==^^=multi-focus objective lens, wherein the convergence, the second f-first beam into-the first wave includes - the first wavelength ~, the second The beam includes an angstrom-wavelength λ2, and the third beam includes a third wavelength λ3. 1-9. The multifocal objective lens described in claim 18 of the patent scope, and the diffractive structure and the third diffraction structure include - the = this! The design wavelength λ" and the first wavelength λ], the second wavelength: ^ the third wavelength λ3, satisfy the following relationship: 2 0< A, Λ m between; 乂 between 390 and 42 〇nm ΙΝΤ{^-) - (Λι Λ Λ <0.4 ΙΝΤ 0< (,\ —φ-(pregnant) <0.4 ΙΝΤ 5 Λ-ι K^2 J mn INT(-^·) - (Ai) < 〇_4 int{4 λ ^ between 600 and 698 nm 0<& between 700 and 89 〇nm Λ m3; and Λ.1 =彳χ(Λ'-1), ”where The first diffraction structure and the depth of the third diffraction structure are the folds of the first-diffraction structure and the (four) three-diffraction structure, and the first light beam includes a first-order diffraction order m, The second beam packet—the second diffraction order %, the third beam includes—the third diffraction order %, 〇949-A218mWF(N2); P51950098TW; Lernon 2I I3j3363 言海繁, second and third The diffraction order (π, Ά) is chosen to free the following series (2,1,0), (2,1,1), (3,2,〇), (3,2,2), (4,3) , 0), (4'3'2), (5,3,0), (5,3,3), (6,4,0), (6,4,3), ,(8'5' 〇), ( 8,5,4), (9,6,〇), (9,6,5), (1〇,6,〇) 乂 and (1〇,6,5) are composed of groups. ^ 20. The multi-focus objective lens of claim 1 wherein the /-diffraction structure comprises a second design wavelength center 2, the second design wavelength 4 and the first wavelength λι and the second wavelength, Between the above, the following relationship is satisfied: 0<between;0< S 0.4 ΙΝΤ Λ m, , 々 between 390 and 420 nm INTi-~) - (Ai) < 0.4 ΙΝΤ , Λ between; and 2 between 600 Up to 698 nm lr2 = d2x (N~\), where d2 is the depth between the second diffraction structure and the second surface, N is the refractive index of the second diffraction structure, and the first beam includes a - The second order beam of the diffraction order I includes a second diffraction pattern, and the first and second diffraction orders are selected as follows: 2, 1), 0, .), "2), (cut, (4) )(;0),, (1)), (6,0), (6,4), (8,〇), (8,5), (call, (9,6), (10,0) and ( 10,6) The family consisting of 21. 21. A multi-focus objective, comprising: , a second aspheric surface, a first surface, including a first aspheric , 0949-A21811 TWF (N2); P51950098TW; Lemon 22 1313363 first-diffraction structure and a second diffraction junction of the first-diffraction structure, the first diffraction structure; surrounding the 'the second diffraction structure a second surface formed on the second surface, a back-fourth aspheric surface of the first surface and a fourth diffraction structure, the surface being included on the fourth aspheric surface, (1), the fourth diffraction structure Form a shot structure. The % shot, the right link should be the second weeping as described in claim 21 of the patent scope of the objective lens pair - the first beam, the second beam to; -1 = into: wave: one: ί includes a first Let the second = brother a wavelength λ2, the third beam includes a third wavelength λ. [23] The multi-focus objective lens of claim 22, wherein the ray diffractive structure and the fourth diffractive structure comprise - the second λ " 'the f = the design wavelength U and the One wavelength λ], the second wavelength ^ between 0 < swim (year) - (year) <〇.4 zvrfΑι AA ,v Λ y 0<<0.4 ΙΝΤ ^2 VJ — call, 乂|between 390 To 42〇nm seven between 600 and 698nm m 2 , /ΛΤ (greedy)—(between; and 乂, 2 = ί/2 X (7V-1), where A is the diffractive structure of the brother and The depth of the gate of the fourth diffraction structure, N is the refractive index of the second diffraction structure and the fourth diffraction structure, and the light beam includes a dipole-diffraction order, and the second beam includes 23 0949-A21811TWF(N2) ;P51950098TW; Lemon 1313363 - the diffraction order 7" 2 'The first and second diffraction orders (%, %) are selected white ^ 2 series (2, G), (1) , (3, G), (3, 2), (4, 〇), :, ;), (5, 0), (5, 3), (6, 0), (6, 4), (8 , 〇), Ο, (9, 〇), (9,6), (10,0), and (1〇,6) 24. The multi-focus objective lens of claim 22, wherein the first-wrap structure includes a first design wavelength, 1, the first set wavelength k and the first wavelength λ], The second wavelength Μ and the third wavelength satisfy the following relationship: 游 (Al) one (between Al 幺0.4 INT 0<; 4 is between 390 and 42 〇nm) < swim (Al) one ( Al) 幺0.4 IMT; % ' & between 600 and 698nm <between; and Αι m, ' * between 700 and 89〇nm Λι χ(Λ^ —]) where 屯 is the first a diffraction structure and a degree between the second surface, N is a refractive index of the first diffraction structure, the first light beam includes - a - diffraction pm, the second light beam includes - a second diffraction order %, The second beam includes a third diffraction, and the first, second, and third orders of incidence (''W3) are selected from the following series (1), 0), (1) (3, 2, 0), (3,2,2), (a), (4,3,2), (5, 0949-A21811TWF(N2); P51950098TW; Lemon 24 1313363 (5,3,3), (6,4,0), (6,4,3), (8,5,0), (8,5,4) > (9,6,0) , (9,6,5), ( 1 The group consisting of 0,6,0) and (10,6,5). 0949-A218l1TWF(N2); P51950098TW; Lemon 25