TWI272416B - Four-pieces lens assemblage - Google Patents

Abstract

This invention relates to four-pieces lens which were assembled with an aperture, a first lens, a second lens, a third lens and a fourth lens in proper order from the object side. The first lens is a double-convex lens. The second lens is a double-concave lens or a minus planoconcave lens, and the object side of the second lens is engaged with the image side of the first lens. The third lens with one aspheric refraction surface at least is a convex lens which faced to the image side with convex surface. The fourth lens with one aspheric refraction surface at least is a convex lens which faced to the object side with its convex surface. Thereby the second lens can ensure the stronger ability of negative refraction and ensure the back focus as the carried lens required. While using the first lens and the second lens as a connecting lens, the connecting surface of the convex surface faces to the object side, and the second lens with the concave surface (or flat surface) facing to the image side is added. The two lenses can be made with high refractive material which are applicable for the lens assemblage with high resolution picture element, and they can not only ensure the back focus but restrain the length of the lens assemblage.

Description

1272416 IX. Description of the Invention: [Technical Field] The present invention relates to a lens set of a device in a portable photographic apparatus, which is suitable for image reading of digital cameras and electric cameras such as high-resolution OT) Take, can determine the negative inflection ability of I, and ensure the back focal length (10) Ο (10) S) and full length of the portable photographic equipment, and the high-quality four-piece mirror required by the market. 〇 【Prior Art】 Since the photographic lens has become more and more popular in the modern era, especially the products of the city, such as the mobile phone products, the handheld computer pc, Μρ 3, etc., have already taken the camera as one of the necessary effects. At present, in the general mobile phone, there will be a group of solid camera elements and =^TDSe__§_), but the _ body camera has two miniaturization and high performance performance requirements. It is also relatively required to be a small chemical manufacturer with the camera phone and the Mm chip lens group to open the phone more urgently, with the high-efficiency fine lens group /, the most important sales point of the manufacturer in competition, therefore, (four) out The four-piece lens group that pays more for the user has become the focus of the time. In the development of the squad, when the camera is equipped with a camera, the C 昼 顶 顶 顶 顶 顶 顶 顶 顶 顶 顶 顶 顶 顶. The degree of 10,000 degrees is 1272416 7 to 1/4 inch. This lower optical performance requirement is sufficient for the photographic lens lens to form a lens number of one to two lenses. At the same time, it is relatively easy to achieve a desired back focus (BACK FOCUS) while maintaining the total length of the optical system in accordance with the thickness of the mobile phone. However, the pixels of the CCDs that have been built in the recent mobile phones are also growing year by year, and it is impossible to reach the Mega-pixel. In order to improve the optical performance of the photographic lens, it is impossible to use the lens of 1 to 2 lenses. Achieve the required performance. Therefore, the number of lenses such as high-performance lenses needs to be composed of four lenses, and the black method maintains the full length of the intended optical system, and the back focal length (Back FOCUS) cannot be ensured, and optical components such as infrared cut filters cannot be disposed. For example, Japanese Patent Laid-Open Publication No. 2003-255222 is a photographic lens group composed of four lenses, and is also an optimum optical system for a digital camera. However, if a small CCD lens of 1/4 inch or less is used, If the standard focal length (BACK FOCUS) is shortened, it is not suitable for a high-quality photographic lens group. If the CCD lens size is increased to ensure the back focus (BACK FOCUS), the optical system will become longer. In the smaller restricted space of the general mobile phone, the conventional configuration cannot meet the dual requirements of quality and space. In order to effectively solve the aforementioned related issues, the creators of the present invention based on the research and development technology and experience accumulated in the field of optical lenses in the past, from the high-level, small business 7 1272416 product demand for the market, finally developed after the guarantee Focal length (BACK (6) and gangguang # full-length Mirror. [Inventive content] The first object of the present invention is to provide a four-piece lens group that is called a smash-proof, distance-the invention from the object side according to the aperture, the first The i-lens, the second lens, the third lens, and the fourth lens are arranged in the order, and the i-th lens is a bi-convex shape, and the second lens has a biconcave shape or a flat-concave negative lens. The second lens can ensure a strong negative inflection' and ensure the back focal length required by the portable photographic apparatus (BACK FOCUS). Another object of the present invention is to provide a trespassing lens _ full length, ensured after = distance (BACK FOCUS The four-piece lens group, the thin ith lens and the second lens of the present invention are connected to each other, the connecting faces of the two lenses are facing the object side, and the second lens is concave toward the image plane (or plane), the two lenses High refractive index The material of the material is silky, which is more suitable for the viewfinder lens group of the image reading of hexamidine, and the full length of the Weitou group is ensured in the back group (ΒΑα刚 s) _. The structural features of the invention are as follows: A four-piece lens assembly is arranged from the object side in the order of the aperture, the work lens, the second lens, the third lens, and the fourth lens, and the first lens 1272416: Γ = Γ ,, the second lens is The side surface of the negative lens 12 having a double concave shape or a flat concave shape is joined to the image side surface of the first lens, and the third lens is at least a refractive surface having an aspherical shape, and the convex surface is oriented toward the object side. The positive lens of the present invention is believed to be the purpose of the above-mentioned purpose, the method, and the pottery effect of the case. It can be obtained from in-depth and specific understanding. [Embodiment] Please refer to the different numerical values of the various embodiments of the four-piece lens group shown in each figure. The numerical changes of the various compensations of the present invention are experimentally obtained, even if they are used. Production of different values and the same structure Still referring to the protection scope of the present invention, the following description will be made. First, various suitable embodiments of the photographic lens group according to the present invention will be described using the drawings and numbers. The drawings in FIGS. 1 to 7 are from the embodiment. The lens configuration diagram of the seventh embodiment (Fig. 1A to Fig. 7A) is shown in Fig. 7 to Fig. 7; Fig. 6 represents the difference diagram and the optical characteristic data (Fig. 1B to Fig. 7B). Fig. 8 to Fig. 1 〇 9 ^ 272 416 非 非 非 非 的 的 非 非 非 ^ ^ =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 =1 The order of the parts constituting the photographic lens group is as follows: aperture ^, ―first lens (Ll), second lens (U), third lens (3) oblique 4 mirror edge 4), parallel plane glass (2) and knot The image plane corresponds to the shed (1) in the direction of the object side and the relative direction is the image side; (L=r: sheet (L1), which is a biconvex positive lens, and the first lens IL1) is made of a material having a south tortuosity. Forming; °Haidi 2 (L2), the side of the object is joined to the image side of the first lens (L 1 ), and the second lens ((3) is a biconcave negative lens or The recessed shape (the object side is concave); the negative example in which the implementation of the pot is a flat concave is a double concave negative lens), and the second lens CL 2) is also formed by a material having a refractive index; /η lens (L3), at least one of the refractive surfaces has an aspherical shape, and the brother 3 (L 3) has a convex surface facing the image side of the fourth lens (L4) and to /, ^ 1 refractive surface As the aspherical shape, the fourth lens α4) is a convex-yang-side red convex-concave lens lens; the three-segment (L3) and the fourth lens (L4) are formed by plastic molding, and both are The material of the low refractive index is made. In addition, the third lens (L3) and the fourth lens (L4) t of the embodiment 1 30 1272416 to 7 are formed by aspherical shapes on both sides; Key technology structure. The parallel plane glass (2) in Bu 0 is attached with the function of infrared ρ, and the preset image reading means (for example, CCD configuration) can be provided on the image plane (3). - 心阅@1B~图7 B 'By the description of the lenses of the various embodiments of the present invention, the data is collected; at the top of the figure, various factors affecting the lens: the focal length of the spear, the F NUMBER, the corner Etc; The data symbols in the table below are described below: 12 9~疋 from the object side in order to represent the face number (but s is the aperture), because the i-th lens (L1) and the second lens (l2) Since the two elements are joined by the 疋 phase, the second surface is a surface common to both sides; the eighth surface and the ninth surface are both sides of the parallel plane glass, and any one of them becomes (7). r~ represents the radius of curvature (mm) on the paraxial axis. d ~ indicates the data of the face interval (mm). Nd~ represents the refractive index of each lens and parallel plane glass. Vd~ represents the Abbe's coefficient (abbe) of each lens and parallel plane glass, and represents the combined focal length of the entire lens lens. 11 1272416 Ϊ34~ is expressed as the combined focal length of the third lens (L3) and the fourth lens (L4).

Ru ~ is expressed as the image side curvature radius of the second lens (L 2 ). R42 to R is expressed as the image side curvature radius of the fourth lens (L 4 ). The difference map is included, the spherical difference, the non-point difference, and the distortion. No matter which of the difference maps is about the d-line data, the non-point-receiving is about the S-picture (SAGITAL) data and the μ-image (meeRidi〇nal) data, and both Do a gesture. The aspherical shape of Fig. 8 to Fig. 1 will be specifically described below. The aspherical shape A A B C, D, E, F, and G are aspherical coefficients, and the high-twist position of the optical axis and the wire amount are regarded as the filaments. The technique of the present invention is established in the following formula. Parent < (1/R) Η. / [ 1 + { 1 —(丄 + k)(H/r) 2 } 1/2] + AH4 +BH6 + cH8+DH10+Eh^+Fh14 + GH16 is only the paraxial radius of curvature. K is the conic coefficient. E 养球面健后加__ Q 3 material mark is 2 〇 _3 means. 12 • I2? 2416. Regarding the photographic lens group of the present invention, the data range of f, f34, Rn, R, 42 can be set as follows: (1) 0 · 3 < f Xf 34<〇. 6 5 If f / f 34$〇· 3, the POWER load of the joint lens composed of the first lens and the second lens phase becomes too large, and it becomes difficult to correct the spherical aberration or the image difference. If f / f 34 - 〇 · 65, when the third lens and the fourth lens are formed of a plastic % material, the movement of the focus position at the time of temperature change becomes large. " (2) 0 · 0$f/R22<0 · 75 - In the case of f/R22<0, since the negative power of the second lens becomes smaller, sufficient BACK FOCUS cannot be ensured. If it is hidden 2^〇75, the radius of curvature will become smaller. In order to confirm the collision height with the surface of the third lens object side, the air space on the shaft of the third lens needs to leave a large-point space, so miniaturization will It becomes difficult. Therefore, it is very difficult to assemble inside a mobile phone with only a limited configuration space. (^ 2 . 0 < f /R42 < 3 . 7

"f/R42^ 2.0" The shape of the peripheral portion of the lens (near the bending point/bending portion): =敎' The performance from the center of the kneading surface to the peripheral portion is also lowered. If f/R

/ 3 7 The amount of sag in the peripheral part will become larger, and the FLANGE BACKING to the image surface will become shorter. The result is that the variant does not guarantee that there is room for the job and C0VER GIASS to be inserted. 13 1272416 [:] The actual data of the examples 1 to 7 is like a heart

Even if the data thorns of the respective embodiments are seen, it can be understood that μ and the second lens (L2) are materials which use a high refractive index material, a lens 1 (L1), and a fourth lens (L4). The third lens (L3 uses a general low fold and a good refractive index for the fourth lens α4) and uses ##. The third lens (L3) and (10) are two: a material having a refractive index. Therefore, in this first! Lens: Γ: The range of the rate becomes as follows: 2nd lens · . · 1. 85>nci>丄85>nd>i.6- 7 LSelect 逑Id® refraction Rate, the length of the full length of the optical system; it is very suitable for inclusion in 7 and can also be suppressed because the size of the lens is also reduced, and the "Lang optical system, also the rate, the lion to the saki plum ^ 2 fine high fold From the perspective of 'manufacturing the above-mentioned Fan_Riding 4' in the cost issue., the material section did not have much 14 $72416 1About the example, the sum of the data of d (face spacing) is the full length of the lens group (However, the part of the parallel plane glass is changed to the air conversion distance to the nose), it will look like the following: ° [Table 2] Full length plugging example 1. 5.92 5.88 5.99 Face example 4 6.01 Face case 5 6.01 Face Example 6 5.99 Wrap Example 7 5.94 It is also understood from this Table 2 that the small size. The lens of the present invention is indeed suitable as a mobile phone. 曰About BACK FOCUS from the configuration diagram of Fig. 1A - Fig. 7A also the implementation of the present invention The case can be fully ensured. The result is that the smoke

2 The photographic lens group of the applicable party and the 鬲昼素0^ is guaranteed to be the same as the BACK FOCUS. For example, it is suitable as a photographic lens for a small and corresponding (5) pixel, especially for a photographic lens group built in a jar.甩,, ' 斤 述 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , In the lens, the second lens has a biconcave shape or a concave lens having a flat concave shape, and the object side surface of the second lens is in contact with the image side surface of the first lens 15^72416. 3 brothers; at least the refractive surface is an aspherical shape. The positive lens with the convex surface facing the image, and the fourth lens is a positive lens with at least the refractive surface as the aspherical shape, and the convex lens facing the object side, 蕤卟, ^ suitable for the image reading of the South pixel: The master group, and ensuring the charm distance (BA_us) _ can also suppress the full length of the photography Tang Tong group, so the "industrial nature" of the present invention should have been

In addition to the above, the _ planting technique disclosed in the embodiment of the present case has not been seen in publications before the stipulation of the stipulations, nor has it been used publicly. The fact that God has the effect of improving as described above is even more indispensable. The "novelty" and "progressiveness" of the invention are both 疋>3, paying & 1 statutes, and applying for invention patents according to law, praying for a review. As soon as the patent is granted, she [simplified illustration] [Fig. 1A] Schematic diagram of the lens of the embodiment 1 16 I2? 24l6 [Fig. 1B] The difference diagram of the embodiment 1 • Schematic diagram of the optical system characteristic data [Fig. 2 A FIG. 2B is a schematic diagram of the lens structure of the embodiment 2, FIG. 3B is a schematic diagram of the lens structure of the embodiment 3 [FIG. 3A] FIG. 3B is a schematic diagram of the lens structure of the embodiment 3 [FIG. 3B] [Fig. 4A] Schematic diagram of the lens structure of the embodiment 4 [Fig. 4B] Schematic diagram of the aberration diagram of the embodiment 4 and the optical system characteristic data [Fig. 5A] The lens composition of the embodiment 5 Schematic diagram [Fig. 5B] Schematic diagram of the data of the embodiment 5 [Fig. 6A] Schematic diagram of the lens of the embodiment 6 [Fig. 6B] The diagram of the difference of the embodiment 6 7A is a schematic view showing the configuration of the lens of the embodiment 7 [FIG. 7B] FIG. 7B. FIG. 8 is a schematic diagram of the aspherical coefficient of the embodiment 1 to the embodiment 3. [FIG. 9] f Example 4 to aspheric coefficient of Example 5 Schematic [Fig. 10] Schematic diagram of aspherical coefficients of Embodiments 6 to 7 [Description of symbols] (1) Aperture (L 1) First lens (L 2 ) Brother 2 Lens 17 1272416 (L 3 ) Third lens ( L4) 4th lens (2) parallel plane glass (3) image plane

Claims (1)

1272416 Red Year π月6日修(更)本本 I, Patent application scope: 1. A four-piece lens group, starting from the object side according to the aperture, the first lens, the second lens, the third lens, the fourth lens a sequential arrangement; wherein: the first lens is a biconvex lens; the second lens is a biconcave shape or a flat concave negative lens, and the second lens object side is joined to the image side of the first lens; a lens having at least one refractive surface as an aspherical shape, a convex-convex lens facing the image side, and a fourth lens having at least one refractive surface as an aspherical shape and a convex-convex lens lens having a convex surface toward the object side Lens. The film 2 is in the four-piece lens group described in the first item, wherein when the mirror is f34, the conditional expression of 〇.3 < f/ f34 < 0.65 is satisfied. When the focal length is R22, it satisfies ◦. The radius of curvature of the side is medium: the lens group, and when it is 42, the image side radius of curvature of condition f full of 〇<f/R42<3.7 is R ^ as claimed in the patent scope In the three items, ί = combined <1=, is f, the image side curve of the fourth lens f Γ lens satisfies the condition of 2.0<"!142<3.7 when the heart is rainbow R42, 19 A four-piece lens unit as described in claim 1 or 2, wherein the four-piece lens unit is housed in a carrying machine. 7. A four-piece lens unit according to claim 3, wherein the four-piece lens unit is housed in a carrying machine. 8. A four-piece lens unit as described in claim 4, wherein the four-piece lens unit is housed in a portable machine. 20