KR20060070813A - Camera module having a replica lens - Google Patents

Abstract

The present invention relates to a camera module having a replica lens manufactured by a replication method and an image capturing element.

The camera module includes a lens element including a transparent lens substrate and a plurality of replica layers formed by stacking two or more layers of two or more transparent optical materials having different refractive indices on at least one surface of the lens substrate. In addition, it may include a side wall formed by a replica layer around the lens element to be higher than the height of the lens element.

According to the present invention, it is possible to realize the desired optical characteristics while reducing the size and weight of the lens module using a small number of lens substrates, to improve the problems caused by shrinkage of the replica layer, and to form sidewalls when forming the replica layer The manufacturing process can be simplified and the material cost can be reduced.

Replica lens, lens substrate, lens element, replication method, refractive index

Description

Camera Module Having a Replica Lens             

1 is a cross-sectional view showing a camera module having a conventional replica lens.

2 is a lens configuration diagram of a lens module using a conventional replica lens.

3 is a cross-sectional view of a camera module having a replica lens according to the present invention.

4 (a) and 4 (b) are cross-sectional views of a replica lens according to an embodiment of the present invention.

5 (a) and 5 (b) are cross-sectional views of a replica lens according to another embodiment of the present invention.

6 (a) and 6 (b) are cross-sectional views of a replica lens according to still another embodiment of the present invention.

7 (a) and 7 (b) are cross-sectional views of a replica lens according to still another embodiment of the present invention.

8 (a) to 8 (f) are cross-sectional views of a replica lens to which the diffractive optical element according to the present invention is applied.

9 (a) to 9 (d) are cross-sectional views of replica lenses having side walls according to the present invention.

FIG. 10 is a cross-sectional view of a replica lens module constructed by stacking the replica lenses of FIGS. 9 (a) to 9 (d).

11 is a lens configuration diagram of a camera module including a replica lens according to the present invention.

FIG. 12 is an MTF curve for the lens system shown in FIG. 11.

FIG. 13 is an aberration diagram for the lens system shown in FIG. 11;

   (a) shows astigmatism and (b) shows distortion.

Explanation of symbols on the main parts of the drawings

L1, L2, L3, L4, L5, L6 ... replica layer LE ... lens element

S ... lens substrate RL1, RL2,10,20,30,40 ... replica lens

50 ... side wall

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera module having a replica lens and an image capturing element manufactured by a replication method. More particularly, the present invention relates to a camera module including a refractive index on at least one surface of a lens substrate. The present invention relates to a camera module having a replica lens having a plurality of replica layers formed by stacking two or more other transparent optical materials.

In general, a replication method is a method of manufacturing a lens on a wafer basis, and when using a replica lens manufactured by the replication method, a semiconductor process can be used to align the lens. In addition, the arrangement may be easily performed as compared to the conventional method, and the tolerance may be improved, and the volume of the lens module may be reduced.

The replication method is a method of manufacturing a replica lens by forming a thin replica layer using a transparent optical material such as a polymer on a transparent lens substrate made of glass or the like.

1 is a cross-sectional view of a camera module having a replica lens manufactured using such a replication method.

As shown in FIG. 1, a camera module including a conventional replica lens is attached to an image sensor 103, a first spacer 105 attached to the image sensor 103, and a spacer 105. Cover plate 107, a first lens substrate 109 having a first lens element 111 formed by a replica layer, and a second spacer 123 attached to the first lens substrate 109. And a second lens substrate 125 having a second lens element 127 formed by a replica layer.

Each of the image sensor 103, the first spacer 105, the cover plate 107, and the first lens substrate 109 is bonded by the adhesive layers 113, 115, and 117. In addition, the first lens substrate 109 includes an infrared reflecting coating 119 and an antireflective coating 121.

In addition, adhesive layers 129 and 131 may be formed between the first lens substrate 109, the second spacer 123, and the second lens substrate 125, and an aperture may be formed on the second lens substrate 125. 133 is provided.

The conventional camera module 110 having a replica lens is provided with a plurality of spacers 105 and 123 to maintain a predetermined distance between the lens substrates 109 and 125 provided with the lens elements 111 and 127 to achieve desired optical characteristics. have.

However, when the spacers 105 and 123 are provided as described above, a separate material and a process for providing the spacers 105 and 123 are required, resulting in an increase in manufacturing cost of the lens module, that is, a camera module, and a complicated work process. .

On the other hand, in the case of a camera module having a conventional replica lens, a single replica layer is formed to form the lens elements 111 and 127.

As such, when a single replica layer is formed, the thickness of the replica layer is limited due to shrinkage of the replica layer, etc., and thus there is a problem in that a replica layer having a thickness necessary for implementing the required optical performance cannot be obtained.

In addition, since a plurality of lens substrates must be provided in order to implement desired optical characteristics, the cost increases, and a plurality of spacers for maintaining a space between the plurality of lens substrates must be provided, and the size of the lens module increases. There is this.

2 is an example of a lens configuration of a camera module having a conventional replica lens, and relates to a 300,000 pixel camera module.

As shown in FIG. 2, in the conventional camera module, three lens substrates S1, S2, and S3 are required to realize a resolution of 300,000 pixels, and the lens substrates S1, S2, and S3 are used. Single replica layers L1, L2, L3, L4, L5, and L6 are formed on both surfaces of, respectively, and have a full length of 3.5 mm or more from the first replica layer L1 to the upper surface of the image sensor IS.

In the case of using a single replica layer as described above, a plurality of lens substrates S1, S2, and S3 are required to realize desired optical characteristics, and in order to maintain the distance between the lens substrates S1, S2, and S3. There is a problem that a plurality of spacers (not shown) are required.

The present invention is to solve the above problems, by laminating two or more layers of transparent optical materials having different refractive index by using a small number of lens substrates to reduce the size of the lens module and to achieve the desired optical characteristics replica lens It is an object to provide a camera module having a.

Another aspect of the present invention is to provide a camera module having a replica lens that does not have a spacer separately.

As one aspect for achieving the above object, the present invention is a camera module having a lens and an image sensor (image capturing element) produced by a replication method (replication method), a transparent lens substrate (lens substrate); And a lens element comprising a plurality of replica layers formed by stacking two or more layers of two or more transparent optical materials having different refractive indices on at least one surface of the lens substrate. It provides a camera module having a replica lens (replica lens) comprising a.

Preferably, the lens substrate may have a concave surface or an iron surface formed on at least one surface by etching or molding, and the lens element may be formed of a plurality of replica layers formed on the concave surface or the iron surface.

Also preferably, a through hole is formed in the lens substrate, and the lens element may be formed of a plurality of replica layers formed in the through hole.

More preferably, each replica layer for forming the lens element is formed of one of a concave refractive surface, a convex refractive surface and a diffractive surface, wherein the lens element further comprises a planar replica layer to increase the height of the lens element. It can be provided.

In addition, an anti-reflective coating may be performed between the replica layer or between the lens substrate and the replica layer, and the optical material is made of a thermosetting resin or an ultraviolet curing resin.

In another aspect, the present invention provides a camera module having a lens manufactured by a replication method and an image capturing element, comprising: a transparent lens substrate; A lens element comprising a plurality of replica layers formed by stacking two or more layers of two or more transparent optical materials having different refractive indices on at least one surface of the lens substrate; And side walls formed by a replica layer around the lens element to be higher than the height of the lens element; It provides a camera module having a replica lens comprising a.

Preferably, the side wall may be formed by an additional replica layer to increase the height of the side wall, and may be in contact with the side wall of the neighboring replica lens to maintain the spacing between the replica lenses.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view of a camera module having a replica lens according to the present invention.

In general, as shown in FIG. 3, the camera module includes a lens module including at least one lens RL1 and RL2, and a housing H1 having a predetermined space formed therein to accommodate the lenses RL1 and RL2. And an optical filter for filtering the light incident on the image sensor IS and the image sensor IS corresponding to the image planes formed by the lenses RL1 and RL2 or protecting the image sensor IS. Is fixed to the other end of the housing (H1) and the image sensor (IS) is mounted on one surface of the circuit board (not shown) for processing the image detected by the image sensor (IS), etc. The present invention relates to a camera module having such a replica lens.

In particular, the lenses RL1 and RL2 provided in the lens module according to the present invention are replica lenses formed by a replication method.

The replica lenses RL1 and RL2 according to the present invention are formed by stacking two or more layers of transparent lens substrates S1 and S2 and two or more transparent optical materials having different refractive indices on at least one surface of the lens substrates S1 and S2. Lens elements formed of replica layers L1, L2, L3, L4, L5, L6, L7.

For example, a plurality of replica layers L6 and L7 are formed on a lower surface of the second lens substrate S2, and a plurality of replica layers L4 and L5 are formed on an upper surface of the second lens substrate S2. L5, L6, L7 form a lens element.

The lens substrates S1 and S2 are transparent wafers on which lens elements are formed, and are formed of pyrex glass or the like, and a plurality of replica layers provided on one side of the lens substrates S1 and S2 may be provided. It is formed by stacking two or more transparent optical materials having different refractive indices.

Therefore, since each replica layer plays the role of a lens, it is possible to obtain the effect of using a plurality of lenses in one lens substrate (S1, S2), the degree of freedom of design of the optical system due to the addition of the lens refractive surface There is an advantage to be increased.

Here, the optical material is made of a thermosetting resin or an ultraviolet curable resin, and as an example, a polymer having a refractive index of 1.4 to 1.6 may be used.

Conventionally, since only a single replica layer is used, there is a problem in that the height of the replica layer cannot be increased due to the reduction of the replica layer. However, the present invention facilitates the manufacture of the replica layer by forming a plurality of replica layers having a low height. There is an advantage in that it is possible to prevent the deterioration of the optical properties due to shrinkage of the layer, thereby providing a replica lens having a high height replica layer.

In addition, the anti-reflective coating between the replica layer or between the lens substrate and the replica layer may prevent a decrease in light transmittance due to a plurality of refractive surfaces, and may implement a camera module without an optical filter by applying an ultraviolet reflection coating.

Meanwhile, as shown in FIG. 3, the lens module according to the present invention may include sidewalls 50 that function to maintain a gap between the lens substrates S1 and S2.

That is, the present invention may be provided with a spacer between the lens substrate (S1, S2) as shown in Figure 1 to maintain the distance between the lens substrate (S1, S2), preferably as shown in FIG. In the manufacture of a plurality of replica layers, there is an advantage that the distance between the lens substrates S1 and S2 can be maintained using the sidewall 50 formed around the lens element higher than the lens element.

In this case, as shown in FIG. 3, the side wall 50 may be formed by using the replica layer used to form the lens element, and a separate replica layer may be further provided to increase the height of the side wall 50. You may.

Hereinafter, various types of replica lenses including lens elements having a plurality of layers according to the present invention will be described.

4 is a cross-sectional view of a replica lens according to an embodiment of the present invention, a flat transparent lens substrate S, a first replica layer L1 forming a concave or convex refractive surface on the lens substrate S, and the A replica lens is provided having a lens element LE consisting of a second replica layer L2 which forms another concave or convex refractive surface on the first replica layer L1.

Such a replica layer may be prepared by a known replication method, and is formed by forming one replica layer and then forming an additional replica layer on the replica layer.

5 is a cross-sectional view of a replica lens according to another embodiment of the present invention, and a transparent lens substrate S having a concave or convex surface D serving as a refractive surface by etching or molding, and A first replica layer L1 forming a concave or convex refractive surface on the lens substrate S and a second replica layer L2 forming another concave or convex refractive surface on the first replica layer L1. A replica lens having a lens element LE is shown.

6 is a cross-sectional view of a replica lens according to another embodiment of the present invention, wherein a transparent lens substrate S having a flat surface D formed by etching or molding, and on the lens substrate S A lens element LE comprising a first replica layer L1 forming a concave or convex refractive surface and a second replica layer L2 forming another concave or convex refractive surface on the first replica layer L1. A replica lens is shown. In the case of FIG. 5 or FIG. 6, the peripheral portion of the lens element LE is formed to have a height higher than that of the lens element LE, so that the function of the side wall 50 of FIG. 3 may be performed.

7 is a cross-sectional view of a replica lens according to another embodiment of the present invention, wherein the lens substrate S having the through hole H is formed, and the concave or convex refractive surface or diffractive surface is formed on both sides of the lens substrate S. And a second replica layer L2 and a second replica layer L3 which form another concave or convex refractive or diffractive surface on the first replica layer L1 and the first replica layer L1. A replica lens with element LE is shown.

As described above, the replica lens having the through hole H forms the first replica layer L1 on both surfaces of the lens substrate S on which the through hole H is formed, and the first replica layer L1 is formed by UV curing or the like. After the) is formed, the second replica layer L2 and / or the third replica layer L3 may be formed.

In the case of the replica lens of FIG. 7, the thickness of the lens can be reduced by simultaneously forming a refractive surface or a diffractive surface on both surfaces of the lens substrate on which the through holes H are formed by etching or the like, and the refractive index of the lens substrate S is also reduced. There is an advantage that a lens element with a refractive index different from that can be obtained, which increases design freedom.

FIG. 8 is a cross-sectional view of another type of replica lens to which a diffractive optical element is applied, the lens comprising a lens substrate S, a replica layer having a diffractive surface on the lens substrate S, and a replica layer having a concave or convex refractive surface. A replica lens with element LE is shown. As such, when the diffractive surface is provided, chromatic aberration can be reduced, thereby reducing the size of the lens module. In particular, when a separate replica layer is formed on the diffractive surface, contamination or deformation of the diffractive surface can be prevented. There is an advantage.

The above-described replica layers L1 and L2 of FIGS. 4 to 8 are formed of optical materials having different refractive indices and dispersion values, and are formed between the replica layers L1 and L2 or between the lens substrate S and the first replica layer L1. The antireflection coating may be applied between the layers to prevent light transmittance from being lowered due to the multilayer.

In addition, the lens element LE may include an additional replica layer by an optical material having a refractive index different from that of an adjacent replica layer in order to add a refractive surface.

In addition, in order to increase the thickness of the first replica layer L1 or the second replica layer L2 (to increase the height), a replica layer may be additionally formed using the same optical material as the adjacent replica layer. .

9 is a cross-sectional view of a replica lens having a side wall 50 according to the present invention.

As illustrated in FIGS. 9A to 9D, the replica lenses 10, 20, 30, and 40 have side walls 50 around the lens element LE formed by the replica layers L1 and L2. It is provided.

The side wall 50 is formed higher than the height of the lens element LE in order to avoid interference between the lens elements LE in stacking replica lenses. At this time, the side wall 50 is preferably formed integrally by the replica layers L1 and L2 forming the lens element LE, but is not limited thereto. In particular, when the height of the side wall 50 is sufficiently high, the side wall 50 may be formed by an additional replica layer.

In addition, when the lens element LE is formed as a concave surface as shown in FIG. 9B, the side wall 50 may be formed as a flat surface without protruding.

10 is a cross-sectional view of a lens module in which the replica lenses illustrated in FIGS. 9A to 9D are stacked.

FIG. 10A is a cross-sectional view of a lens module in which the replica lens 20 of FIG. 9B and the replica lens 30 of FIG. 9C are stacked, and FIG. 10B is a cross section of FIG. 9A. It is sectional drawing of the lens module which laminated | stacked the replica lens 10 and the replica lens 40 of FIG.9 (d).

As illustrated in FIG. 10, a plurality of replica lenses may be formed by a replication method and then cut along a cutting line 60, which is the same in FIGS. 4 to 9.

FIG. 11 is a lens configuration diagram illustrating a lens arrangement of a camera module having a replica lens according to an exemplary embodiment of the present invention. FIG. 12 is a MTF curve of the lens system shown in FIG. 11, and FIG. 13A. And Fig. 13B show astigmatism and distortion of the lens system shown in Fig. 11, respectively. "T" in the MTF curve of FIG. 12 represents a tangential, "R" represents radial, and "S" in the astigmatism diagram of FIG. 13A represents sagital, "T". Represents a tangential.

This embodiment implements a lens system of a 30-400,000 pixel class (VGA class) camera module, and implements the same optical characteristics for contrast with the lens system having the conventional replica lens shown in FIG. 2. .

That is, the sensor size is 1/6 inch, the pixel size is 3.6 μm, the image height is 1.44 mm, the F number (F _No ) is 2.8, and the full-angle (2ω) of the lens is 60 °. It was made.

The effective focal length f of the entire lens system thereby is 2.466 mm, and the total length TL from the aperture stop to the top surface is 3.0 mm.

In the present exemplary embodiment, two replica layers L1 and L2 are formed on one surface of the first lens substrate S1, and two replica layers L3 and L4 are formed on the other surface of the first lens substrate S1. One replica layer (L5, L6) is formed on both sides of S2), and an image sensor (IS) is installed at the rear.

Spacers S are provided between the first lens substrate S1 and the second lens substrate S2 and between the second lens substrate S2 and the image sensor IS to maintain respective spacings. When using the side wall 50 of FIG. 9 or FIG. 10, no separate spacer is required.

In addition, in the present exemplary embodiment, a coating corresponding to an infrared filter is applied to the replica layer without providing an optical filter, or an optical filter may be further provided between the second lens substrate S2 and the image sensor IS. As a result, the optical characteristics of the entire lens system are not large.

Compared to the case of the conventional replica lens module in which one replica layer is formed on one surface of the lens substrate as shown in FIG. 2, the embodiment reduces the number of lens substrates, thereby reducing the material cost. There is an advantage that the lens module can be implemented.

That is, in the case of the present embodiment it can be seen that there is an advantageous advantage that the overall length of the lens module is reduced by about 20% compared to the conventional lens module shown in FIG.

Table 1 below shows specific numerical examples of the lens configuration shown in FIG. 11 of the present invention.

In Table 1, * represents an aspherical surface, and the aspherical surface is obtained from a known equation (1).

Z: Distance from the vertex of the lens to the optical axis direction

Y: distance in the direction perpendicular to the optical axis

r: radius of curvature at the vertex of the lens

K: Conic constant

A, B, C, D, E: Aspheric coefficient

(Conic constant and aspheric coefficient of the first side)

K: -0.433123 A: -0.044606 B: 0.356269

C: -1.308088 D: -1.660163 E: 12.224909

(Conic constant and aspherical coefficient on page 6)

K: -3.850851 A: 0.136076 B: 1.111474

C: -2.021003 D: -1.395288 E: 10.126553

F: -10.003281

(Conic constant and aspherical coefficient on page 7)

K: -14.081221 A: -0.010462 B: 0.0140288

C: -0.076836 D: 0.073678 E: -0.020219

(Conic constant and aspherical coefficient on page 10)

K: -412.617674 A: 0.029756 B: -0.102189

C: 0.029150 D: -0.004709

According to this embodiment, an excellent resolution of 140 cycles / mm (30% MTF) or more can be obtained for a telephone angle up to 60 ° as shown in FIG. 12, and good aberration characteristics such as distortion within 1.5% as shown in FIG. You can get it.

As described above, according to the present invention, by forming a plurality of replica layers formed by stacking two or more transparent optical materials having different refractive indices on at least one surface of a lens substrate, the effect of using multiple lenses with one replica lens can be obtained. The addition of the refractive surface has the effect of increasing the design freedom.

In addition, by using a small number of lens substrates, the lens module can be miniaturized and lightweight, and the desired optical characteristics can be realized, and by forming a plurality of low height replica layers, there is an advantageous effect that the problems caused by shrinkage of the replica layers can be improved. .

Furthermore, there is an effect that the lens module can be miniaturized and lightened by introducing a diffractive surface into the plurality of replica layers to remove chromatic aberration.

In addition, the sidewalls are formed when the replica layer is formed to maintain the gap between the lens substrates, thereby simplifying the manufacturing process and reducing the material cost.

While the invention has been shown and described with respect to particular embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as set forth in the claims below. I want to make it clear.

Claims (10)

In the camera module having a replica lens and an image capturing element manufactured by a replication method, Transparent lens substrate; And A lens element comprising a plurality of replica layers formed by stacking two or more layers of two or more transparent optical materials having different refractive indices on at least one surface of the lens substrate; Camera module having a replica lens, characterized in that it comprises a. The method of claim 1, The lens substrate is provided with a concave surface or an iron surface on at least one surface by etching or molding, And the lens element comprises a plurality of replica layers formed on the concave or convex surface. The method of claim 1, Through holes are formed in the lens substrate, And the lens element comprises a plurality of replica layers formed in the through-holes. The method according to any one of claims 1 to 3, Each replica layer for forming said lens element is formed with one of a concave refractive surface, a convex refractive surface and a diffractive surface. The method of claim 4, wherein And the lens element further comprises a planar replica layer to increase the height of the lens element. The method according to any one of claims 1 to 3, A camera module having a replica lens, characterized in that the anti-reflective coating treatment between the replica layer or between the lens substrate and the replica layer. The method of claim 1, The optical module is a camera module having a replica lens, characterized in that made of a thermosetting resin or an ultraviolet curing resin. In the camera module having a replica lens and an image capturing element manufactured by a replication method, Transparent lens substrate; A lens element comprising a plurality of replica layers formed by stacking two or more layers of two or more transparent optical materials having different refractive indices on at least one surface of the lens substrate; And A side wall formed by a replica layer around the lens element so as to be higher than the height of the lens element; Camera module having a replica lens, characterized in that it comprises a. The method of claim 8, And the side wall is formed by an additional replica layer for raising the height of the side wall. The method according to claim 8 or 9, And the side wall is in contact with a side wall of a neighboring replica lens to maintain a gap between the replica lenses.

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