KR20020004157A - Optical system unified lens and body for supporting the same - Google Patents

Abstract

PURPOSE: An optical system having a corporate body of a lens and a lens supporter is provided to reduce a manufacturing costs by forming a lens portion and a lens supporter with one body. CONSTITUTION: An image sensor(42) is installed on a substrate in order to record information included in incident ray. The image sensor(42) includes a CCD(Charge Coupled Device) or a CMOS( Complementary Metal Oxide Semiconductor). A body(48) is used for concentrating the incident ray to the image sensor(42). An infrared ray shield portion(49) transmits only visible ray of the incident ray to the image sensor(42). An iris diaphragm(50) is used for controlling the amount of the incident ray transmitted to the body(48). A lens portion(44) is formed at a position facing an upper face of the image sensor(42). A support portion(46) is combined with the substrate(40) in order to support the lens portion(44). The lens portion(44), the body(48), and the support portion(46) are formed with one body.

Description

Optical system unified lens and body for supporting the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical system integrating a lens and its support, and is used in an optical system using a solid-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) as an image sensor. An optical system incorporating a lens and a support thereof.

Regardless of the size, the optical system may be largely divided into a lens system for condensing and a structure for supporting the optical system.

1 is a cross-sectional view illustrating an optical system 12 for condensing light reflected from a subject onto an image sensor 10 including an image sensor 10 using a CCD or CMOS as an optical sensor. The optical system 12 shown in FIG. 1 is composed of a condenser lens 14 at a position opposite to the image sensor 10 and a metal or plastic support 16 for accurately supporting the condenser lens 14. Reference numeral G denotes a protective film or cover glass of the image sensor 10.

In the conventional optical system 12, the condenser lens 14 is a glass lens. Therefore, the condenser lens 14 is usually spherical due to processing difficulties. Although the condenser lens 14 may be aspherical, in this case, the manufacturing cost increases due to difficulty in processing, and the optical system 12 becomes an expensive product, thereby lowering economic efficiency. In addition, since the conventional optical system uses the metal support 16 for supporting the condensing lens 14, there is a problem that the optical system 12 becomes heavy with an increase in volume.

In order to solve this problem, a small optical system including an aspherical lens using optical plastic has been proposed, but the angle of view is low enough to be suitable for video communication, and the f-number is sufficient to provide sufficient screen brightness. f / #).

Therefore, the technical problem to be achieved by the present invention is to solve the above-mentioned problems of the prior art, and has a sufficient angle of view and F-number suitable for video communication, while reducing the production cost by simplifying the assembly process for light and mass production It is an object of the present invention to provide an optical system integrating a lens and a support thereof.

1 is a cross-sectional view of an optical system composed of a lens and its support according to the prior art.

2 to 5 are cross-sectional views of an optical system incorporating a lens and a support according to the first to fourth embodiments of the present invention.

6 is a case in which the height at the optical axis is Y in the plane where the curvature on the optical axis of the reference spherical surface is C (= 1 / R, R is the radius of curvature) in the spherical surface of the lens constituting the lens unit of the optical system according to the embodiment of the present invention; , Is a graph for explaining Sag Xa in aspherical surface and Sag Xs in spherical surface.

FIG. 7 is a schematic cross-sectional view of a lens and an optical system incorporating a support according to a fifth embodiment of the present invention to which an aperture including horizontally movable and different sized light-transmitting regions is applied.

FIG. 8 is a plan view of an aperture of the optical system illustrated in FIG. 7.

* Description of Signs of Major Parts of Drawings *

40: board 42, 74: image sensor

44, 62, 72: lens 46, 63, 70: support

49, 78: light blocking means

48, 60, 73: Integrated body 50, 66, 76, 100: Aperture

L1, L2: Image sensor incident light 80: Infrared shielding film

102, 104: First and second floodlight areas

106: shading area

G: Cover glass of transparent protective film or sensor

In order to achieve the above technical problem, the present invention provides a substrate, an image sensor mounted on the substrate and recorded in the incident light, an integrated body for condensing the incident light on the image sensor, the It provides an optical system incorporating a lens and its support, comprising a light blocking means for allowing only light in the visible region to be incident on the image sensor among the incident light, and an aperture for limiting the amount of light incident on the integrated body.

Here, the integrated body is composed of a lens unit provided at a position facing the upper surface of the image sensor and a support unit integrated with the lens unit and coupled to the substrate while supporting the lens unit.

The unitary body includes the lens part and the support part, wherein the support part is coupled to the non-condensing area of the image sensor.

The light blocking means is provided between the diaphragm and the unitary body, and is attached to the unitary body to cover the lens unit. In addition, the light blocking means is a coating film provided between the subject and the iris close to the lens of the integrated body, between the iris and the lens, or between the lens and the image sensor, or coated on the sensor protective film or coated on the sensor protective film. The light blocking means may be a light blocking coating film coated on a first refractive surface facing the subject of the lens unit or a second refractive surface facing the image sensor.

The lens unit integrated with the integrated body has a meniscus shape or a convex shape.

The lens surface of the lens unit integrated with the integrated body is a spherical surface or an aspherical surface, and at least one of the lens surfaces is a diffraction surface. Thus, the lens portion is also a diffractive optical element.

The support is corroded or blackened for shading.

The material of the support is black plastic.

At least two light transmissive areas having different sizes are formed in the stop.

As described above, the present invention is made of an optical plastic material for blocking the image sensor from an external contaminant on the substrate, comprising a lens unit for collecting incident light having image information on an image sensor attached to a substrate and a support unit supporting the image unit. It provides an integrated optical system. Therefore, the optical system of the present invention is lighter than the conventional optical system composed of a glass lens and a metal structure for supporting the same, and is suitable for mass production because it is produced in an integrated form, and the integrated body serves as an image sensor protective film. As a result, the components are simpler than in the related art, thereby reducing productivity and improving productivity.

Hereinafter, a lens and an optical system incorporating the support according to the first to fourth embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of layers or regions illustrated in the drawings are exaggerated for clarity.

First, the optical system integrating the lens and its support according to the first embodiment will be described.

Referring to FIG. 2, reference numeral 40 denotes a substrate, and 42 an optical sensor, for example, an image sensor including a CCD or a CMOS, used to recognize image information included in the incident light in response to incident light formed on the substrate 40. to be. In addition, L1 and L2 are incident light which are condensed on the image sensor 42 which contains the information about a subject, respectively. The image sensor 42 is covered with the transparent protective film G. An integrated body 48 is coupled to the substrate 40 to block the image sensor 42 from an external pollution source on the substrate 40 and to condense the incident light L1 and L2 to the image sensor 42. have. In other words, the unitary body 48 is fastened to the substrate 40 in such a manner as to cover the front surface of the image sensor 42 in a state spaced apart from the image sensor 42 by a predetermined distance. The integrated body 48 is composed of a lens unit 44 for condensing incident light including information on a subject reflected from a subject (not shown) to the image sensor 42 and a support unit 46 supporting the same. This division of the integral body 48 depends on the function of each part and is not meant to mean that each part is physically separated. As can be seen in the figure, there is no physical boundary between the lens portion 44 and the support 46, both of which are one continuous structure. However, the inner and outer surfaces of the support 46 are corroded or blackened for shading. Alternatively, the support 46 may be made of black plastic. In this way, the lens portion 44 and the support portion 46 can be distinguished. The integral body 48 is fastened to the substrate 40 by inserting the end of the support portion 46 at a predetermined position of the substrate 40. The lens unit 44 of the unitary body 48 is a lens system composed of a lens of Meniscus type or Convex type. Preferably, the first and second refractive surfaces A1 and A2 of the meniscus lens are aspherical, but one surface may be spherical. At least one lens surface among the first and second refractive surfaces A1 and A2 may be a diffractive surface. In this case, the lens section 44 corresponds to a diffractive optical element.

On the unitary body 48, light blocking means 49 is provided that covers the lens unit 44 and transmits only the light in the visible region among the light incident on the lens unit 44. The light blocking means 49 is an infrared cut filter for blocking the light in the infrared region among the light which is incident on the lens unit 44, which is reflected from the subject. To this end, an infrared blocking film 49a is coated on a surface of the light blocking means 49 opposite to the first refractive surface A1. The stop 50 is provided on the light blocking means 49 to limit the amount of light incident on the lens unit 44. The light blocking means 49 is a coating film provided between the diaphragm 50 and the lens unit 44 or between the lens unit 44 and the image sensor 42 or attached to the sensor protective film or coated on the sensor protective film.

On the other hand, the meniscus lens constituting the lens unit 44 satisfies the following equations (1) to (4).

f / fb≥0.8

Where f is a focal length of the meniscus lens and fb is a back focal length.

｜ Xa ｜-｜ Xs ｜> 0

Equation 2 is a conditional expression that satisfies the first refractive surface A1 facing the subject in the meniscus lens, wherein Xs is a surface where the curvature on the optical axis of the reference sphere is C (= 1 / R, R is the radius of curvature). If the height at the optical axis is Y, it is Sag at the spherical surface, and Xa is the Sag at the aspherical surface. The definition of this value also applies to Equation 3 below.

Equation 3 is a conditional expression that satisfies the second refractive surface A2 facing the image sensor 42 in the meniscus lens.

Here, T is the distance between the first vertex V1 and the second vertex V2 of the meniscus lens, that is, the thickness of the meniscus lens.

Meanwhile, referring to FIG. 6, values measured along the optical axis of the sag of the surfaces I1 and I2 corresponding to the spherical and aspherical surfaces at an arbitrary height Y perpendicular to the optical axis. (Xs, Xa) can be obtained by the following equations (5) and (6), respectively.

Where C is the curvature (1 / R, R is the radius of curvature), Y is the height from the vertex of the face, K is the conic constant, and A ₃ to A ₁₂ are aspherical coefficients.

The optical system according to the present invention has a full length of 3mm to 16mm and an angle of view of 45 ° to a condition that satisfies Equation 7 below for the conical constant K and aspherical coefficients A ₃ to A ₁₂ . It is an optical system whose f-number of a lens is 65 degrees and is about f / 2.0-f / 3.2.

Equation 7 means that the absolute value of each of the coefficients is less than or equal to 0.3. At this time, K = 0.XX and A ₃ to A ₁₂ are all 0.0XX. Here, the range of XX is 01 to 99.

As such, the angle of view is 45 ° or more, which is much wider than in the prior art, while the lowest value of F-number is f / 2.0, which is much smaller than in the prior art. Accordingly, the present invention can provide an optical system having a good aberration correction state while improving an angle of view and screen brightness suitable for video communication. The characteristic values of each refractive surface constituting the optical system shown in FIG. 1 are summarized in Table 1 below.

Cotton number Radius of curvature thickness Refractive index Dispersion coefficient Remarks Front page ∞ 0.XX 1.00 0.0 iris The second page ∞ 0.XX 1.XX 6X.0 First side of filter Page 3 ∞ 0.XX 1.00 0.0 The second side of the filter The fourth page -40.XX 1.XX 1.XX 5X.0 First side of the lens The fifth page -1.XX 4.XX 1.00 0.0 Second side of the lens

The characteristic of the third surface corresponds to the second surface of the infrared cut filter, which is an embodiment of the light blocking means 49, and is a characteristic of the coating film for blocking infrared rays. In the characteristic of each surface, the value of XX ranges from 01 to 99 with a radius of curvature, from 40 to 95 with a refractive index, from 0 to 9 with a dispersion coefficient of 01 to 99, and a thickness of 01 to 99.

In the case of thickness, it can adjust suitably within the said full-length length (3 mm-16 mm) range.

Second Embodiment

Referring to FIG. 3, the light blocking means 64, the integrated body 60, and the aperture 66 are sequentially provided on the image sensor 42. The light blocking means 64 and the infrared blocking film 64a coated on the rear surface thereof are the same as those of the first embodiment. However, the unitary body 60 is not fastened to the substrate 40 as that of the first embodiment but is attached to the light blocking means 64. However, the configuration is similarly composed of the lens 62 facing the image sensor 42 and the support 63 supporting it. In addition, the inner and outer surfaces of the support portion 63 are corroded for shading as in the first embodiment.

The characteristics of each surface constituting the optical system incorporating the lens and the support body according to the second embodiment are summarized in Table 2 below.

Cotton number Radius of curvature thickness Refractive index Dispersion coefficient Remarks Front page ∞ 0.XX 1.00 0.0 iris The second page -40.XX 1.XX 1.XX 5X.0 First side of the lens Page 3 -1.XX 0.XX 1.00 0.0 Second side of the lens The fourth page ∞ 0.XX 1.XX 6X.0 First side of filter The fifth page ∞ 3.XX 1.00 0.0 The second side of the filter

The aspheric coefficients of the second and third surfaces are the same as those of the fourth and fifth surfaces of Table 1. In other words, the lens constituting the lens portion 62 of the second embodiment is the same as the lens of the first embodiment, except that only the distance from the second refractive surface of the lens to the next optical element is different.

Third Embodiment

Referring to FIG. 4, the integrated body 73 including the lens support 70 and the lens unit 72 is not fastened to the substrate 40 but fastened to the non-condensing region of the image sensor 74. That is, the integrated body 73 is fastened to an area in which an optical sensor such as a CCD or a CMOS is not formed in order to block the image sensor 74 from an external pollution source in the area 79 where the image sensor 74 is formed. It is. Therefore, immediately after the image sensor 74 is formed in the image sensor forming region 79 on the substrate 40, the prepared integrated body 73 is fastened to a predetermined position of the image sensor forming region 79, thereby making it possible to obtain an image sensor. A translucent protective film for protecting 74 is not necessary. In other words, since the integrated body 73 itself serves as the transparent protective film, the number of components of the optical system according to the third embodiment is reduced.

Meanwhile, an aperture 76 is provided around the lens portion 72 of the integrated body 73 to limit the amount of light incident on the lens portion 72, and the lens portion is spaced apart from the aperture 76 by a predetermined interval. Light blocking means 78 covering 72 and aperture 76 are located. The light blocking means 78 is an infrared blocking means for passing only light in the visible region and blocking light in the infrared region.

Fourth Example

As shown in Fig. 5, the fourth embodiment is provided in front of the second refracting surface A2 of the lens portion 44 instead of removing the light blocking means (49 in Fig. 2) from the optical system according to the first embodiment. This is the case where the infrared blocking film 80 is provided. The infrared coating film 80 may be provided on the first refractive surface A1 of the lens unit 44.

The technical idea applied to the fourth embodiment may be applied to the optical system according to the second and third embodiments.

Fifth Embodiment

The present invention relates to an optical system employing an aperture having a different characteristic from that of the aperture applied to the optical system according to the first to fourth embodiments.

FIG. 7 illustrates this, and the lower structure of the optical system is similar to that of the first to fourth embodiments, and thus not shown. Referring to FIG. 7, the diaphragm 100 includes first and second light emitting regions 102 and 104 and a light blocking region 106. As shown in FIG. 8, the first and second light transmitting regions 102 and 104 have different light transmitting areas. In other words, the first light transmitting region 102 has a larger light transmitting area than the second light transmitting region 104. Therefore, the diaphragm having the first light transmitting area 102 and the diaphragm having the second light emitting area 104 may be simultaneously used as one stop 100. If necessary, the diaphragm 100 may further include third and fourth light emitting regions in addition to the first and second light emitting regions 102 and 104.

While many details are set forth in the foregoing description, they should be construed as illustrative of preferred embodiments, rather than to limit the scope of the invention. For example, those skilled in the art may use a convex lens instead of a meniscus lens as the lens constituting the lens unit in the above embodiments. In addition, the support portion of the integrated body may be modified in other forms in addition to those shown in FIGS. In addition, there may be a rotatable disk-type aperture having at least two light-transmitting areas having different light-emitting areas. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

As described above, the lens includes a lens unit for collecting incident light having image information on an image sensor attached to a substrate and a support unit for supporting the incident light, and integrated with an optical plastic material to focus the incident light on the image sensor on the substrate. It provides an optical system. Accordingly, the optical system of the present invention is lighter than the conventional optical system composed of a glass lens and a metal structure for supporting the same, and thus is suitable for mass production, and the integrated body is a protective glass of the image sensor. Since it can replace the role, such as a separate protective glass is not required as in the prior art, since the components are simpler than the conventional one, the productivity can be improved while reducing the production cost.

Claims (12)

Board; An image sensor mounted on the substrate and recording information included in incident light; An integrated body condensing the incident light onto the image sensor on the substrate; Infrared ray blocking means for allowing only the light in the visible region of the incident light to enter the image sensor; And And an aperture for limiting the amount of light incident on the unitary body. The method of claim 1 wherein the unitary body is A lens unit provided at a position opposite to an upper surface of the image sensor; And An optical system incorporating a lens and its support, wherein the lens and the support are integrated with the lens unit. 3. The lens and the optical system integrating the support of claim 2, wherein the unitary body comprises the lens unit and the support unit, wherein the support unit is coupled to a non-condensing area of the image sense. The optical system integrating the lens and its support according to claim 1, wherein the infrared ray blocking means is provided between the diaphragm and the unitary body and is attached to the unitary body to cover the lens unit. The optical system integrating the lens and its support according to claim 1, wherein the infrared ray blocking means is provided between the subject and the image sensor. The optical system integrating the lens and the support according to claim 1, wherein the infrared ray blocking means is a light blocking coating film coated on a first refractive surface facing the subject of the lens unit or a second refractive surface facing the image sensor. . The optical system of claim 1, wherein the lens integrated body is made of plastic. The optical system incorporating the lens and the support of claim 2, wherein the lens unit integrated into the unitary body has a meniscus form or a convex form. The optical system integrating the lens and its support according to claim 8, wherein a lens surface of the lens portion integrated into the unitary body is a spherical surface or an aspherical surface, of which at least one lens surface is a diffractive optical element. 3. The optical system incorporating a lens and its support according to claim 2, wherein the support is corroded or blackened for light shielding. The optical system integrating the lens and the support thereof according to claim 2, wherein the support is made of black plastic. The optical system incorporating a lens and a support thereof according to claim 1, wherein a light transmitting region having at least two different sizes is formed in the aperture.