KR101009406B1 - Scanning Asymmetric Projection Lens - Google Patents

Abstract

The present invention relates to a scanning asymmetric projection lens, wherein the light having a strong directivity formed in the semiconductor light source portion passes through a reflecting member such as a mirror or an optical prism, and thus the light path is changed, and the light whose path is changed by the reflecting member is two pieces. As it passes through the projection lens configured as described above, the distortion of the image and the deformation of the aspect ratio can be corrected and projected on the screen.

According to the present invention, when the light travels in the Z-axis, the optical power in the X-axis direction and the Y-axis direction is different, and when the light passes through the projection lens, the spot size is adjusted. By correcting the distortion or aspect ratio of the projected image, a scanning projector that can obtain a 2D image having a desired resolution can be implemented.

Scanning optics, projection lens, asymmetrical, aspherical

Description

Asymmetric projection lens of the scanning optical system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scan type asymmetric aspherical projection lens that produces distortion or aspect ratio correction and optimal spots in a two-dimensional image in a projection system projection optical system.

Currently, projectors are widely used, and various projectors have been proposed to enable miniaturization and light weight of a projector by projecting light from a back side of a transmissive screen. Particularly, in the case of the scanning type without using the image panel, the research and development are proceeding steadily since it can achieve miniaturization and low price at the same time.

However, in the case of the scanning optical system, the aspect ratio of the projection, the angle of view decrease and the distortion phenomenon due to the change of the optical path depending on the small angle of the scan mirror and the path difference between the rotational center of the polygon mirror and the reflecting part, etc. Problem occurs.

The role of the projection optical system has appeared to be a very important problem to compensate for the above problem, but when using the conventional rotationally symmetric optical system, there is a limit to supplementing these problems, and the problem of miniaturization of the projection due to the increase in the number of lenses Will be issued.

Therefore, while using a small number of lenses, it is possible to overcome the size, angle of view and distortion of the screen, etc., and there is a need for an inexpensive and lightweight miniature projection lens.

The present invention includes at least one aspheric asymmetric projection lens of plastic material to solve the problems of the prior art, consisting of a total of two to four optical lenses to adjust the aspect ratio of the scanning projection system, and the angle of view and distortion phenomenon It is an object of the present invention to provide a scanning asymmetric projection lens that corrects the optical performance by improving the optical performance.

In order to achieve the above object, in the scanning asymmetric projection lens of the present invention, it is possible to implement a projection system including at least one aspheric asymmetric lens made of plastic material and including a high resolution micro-projection optics.

The present invention provides a scanning asymmetric projection lens of the scanning optical system, correcting the angle of view and distortion of the light source received by the reflective member, including at least one aspheric asymmetric lens and comprises a lens unit consisting of two to four lenses It is desirable to.

In the present invention, the reflective member is preferably made of a member selected from a scan mirror, a polygon mirror and an optical prism.

In the present invention, the lens unit includes a first lens member positioned adjacent to the reflective member and having a positive refractive index, positioned in a projection direction of the first lens member, and including asymmetric aspherical surface and having a negative refractive index. It is preferable to include a member.

In the present invention, it is preferable to further include a third lens member and a fourth lens member positioned in the projection direction of the second lens member and including an asymmetric aspheric surface and having a negative refractive index.

In the present invention, the second lens member, the third lens member and the fourth lens member is preferably formed of plastic.

In the present invention, the distance from the reflective member to the fourth lens member with respect to the refractive index of the first lens member is preferably 0.95 to 1.5.

In the present invention, the magnitude (Y-axis refractive power / X-axis refractive index Power) of the Y-axis refractive power (Power) to the X-axis refractive power (Power) of the lens member forming the lens unit is preferably 1.05 to 1.5.

The present invention has the effect of improving the optical performance by implementing a high resolution by correcting the distortion of the image and distortion of the aspect ratio that can occur in the projection scanning optical system for two-dimensional image realization using a plastic aspherical asymmetric lens.

In addition, by configuring the scanning asymmetric projection lens with two to four lens members, there is an effect that can implement a variety of optical devices (projection optics, scanner optics, etc.) of a very small size.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1A is a view illustrating a scanning asymmetric projection lens according to an embodiment of the present invention.

Referring to FIG. 1A, the light source 100 includes a light source 100, a reflective member 110, and a lens unit 120.

The light formed by the light source 100 is refracted at a predetermined angle while passing through the reflective member 110 to change the light path. The reflective member 110 may be formed of a member selected from a scan mirror, a polygon mirror, and an optical prism.

The lens unit 120 may be formed of two to four lenses, and in FIG. 1, a total of three lenses is illustrated, but is not limited thereto.

The lens unit 120 includes first, second, and third lens members 122, 124, and 126, and a light source received by the reflective member 110 is provided in the first, second, third lens members 122, While passing through 124 and 126, the angle of view and distortion of the light source are corrected, and the aspect ratio problem is improved.

The first lens member 122 may be formed adjacent to the reflective member 110, and may be spaced apart from the optical axis distance of at least 10 mm from the reflective member 110. In addition, the first lens member 122 may include an asymmetric aspherical surface made of a plastic material and may exhibit positive refractive power.

The second lens member 124 is installed in the projection direction and is formed adjacent to the first lens member 122. In addition, the second lens member 124 includes an asymmetric aspheric surface, has a negative refractive index, and is not limited thereto, but may be formed of a plastic material.

The third lens member 126 may be formed to be adjacent to the second lens member 124, may be formed of a plastic material having an asymmetric aspheric surface, and may exhibit a negative refractive index.

That is, all lens members except the first lens member may exhibit negative refractive indices. For example, in the case of a projection lens using four lens members, only the lens member adjacent to the reflective member exhibits a positive refractive index, and the other three lens members except for the adjacent one lens member exhibit a negative refractive index.

Surfaces facing each other of the second lens member 124 and the three lens member 126 may be formed of X-Toric, and opposite surfaces of the surface of the second lens member 124 formed of X-Toric may be formed. An ASP may be formed, and an opposite surface (the last surface of the projection surface side) of the third lens member 126 formed of X-Toric may be formed of AAS.

The X-Toric is a surface having an aspherical surface in the X-axis direction, and having a spherical surface only in the Y-axis direction, where the curvatures of the X-axis and the Y-axis are different from each other, and ASP stands for ASPheric surface.

In addition, the AAS surface is an abbreviation of Anamorphic Aspheric Surface, indicating that both the X-axis and the Y-axis have aspherical surfaces, and the respective curvatures and aspheric coefficients are different, and can be used for the last surface of the last lens on the projection surface side of the projection lens. have. 1, the third lens member is the last lens on the projection surface side, but when two or four lens members are used, the last surface on the projection surface side of the second lens member or the fourth lens member is used. This AAS can be represented.

According to the present invention, it is assumed that the refractive index of the first lens member 122 is f1, and the distance from the reflective member 110 to the last surface of the projection lens, that is, the surface AAS of the third lens member 126 is determined. Assuming L, L / f is designed to be larger than 0.95 and less than or equal to 1.5 to form a scanning asymmetric projection lens (first, second, third lens members).

Also, assuming that the refractive power in the Y-axis direction of the scanning asymmetric projection lens (first, second, and third lens members) is EFY, and the refractive power in the X-axis direction is EFX, EFY / EFX is greater than 1.05 and greater than 1.5. By designing small, the optical performance can be improved by improving the resolution of light passing through the projection lens.

In addition, referring to FIG. 1B, the scan type asymmetric projection lens may be manufactured. The design data of the asymmetric projection lens may be referred to the following equation.

The following equation represents an asymmetric projection lens designed as -108.822, EFX -93.807, f1 45.256, and L 44.742.

In the above table, OBJ is the object, STO is the stop, RDY is the radius of curvature, THI is the thickness and lens thickness, RMD is the refractive mode, GLA is the lens material Indicates.

2A is a view illustrating a projector equipped with a scanning asymmetric projection lens according to an embodiment of the present invention, in which light emitted from the semiconductor light source 100 passes through the scanning asymmetric projection lens 200 formed in FIG. 1. As a result of forming a spot on the screen 210, the resolution of the projector may be improved.

That is, in a projection system equipped with a scanning asymmetric projection lens, an optical path may be used to change an optical path using a reflective member such as a laser light source, or a visual change in the reflection angle due to rotation of light may be used. When using a projection lens composed of at least two or more asymmetric aspherical lens members, it is possible to improve the resolution of light, and to improve aspect ratio problems and distortion.

FIG. 2B is a diagram illustrating aspect ratio adjustment of a projector equipped with a scanning asymmetric projection lens according to an embodiment of the present invention, and adjusting TV distortion and aspect ratio using the scanning asymmetric projection lens. I can see that.

3A to 3B illustrate a scanning asymmetric projection lens according to another embodiment of the present invention.

3A and Table 2 below, a scanning asymmetric projection lens composed of two lens members, wherein EFY is -93.4, EFX is -87.588, f1 is 26.058, and L is 36.19. The optical performance passing through can be seen.

Referring to FIG. 3B and Table 3 below, a scanning asymmetric projection lens composed of three lens members, wherein EFY is -92.875, EFX is -70.120, f1 is 44.723, and L is 58.294. Indicates.

Tables 2 and 3 above relate to a scanning asymmetric projection lens formed in such a way as to satisfy a specific target value (a characteristic value to be improved; aspect ratio, distortion, spot, etc.) of the lens, in particular, first convergence from a light source. The effective luminous flux varies depending on the distance to the lens (Table 2: 2.552127, Table 3: 0.998057), and as the effective luminous flux increases as shown in Table 2, an asymmetric projection lens can be used through aberration correction.

1A to 1B illustrate a scanning asymmetric projection lens according to an embodiment of the present invention.

2A illustrates a projector equipped with a scanning asymmetric projection lens according to an embodiment of the present invention.

2B is a diagram illustrating aspect ratio adjustment of a projector equipped with a scanning asymmetric projection lens according to an embodiment of the present invention.

3A to 3B illustrate a scanning asymmetric projection lens according to another embodiment of the present invention.

                <Explanation of symbols for the main parts of the drawings>

100: light source 110: reflective member

120 lens portion 122 first lens member

124: second lens member 126: third lens member

200: scanning asymmetric projection lens 210: screen

Claims (7)

In the scanning asymmetric projection lens of the scanning optical system, Compensating the angle of view and distortion of the light source received by the reflective member, including at least one aspherical asymmetric lens and comprises a lens unit consisting of two to four lenses, The lens unit, A first lens member positioned adjacent to the reflective member and having a positive refractive index; And A second lens member positioned in the projection direction of the first lens member and including an asymmetric aspheric surface and having a negative refractive index; Scanning asymmetrical projection lens comprising a. The method of claim 1, wherein the reflective member A scanning asymmetric projection lens comprising a member selected from among a scan mirror, a polygon mirror and an optical prism. delete The method of claim 1, And a third lens member and a fourth lens member selectively positioned in the projection direction of the second lens member and including an asymmetric aspheric surface and having a negative refractive index. The scanning asymmetric projection lens of claim 4, wherein the second lens member, the third lens member, and the fourth lens member are made of plastic. The scanning asymmetric projection lens of claim 4, wherein a distance from the reflective member to the fourth lens member with respect to the refractive index of the first lens member is 0.95 mm to 1.5 mm. The method of claim 1, The size of the Y-axis refractive power (Y-axis refractive power / X-axis refractive power) to the X-axis refractive power of the first and second lens members forming the lens portion, characterized in that 1.05 to 1.5.

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