KR102295862B1 - Lens system for providing maximum incident light efficiency - Google Patents

Abstract

The present invention relates to a lens arrangement providing maximum incident light efficiency, and more particularly, to a lens arrangement for securing maximum incident light efficiency by arranging a plurality of lenses having a specific curvature and thickness at a specific position.
According to the present invention, by arranging a plurality of lenses having a specific curvature and thickness at a specific position, even the light passing through the edge of the lens is used to form a clear image without distortion of the image and to secure the maximum incident light efficiency. A lens arrangement is provided.

Description

Lens system for providing maximum incident light efficiency

The present invention relates to a lens arrangement providing maximum incident light efficiency, and more particularly, to a lens arrangement for securing maximum incident light efficiency by arranging a plurality of lenses having a specific curvature and thickness at a specific position.

In the case of the conventional objective lens, the light-passing area for forming an effective image is limited to a partial area with respect to the central axis of the lens. That is, since the light passing through the region near the edge of the lens does not form a clear image, only a partial region of the center of the lens is used, which causes a relatively small amount of incident light.

US 10-2014-0121431 A

The present invention was devised to solve this problem, and by arranging a plurality of lenses having a specific curvature and thickness at a specific position, even the light passing through the edge of the lens is used to form a clear image without distortion of the image. It is an object of the present invention to provide a lens arrangement that ensures maximum incident light efficiency while keeping

In order to achieve the above object, the lens arrangement providing the maximum incident light efficiency according to the present invention includes a first lens, a second lens, a third lens, a fourth lens, and the third lens and the fourth sequentially arranged. The first lens includes an aperture disposed between the lenses, wherein the target object-side surface of each lens is referred to as the front surface and the focal plane-side surface is referred to as the rear surface. The front and rear surfaces of the second and third lenses are formed to have positive radii of curvature, the front and rear surfaces of the fourth lens are formed to have negative radii of curvature, and the first lens is on a central axis. The thickness is 5.21, the radius of curvature of the front surface is 29.79, the radius of curvature of the rear surface is 80.49, the thickness of the second lens is 7.68 on the central axis, the radius of curvature of the front surface is 17.08, the radius of curvature of the rear surface is 125.8, and the third The lens has a thickness on the central axis of 1.55, a radius of curvature of the front side of 125.8, and a radius of curvature of the rear side of 10.37, and the fourth lens has a thickness of 4.53 on the central axis, a radius of curvature of the front surface of -52.54, and a radius of curvature of the rear surface. is -22.3, the distance on the central axis between the rear surface of the first lens and the front surface of the second lens is 0.2, the rear surface of the second lens and the front surface of the third lens are in contact without a gap, and the second lens 3 The distance on the central axis between the rear surface of the lens and the diaphragm is 8.01, the distance on the central axis between the diaphragm and the front surface of the fourth lens is 13.95, and the central axis between the rear surface of the fourth lens and the focal plane The distance between the phases may be 28.62063, and the unit of the numerical value is millimeters (mm).

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The Clear Aperture of the front surface of the first lens is 31.8, the Clear Aperture of the rear surface of the first lens is 30.0, the Clear Aperture of the front surface of the second lens is 24.6, the Clear Aperture of the rear surface of the second lens is 19.9, and the 3 The Clear Aperture of the front of the lens is 19.9, the Clear Aperture of the rear of the third lens is 14.0, the Clear Aperture of the front of the fourth lens is 22.0, the Clear Aperture of the rear of the fourth lens is 23.8, and the Clear Aperture of the aperture is Aperture may be 11.3, and the unit of the numerical value is millimeters (mm).

The physical property number of glass constituting the first lens is 744449, the physical property number of glass constituting the second lens is 678555, and the physical property number of glass constituting the third lens may be 755275, and the physical property number of glass constituting the fourth lens may be 744449.

According to the present invention, by arranging a plurality of lenses having a specific curvature and thickness at a specific position, even the light passing through the edge of the lens is used to form a clear image without distortion of the image and to secure the maximum incident light efficiency. It has the effect of providing a lens arrangement that does.

1 is a view showing the configuration and condensing state of a lens arrangement for securing maximum incident light efficiency according to the present invention.
Fig. 2 is a view showing numerical data constituting the lens arrangement of Fig. 1;
3 is a graph showing the lens performance of the lens arrangement.
4 is a graph showing ray aberration of a lens arrangement;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the configuration shown in the embodiments and drawings described in the present specification is only the most preferred embodiment of the present invention and does not represent all of the technical spirit of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations.

1 is a view showing the configuration and condensing state of a lens arrangement 100 for securing maximum incident light efficiency according to the present invention, and FIG. 2 is a view showing numerical data constituting the lens arrangement 100 of FIG. It is a drawing.

In the lens arrangement 100 of FIG. 1, the focal length is 60 mm.

1 and 2 , the lens assembly 100 includes first lenses G1 and 110 , second lenses G2 and 120 , third lenses G3 and 130 , and fourth lenses G4 and 140 . ) and an aperture (STO, 150). Hereinafter, all distance units are millimeters (mm), and notation is omitted.

Assuming that the target object-side surface of each lens described above is the front surface and the focal plane 10 side surface is the rear surface, the first lenses G1 and 110 have positive curvatures of the front surfaces G11 and G12. The radius of curvature of the front surface G11 of the first lenses G1 and 110 is 29.79, and the radius of curvature of the rear surface G12 is 80.49. The thickness on the central axis 20 of the first lens 110 is 5.21, and the distance on the central axis 20 between the rear surface G12 of the first lens 110 and the front surface G21 of the second lens 120 is is 0.2. The physical property number of the glass constituting the first lenses G1 and 110 is 744449.

The first 3 digits of the glass property number indicate the refractive index, and the first 3 digits of '744' in '744449' indicate the refractive index. That is, 1.744 is the refractive index. In addition, the last 3 digits of the glass property number are called 'Abbe number' and indicate the degree of dispersion. It will be 44.9. The meaning of such a glass property number is equally applied to all lenses below.

'Clear Aperture (CA)' of each lens surface in FIG. 2 refers to the diameter of a region through which a light beam passes in each lens surface of the lens assembly 100 of FIG. The CA of the plane refers to the distance between the extreme points 31 and 32 through which the light beam passes. Referring to FIG. 2 , in the lens arrangement 100 of the present invention, the Clear Aperture of the G11 surface, which is the front surface of the first lenses G1 and 110 , is 31.8, and the Clear Aperture of the G12 surface, which is the rear surface, is 30.0.

The second lenses G2 and 120 have a front surface G21 and a rear surface G22 having a positive radius of curvature, and the front surface G21 has a radius of curvature of 17.08. The rear surface G22 is a portion in contact with the front surface G31 of the third lenses G3 and 130 without a spaced interval, and the radius of curvature of the surface G22 is 125.8, the same as the radius of curvature of the surface G31. The thickness on the central axis 20 of the second lenses G2 and 120 is 7.68, and the physical property number of the glass constituting the second lenses G2 and 120 is 678555. The Clear Aperture of the G21 surface is 24.6, and the Clear Aperture of the G22 surface is 19.9.

The third lens (G3, 130) has a positive radius of curvature on the front surface (G31) and the rear surface (G32), the radius of curvature of the front surface (G31) of the third lens (G3, 130) is 125.8, the curvature of the rear surface (G32) The radius is 10.37, and the radius of curvature of the G31 surface is the same as the radius of curvature of the G22 surface as described above. The thickness on the central axis 20 of the third lenses G3 and 130 is 1.55, and the distance on the central axis 20 from the rear surface G32 of the third lenses G3 and 130 to the stop 150 is 8.01. . The physical property number of the glass constituting the third lenses G3 and 130 is 755275. The Clear Aperture of the G31 side is 19.9, the same as the G22 side, and the Clear Aperture of the G32 side is 14.0.

The distance on the central axis 20 from the stop (STO, 150) to the front surface (G41) of the fourth lens (G4, 140) is 13.95, and the clear aperture of the stop (STO, 150) is 11.3.

The fourth lens (G4, 140) has a negative radius of curvature of the front surface (G41) and the rear surface (G42), the radius of curvature of the front surface (G41) of the fourth lens (G4, 140) is -52.54, the rear surface (G42) The radius of curvature is -22.3. The thickness on the central axis 20 of the fourth lenses G4 and 140 is 4.53, and the central axis 20 from the rear surface G42 of the fourth lenses G4 and 140 to the focal plane 10 . The spacing of the phases is 28.62063. The physical property number of the glass constituting the fourth lenses G4 and 10 is 744449. On the G41 side, the Clear Aperture is 22.0, and on the G42 side, the Clear Aperture is 23.8.

In a lens system, f-number is a value (=f'/D) obtained by dividing the focal length (f') by the diameter (D) through which light passes. means When the value of f-number is large, it means that the amount of incoming light is small. Conversely, when the value is small, it means that the amount of incoming light is large.

In the lens arrangement 100 of the present invention configured exactly as described above, f-number = f'/D = 60/31.8. D is the light passage diameter of the G11 surface of the first lenses G1 and 110, which is the first lens surface through which light passes, that is, the Clear Aperture value, and f' is the focal length 60 of the lens arrangement 100.

As described above, the f-number of the lens array 100 of FIG. 1 composed of numerical data as shown in FIG. 2 of the present invention is designed to be a value of 2 or less, and it is It can be seen that by absorbing light, even the light passing through the edge of the lens is used to form a clear image without distortion of the image, while ensuring maximum incident light efficiency.

3 is a graph showing the lens performance of the lens assembly 100, and FIG. 4 is a graph showing ray aberration of the lens assembly.

3(a) is spherical aberration of the lens arrangement 100, FIG. 3(b) is astigmatism, and FIG. 3(c) is distortion.

The spherical aberration of FIG. 3( a ) refers to the vertical distance from the focal plane to the actual focal point. In FIG. 3A , the vertical axis is the distance from the center (=0) of the focal plane in the left and right direction, and the horizontal axis is the vertical distance (aberration) from the focal plane to the actual focal point at the corresponding position. As shown in FIG. 3A , the spherical aberration of the lens arrangement 100 of the present invention is approximately 0.1 or less, indicating excellent performance.

The astigmatism of FIG. 3(b) refers to an aberration in which a dot-shaped object is formed to hang vertically (in a concentric circle direction) radially from an off-axis.

The distortion aberration of FIG. 3( c ) represents the degree to which the screen looks curved in %, and it can be seen that excellent performance is exhibited by showing aberration of 2.5% or less even at the edge of the image.

10: focal plane
20: lens central axis
100: lens arrangement
110: first lens
120: second lens
130: third lens
140: fourth lens
150: aperture

Claims (4)

As a lens arrangement providing maximum incident light efficiency,
A first lens, a second lens, a third lens, a fourth lens, which are sequentially arranged, and an iris arranged between the third lens and the fourth lens
including,
If the target object side of each lens is referred to as the front surface and the focal plane side surface is referred to as the rear surface,
the first lens. The front and rear surfaces of the second and third lenses are formed to have a positive radius of curvature,
The front and rear surfaces of the fourth lens are formed to have a negative radius of curvature,
The first lens is
The thickness on the central axis is 5.21, the radius of curvature of the front is 29.79, the radius of curvature of the rear is 80.49,
The second lens,
The thickness on the central axis is 7.68, the radius of curvature of the front is 17.08, the radius of curvature of the rear is 125.8,
The third lens,
The thickness on the central axis is 1.55, the radius of curvature of the front is 125.8, the radius of curvature of the rear is 10.37,
The fourth lens,
The thickness on the central axis is 4.53, the radius of curvature of the front is -52.54, the radius of curvature of the rear is -22.3,
The distance on the central axis between the rear surface of the first lens and the front surface of the second lens is 0.2,
The rear surface of the second lens and the front surface of the third lens are in contact without a separation interval,
The distance on the central axis between the rear surface of the third lens and the diaphragm is 8.01,
The distance on the central axis between the diaphragm and the front surface of the fourth lens is 13.95,
The distance on the central axis between the rear surface of the fourth lens and the focal plane is 28.62063,
The unit of the numerical value is millimeters (mm),
Lens arrangement providing maximum incident light efficiency.
delete The method according to claim 1,
Clear Aperture of the front of the first lens is 31.8,
Clear Aperture of the rear of the first lens is 30.0,
Clear Aperture of the front surface of the second lens is 24.6,
Clear Aperture of the rear side of the second lens is 19.9,
Clear Aperture of the front of the third lens is 19.9,
Clear Aperture of the rear side of the third lens is 14.0,
Clear Aperture of the front of the fourth lens is 22.0,
Clear Aperture of the rear side of the fourth lens is 23.8,
Clear Aperture of the aperture is 11.3,
The unit of the numerical value is millimeters (mm)
A lens arrangement that provides maximum incident light efficiency, characterized in that. 4. The method according to claim 3,
The physical property number of the glass constituting the first lens is 744449,
The physical property number of the glass constituting the second lens is 678555,
The physical property number of the glass constituting the third lens is 755275,
The physical property number of the glass constituting the fourth lens is 744449
A lens arrangement that provides maximum incident light efficiency, characterized in that.

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