JP2018128523A - Projection optical system and image projection device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a projection optical system having good telecentricity on a reduction conjugate side and giving a long back focus and good optical performance.SOLUTION: The projection optical system is disposed on a reduction conjugate side and projects an image displayed by an image display element to an enlargement conjugate side, and the projection optical system includes three lenses immobile along the optical axis direction on a side closest to the reduction conjugate side. The three lenses include, successively from the enlargement conjugate side to the reduction conjugate side, a meniscus first lens having a convex surface on the enlargement conjugate side, a second lens having negative refractive power, and a third lens having positive refractive power, in which the second lens and the third lens are cemented to form a cemented lens, and a radius of curvature G1R2 of a lens surface on the reduction conjugate side of the first lens, a radius of curvature G2R1 of a lens surface on the enlargement conjugate side of the second lens, a focal distance FG3 of the third lens, and a focal distance FG of the synthesized system from the first lens to the third lens are each appropriately set.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a projection optical system, and is suitable, for example, as a projection optical system used in an image projection apparatus (projector) that enlarges and projects an image on a screen.

  2. Description of the Related Art Conventionally, various image projection apparatuses (projectors) that use an image display element such as a liquid crystal or a micromirror array and project an image based on the image display element on a screen surface by a projection optical system have been proposed. The projection optical system used in the projector is a zoom lens that can project at various projection magnifications in addition to a projection optical system with a single focal length, and has a wide field angle and high optical performance that can be projected onto a large screen from a short distance. There is a desire to be.

  In addition, in order to arrange a color separation optical system, a color synthesis optical system, etc. between the projection optical system and the image display element, there is a demand for a long back focus and good telecentricity on the reduction conjugate side. Yes. 2. Description of the Related Art Conventionally, there are known projection lenses for projectors having a wide angle of view, a long back focus, and good telecentricity on the reduction conjugate side (Patent Documents 1 to 3).

  Patent Document 1 discloses a projection lens that includes a first lens group and a second lens group having a positive refractive power in order from the magnification conjugate side to the reduction conjugate side, and has a projection field angle of 90 degrees or more. The zoom lenses disclosed in Patent Documents 2 and 3 disclose a zoom lens including first to sixth lens groups having negative, positive, positive, negative, positive, and positive refractive powers in order from the magnification conjugate side to the reduction conjugate side. doing. A zoom lens is disclosed in which the first lens unit and the sixth lens unit do not move during zooming, and the second to fifth lens units move.

JP 2012-073337 A JP 2009-186469 A JP 2005-257896 A

  A projection optical system used in a projector is strongly demanded to be able to project a wide angle of view, to have a high-quality projected image, and to have good telecentricity on the reduction conjugate side. In order to make the reduction conjugate side telecentric, Patent Document 1 uses a cemented lens in which a meniscus negative lens and a biconvex positive lens are joined on the most reduction conjugate side. In addition, by arranging a positive lens made of a material with strong low dispersion on the magnification conjugate side of the cemented lens, the axial chromatic aberration is corrected well.

  In general, when maintaining the telecentricity on the reduction conjugate side while maintaining a long back focus on the reduction conjugate side of the projection optical system, many spherical aberrations, axial chromatic aberration, lateral chromatic aberration, and the like are generated. In order to project an image with good telecentricity on the reduction conjugate side, long back focus, and high image quality, the lens configuration of the lens group on the most reduction conjugate side can be appropriately set in the case of a zoom lens. In the case of a projection optical system having a single focal length, it is important to appropriately set the lens configuration of the lens system closest to the reduction conjugate side.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a projection optical system that has good telecentricity on the reduction conjugate side, a long back focus, and good optical performance.

The projection optical system of the present invention is a projection optical system that is arranged on the reduction conjugate side and projects an image displayed on the image display element to the enlargement conjugate side,
It has three lenses that do not move in the optical axis direction on the most conjugate side,
The three lenses are, in order from the magnification conjugate side to the reduction conjugate side, a meniscus first lens having a convex surface facing the magnification conjugate side, a second lens having a negative refractive power, and a third lens having a positive refractive power. ,
The second lens and the third lens are cemented lenses which are cemented;
The radius of curvature of the lens surface on the reduction conjugate side of the first lens is G1R2, the radius of curvature of the lens surface on the magnification conjugate side of the second lens is G2R1, the focal length of the third lens is FG3, and from the first lens to the lens When the focal length of the synthesis system up to the third lens is FG,
0.4 <FG3 / FG <1.0
0.0 <G1R2 / G2R1
It satisfies the following conditional expression.

  According to the present invention, it is possible to obtain a projection optical system that has good telecentricity on the reduction conjugate side, a long back focus, and good optical performance.

(A), (B) Lens sectional view at the wide-angle end and the telephoto end of Example 1 of the projection optical system of the present invention (A), (B) Longitudinal aberration diagram and lateral chromatic aberration diagram at the wide-angle end and the telephoto end of Example 1 of the projection optical system of the present invention (A), (B) Lens cross-sectional views at the wide-angle end and the telephoto end of Example 2 of the projection optical system of the present invention (A), (B) Longitudinal aberration diagrams and lateral chromatic aberration diagrams at the wide-angle end and the telephoto end of Example 2 of the projection optical system of the present invention Sectional Lens View of Example 3 of Projection Optical System of the Present Invention Aberration diagram of Embodiment 3 of the projection optical system of the present invention Lens sectional view of Example 4 of the projection optical system of the present invention Aberration diagram of Embodiment 4 of the projection optical system of the present invention Lens sectional view of Example 5 of the projection optical system of the present invention Aberration diagram of Embodiment 5 of the projection optical system of the present invention Lens sectional view of Reference Example 1 of the projection optical system of the present invention Longitudinal aberration diagram and lateral chromatic aberration diagram of Reference Example 1 of the projection optical system of the present invention

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The projection optical system of the present invention is disposed on the reduction conjugate side, and projects an image displayed on the image display element to the enlargement conjugate side (screen side). The projection optical system has three lenses that are stationary in the optical axis direction on the most reduction conjugate side, and the three lenses are meniscus-shaped first with a convex surface facing the enlargement conjugate side in order from the enlargement conjugate side to the reduction conjugate side. One lens, a second lens having a negative refractive power, and a third lens having a positive refractive power. The second lens and the third lens are cemented lenses that are cemented. A lens system including the first lens, the second lens, and the third lens has a positive refractive power.

  FIGS. 1A and 1B are lens cross-sectional views corresponding to the wide-angle end and the telephoto end of the first embodiment of the projection optical system of the present invention. 2A and 2B are longitudinal aberration diagrams at the wide-angle end and the telephoto end when the projection distance (distance from the first lens surface to the screen surface) of Example 1 of the projection optical system of the present invention is 1508 mm. It is a chromatic aberration diagram of magnification. Here, the projection distance is when numerical data described later is expressed in mm.

  3A and 3B are lens cross-sectional views corresponding to the wide-angle end and the telephoto end of the second embodiment of the projection optical system of the present invention. 4A and 4B are longitudinal aberration diagrams at the wide-angle end and the telephoto end when the projection distance (distance from the first lens surface to the screen surface) of Example 2 of the projection optical system according to the present invention is 2240 mm. It is a chromatic aberration diagram of magnification.

  FIG. 5 is a lens cross-sectional view corresponding to Example 3 of the projection optical system of the present invention. FIG. 6 is a longitudinal aberration diagram and a magnification chromatic aberration diagram when the projection distance of Example 3 of the projection optical system of the present invention is 1210 mm. FIG. 7 is a lens cross-sectional view corresponding to Example 4 of the projection optical system of the present invention. FIG. 8 is a longitudinal aberration diagram and a chromatic aberration diagram of magnification when the projection distance of Example 4 of the projection optical system according to the present invention is 3290 mm.

  FIG. 9 is a lens cross-sectional view corresponding to Example 5 of the projection optical system of the present invention. FIG. 10 is a longitudinal aberration diagram and a chromatic aberration diagram of magnification when the projection distance of Example 5 of the projection optical system according to the present invention is 5390 mm. FIG. 11 is a lens cross-sectional view corresponding to Reference Example 1 of the projection optical system of the present invention. FIG. 12 is a longitudinal aberration diagram and a lateral chromatic aberration diagram when the projection distance of Reference Example 1 of the projection optical system of the present invention is 2063 mm.

  The projection optical system of each embodiment is used in an image projection apparatus (projector). In the lens cross-sectional view, the left is the enlargement conjugate side (screen) (front), and the right is the reduction conjugate side (image display element side) (rear). P1 is a projection optical system. Bi is the i-th lens group, where i is the order of the lens groups counted from the magnification conjugate side. L11 to L28 are lenses. ST is an aperture stop. IE corresponds to an original image (projected image) of a liquid crystal panel (image display element) or the like.

  S is the screen surface. DG and CG are glass blocks corresponding to prisms for color separation and color synthesis, optical filters, face plates (parallel plate glass), crystal low-pass filters, infrared cut filters, and the like.

  In FIGS. 1 and 3, the arrows indicate the movement direction (movement locus) of the lens group during zooming from the wide-angle end to the telephoto end. The wide-angle end and the telephoto end are zoom positions when the zooming lens units are positioned at both ends of a range in which the zoom lens group can move on the optical axis.

  In the aberration diagrams, Fno is the F number and ymax is the maximum image height. In the spherical aberration diagram, a wavelength of 470 nm, a wavelength of 550 nm, and a wavelength of 620 nm are shown. In the astigmatism diagram, a dotted line M indicates a meridional image plane at a wavelength of 550 nm, and a solid line S indicates a sagittal image plane at a wavelength of 550 nm. The distortion diagram shows a wavelength of 550 nm. The lateral chromatic aberration diagram shows a wavelength of 470 nm and a wavelength of 620 nm with respect to a wavelength of 550 nm.

  The zoom lenses according to the first and second embodiments include the first lens unit L1 having a negative refractive power that partially or entirely moves (has a focus function) during focusing in order from the magnification conjugate side to the reduction conjugate side. Further, the second lens unit L2 having a positive refractive power, the third lens unit L3 having a positive refractive power, the fourth lens unit L4 having a negative refractive power, the fifth lens unit L5 having a positive refractive power, and the positive lens unit having a positive refractive power. The sixth lens unit L6 is configured.

  During zooming, the first lens unit L1 and the sixth lens unit L6 do not move. During zooming from the wide-angle end to the telephoto end, the second lens unit L2 to the fifth lens unit L5 all move to the magnification conjugate side. Examples 3 to 5 and Reference Example 1 are projection optical systems having a single focal length.

  The projection optical system P1 of each embodiment has three lenses that do not move in the optical axis direction on the most reduction conjugate side. The three lenses are, in order from the magnification conjugate side to the reduction conjugate side, a meniscus first lens G1 having a convex surface facing the magnification conjugate side, a second lens G2 having a negative refractive power, and a third lens G3 having a positive refractive power. It has become more. The second lens G2 and the third lens G3 are cemented lenses that are cemented.

  The first lens G1 has a positive or negative refracting power in which the surface on the magnification conjugate side has a convex shape on the magnification conjugate side. The second lens G2 has a negative refractive power, and the third lens G3 has a positive refractive power. The second lens G2 and the third lens G3 are composed of cemented lenses. With such a lens configuration, the third lens G3 has a strong positive refractive power while a convex surface is directed to the magnification conjugate side of G1R1, which is the lens surface on the magnification conjugate side of the first lens G1.

  By adopting the above configuration, the surface for correcting spherical aberration and axial chromatic aberration is arranged on the reduction conjugate side, and the surface for correcting curvature of field aberration and distortion is arranged on the enlargement conjugate side. Arranged to effectively correct various aberrations.

  In the above conditions, more preferably, the third lens G3 may have a biconvex shape. With such a configuration, the above-described various aberrations can be easily corrected. As a more preferable condition, the first lens G1 may have a meniscus shape with a convex surface facing the magnification conjugate side. With this configuration, spherical aberration and axial chromatic aberration are effectively corrected as a lens configuration in which the positive refracting power is brought closer to the reduction conjugate side while satisfactorily correcting curvature of field aberration and distortion. ing. The second lens G2 preferably has a meniscus shape with a convex surface facing the magnification conjugate side. This makes it easier to correct various aberrations.

  The projection optical system P1 of each embodiment is telecentric or substantially telecentric with respect to the reduction conjugate side. In the projection optical system of each embodiment, the three lenses closest to the reduction conjugate side do not move during focusing. Alternatively, as in Examples 1 and 2, when the projection optical system is a zoom lens, it does not move during zooming.

  The projection optical system P1 of each embodiment may be a zoom lens or a single focal length lens system as described above. The projection optical system P1 of Examples 1 and 2 includes, for example, the first lens group B1 to the sixth lens group B6 in order from the magnification conjugate side, and the number N of the lens groups is N = 6, for example. The number of lens groups is not limited to N = 6 and may be at least many.

  The focus from infinity to the closest point in each example and reference example is as follows. In the first embodiment, the lens L14 and the lens L15 move (floating) to the reduction conjugate side at different speeds with respect to the lenses L11 to L13. In the second embodiment, the lens L14 moves (floats) at different speeds toward the reduction conjugate side with respect to the lenses L11 to L13. In the third embodiment, the lenses L14 to L16 move (floating) with respect to the lenses L12 and L13 at different speeds toward the reduction conjugate side.

  In Example 4, the lens L15 moves to the reduction conjugate side. In Example 5, the lenses L11 to L13 move to the magnification conjugate side. In Reference Example 1, the lenses L11 to L14 move to the reduction conjugate side.

In the projection optical system P1 of each embodiment, the curvature radius of the lens surface on the reduction conjugate side of the first lens G1 is G1R2. Let G2R1 be the radius of curvature of the lens surface on the magnification conjugate side of the second lens G2. The focal length of the third lens G3 is FG3. The focal length of the synthesis system from the first lens G1 to the third lens G3 is FG. At this time,
0.4 <FG3 / FG <1.0 (1)
0.0 <G1R2 / G2R1 (2)
The following conditional expression is satisfied.

Preferably, the refractive index of the material of the third lens G3 is Nd3. At this time,
1.7 <Nd3 (3)
It is good to satisfy the following conditional expression.

  Next, the technical meaning of each conditional expression described above will be described. Conditional expression (1) relates to the focal length (refractive power) of the third lens G3. If the lower limit of conditional expression (1) is exceeded and the refractive power of the third lens G3 becomes too strong, the effect of correcting spherical aberration and curvature of field becomes too strong, and the resolution is undesirably reduced. If the upper limit of conditional expression (1) is exceeded and the refractive power of the third lens G3 becomes too weak, the refractive power of the first lens becomes too strong due to the sharing of the refractive power, which is not preferable.

  In the conditional expression (2), the radius of curvature of the reduction conjugate side surface of the first lens G1 having a positive or negative refractive power and the radius of curvature of the enlargement conjugate side surface of the second lens G2 having a negative refractive power have the same sign. Is meant to be. By satisfying conditional expression (2), field curvature aberration and distortion aberration are generated in the positive direction on the enlargement conjugate side from the first lens G1, and the power distribution is brought closer to the reduction conjugate side to obtain spherical aberration and axis. Upper chromatic aberration is corrected in the positive direction. Thereby, various aberrations are corrected satisfactorily.

  Conditional expression (3) relates to the refractive index Nd3 of the material of the third lens G3. When the lower limit of conditional expression (3) is exceeded, the curvature of the lens surface G3R2 on the reduction conjugate side of the third lens G3 becomes strong, and it becomes difficult to correct spherical aberration and axial chromatic aberration in a well-balanced manner. Is not preferable because it deteriorates.

More preferably, the numerical ranges of the conditional expressions (1) to (3) are set as follows.
0.45 <FG3 / FG <0.90 (1a)
0.5 <G1R2 / G2R1 <2.5 (2a)
1.75 <Nd3 (3a)

  In the image projection apparatus of the present invention, the projection optical system P1, the image display element IE for displaying an image, and the glass blocks DG and CG are provided between the projection optical system P1 and the image display element IE. Here, the glass block includes a prism, an optical filter, and the like that become parallel plates when the optical path is developed.

  The image displayed on the image display element IE is projected onto the screen S1 by the projection optical system P1. At this time, the distance from the lens surface on the reduction conjugate side of the third lens G3 to the image display surface of the image display element IE is L, and the optical axis directions of the glass blocks DG and CG arranged on the reduction conjugate side of the third lens G3 The total sum of the thicknesses is defined as Dpsum. Ymax is half the diagonal length of the image display surface of the image display element IE. Let Dsum be the length in the optical axis direction from the magnification conjugate side lens surface of the first lens G1 to the reduction conjugate side lens surface of the third lens G3.

At this time,
1.5 <Dpsum / Ymax <3.0 (4)
0.3 (L-Dpsum) / L <0.5 (5)
1.4 <Dsum / Ymax <2.5 (6)
It is preferable to satisfy the conditional expression Of course, it is not necessary to satisfy all of the conditional expressions (4) to (6), and it is preferable to satisfy at least one of the conditional expressions.

More preferably, the thickness of the third lens G3 on the optical axis is DG3. At this time,
0.8 <DG3 / Ymax <1.6 (7)
It is good to satisfy the following conditional expression.

  Next, the technical meaning of each conditional expression described above will be described. Conditional expression (4) relates to the total thickness of the glass block (optical member) and the filter made of parallel plates arranged between the lens on the most reduction conjugate side and the reduction conjugate point.

  In each embodiment, good optical performance can be obtained in an image projection apparatus that satisfies the conditional expression (4). As such a form, for example, there is an image projection apparatus using a single plate DMD. Exceeding the lower limit of conditional expression (4) is not preferable because the back focus of the entire lens system increases and the size of the optical system increases. Exceeding the upper limit value of conditional expression (4) is not preferable because the air space between the lens system and the prism system becomes too narrow, the structural restrictions increase, and the spherical aberration balance decreases and affects the resolution performance. .

  Conditional expression (5) relates to the distance between the lens on the most reduction conjugate side and the reduction conjugate point. For example, in an image projection apparatus for a single-plate micromirror array, this is done in view of securing a space where a light-shielding shutter or the like can be disposed between a total reflection prism (TIR) and a projection optical system. In addition, although the form as one side surface of the image projection apparatus of this invention is a projection optical system for single plate | board micromirror arrays, it is not necessarily limited to this, If it is the range which satisfies conditional expression (5) Good. For example, the present invention may be applied to an image projection apparatus having a color separation / synthesis system using a transmissive liquid crystal using a cross dichroic prism.

  Conditional expression (6) appropriately sets the length in the optical axis direction from the surface on the magnification conjugate side of the first lens G1 to the surface on the reduction conjugate side of the third lens G3, and each lens surface is responsible for aberration correction. It goes well-balanced. Thus, field curvature aberration and distortion are corrected by the lens surface on the enlargement conjugate side, and spherical aberration and lateral chromatic aberration are corrected by the lens surface on the reduction conjugate side.

  If the upper limit of conditional expression (6) is exceeded, the lens thicknesses of the first lens G1, the second lens G2, and the third lens G3 become too long, making it difficult to manufacture and increasing the size of the entire projection optical system. It is not preferable. If the lower limit of conditional expression (6) is exceeded, the aberration correction sharing function of the first lens G1, the second lens G2, and the third lens G3 will be weakened, and in particular, field curvature aberration and astigmatism will increase. This is not preferable.

  Conditional expression (7) relates to the thickness of the third lens G3 on the optical axis. Exceeding the upper limit of conditional expression (7) is not preferable because the entire projection optical system P1 becomes large and the transmittance of the entire projection optical system P1 decreases due to the internal transmittance of the third lens G3. When the lower limit of the conditional expression (7) is exceeded, the correction sharing of spherical aberration and axial chromatic aberration in the first lens G1 to the third lens G3 moves relatively to the enlargement conjugate side, and distortion aberration and field curvature This is not preferable because the image aberration is increased and the image quality is lowered.

More preferably, the numerical ranges of the conditional expressions (4) to (7) are set as follows.
1.7 <Dpsum / Ymax <2.7 (4a)
0.35 (L-Dpsum) / L <0.48 (5a)
1.5 <Dsum / Ymax <2.0 (6a)
0.9 <DG3 / Ymax <1.4 (7a)

  Next, the projection optical systems of Examples 1 to 5 and Reference Example 1 will be described. The projection optical system P1 of Examples 1 and 2 is a zoom lens, and has a plurality of lens groups, and the interval between adjacent lens groups changes during zooming.

  Examples 1 and 2 include the following lens groups arranged in order from the enlargement conjugate side to the reduction conjugate side. The first lens unit B1 having a negative refractive power, the second lens unit B2 having a positive refractive power, the third lens unit B3 having a positive refractive power, the fourth lens unit B4 having a negative refractive power, and the first lens unit B4 having a positive refractive power. 5 lens group B5 and 6th lens group B6 of positive refractive power. The sixth lens group B6 includes a first lens G1, a second lens G2, and a third lens G3. During zooming, the second lens unit B2 to the sixth lens unit B6 move along different paths.

  Although Example 1 is a zoom lens that covers a standard region from a wide angle of view, distortion at the wide-angle end is 0.2% or less, and good optical performance is obtained with respect to lateral chromatic aberration.

  The second exemplary embodiment is a zoom lens that covers from the standard range to the mid-telephoto range, and corrects meridional field curvature aberration and distortion aberration well over the entire zoom range to obtain high optical performance.

  The projection optical systems P1 of Examples 3 to 6 have a single focal length. The third embodiment is intended for a wide-angle region, and particularly corrects blue lateral chromatic aberration, which is easily manifested by a retrofocus type wide-angle projection optical system, while correcting spherical aberration well. The fourth embodiment is intended for the middle telephoto region, and particularly corrects field curvature and astigmatism. In this embodiment, the above-described aberration is corrected favorably by increasing the curvature of the lens surface on the magnification conjugate side of the first meniscus lens G1 (L25).

  The fifth embodiment is intended for the telephoto area. In particular, in order to reduce the occurrence of longitudinal chromatic aberration, the third lens G3 (L28) is configured to be biconvex, and the first lens G1 (L26) is negative. By adopting a meniscus shape, a relatively strong power is arranged on the reduction conjugate side. In addition, the effect of correcting axial chromatic aberration is strengthened, and good optical performance is obtained.

  Reference Example 1 targets the standard area, and adopts two aspherical lenses to reduce the total number of lenses.

  At this time, the coma aberration correction balance required in the rear group is generated in the opposite direction to the spherical aberration, so that the power of the first lens G1 (L22) is increased. A meniscus type between the first lens G1 (L22) and the second lens G2 (L23) while relatively increasing the negative power of the second lens G2 (L23) and the positive power of the third lens G3 (L24). With this air lens, field curvature and lateral chromatic aberration are corrected well.

  Next, numerical data 1 to 6 of the projection optical systems of Examples 1 to 5 and Reference Example 1 are shown. The surface number in the lens configuration of the numerical data is a number assigned to each lens surface in order from the enlargement conjugate side to the reduction conjugate side. r represents the radius of curvature of each lens surface, and d represents the distance (physical distance) on the optical axis between the lens surface i and the lens surface (i + 1).

  The interval described as variable in the numerical data 1 and 2 changes with zooming. Further, nd and νd indicate the refractive index and the Abbe number for the d-line of the material constituting each lens, respectively. Numerical data indicates the focal length f, the aperture ratio (F number), the half angle of view ω, and the image height Ymax. Further, a surface written with * next to the surface number is an aspheric surface, and aspheric coefficients C4, C6, C8, C10, and C12 are shown for indicating the aspheric shape.

The aspherical shape is the x axis in the optical axis direction, the y axis in the direction perpendicular to the optical axis, the light traveling direction is positive, R is the paraxial radius of curvature, K is the conic constant, C4, C6, C8, C10, C12 aspherical coefficients, when E-X is to be ^{10 -X,} is as follows.

x = (y ² / R) / [1+ {1− (1 + K) (y ² / R ² )} ^1/2 ] + C4y ⁴ + C6y ⁶ + C8y ⁸ + C10y ¹⁰ + C12y ¹²
Tables 1 and 2 show the relationship between the above-described embodiments and numerical values.

(Numeric data 1)
(A) Lens configuration Surface number rd nd νd
1 * 487.2891 3 1.518051 64.1411
2 53.08327 13.56 1 0
3 * 180.1283 3 1.775821 49.5976
4 28.48656 15.67 1 0
5 -35.1207 1.8 1.498303 81.5447
6 94.9287 5.7464 1 0
7 176.9271 1.9 1.933071 18.8966
8 86.98286 8.6 1.724867 34.7074
9 -49.7214 (variable) 1 0
10 86.15302 3.3 1.550686 45.7836
11 681.9018 (variable) 1 0
12 78.90141 4.1 1.703844 30.1274
13 -325.809 23.95 1 0
14 -169.695 4.7 1.518051 64.1411
15 -22.5914 4.9 1.887605 40.7645
16 -33.4289 (variable) 1 0
17 (Aperture stop) 0.6 1 0
18 -77.9862 1.1 1.855835 32.2696
19 23.54155 5.9 1.518051 64.1411
20 -40.7197 (variable) 1 0
21 -21.8245 1.3 1.855835 32.2696
22 100.0833 6.9 1.518051 64.1411
23 -27.7655 1.71 1 0
24 226.7986 10.5 1.439739 94.9446
25 -28.9797 (variable) 1 0
26 95.31881 4.5 1.815547 22.7604
27 150.202 1.3 1 0
28 118.7455 2.9 1.746389 27.7889
29 40.5752 16 1.811841 25.456
30 -290.399 15.72 1 0
31 0 25.41 1.518522 64.1664
32 0 2.33 1 0
33 0 2.997 1.488591 65.499
34 0 0.0 1 0

(B) Aspheric coefficient surface 1 3
K 0 0
C4 7.47E-06 -5.4E-06
C6 -5.7E-09 5.41E-09
C8 6.28E-12 -1.2E-12
C10 -4.1E-15 -6.6E-15
C12 1.54E-18 6.98E-18

(C) Focal length, F number, half angle of view and image height
Wide-angle telephoto f 15.8824 23.8502
Fno 2.08 2.33
ω 39.4274 28.7551
Ymax 13.1 13.1

(D) Surface spacing corresponding to the zoom position
Wide angle telephoto
d9 41.147 5
d11 2.005 9.098
d16 1.505 9.137
d20 4.616 3.481
d25 1 23.558

(Numeric data 2)
(A) Lens configuration Surface number rd nd νd
1 47.29351 2.2 1.72746 37.955
2 22.95867 5.5 1 0
3 * 132.164 3 1.533128 55.8991
4 * 47.54235 10.46 1 0
5 -34.2595 1.7 1.591189 61.1341
6 150.5795 7.954 1 0
7 813.0952 5.6 1.810284 40.9253
8 -51.0923 (variable) 1 0
9 60.04648 4.95 1.805851 34.9668
10 -1313.06 (variable) 1 0
11 46.78645 5.65 1.680515 55.3404
12 -46.803 1.25 1.838729 37.3597
13 59.55333 2.14 1 0
14 -110.367 1.9 1.699477 55.5314
15 -54.9731 0.57 1 0
16 (Aperture stop) (Variable) 1 0
17 -122.206 1.15 1.811232 33.2688
18 25.81517 6.5 1.518051 64.1411
19 -36.6775 (variable) 1 0
20 -22.2654 1.45 1.811232 33.2688
21 69.89401 7.3 1.488975 70.2353
22 -35.504 0.22 1 0
23 196.9267 9.95 1.498303 81.5447
24 -30.71 (variable) 1 0
25 95.31881 4.5 1.815547 22.7604
26 150.202 1.3 1 0
27 118.7455 2.9 1.746389 27.7889
28 40.5752 16 1.811841 25.456
29 -290.399 15.72 1 0
30 0 25.41 1.518522 64.1664
31 0 2.33 1 0
32 0 2.997 1.488591 65.499
33 0 0.00 1 0

(B) Aspheric coefficient Surface 1 3
K 0 0
C4 4.18E-05 3.84E-05
C6 -1E-07 -1E-07
C8 2.28E-10 1.67E-10
C10 -2.6E-13 -6.9E-14
C12 8.81E-17 -2.9E-16

(C) Focal length, F number, half angle of view and image height
Wide angle telephoto f 23.3887 35.1621
Fno 1.8913 2.6623
ω 29.2348 20.4318
Ymax 13.1 13.1

(D) Surface spacing corresponding to the zoom position
Wide angle telephoto
d8 33.16874 5.768713
d10 29.89072 20.71161
d16 2.645743 22.39568
d19 2.843772 5.008598
d24 1.707025 16.3714

(Numerical data 3)
(A) Lens configuration Surface number rd nd νd
1 * 103.6244 4.15 1.585224 59.3738
2 40.85557 1.09E + 01 1.00E + 00 0.00E + 00
3 52.71172 2.30E + 00 1.78E + 00 4.96E + 01
4 28.22887 15.43 1 0
5 -39.0142 1.85 1.498303 81.5447
6 44.05311 9.24141 1 0
7 41.99981 12.0569 1.811232 33.2688
8 -48.5128 2.4 1.815547 22.7604
9 36.89334 7.17 1 0
10 64.21266 7.55 1.811849 25.4249
11 -72.6236 42.48348 1 0
12 -30.6952 1.7 1.775821 49.5976
13 -359.956 0.8 1 0
14 (Aperture stop) 0.75 1 0
15 47.82913 2.5 1.811849 25.4249
16 -111.589 16.17 1 0
17 -261.008 1.7 1.838763 37.1599
18 20.77633 5.7 1.488975 70.2353
19 -39.4879 0.49 1 0
20 132.9031 6.65 1.488975 70.2353
21 -16.8157 1.4 1.811849 25.4249
22 -116.202 7.69 1 0
23 -1312.26 7 1.488975 70.2353
24 -25.9871 0.5 1 0
25 104.0853 3.5 1.815547 22.7604
26 171.0077 1.3 1 0
27 133.9581 2 1.722491 29.5176
28 66.17851 14.1 1.811849 25.4249
29 -161.57 17.08 1 0
30 0 25.41 1.518522 64.1664
31 0 2.33 1 0
32 0 2.997 1.488591 65.499
33 0 0.007 1 0

(B) Aspheric coefficient surface 1
K 0
C4 2.94E-06
C6 -6.50E-10
C8 5.68E-13
C10 -7.66E-17
C12 6.16E-20

(C) Focal length, F-number, half angle of view and image height f 12.7997
Fno 2.0017
ω 36.1732
Ymax 9.4

(Numeric data 4)
(A) Lens configuration Surface number rd nd νd
1 31.68066 4 1.811841 25.456
2 22.01822 8.51 1 0
3 * 118.7634 2.5 1.585223 59.3848
4 * 37.14066 7.99 1 0
5 -42.7342 1.8 1.488975 70.2353
6 138.9885 3.45 1.811849 25.4249
7 -171.359 2.76198 1 0
8 -174.681 3 1.732005 54.6792
9 -67.2342 2.57786 1 0
10 0 30.244 1 0
11 55.15089 4.35 1.732005 54.6792
12 207.9653 25.946 1 0
13 53.25533 3.3 1.811849 25.4249
14 225.3328 5.642 1 0
15 (Aperture stop) 4.488 1 0
16 -437.403 1.5 1.703844 30.1274
17 26.59552 5.8 1.518051 64.1411
18 -122.853 0.5 1 0
19 0 1.113 1 0
20 36.90814 6.25 1.518051 64.1411
21 -57.7762 2.3 1.677118 32.1849
22 29.73088 6.78 1 0
23 -20.4011 1.35 1.724867 34.7074
24 113.1194 8.1 1.488975 70.2353
25 -26.3992 0.5 1 0
26 152.6575 8.05 1.498303 81.5447
27 -37.557 1.025 1 0
28 75.98817 4.5 1.815547 22.7604
29 131.5539 1.3 1 0
30 135.8258 2.9 1.746389 27.7889
31 50.69457 16 1.811849 25.4249
32 -550 13.88 1 0
33 0 25.41 1.518522 64.1664
34 0 2.33 1 0
35 0 2.997 1.488591 65.499
36 0 0.0 1 0
* Surface number 10 corresponds to a flare cut diaphragm.

(B) Aspheric coefficient Surface 3 4
K 0 0
C4 -3.89E-06 -9.88E-06
C6 -6.12E-09 -1.50E-08
C8 5.73E-11 7.92E-11
C10 -2.19E-13 -3.39E-13
C12 2.08E-16 3.65E-16

(C) Focal length, F-number, half angle of view and image height f 33.9625
Fno 1.9959
ω 21.0912
Ymax 13.1

(Numerical data 5)
(A) Lens configuration Surface number rd nd νd
1 123.3085 9.85 1.488975 70.2353
2 -106.082 3.16 1.723331 46.0238
3 -188.372 0.22 1 0
4 65.11549 4.05 1.518051 64.1411
5 90.4596 23.38636 1 0
6 238.2174 1.65 1.605237 60.6402
7 26.67574 7.52 1 0
8 -60.008 1.4 1.518051 64.1411
9 30.70769 3.4 1.803543 42.2243
10 207.7377 28.13599 1 0
11 (Aperture stop) 3.83 1 0
12 -25.981 1.83 1.703844 30.1274
13 56.19286 7.1 1.699477 55.5314
14 -46.3395 2.77409 1 0
15 -479.991 4.05 1.815547 22.7604
16 -53.4634 17.63 115 1 0
17 33.54504 4.75 1.815547 22.7604
18 63.73275 4.19 1 0
19 -119.184 2.53 1.518051 64.1411
20 -82.12 3.54 1 0
21 92.61909 1.72 1.811841 25.456
22 20.40421 13.75 1.605237 60.6402
23 -116.593 2.03 1 0
24 -38.4739 1.95 1.811232 33.2688
25 38.48183 7.35 1.518051 64.1411
26 -56.368 8.83084 1 0
27 80 4.5 1.623661 36.2628
28 61.03541 1.5 1 0
29 75.16248 2.9 1.488975 70.2353
30 58.18785 11.72285 1.805661 29.8442
31 -154.365 22.68615 1 0
32 0 25.41 1.518522 64.1664
33 0 2.33 1 0
34 0 2.997 1.488591 65.499
35 0 0.13566 1 0

(C) Focal length, F-number, half angle of view and image height f 56.2
Fno 2.28
ω 13.1002
Ymax 13.1

(Numeric data 6)
(A) Lens configuration
bn krd nd νd
1 40.57915 2.2 1.854151 23.7775
2 22.84827 6.77 1 0
3 * 98.25925 3.15 1.531987 55.7991
4 * 31.98965 15 1 0
5 -25.8839 2 1.605237 60.6402
6 1581.262 1.25 1 0
7 -127.938 3.1 1.838763 37.1599
8 -51.8378 6.56717 1 0
9 190.7347 4.6 1.838763 37.1599
10 -71.9469 36.81521 1 0
11 59.41962 3.35 1.747531 44.7857
12 589.4665 10.15749 1 0
13 (Aperture stop) 18.96969 1 0
14 -39.4581 1.4 1.791156 25.683
15 -92.6383 7.25482 1 0
16 507.1442 1.5 1.838763 37.1599
17 30.46855 5.2 1.488975 70.2353
18 1387.659 0.15 1 0
19 56.56261 7.65 1.498303 81.5447
20 -40.4171 0.15 1 0
21 * -103.632 3.3 1.531987 55.7991
22 * -63.5273 0.70989 1 0
23 125.6666 4.5 1.770328 49.9767
24 -150.23 2 1 0
25 -64.9696 2.5 1.811683 25.3995
26 46.49525 14.17718 1.816141 26.8431
27 -72.672 16 1 0
28 0 25.41 1.518522 64.1664
29 0 2.33 1 0
30 0 2.997 1.488591 65.499
31 0 0.10289 1 0

(B) Aspheric coefficient Surface 3 4 21 22
K -0.86529 -4.3291 -65.8661 -7.91329
C4 1.13E-05 1.84E-05 -1.19E-05 -6.71E-06
C6 -5.27E-09 -2.34E-08 3.10E-09 -1.29E-08
C8 -3.32E-11 -9.91E-11 6.28E-11 9.85E-11
C10 2.04E-13 5.82E-13 -2.90E-13 -3.33E-13
C12 -2.26E-16 -8.77E-16 5.41E-16 5.21E-16

(C) Focal length, F number, half angle of view and image height

f 21.7707
Fno 1.8542
ω 29.2361
Ymax 12.2

P1 Projection optical system B1 1st lens group B2 2nd lens group B3 3rd lens group B4 4th lens group B5 5th lens group B6 6th lens group DG, CG Glass block S Screen surface IE Image display element

Claims (8)

A projection optical system that is arranged on the reduction conjugate side and projects an image displayed on the image display element to the enlargement conjugate side,
It has three lenses that do not move in the optical axis direction on the most conjugate side,
The three lenses are, in order from the magnification conjugate side to the reduction conjugate side, a meniscus first lens having a convex surface facing the magnification conjugate side, a second lens having a negative refractive power, and a third lens having a positive refractive power. ,
The second lens and the third lens are cemented lenses which are cemented;
The radius of curvature of the lens surface on the reduction conjugate side of the first lens is G1R2, the radius of curvature of the lens surface on the magnification conjugate side of the second lens is G2R1, the focal length of the third lens is FG3, and from the first lens to the lens When the focal length of the synthesis system up to the third lens is FG,
0.4 <FG3 / FG <1.0
0.0 <G1R2 / G2R1
A projection optical system characterized by satisfying the following conditional expression: When the refractive index of the material of the third lens is Nd3,
1.7 <Nd3
The projection optical system according to claim 1, wherein the following conditional expression is satisfied.   3. The projection optical system according to claim 1, wherein the second lens has a meniscus shape with a convex surface facing the magnification conjugate side. 4.   The projection optical system according to claim 1, wherein the third lens has a biconvex shape. 5. The projection optical system according to claim 1, an image display element that displays an image, a glass block between the projection optical system and the image display element, and the image display element An image projection apparatus that projects an image displayed on the projection optical system,
When the total thickness in the optical axis direction of the glass block disposed on the reduction conjugate side of the third lens is Dpsum, and half of the diagonal length of the image display surface of the image display element is Ymax,
1.5 <Dpsum / Ymax <3.0
An image projection apparatus satisfying the following conditional expression: When the distance from the lens surface on the reduction conjugate side of the third lens to the image display surface of the image display element is L,
0.3 (L-Dpsum) / L <0.5
The image projection apparatus according to claim 5, wherein the following conditional expression is satisfied. When the length in the optical axis direction from the lens surface on the magnification conjugate side of the first lens to the lens surface on the reduction conjugate side of the third lens is Dsum,
1.4 <Dsum / Ymax <2.5
The image projection apparatus according to claim 5, wherein the following conditional expression is satisfied. When the thickness on the optical axis of the third lens is DG3,
0.8 <DG3 / Ymax <1.6
The image projection apparatus according to claim 5, wherein the following conditional expression is satisfied.