JP2006235372A - Projection lens and projector device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a projection lens which has a wide viewing angle, which has high resolving power, whose chromatic difference of magnification is restrained to be small, which is bright with a small F value, which is telecentric on a reduction side and whose distortion aberration is restrained to be small. <P>SOLUTION: The projection lens has a reflection member, a 1st lens group I positioned on an optical path on an enlargement side from the reflection member and having negative refractive power, and a 2nd lens group II positioned on an optical path on a reduction side and having positive refractive power. The focal distance: f of an entire system, the back focus: Bf in the air of the entire system, the reciprocal: ϕ<SB>1G</SB>of the focal distance of the 1st lens group, the reciprocal:ϕ<SB>2G</SB>of the focal distance of the 2nd lens group, the refractive index: n<SB>2GN</SB>of the lens material having the highest refractive index in the material of a lens having negative refractive power and included in the 2nd lens group to a d-line, and the partial dispersion ratio (n<SB>g</SB>-n<SB>F</SB>)/(n<SB>F</SB>-n<SB>c</SB>): P<SB>gF</SB>2GN of the lens material having the highest refractive index in the material of the lens having the negative refractive power and included in the 2nd lens group satisfy conditions: (1) 4.0≤Bf/f≤6.0, (2) 2≤¾ϕ<SB>1G</SB>¾/ϕ<SB>2G</SB>≤3, (3) n<SB>2GN</SB>≥1.87 and (4) P<SB>gF</SB>2GN≤0.6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projection lens for enlarging and projecting a planar image displayed on an image display device such as a liquid crystal panel, and a projector apparatus using the projection lens.

  In recent years, a “rear projector that projects an image from the back of the screen and observes an image from the opposite side of the screen” has become widespread as a display device for TV broadcasting, video playback images, and computer images. Rear projectors have existed for some time, but as a recent trend, the screen size is large, the depth is small, and the pixel pitch of the image display device is becoming small for higher definition of the projected image.

  Therefore, the projection lens used in the rear projector is particularly required to have a wide angle of view and a high resolving power so that the depth of the apparatus can be reduced.

  Further, since the projected image becomes unsightly when the size differs for each color, the chromatic aberration of magnification is suppressed to be small, and since the illumination side light is used effectively, the lens has a small F value and is bright. Is required.

  In addition, since transmissive liquid crystal, reflective liquid crystal, or DMD (digital mirror device) is used as an image display device, “light component parallel to the optical axis” is mainly used as illumination light. In some cases, telecentricity is required on the reduction side which is the image display device side. Further, it is also required that the distortion aberration is small so as not to impair the shape reproducibility of the projected image.

The applicant has previously proposed a "reflective surface in the projection lens to bend the optical path inside the lens system" so that the thickness (depth) on the back side of the screen can be effectively reduced (patent) References 1, 2)
JP 2004-354405 A JP2004-333688

  The present invention effectively satisfies the above-mentioned requirements in the “projection lens of a type in which a reflection surface is provided in the projection lens and the optical path is bent inside the lens system” described in Patent Documents 1 and 2. An object of the present invention is to realize a novel projection lens that can be used and a rear projector device that uses the projection lens.

  The projection lens of the present invention is a “projection lens for enlarging and projecting a planar image”. The “planar image” is generally an image displayed on an “image display device” such as a transmissive or reflective liquid crystal panel or DMD.

  As illustrated in FIG. 1, the projection lens of the present invention includes a reflection member RF for bending the optical path, and a first lens having a negative refractive power disposed on the optical path on the enlargement side of the reflection member RF. And a second lens group II having a positive refractive power disposed on the optical path closer to the reduction side than the reflecting member RF. In FIG. 1, the symbol ST indicates “aperture”, and the symbol CG indicates “a cover glass of an image display device”.

The projection lens according to claim 1 is configured as described above.
Focal length of the entire system: f,
Back focus in air for all systems: Bf,
Reciprocal of focal length of first lens group: φ _1G ,
Reciprocal of focal length of second lens group: φ _2G
Among the lens materials having negative refractive power included in the second lens group, those having the highest refractive index but having a refractive index with respect to d-line: n _2GN
During the material of the lens having the negative refractive power in the second lens group, the highest refractive index partial dispersion ratio of those with _{(n g -n F) / (} n F -n c): P gF 2GN is less Conditions:
(1) 4.0 ≦ Bf / f ≦ 6.0
(2) 2 ≦ | _φ1G | / _φ2G ≦ 3
(3) n _2GN ≧ 1.87
(4) P _gF 2GN ≦ 0.6
It is characterized by satisfying.

The projection lens according to claim 1 is:
The distance on the optical axis from the lens surface located closest to the magnification side of the first lens group to the lens surface located closest to the reflecting member: L _1G ,
Distance on the optical axis from the lens surface located closest to the enlargement side of the first lens group to the lens surface located closest to the reduction side of the second lens group: OAL
Is the condition:
(5) 0.1 ≦ L _1G /OAL≦0.3
Is preferably satisfied (claim 2).

The projection lens according to claim 1 or 2,
The first lens group consists of two lenses,
The radius of curvature of the surface on the magnification side of the second lens from the magnification side of the first lens group: L2R1,
Radius of curvature of the reduction side surface of the second lens from the enlargement side of the first lens group: L2R2
Is the condition:
(6) 5.0 ≦ | L2R1 | / L2R2
It is preferable that the configuration satisfies the above.

The projection lens according to any one of claims 1 to 3 can have “a diaphragm ST between the first lens group I and the second lens group II” as illustrated in FIG. Item 4).
In the projection lens according to any one of claims 1 to 4, the second lens group II is a positive lens, a negative lens, a positive lens, a positive lens, “negative” in order from the magnification side, as illustrated in FIG. A cemented lens in which a lens and a positive lens are bonded to each other ”, and seven lenses of a positive lens can be provided (claim 5).

  The projector device of the present invention is a rear type in which the projection lens according to any one of claims 1 to 5 is mounted.

  As a supplementary explanation, the projection lens of the present invention is used in a rear projector device. However, the rear projector device body (entirely including the projector portion and the screen) is becoming thinner, and the projection lens has a wide angle. Is required.

  As often seen in this type of lens, the projection lens of the present invention also has a first lens group having a negative refractive power on the enlargement side and a second lens group having a positive refractive power on the reduction side. By arranging it, it corresponds to the wide angle as “retro focus type as a whole”.

  Further, a mirror, a prism or the like is inserted as a “reflecting member that bends the optical path” between the first lens group and the second lens group, and “bending the optical path within the lens system” as shown in FIG. This arrangement makes it easy to achieve a thin projector apparatus body.

Each of the above conditions will be described.
Condition (1) is that a space where a “mirror or prism for guiding illumination light, or a dichroic prism or dichroic mirror for color synthesis” can be inserted on the reduction side, or a reflective image display device is used. This is a condition that regulates the “focal length of the lens that can project a large screen at a short projection distance” while ensuring a space for “illuminating light obliquely incident from the projection lens side”.

  When the lower limit of the condition (1) is exceeded, the space on the reduction side of the projection lens becomes narrow, or the focal length becomes longer and the projection distance becomes longer in proportion thereto. Further, if the upper limit of the condition (1) is exceeded, the reduction principal point of the entire system is too far from the lens, and it is difficult to ensure “basic performance” to obtain “a high-resolution projected image without distortion”.

  Condition (2) is a condition for facilitating securing of “sufficient space on the reduction side”, widening the angle of view, and securing of imaging performance as described above. The refractive power becomes relatively weak with respect to the refractive power of the second lens group, and the “interval between the first lens group and the second lens group” must be taken very large, and the entire projection lens becomes long. When the upper limit of the condition (2) is exceeded, the refractive power of the first lens group with respect to the second lens group becomes relatively strong, increasing various aberrations, and it becomes difficult to correct various aberrations in the second lens group. .

  As in the projection lens of the present invention, in the configuration in which the optical path is bent in the lens system, the “lens whose length is significantly longer than that in which the lens length is not bent”, the paraxial between the first lens group and the second lens group The beam height is significantly different. That is, the height of the paraxial light beam is lower in the first lens group, but becomes “a height several times the light beam height in the first lens group” in the second lens group. For this reason, the Petzval sum, which is an index of field curvature, becomes too small and tends to take a negative value.

  Condition (3) is for avoiding such a situation. When the second lens group includes a plurality of negative lenses, the material of at least one of the lenses is defined as in condition (3). By making the lens very high, the contribution of the negative lens to the Petzval sum is effectively reduced, thereby making it easier to obtain a flat image surface.

  In a wide-angle lens such as the projection lens of the present invention, it is very difficult to correct lateral chromatic aberration, but “a material having a partial dispersion ratio that satisfies the condition (4)” is the most suitable in the second lens group. By using it for a negative lens having a large refractive power, it is possible to realize correction of lateral chromatic aberration in a balanced manner from a short wavelength to a long wavelength.

  When the upper limit of condition (4) is exceeded, the “movement of lateral chromatic aberration on the short wavelength side” is too steep with respect to the lateral chromatic aberration on the long wavelength side, and on the short wavelength side with respect to the reference wavelength (550 nm in the examples described later). Is sufficiently corrected, but the long wavelength side is insufficiently corrected.

  In the wide-angle lens such as the projection lens of the present invention, the lens diameter of the first lens group, particularly the “lens closest to the enlargement side” tends to be very large. However, the condition (5) is wide. This is a condition for making the lens diameter small and inexpensive while maintaining the angle of view.

  When the upper limit of the condition (5) is exceeded, the “magnification side pupil position” moves away from the magnification side surface of the first lens group and approaches the reflecting member, so that the diameter of the first lens group increases and exceeds the lower limit. Although the diameter of the first lens group can be kept small, it is difficult to correct distortion, curvature of field, and field curvature.

  In order to realize an inexpensive projection lens, it is a common technique for this type of lens to make a lens with a large diameter aspherical, and to make it by molding with resin instead of glass. In this case, since the resin has a low refractive index and a large amount of deformation due to environmental changes, it cannot have a large refractive power, and as a result, the refractive power concentrates on the glass lens.

  When the shape of the glass lens having a large refractive power does not satisfy the condition (6) and exceeds the lower limit of the condition (6), the glass lens has a large magnification on the magnification side (relative curvature with respect to the reduction-side lens surface). Distortion occurs and correction by other lenses becomes difficult.

  In addition, when a parallel light beam is mainly used for illumination, it is desirable to be “telecentric on the reduction side of the projection lens”, but by arranging a stop between the first lens group and the second lens group, “off-axis main The light beam can be made substantially parallel to the optical axis in the space on the reduction side, and telecentricity can be ensured.

  As described above, the projection lens according to the present invention can achieve high imaging performance with the above-described configuration, with a bright, wide field angle, long back focus, little distortion, and the like.

Examples of the present invention will be described below.
Three specific numerical examples will be given below as embodiments of the projection lens.
The meanings of symbols used in each example are as follows.

IMG: Image display surface Ri: Radius of curvature of the i-th lens surface counted from the magnification side Di: Axis upper surface distance between the i-th lens surface and the i + 1-th lens surface counted from the magnification side Do: Screen side To the first lens surface Nj: Refractive index with respect to the d-line of the jth lens counted from the magnification side νj: Abbe number of the jth lens counted from the magnification side P _gF 2GNj: Expansion side The partial dispersion ratio of the j-th lens counted from

The shape of the aspherical surface used in each example is as follows: coordinate in optical axis direction: Z, coordinate in optical axis orthogonal direction: h, on-axis radius of curvature: Ri, conic constant: K, higher order coefficients: A, B , C, D, E, F, G are known aspherical formulas:
Z = (1 / Ri) · h ² / [1 + √ {1− (K + 1) · (1 / Ri) ² · h ² }]
+ A · h ⁴ + B · h ⁶ + C · h ⁸ + D · h ¹⁰ + E · h ¹² + F · h ¹⁴ + G · h ¹⁶
The shape is specified by giving values of Ri, K, A, B, C, D, E, F, and G.
In each example, the calculation reference wavelength is 550 nm.

  In addition, each embodiment is expressed as “a linear optical system without a reflecting member for bending” in order to avoid confusion of symbols. The unit of quantity having a length dimension is “mm” unless otherwise specified.

i Ri Di j Nj νj P _gF
0 ∞ 590.000
1 -118.35305 (*) 5.000 1 1.49154 57.8 0.545
2 76.55042 (*) 20.000
3 -196.18816 2.000 2 1.77250 49.6 0.550
4 19.67858 87.0544 (Reflecting member insertion part)
5 (Aperture) ∞ 11.863995
6 26.75972 6.685335 3 1.84666 23.8 0.619
7 -36.83243 0.500
8 -31.86537 5.500 4 1.90366 31.3 0.595
9 20.33193 0.535881
10 22.50981 5.732204 5 1.48749 70.4 0.531
11 -79.98690 2.169560
12 74.84632 6.736599 6 1.49700 81.6 0.539
13 -20.24763 0.500
14 -23.84893 2.900 7 1.90366 31.3 0.595
15 26.61008 7.186707 8 1.48749 70.4 0.531
16 -34.36689 0.500
17 34.87926 6.635256 9 1.49700 81.6 0.539
18 -52.15952 37.5
19 ∞ 3.000 10 1.486400 66.6
20 ∞ 0.0
IMG ∞
The 19th and 20th surfaces are both surfaces of the cover glass of the image display device. The surface marked with (*) is an aspherical surface.

Aspheric surface 1st surface
K = 0.000
A = 0.321517E-04 B = -0.554040E-07 C = 0.838695E-10 D = -0.941301E-13
E = 0.710416E-16 F = -0.310018E-19 G = 0.589780E-23.

Second side
K = 0.000
A = 0.270826E-04 B = -0.223720E-07 C = -0.266351E-11 D = 0.495250E-14
In the above notation, for example, “0.495250E-14” means “0.495250 × 10 ⁻¹⁴ ”. The same applies to the following. .

Parameter value for each condition Condition (1) 5.89
Condition (2) 2.77
Condition (3) 1.9036
Condition (4) 0.595
Condition (5) 0.157
Condition (6) 9.9.

i Ri Di j Nj νj P _gF
0 ∞ 630.000
1 -112.10996 (*) 5.000 1 1.49154 57.8 0.545
2 142.32549 (*) 18.452447
3 1748.54012 2.000 2 1.77250 49.6 0.550
4 19.73624 87.167 (Reflecting member insertion part)
5 (Aperture) ∞ 14.847044
6 27.36665 7.087918 3 1.84666 23.8 0.619
7 -36.50765 0.500412
8 -30.62906 2.885455 4 1.87000 30.1 0.595
9 25.00939 1.497899
10 48.91799 5.483100 5 1.48749 70.4 0.531
11 -102.62745 1.012683
12 52.39013 7.969849 6 1.49700 81.6 0.539
13 -21.43585 2.248413
14 -22.49771 4.000 7 1.87000 30.1 0.595
15 29.78422 7.685895 8 1.49700 81.6 0.539
16 -33.59302 0.500
17 35.05317 7.412115 9 1.49700 81.6 0.539
18 -50.69144 33.294
19 ∞ 3.000 1.51680 64.2
20 ∞ 0.0
IMG ∞
The 19th and 20th surfaces are both surfaces of the cover glass of the image display device. The surface marked with (*) is an aspherical surface.

Aspheric surface 1st surface
K = 0.000
A = 0.320785E-04 B = -0.532818E-07 C = 0.836817E-10 D = -0.971441E-13
E = 0.730288E-16 F = -0.3306165E-19 G = 0.537772E-23
Second side
K = 0.000
A = 0.283107E-04 B = -0.221315E-07 C = -0.699929E-12 D = 0.346657E-14.

Parameter value for each condition Condition (1) 4.91
Condition (2) 2.22
Condition (3) 1.87
Condition (4) 0.595
Condition (5) 0.144
Condition (6) 88.6

i Ri Di j Nj νj P _gF
O ∞ 620.000
1 -109.43980 (*) 5.000 1 1.491540 57.8 0.545
2 156.75706 (*) 14.395625
3 -377.06828 2.000 2 1.77250 49.6 0.550
4 20.61504 93.1
5 (Aperture) ∞ 11.497346
6 26.94293 7.222491 3 1.84666 23.8 0.619
7 -32.39280 0.500
8 -27.92039 4.825236 4 1.87000 30.1 0.595
9 23.94773 1.177708
10 38.79667 4.850489 5 1.48749 70.4 0.531
11 -63.06204 0.500
12 64.24860 7.231580 6 1.49700 81.6 0.539
13 -19.55889 0.500
14 -22.49802 4.000 7 1.87000 30.1 0.595
15 21.96135 7.841630 8 1.48749 70.4 0.531
16 -37.66340 3.325334
17 37.41182 8.532030 9 1.49700 81.6 0.539
18 -36.62523 32.5
19 ∞ 3.000 1.48640 66.6
20 ∞ 0.0
IMG ∞
The 19th and 20th surfaces are both surfaces of the cover glass of the image display device. The surface marked with (*) is an aspherical surface.

Aspheric surface 1st surface
K = 0.000
A = 0.319385E-04 B = -0.525809E-07 C = 0.839521E-10 D = -0.970182E-13
E = 0.730044E-16 F = -0.3304735E-19 G = 0.549432E-23
Second side
K = 0.000
A = 0.258857E-04 B = -0.212155E-07 C = -0.167985E-11 D = 0.426610E-14.

Parameter value for each condition Condition (1) 4.84
Condition (2) 2.25
Condition (3) 1.87
Condition (4) 0.595
Condition (5) 0.121
Condition (6) 18.3.

  FIG. 2 shows a sectional view of the projection lens of Example 1 in a “state where bending of the optical path is omitted”. FIG. 3 shows a longitudinal aberration diagram regarding the projection lens of Example 1, and FIG. 4 shows a lateral aberration diagram regarding the projection lens of Example 1. In FIG. 3 showing longitudinal aberration, “S” in the astigmatism diagram indicates a sagittal image plane, and “T” indicates a tangential image plane. In Example 1, the wavelengths of R, G, and B representing red, green, and blue are R: 640 nm, G: 550 nm, and B: 440 nm, respectively.

  FIG. 5 shows a sectional view of the projection lens of Example 2 in a “state where bending of the optical path is omitted”. FIG. 6 is a longitudinal aberration diagram related to the projection lens of Example 2, and FIG. 7 is a lateral aberration diagram related to the projection lens of Example 2, following FIGS. In Example 2, the wavelengths of R, G, and B representing red, green, and blue are R: 650 nm, G: 550 nm, and B: 450 nm, respectively.

  FIG. 8 shows a sectional view of the projection lens of Example 3 in a “state where bending of the optical path is omitted”. FIG. 9 is a longitudinal aberration diagram relating to the projection lens of Example 3, and FIG. 10 is a lateral aberration diagram relating to the projection lens of Example 3, following FIGS. 3 and 4, respectively. In Example 3, the wavelengths of R, G, and B representing red, green, and blue are R: 640 nm, G: 550 nm, and B: 440 nm, respectively.

Each of the projection lenses of Examples 1 to 3 described above is a projection lens for enlarging and projecting a planar image, and includes a reflection member RF for bending the optical path, and the reflection member RF. A first lens group I having a negative refractive power disposed on the optical path on the enlargement side, and a second lens group II having a positive refractive power disposed on the optical path on the reduction side with respect to the reflecting member RF. And
Focal length of the entire system: f,
Back focus in air for all systems: Bf,
Reciprocal of focal length of first lens group: φ _1G ,
Reciprocal of focal length of second lens group: φ _2G
Among the lens materials having negative refractive power included in the second lens group, those having the highest refractive index but having a refractive index with respect to the d-line: n _2GN ,
Partial dispersion ratio (n _g −n _F ) / (n _F −n _c ) of the lens material having the negative refractive power included in the second lens group having the highest refractive index is P _gF 2GN:
(1) 4.0 ≦ Bf / f ≦ 6.0
(2) 2 ≦ | _φ1G | / _φ2G ≦ 3
(3) n _2GN ≧ 1.87
(4) P _gF 2GN ≦ 0.6
(Claim 1).

Further, the distance on the optical axis from the lens surface located closest to the enlargement side of the first lens group I to the lens surface located closest to the reflecting member: L _1G ,
Distance on the optical axis from the lens surface located closest to the enlargement side of the first lens group I to the lens surface located closest to the reduction side of the second lens group II: OAL
Is the condition:
(5) 0.1 ≦ L _1G /OAL≦0.3
(Claim 2), the first lens group comprises two lenses,
The radius of curvature of the surface on the magnification side of the second lens from the magnification side of the first lens group I: L2R1,
Radius of curvature of the reduction side surface of the second lens from the enlargement side of the first lens group I: L2R2
Is the condition:
(6) 5.0 ≦ | L2R1 | / L2R2
(Claim 3). Further, a stop ST is provided between the first lens group I and the second lens group II.

  Further, in each of the projection lenses of Examples 1 to 3, the second lens group II is in order from the enlargement side, the positive lens, the negative lens, the positive lens, the positive lens, the cemented lens in which the negative lens and the positive lens are bonded, and the positive lens. 7 lenses are arranged (claim 5).

  Therefore, the light from the light source is passed through the image display device, and the light having the image information is projected onto a known rear projector apparatus that displays an enlarged projection from the back of the transmission screen SC as shown in FIG. By mounting an appropriate one of the first to third embodiments as the lens PL, it is possible to display a high-definition image while being compact. In FIG. 11, reference numeral RF1 denotes a reflecting surface that reflects the imaged light beam from the projection lens PL toward the transmissive screen SC.

It is a figure for demonstrating the projection lens of this invention. It is a figure which shows sectional drawing of the lens for projection of Example 1 in the state which abbreviate | omitted the bending of the optical path. 3 is a longitudinal aberration diagram regarding the projection lens of Example 1. FIG. 2 is a lateral aberration diagram regarding the projection lens of Example 1. FIG. It is a figure which shows sectional drawing of the lens for projection of Example 2 in the state which abbreviate | omitted bending of the optical path. 6 is a longitudinal aberration diagram for the projection lens of Example 2. FIG. 6 is a lateral aberration diagram regarding the projection lens of Example 2. FIG. It is a figure which shows sectional drawing of the projection lens of Example 3 in the state which abbreviate | omitted bending of the optical path. 6 is a longitudinal aberration diagram for the projection lens of Example 3. FIG. 6 is a lateral aberration diagram regarding the projection lens of Example 3. FIG. It is a figure for demonstrating one Embodiment of a projector apparatus.

Explanation of symbols

I First lens group II Second lens group RF reflecting member ST Aperture CG Cover glass, etc.

Claims (6)

A projection lens for enlarging and projecting a planar image,
A reflecting member for bending the optical path in the lens system, a first lens group having a negative refractive power disposed on the optical path on the enlargement side with respect to the reflecting member, and an optical path on the reduction side with respect to the reflecting member A second lens group disposed and having a positive refractive power;
Focal length of the entire system: f,
Back focus in air for all systems: Bf,
Reciprocal of focal length of first lens group: φ _1G ,
Reciprocal of focal length of second lens group: φ _2G
Among the lens materials having negative refractive power included in the second lens group, those having the highest refractive index but having a refractive index with respect to d-line: n _2GN
Partial dispersion ratio of the material having the highest refractive index among the materials of lenses having negative refractive power included in the second lens group: P _gF 2GN (= (n _g −n _F ) / (n _F −n _c )) But the following conditions:
(1) 4.0 ≦ Bf / f ≦ 6.0
(2) 2 ≦ | _φ1G | / _φ2G ≦ 3
(3) n _2GN ≧ 1.87
(4) P _gF 2GN ≦ 0.6
A projection lens characterized by satisfying The projection lens according to claim 1,
The distance on the optical axis from the lens surface located closest to the magnification side of the first lens group to the lens surface located closest to the reflecting member: L _1G ,
Distance on the optical axis from the lens surface located closest to the enlargement side of the first lens group to the lens surface located closest to the reduction side of the second lens group: OAL
Is the condition:
(5) 0.1 ≦ L _1G /OAL≦0.3
A projection lens characterized by satisfying The projection lens according to claim 1 or 2,
The first lens group consists of two lenses,
The radius of curvature of the surface on the magnification side of the second lens from the magnification side of the first lens group: L2R1,
Radius of curvature of the reduction side surface of the second lens from the enlargement side of the first lens group: L2R2
Is the condition:
(6) 5.0 ≦ | L2R1 | / L2R2
A projection lens characterized by satisfying The projection lens according to any one of claims 1 to 3,
A projection lens having a stop between a first lens group and a second lens group. The projection lens according to any one of claims 1 to 4,
The second lens group includes, in order from the magnification side, a positive lens, a negative lens, a positive lens, a positive lens, a cemented lens in which a negative lens and a positive lens are bonded, and a positive lens. Projection lens A projector device equipped with the projection lens according to any one of claims 1 to 5.

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