JP2528771B2 - Projection lens - Google Patents

Description

Detailed Description of the Invention

[0001]

[Industrial applications] The present invention relates to a projection lens, and
It has excellent optical performance, wide angle and compact,
Maybe F_NO≤1.15 or F_NOVery bright with ≦ 1.1
The present invention relates to a projection lens for a projector.

[0002]

2. Description of the Related Art In recent years, projection televisions (hereinafter,
(Abbreviated as PTV) is not only for receiving TV broadcast images but also for VT
There is an increasing demand as a display device for electronic image devices such as R and Debio disk, and for a computer output display for displaying characters and still images. In addition, recently, the demand for large-screen televisions is increasing even in ordinary households.
Therefore, in PTV, improvement in brightness, contrast, resolution, etc. is desired so that the image quality is close to that of a direct-view television, and in addition to performance, there is an increasing demand for compactness and cost reduction. There is.

In particular, the image quality of PTV depends on the projection lens for the projector used, and the image forming performance of the projection lens is required to be high not only on the axis but also on the periphery. Further, in order to reduce the size and cost of the PTV, the size reduction of the lens unit of the projection lens and the cost reduction of the lens itself have a great influence.

Conventionally, a combination of a large number of glass lenses has been used as a projection lens, but a spherical lens system is generally used for a glass lens, and this increases the number of constituent lenses, resulting in a glass material. Since it has a large specific gravity, it was not possible to reduce the weight.

However, recently, large-aperture aspherical plastic lenses can be produced with high precision, so that glass lenses and plastic lenses are used in combination to maintain compactness and cost while maintaining optical performance. A projection lens is used.

[0006]

By the way, in the manufacture of plastic lenses, injection molding using a mold is generally used, and of course a high-precision mold is required to mold a high-precision lens. . Therefore, although the cost has been reduced by reducing the number of lens components due to the progress from the configuration of all glass lenses to the combination configuration of glass lenses and plastic lenses (hybrid type), high precision mold as an initial cost is expensive. There was a problem that was. The current mainstream projection lens for PTV is a 4-group 4-lens structure with the exception of the negative lens, which is the most distant from the screen and has a strong concave surface facing the screen.
One is a glass lens having a strong positive power, the other three are plastic lenses each having an independent shape, and three molds are required to mold the plastic lens.

On the other hand, the linear expansion coefficient of the plastic material is
It is significantly larger than optical glass, and its refractive index fluctuates greatly due to temperature changes. Therefore, the plastic lens
There is a problem that the back focus changes largely due to the temperature change, which deteriorates the image forming performance and deteriorates the PTV image quality. Even a conventional projection lens that uses both a glass lens and a plastic lens satisfies the optical performance such as geometrical optical aberration, has a wide angle and is compact, and F _NO ≤
Very few satisfy the value of 1.15.

[0008] The present invention has been made in view of such conventional problems.
The expensive molding dies have been changed from the conventional 3 dies to 2 dies.
1 mold can be reduced, mold cost is low, and optical performance is also
Good, wide angle, compact and F_NO≤1.15 again
Is F_NOAim to provide a bright projection lens with ≦ 1.1
Target.

[0009]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
In the invention according to claim 1,
The first lens group of, the second lens group of positive,
Also has a strong positive third lens group, a positive fourth lens group,
Negative fifth lens group and concave surface with strong curvature on the screen side
A 6-lens 6-lens configuration consisting of a negative sixth lens group
And the first lens group and the fifth lens group, and
The second group lens and the fourth group lens have the same shape.
And a plastic lens made of the same material,
From the first lens group to the fifth lens group, the third lens group is medium
Left and right symmetrical arrangement, and the first and fifth groups
The lenses each have aspherical surfaces on both sides, and include a second lens group and a second lens group.
Each of the fourth group lenses includes a lens including at least one aspherical surface.
(1) 0.03 < | F₂/ F₁｜ <0.6 (2) 1.0 < f₃/ F <1.4 (3) D₂/ F <0.07 (4) 2 < E₁/ D₁<4 where  f ; Synthetic focal length of whole system  f_i; Focal length of group i lens  D₁; Center thickness of the first lens group  D₂; On-axis lens spacing between the first and second lens groups  E₁At the maximum ray height of the first lens group (fifth lens group)
The projection lens was constructed so as to satisfy the condition of the inter-plane distance of.

[0010] The invention according to claim 2 is a screen
In order from the side, the negative first group lens, the positive second group lens, the structure
The positive third lens group, which has the strongest power among the synthetic lenses,
The fourth lens group and the concave surface with a strong curvature on the screen side
Lens with 5 elements in 5 groups consisting of negative 5th lens group
The second group lens and the fourth group lens are each
Both are plastic lenses of the same shape and the same material
In addition, the second lens group to the fourth lens group are
Symmetrical arrangement centered on the group lens, and the first group
The lens has aspherical surfaces on both sides, and the second and fourth lens units are
Is a lens including at least one aspherical surface.
(1) 0.03 < | F₂/ F₁｜ <0.6 (2) 1.0 < f₃/ F <1.4 (3) D₂/ F <0.07 (4) 2 < E₁/ D₁<4 where  f ; Synthetic focal length of whole system  f_i; Focal length of group i lens  D₁; Center thickness of the first lens group  D₂; On-axis lens spacing between the first and second lens groups  E₁The projection lens was constructed so as to satisfy the condition of the surface distance at the maximum ray height of the first lens group.

[0011]

[Action] The above conditions in the present invention will be described below.
You. Condition (1) applies to large-diameter lenses like the present invention.
Two that mainly contribute to correction of spherical aberration and coma
First group lens and second group lens (fourth group lens and claim)
In the invention of item 1, the power distribution of the fifth lens group is the same).
It is a limiting condition.

The projection lens of the present invention has a large aperture in recent years,
This is a projection lens for a projector that is compact and has a wide angle of view. The first lens group (the fifth lens group) is mainly formed by the two plastic lenses of the first lens group and the second lens group including an aspherical surface. Contributes to the correction of the underline (upper line) coma aberration with respect to off-axis light, and the second lens group (fourth lens group) corrects the spherical aberration, especially as the fourth lens group, corrects the off-axis light upper line coma aberration. Contribute. ｜ f ₂ / f ₁ ｜
When becomes 0.6 or more, spherical aberration becomes over,
On the other hand | f ₂ / f ₁ | Is less than 0.03, the spherical aberration becomes under, and it becomes difficult to correct the spherical aberration in both cases, and the performance deteriorates.

[0013] Condition (2) is the most powerful of all the constituent lenses.
This is a condition for the focal length of the third group lens with strong
You.

[0014] f₃/ F When is 1.4 or more
That is, if the power of the third lens group becomes weaker,
The power of other plastic lenses must be
It becomes stronger and the aberration worsens, or the total lens length is long.
It is against the compactness, and the temperature characteristics
Also gets worse. The temperature characteristics mentioned here refer to changes in temperature.
Back focus caused by large changes in refractive index
And the deterioration of aberration. On the other hand, f₃/ F
Is less than 1.0, that is, the power of the third lens group
Sphere becomes stronger, the sphere generated by this third lens group
Surface aberration and coma increase, and aberration correction with other lenses
It will be difficult.

The condition (3) is a condition for limiting the axial lens interval between the first lens group and the second lens group.

[0016] D₂/ F Is 0.07 or more,
That is, the axial lens interval between the first lens group and the second lens group is
The longer the length, the larger the light flux expanded by the first lens group.
That is, the luminous flux diameter of the axial light incident on the second lens group is
The spherical aberration becomes large and the correction becomes difficult.

[0017] The condition (4) is that the first lens group (the fifth lens group)
Thickness) and the surface distance at the maximum ray height (lens circumference)
This is a condition that limits the ratio of (side thickness), that is, the wall thickness ratio.

[0018] The first lens group (fifth lens group) has a paraxial axis
It is a negative lens with relatively small power in the vicinity, but aspherical
By providing power to the lens periphery by
It is a lens that corrects the coma aberration of the off-axis light flux. E₁/
D₁Is 4 or more, that is, the lens thickness ratio is large
, The spherical aberration and coma will be over,
It becomes difficult to correct and processing of plastic lenses
Property, so-called moldability, deteriorates. Generally, plastic
In injection molding of lenses, this wall thickness ratio must be small
Is desired, and the lens shape will exceed this condition.
Makes it difficult to manufacture high-precision lenses, and the cost is high.
This is also a factor and is not preferable. On the other hand, E₁/ D₁Is 2
When it is below, that is, the lens thickness ratio becomes smaller
When spherical aberration and coma are under,
It will be difficult.

[0019]

【Example】 Hereinafter, Examples 1 to 5 of the invention according to claim 1 will be described.
explain. Where r is the radius of curvature of each surface of the lens, and d is
Lens thickness or lens spacing, n is refraction of e-line of each lens
Rate.

[0020] Also, the aspherical shape has the optical axis direction as the X axis.
In the orthogonal coordinate system, the vertex paraxial curvature is C and the conic constant is
K, Aspheric coefficient A_iThen, the table is shown in Equation 1 and Equation 2.
Is a rotationally symmetric aspherical surface.

[0021]

[Equation 1]

[0022]

[Equation 2]

[0023]

Embodiment 1 FIG. 1 is a lens showing the projection lens of this embodiment.
In the configuration diagram, the first group lens G₁And the fifth lens group G_FiveIs
They have the same shape and are both made of acrylic resin.
ing. In addition, the second lens group G₂And the fourth lens group G_FourWhen
Also have the same shape, both made of acrylic resin
Has been done. Third lens group G₃And the sixth lens group G₆
Is a plus of BK7 glass lens and acrylic resin
It is a tic lens. Then, the first to fifth lens groups
G₁~ G_FiveUp to the third lens group G₃Symmetric about
It is arranged. M is the sixth lens group G₆And CRT fae
A filling material made of liquid provided between the splat T and
Yes, this filler M has a low contrast due to surface reflection.
Provided for the purpose of preventing lowering and cooling of heat generated from CRT
It has been done. Instead of providing the filler M,
For example, the sixth lens group G₆CRT face plate T side
The medium may be air if the surface is flat. FIG.
(A)-(c) is each aberration figure of the projection lens of a present Example.
You.

F _NO = 1.15 f = 72 Magnification _{= -0.1 f 2 / f 1 =} 0.440 f ₃ / f = 1.19 D ₂ / f = 0.021 E ₁ / D ₁ = 2.55 r d n 1 -47.246 2.88 1.49368 Two -59.151 1.50 Three 63.412 9.00 1.49368 Four 138.883 6.50 5 85.402 23.00 1.51633 6 -83.629 8.00 7 -138.883 9.00 1.49368 8 -63.412 1.50 9 59.151 2.88 1.49368 10 47.246 30.58 11 -43.175 3.00 1.49368 12 -48.200 8.00 1.44185 (liquid) 13 -350.000 14.10 1.51633 (CRT face plate) 14 -350.000 First side Second side K 0 K 0 A ₄ 0.104136E-04 A ₄ 0.107541E-04 A ₆ 0.408716E-09 _{A 6 0.224534E-08 A 8 -0.293510E} -11 A ₈ -0.282207E-11 A ₁₀ 0.974569E-15 A ₁₀ 0.857372E-15 Third side 4th surface K 0 K 0 A ₄ -0.115632E-05 A ₄ -0.976492E-06 A ₆ 0.569059E-09 A ₆ -0.316086E-09 A ₈ 0.820709E-13 A ₈ 0.715141E-12 A ₁₀ -0.200090E-15 A ₁₀ -0.231902E-15 7th side Eighth surface K 0 K 0 A ₄ 0.976492E-06 A ₄ 0.115632E-05 A ₆ 0.316086E-09 _{A 6 -0.569059E-09 A 8 -0.715141E} -12 _{A 8 -0.820709E-13 A 10 0.231902E} -15 A ₁₀ 0.200090E-15 9th surface 10th surface K 0 K 0 A ₄ -0.107541E-04 A ₄ -0.104136E-04 A ₆ -0.224534E-08 A ₆ -0.408716E-09 A ₈ 0.282207E-11 A ₈ 0.293510E-11 A ₁₀ -0.857372E-15 A ₁₀ -0.974569E-15 11th surface 12th surface K -0.122574E + 01 K 0.190133E + 00 A ₄ -0.280911E-05 A ₄₀ A ₆ -0.105685E-08 A ₆₀ A ₈ 0.171171E-11 A ₈ 0 A ₁₀ -0.112879E-14 A10 0

[0025]

Embodiment 2 FIGS. 3A to 3C are aberration diagrams of the projection lens of this embodiment.

F _NO = 1.15 f = 72.23 Magnification _{= -0.1 f 2 / f 1 =} 0.582 f ₃ / f = 1.11 D ₂ / f = 0.037 E ₁ / D ₁ = 3.30 rd n 1 -41.761 2.47 1.49368 2 -52.483 2.68 3 77.032 9.00 1.49368 4 184.193 5.33 5 77 .864 27.00 1.516333 6 -78.652 8.00 7 -184.193 9.00 1.493688 -77.032 2.68 9 52.483 2.47 1.49368 10 41.761 30. .00 11 -50.370 3.00 1.49368 12 -48.200 8.00 1.44185 (liquid) 13 -350.000 14.10 1.51633 (CRT face plate) 14 -350.000 First side Second side K 0 K 0 A ₄ 0.112516E-04 A ₄ 0.110312E-04 A ₆ -0.350637E-09 _{A 6 0.956368E-09 A 8 -0.256154E} -11 _{A 8 -0.306231E-11 A 10 0.129368E} -14 A ₁₀ 0.131226E-14 Third side Eighth surface K 0 K 0 A ₄ -0.567376E-06 A ₄ 0.567376E-06 A ₆ 0.859149E-09 A ₆ -0.859149E-09 A ₈ -0.850993E-12 A ₈ 0.850993E-12 A ₁₀ 0.177449E-15 A ₁₀ -0.177449E-15 9th surface 10th surface K 0 K 0 A ₄ -0.110312E-04 A ₄ -0.112516E-04 A ₆ -0.956368E-09 _{A 6 0.350637E-09 A 8 0.306231E} -11 A ₈ 0.256154E-11 A ₁₀ -0.131226E-14 A ₁₀ -0.129368E-14 11th surface 12th surface K 0.573241E + 00 K 0.242159E + 00 A ₄ -0.330274E-05 A ₄ 0 A ₆ 0.452280E-08 A ₆ 0 A ₈ -0.341917E-11 A ₈₀ A ₁₀ 0.938636E-15 A ₁₀₀

[0027]

Example 3 4A to 4C are projection lenses of this embodiment.
FIG. 7 is a diagram illustrating each aberration of S.

F _NO = 1.12 f = 86.93 Magnification _{= -0.1 f 2 / f 1 =} 0.340 f ₃ / f = 1.27 D ₂ / f = 0.058 E ₁ / D ₁ = 3.85 rd n 1 -49.862 2.44 1.49368 2 -58.799 5.00 3 78.536 9.00 1.49368 4 170.877 7.50 5 111.217 28.00 1.5163336 -107.130 9.60 7 -170.877 9.00 1.00 43968 8 -78.536 5.20 9 58.799 2.44 1.49368 10 49.862 37.97 11 -60.973 3. 00 1.49368 12 -57.840 12.00 1.44185 (liquid) 13 -350.000 14.10 1.51633 (CRT face plate) 14 -350.000 First side Second side K 0 K 0 A ₄ 0.773189E-05 A ₄ 0.790306E-05 A ₆ -0.325927E-09 A ₆ 0.888739E-10 A ₈ -0.825162E-12 _{A 8 -0.825455E-12 A 10 0.286335E} -15 A ₁₀ 0.275969E-15 Third side 4th surface K 0 K 0 A ₄ -0.340034E-06 A ₄ -0.263603E-06 A ₆ 0.117741E-09 A ₆ 0.229125E-10 A ₈ -0.473105E-13 A ₈ 0.359616E-13 A ₁₀ 0.185531E-17 A ₁₀ -0.595138E-17 7th side Eighth surface K 0 K 0 A ₄ 0.263603E-06 A ₄ 0.340034E-06 A ₆ -0.229125E-10 _{A 6 -0.117741E-09 A 8 -0.359616E} -13 A ₈ 0.473105E-13 A ₁₀ 0.595138E-17 A ₁₀ -0.185531E-17 9th surface 10th surface K 0 K 0 A ₄ -0.790306E-05 A ₄ -0.773189E-05 A ₆ -0.888739E-10 _{A 6 0.325927E-09 A 8 0.825455E} -12 A ₈ 0.825162E-12 A ₁₀ -0.275969E-15 A ₁₀ -0.286335E-15 11th surface 12th surface K 0.490315E + 00 K -0.189142E-01 A ₄ -0.135388E-05 A ₄ 0 A ₆ 0.127895E-08 A ₆₀ A ₈ -0.670598E-12 A ₈ 0 A ₁₀ 0.142500E-15 A ₁₀₀

[0029]

Embodiment 4 FIG. 5 is a lens showing the projection lens of this embodiment.
In the configuration diagram, the first group lens G₁And the fifth lens group G_FiveIs
They have the same shape and are both made of acrylic resin.
ing. In addition, the second lens group G₂And the fourth lens group G_FourWhen
Also have the same shape, both made of acrylic resin
Has been done. Third lens group G₃And the sixth lens group G₆
Is a plus of BK7 glass lens and acrylic resin
It is a tic lens. Then, the first to fifth lens groups
G₁~ G_FiveUp to the third lens group G₃Symmetric about
It is arranged. 6A to 6C are projections of this embodiment.
It is each aberration figure of a lens.

F _NO = 1.12 f = 85.91 Magnification _{= -0.1 f 2 / f 1 =} 0.046 f ₃ / f = 1.15 D ₂ / f = 0.040 _{E 1 / D 1 = 2.073 r} d n 1 -54.558 4.36 1.49368 2 -56.625 3.43 3 61.581 9.00 1.49368 4 80.293 5.35 5 98 0.089 28.30 1.516333 6 -96.466 9.60 7 -80.293 9.00 1.49368 8 -61.581 3.41 9 56.625 4.36 1.49368 10 54.5558 34 .99 11 −43.114 3.00 1.49368 12 −45.017 12.00 1.44185 (liquid) 13 ∞ 14.10 1.51633 (CRT face plate) 14 ∞ First side Second side K 0 K 0 A ₄ 0.457812E-05 A ₄ 0.563548E-05 A ₆ 0.233838E-08 _{A 6 0.242488E-08 A 8 -0.150669E} -11 _{A 8 -0.116131E-11 A 10 0.262942E} -15 A ₁₀ 0.273798E-15 Third side 4th surface K 0 K 0 A ₄ -0.145107E-05 A ₄ -0.223396E-05 A ₈ 0.723499E-13 A ₈ -0.693895E-13 A ₁₀ -0.150023E-15 A ₁₀ -0.104407E-15 7th side Eighth surface K 0 K 0 A ₄ 0.223396E-05 A ₄ 0.145107E-05 A ₆ -0.753736E-09 A ₆ -0.249198E-09 A ₈ 0.693895E-13 _{A 8 -0.723499E-13 A 10 0.104407E} -15 A ₁₀ 0.1500023E-15 9th surface 10th surface K 0 K 0 A ₄ -0.563548E-05 A ₄ -0.457812E-05 A ₆ -0.242448E-08 A ₆ -0.233838E-08 A ₈ 0.116131E-11 A ₈ 0.150669E-11 A ₁₀ -0.273798E-15 A ₁₀ -0.262942E-15 11th surface 12th surface K 0.201919E-01 K -0.100000E + 00 A ₄ -0.230718E-05 A ₄ 0 A ₆ 0.374625E-08 A ₆ 0 A ₈ -0.241349E-11 A ₈₀ A ₁₀ 0.641452E-15 A ₁₀₀

[0031]

Example 5 7A to 7C are projection lenses of this embodiment.
FIG. 7 is a diagram illustrating each aberration of S.

F_NO= 1.12 f = 85.66 Magnification = -0.1 f₂/ F₁= 0.323 f₃/ F = 1.18 D₂/ F = 0.055 E₁/ D₁= 2.13 rdn 1 −50.28 2.50 1.493682 −57.236 4.67 3 73.564 9.00 1.49368 4 116.238 4.21 5 98.971 32.00 1.516333 -98.420 9.60 7 -116.238 9.00 1.49368 8 -73.564 4.67 9 57.236 5.50 1.49368 10 50.282 33.48 11 -50 .135 15.00 1.49368 12 ∞ 14.10 1.51633 (CRT face plate) 13 ∞  First side Second side K 0 K 0 A_Four0.508341E-05 A_Four0.568487E-05 A₆0.148481E-08 A₆0.178970E-08 A₈-0.134567E-11 A₈-0.133563E-11 A_Ten0.342177E-15 A_Ten0.367078E-15  Third side 4th surface K 0 K 0 A_Four-0.922801E-06 A_Four-0.155550E-05 A₆0.247224E-09 A₆0.656939E-09 A₈0.862530E-14 A₈-0.604272E-13 A_Ten-0.942701E-16 A_Ten-0.793691E-16  7th side Eighth surface K 0 K 0 A_Four0.155950E-05 A_Four0.922801E-06 A₆-0.656939E-09 A₆-0.247224E-09 A₈0.604272E-13 A₈-0.862530E-14 A_Ten0.793691E-16 A_Ten0.942701E-16  9th surface 10th surface K 0 K 0 A_Four-0.568487E-05 A_Four-0.508341E-05 A₆-0.178970E-08 A₆-0.148481E-08 A₈0.133563E-11 A₈0.134567E-11 A_Ten-0.367078E-15 A_Ten-0.342177E-15  11th surface K 0.354429E + 00 A_Four-0.213021E-05 A₆0.286991E-08 A₈-0.191075E-11 A_Ten0.504101E-15

[0033] Hereinafter, Examples 6 to 1 of the invention according to claim 2
0 will be described. Where r is the radius of curvature of each surface of the lens,
d is the lens thickness or lens spacing, n is the e-line of each lens
Is the refractive index.

[0034] Also, the aspherical shape has the optical axis direction as the X axis.
In the orthogonal coordinate system, the vertex paraxial curvature is C and the conic constant is
K, Aspheric coefficient A_iThen, the table is shown in Equation 3 and Equation 4.
Is a rotationally symmetric aspherical surface.

[0035]

(Equation 3)

[0036]

[Equation 4]

[0037]

Sixth Embodiment FIG. 8 is a lens showing a projection lens of this embodiment.
In the configuration diagram, the first group lens G₁Is made of acrylic resin
Has been established. In addition, the second lens group G₂And fourth group lens
G_FourBoth have the same shape, and both are made of acrylic resin.
Are formed. Third lens group G₃And the fifth lens group
SUZ G_FiveOf BK7 glass lens and acrylic resin
It is a plastic lens. And the second to fourth groups
Lens G₂~ G_FourUp to the third lens group G₃Centered on
Are arranged symmetrically. M is the fifth lens group G_FiveAnd CRT
A liquid filled between the face plate T and the face plate T.
This is a filler, and this filler M is a contra
Purposes such as prevention of strike drop and cooling of heat generated from CRT
It was installed in. Instead of providing the filler M,
For example, the fifth lens group G_FiveCRT face play
If the surface on the T side is flat, the medium may be air.
Figure 9 (A)-(c) is each aberration figure of the projection lens of a present Example.
Is.

F _NO = 0.98 f = 77.44 Magnification _{= -0.1 | f 2 / f 1} | = 0.52 f ₃ / f = 1.27 D ₂ / f = 0.003 E ₁ / D ₁ = 3.64 rd n 1 -52.16 2.70 1.494 2 -67.42 0.20 1.000 3 86.74 8.20 1.494 4 263.20 8.31 1.000 5 95.76 27 .00 1.516 6 −98.60 16.60 1.000 7 −263.20 8.20 1.494 8 −86.74 35.98 1.000 9 −50.90 3.00 1.494 10 -53.50 10.00 1.440 (liquid) 11 ∞ 13.00 1.560 (CRT face plate) 12 -350.00 First side Second side K 0 K 0 A ₃₀ A ₃ 0.1851E-04 A ₄ 0.5907E-05 A ₄ 0.7882E-05 A ₅ 0 A ₅ -0.4486E-06 A ₆ -0.7798E-09 A ₆ 0.2779E-07 A ₇₀ A ₇ -0.8364E-09 A ₈ -0.1071E-12 A ₈ 0.1017E-10 A ₉₀ A ₉₀ A ₁₀ 0.8477E-16 A ₁₀ -0.6485E-15 Third side Fourth side K 0 K 0 A ₃₀ A ₃₀ A ₄ -0.1964E-06 A ₄ 0.4589E-06 A ₅ 0 A ₅ 0 A ₆ 0.4046E-10 A ₆ -0.1216E-09 A ₇₀ A ₇₀ A ₈ -0.3100E-12 A ₈ -0.2086E-12 A ₉₀ A ₉₀ A ₁₀ -0.1443E-16 A ₁₀ -0.1763E-16 7th side Eighth surface K 0 K 0 A ₃₀ A ₃₀ A ₄ -0.4589E-06 A ₄ 0.1964E-06 A ₅ 0 A ₅ 0 A ₆ 0.1216E-09 A ₆ -0.4046E-10 A ₇₀ A ₇₀ A ₈ 0.2086E-12 A ₈ 0.3100E-12 A ₉₀ A ₉₀ A ₁₀ 0.1763E-16 A ₁₀ 0.1443E-16 9th surface Surface 10 K 0.2668 K 0.2668 A ₃₀ A ₃₀ A ₄ -0.3224E-05 A ₄ -0.2673E-05 A ₅ 0 A ₅ 0 A ₆ 0.1453E-08 A ₆ 0.1623E-08 A ₇₀ A ₇₀ A ₈ -0.4666E-12 A ₈ -0.7558E-12 A ₉₀ A ₉₀ A ₁₀ -0.2333E-16 A ₁₀ 0.1067E-15

[0039]

Embodiment 7 FIGS. 10A to 10C are projection projections of this embodiment.
It is each aberration figure of lens.

F_NO= 1.0 f = 78.39 Magnification = -0.1 | f₂/ F₁| = 0.41 f₃/ F = 1.44 D₂/ F = 0.003 E₁/ D₁= 2.40 rdn 1 −51.85 5.00 1.494 2 −64.96 0.30 1.000 3 79.46 8.56 1.494 4 222.00 7.13 1.000 5 111.23 27.00 1.516 6 -111.23 12.77 1.000 7 -222.00 8.56 1.494 8 -79.46 40.69 1.000 9 -58.92 3.00 1.494 10 −58.00 10.00 1.440 (liquid) 11 ∞ 13.00 1.560 (CRT face plate) 12 −350.00  First side Second side  K 0 K 0  A₃-0.1522E-03 A₃-0.8311E-04  A_Four0.1875E-04 A_Four0.1197E-04  A_Five-0.6976E-06 A_Five-0.3780E-06  A₆0.1718E-07 A₆0.8085E-08  A₇-0.1476E-09 A₇0.3092E-10  A₈-0.9585E-12 A₈-0.2827E-11  A₉0 A₉0  A_Ten0.3251E-15 A_Ten0.4570E-15  Third side Eighth surface  K 0 K 0  A_Four-0.6672E-06 A_Four0.6672E-06  A₆0.3683E-09 A₆-0.3683E-09  A₈-0.2578E-12 A₈0.2578E-12  A_Ten0.5576E-16 A_Ten-0.5576E-16  9th surface Surface 10  K 0.2668 K 0.2668  A_Four-0.3882E-05 A_Four-0.2673E-05  A₆0.1105E-08 A₆0.1623E-08  A₈-0.2497E-12 A₈-0.7558E-12  A_Ten-0.1489E-15 A_Ten0.1067E-15

[0041]

Example 8 11A to 11C are projection projections of this embodiment.
It is each aberration figure of lens.

F_NO= 1.05 | F₂/ F₁| = 0.54 D
₂/ F = 0.052 f = 77.93 f₃/ F = 1.37 E₁/ D
₁= 2.56 Magnification = -0.1  rd n 1 -50.29 4.31 1.494 2 -67.29 4.07 1.000 3 78.66 9.00 1.494 4 226.99 6.45 1.000 5 100.30 24 .17 1.516 6 -112.64 11.40 1.000 7 -226.99 9.00 1.494 8 -78.66 40.29 1.000 9 -58.86 15.00 1.494 10. ∞ 13.00 1.560 (CRT face plate) 11 -350.00 First side Second side  K 0 K 0  A_Four0.4413E-05 A_Four0.4131E-05  A₆0.9625E-09 A₆0.1265E-08  A₈-0.9729E-12 A₈-0.1010E-11  A_Ten0.2774E-15 A_Ten0.2592E-15  Third side Fourth side  K 0 K 0  A_Four0.1445E-06 A_Four0.7886E-06  A₆-0.4329E-09 A₆-0.6261E-09  A₈0.3740E-12 A₈0.5590E-12  A_Ten-0.1329E-15 A_Ten-0.1728E-15  7th side Eighth surface K 0 K 0 A_Four-0.7886E-06 A_Four-0.1445E-06 A₆0.6261E-09 A₆0.4329E-09 A₈-0.5590E-12 A₈-0.3740E-12 A_Ten0.1728E-15 A_Ten0.1329E-15  9th surface K 0.7569 A_Four-0.3700E-05 A₆0.2014E-08 A₈-0.1268E-11 A_Ten0.2686E-15

[0043]

[Example 9] FIG. 12 is a lens showing the projection lens of this embodiment.
In the configuration diagram, the first group lens G₁Is based on acrylic resin
Has been formed. In addition, the second lens group G₂And the fourth group Ren
SUZ G_FourBoth have the same shape, and both are made of acrylic resin.
Is formed. Third lens group G₃And 5th group
G's_FiveIs a BK7 glass lens and acrylic resin
It is a plastic lens. And from the second group to the fourth
Group lens G₂~ G_FourUp to the third lens group G₃Centered around
And they are arranged symmetrically. 13 (a) to 13 (c) are actual
It is each aberration figure of the projection lens of execution example.

F_NO= 1.05 | F₂/ F₁| = 0.38 D
₂/ F = 0.006 f = 77.71 f₃/ F = 1.07 E₁/ D
₁= 2.23 Magnification = -0.1 rdn 1-51.00 3.50 1.494 2 -57.67 0.50 1.000 3 59.21 8.20 1.494 4 79.468 .31 1.000 5 78.00 29.20 1.516 6 −83.70 16.60 1.000 7 −79.46 8.20 1.494 8 −59.21 32.40 1.000 9 − 50.15 3.00 1.494 10 −53.16 10.00 1.440 (liquid) 11 ∞ 13.00 1.560 (CRT face plate) 12 −350.00 1st surface 2nd surface  K 0 K 0  A₃-0.8821E-05 A₃0.2774E-04  A_Four0.4130E-05 A_Four0.4518E-05  A_Five-0.4454E-08 A_Five-0.3827E-06  A₆0.4662E-09 A₆0.2776E-07  A₇0.4840E-11 A₇-0.8422E-09  A₈-0.1982E-12 A₈0.1079E-10  A₉0 A₉0  A_Ten0.2874E-16 A_Ten-0.7968E-15  Third side Fourth side  K 0 K 0  A_Four0.9520E-07 A_Four0.1237E-05  A₆-0.5067E-09 A₆-0.4454E-09  A₈0.4715E-13 A₈0.1228E-13  A_Ten-0.7012E-16 A_Ten-0.2238E-16  7th side Eighth surface  K 0 K 0  A_Four-0.1237E-05 A_Four-0.9520E-07  A₆0.4454E-09 A₆0.5067E-09  A₈-0.1228E-13 A₈-0.4715E-13  A_Ten0.2238E-16 A_Ten0.7012E-16  9th surface Surface 10  K 0.2668 K 0.2668  A_Four-0.6582E-06 A_Four-0.2673E-05  A₆-0.3121E-08 A₆0.1623E-08  A₈0.3266E-11 A₈-0.7558E-12  A_Ten-0.1351E-14 A_Ten0.1067E-15

[0045]

Example 10 14A to 14C are projections of this embodiment.
It is each aberration figure of a lens. F_NO= 1.0 | F₂/ F₁| = 0.01 D
₂/ F = 0.003 f = 77.42 f₃/ F = 1.30 E₁/ D
₁= 2.05 Magnification = -0.1  rd n 1 -84.92 4.00 1.494 2 -86.72 0.20 1.000 3 77.03 8.20 1.494 4 149.59 8.31 1.000 5 134.008 27 .00 1.516 6 -79.27 16.60 1.000 7 -149.59 8.20 1.494 8 -77.03 33.27 1.000 9 -49.50 3.00 1.494 10 -53.16 10.00 1.440 (liquid) 11 ∞ 13.00 1.560 (CRT face plate) 12 -350.00 1st surface 2nd surface K 0 K 0  A_Four-0.1050E-05 A₃0.2567E-04  A₆0.3132E-08 A_Four-0.6995E-06  A₈-0.7792E-12 A_Five-0.1724E-06  A_Ten-0.6978E-17 A₆0.1668E-07  A₇-0.4157E-09  A₈0.4494E-11  A₉0  A_Ten-0.2395E-15  Third side Fourth side  K 0 K 0  A_Four-0.1016E-05 A_Four-0.9739E-07  A₆0.1237E-09 A₆-0.7477E-09  A₈-0.2943E-12 A₈0.3519E-12  A_Ten-0.2928E-16 A_Ten-0.1871E-15  7th side Eighth surface  K 0 K 0  A_Four0.9739E-07 A_Four0.1016E-05  A₆0.7477E-09 A₆-0.1237E-09  A₈-0.3519E-12 A₈0.2943E-12  A_Ten0.1871E-15 A_Ten0.2928E-16  9th surface Surface 10  K 0.3 K 0.3  A_Four-0.3759E-05 A_Four-0.2673E-05  A₆0.3757E-08 A₆0.1623E-08  A₈-0.2154E-11 A₈-0.7860E-12  A_Ten0.4817E-15 A_Ten0.1070E-15

[0046]

【The invention's effect】 As described above, according to the projection lens of the present invention,
If you do so, you can cut the expensive molding die from one type to two by one type.
It is possible to reduce the cost, and the die cost can be reduced to reduce the cost.
Optical performance such as imaging performance and geometrical optical aberration
Is also good, wide angle and compact and F_NO≤1.15
Or F_NOIt becomes a bright lens of ≦ 1.1.

[Brief description of drawings]

FIG. 1 is a lens configuration diagram showing a projection lens of Example 1 of the present invention.

2A and 2B are diagrams showing the optical performance of the projection lens in Example 1 of the present invention, where FIG. 2A is a spherical aberration diagram, FIG. 2B is an astigmatism diagram,
(C) is a distortion diagram.

3A and 3B are diagrams showing the optical performance of the projection lens of Example 2 of the present invention, where FIG. 3A is a spherical aberration diagram, and FIG. 3B is an astigmatism diagram;
(C) is a distortion diagram.

FIG. 4 is a diagram showing the optical performance of the projection lens of Example 3 of the present invention, (a) is a spherical aberration diagram, (b) is an astigmatism diagram,
(C) is a distortion diagram.

FIG. 5 is a lens configuration diagram showing a projection lens of Example 4 of the present invention.

6A and 6B are diagrams showing the optical performance of the projection lens in Example 4 of the present invention, where FIG. 6A is a spherical aberration diagram, and FIG. 6B is an astigmatism diagram;
(C) is a distortion diagram.

7A and 7B are diagrams showing the optical performance of the projection lens in Example 5 of the present invention, in which FIG. 7A is a spherical aberration diagram, FIG. 7B is an astigmatism diagram,
(C) is a distortion diagram.

FIG. 8 is a lens configuration diagram showing a projection lens of Example 6 of the present invention.

FIG. 9 is a diagram showing the optical performance of the projection lens of Example 6 of the present invention, in which (a) is a spherical aberration diagram, (b) is an astigmatism diagram,
(C) is a distortion diagram.

FIG. 10 is a diagram showing the optical performance of the projection lens of Example 7 of the present invention, (a) is a spherical aberration diagram, (b) is an astigmatism diagram,
(C) is a distortion diagram.

FIG. 11 is a diagram showing the optical performance of the projection lens of Example 8 of the present invention, (a) is a spherical aberration diagram, (b) is an astigmatism diagram,
(C) is a distortion diagram.

FIG. 12 is a lens configuration diagram showing a projection lens of Example 9 of the present invention.

FIG. 13 is a diagram showing the optical performance of the projection lens of Example 9 of the present invention, (a) is a spherical aberration diagram, (b) is an astigmatism diagram,
(C) is a distortion diagram.

FIG. 14 is a diagram showing the optical performance of the projection lens of Example 10 of the present invention, (a) is a spherical aberration diagram, (b) is an astigmatism diagram, and (c) is a distortion diagram.

[Explanation of symbols]

G ₁ 1st group lens G ₂ 2nd group lens G ₃ 3rd group lens G ₄ 4th group lens G ₅ 5th group lens G ₆ 6th group lens

Claims (2)

(57) [Claims] 1. Negative first group lens in order from the screen side
, The positive second lens group, the most powerful of the constituent lenses
Positive third lens group, positive fourth lens group, negative fifth lens group
Negative with a concave surface with a strong curvature facing the lens and screen sides.
It is a lens system of a 6-group 6-lens configuration consisting of a 6-group lens,
The first lens group and the fifth lens group, and the second lens group
The fourth group lenses have the same shape and the same material.
It is a plastic lens of
From the fifth lens group to the left and right centered on the third lens group
It has a symmetrical arrangement, and the first and fifth lens groups are
Each is aspherical on both sides, and the second and fourth lens groups are
Lenses each including at least one aspherical surface, (1) 0.03 < | F₂/ F₁｜ <0.6 (2) 1.0 < f₃/ F <1.4 (3) D₂/ F <0.07 (4) 2 < E₁/ D₁<4 where  f ; Synthetic focal length of whole system  f_i; Focal length of group i lens  D₁; Center thickness of the first lens group  D₂; On-axis lens spacing between the first and second lens groups  E₁At the maximum ray height of the first lens group (fifth lens group)
A projection lens that satisfies the condition of the inter-plane distance of. (2) Negative first group lens in order from the screen side
, The positive second lens group, the most powerful of the constituent lenses
Positive third lens group, positive fourth lens group, and screen
From the negative fifth lens group with a strong concave surface facing the lens side
It is a lens system of 5 groups 5 elements,
The 4 group lenses have the same shape and the same material.
In addition to being a plastic lens, from the second lens group
Up to the fourth lens group, left and right pair centered on the third lens group
And the first lens group is aspherical on both sides.
And the second and fourth lens groups each have at least 1
A lens including an aspherical surface, (1) 0.03 < | F₂/ F₁｜ <0.6 (2) 1.0 < f₃/ F <1.4 (3) D₂/ F <0.07 (4) 2 < E₁/ D₁<4 where  f ; Synthetic focal length of whole system  f_i; Focal length of group i lens  D₁; Center thickness of the first lens group  D₂; On-axis lens spacing between the first and second lens groups  E₁A projection lens satisfying the condition of the inter-plane distance at the maximum ray height of the first lens group.