JPH01285911A - Zoom lens - Google Patents

Abstract

PURPOSE:To obtain the zoom lens which is well corrected in various aberrations, has high performance and is sufficiently reduced in size by effectively using aspherical surfaces. CONSTITUTION:This lens has a 1st aspherical surface at least on the surface near a diaphragm and the 2nd aspherical surface on the surface near the image plane of an imaging lens group and is so constituted as to satisfy the conditions expressed by equation I. In equation I, the equation of the aspherical surface is expressed as equations II, III, then (x) is the coordinates in the optical axis direction from the peak of the aspherical surface; y is the coordinate in the normal direction of the optical axis; R is the radius of paraxial curvature; a3, a4, a6... are aspherical surface coeffts.; A4 is the aspherical surface coefft. a4 at the 1st aspherical surface; B4 is the aspherical surface coefft. a4 at the 2nd aspherical surface. The zoom lens which is well corrected in the respective aberrations, has the high performance and is sufficiently reduced in size is thereby obtd.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a zoom lens, particularly a zoom lens with an angle of view of 63°.
The present invention relates to a compact zoom lens that includes a wide-angle lens and is composed of three or more lens groups.

[Conventional technology]

Conventionally, this type of lens has a positive first lens in order from the object side.
zooming is performed by moving the first, third, and fourth groups, and especially the power of the second group. JP-A-59-57213, JP-A-59-57214, etc. are known in which the structure is made more compact by increasing the strength.

In addition, the one using an aspheric surface consists of four groups: a positive first group, a negative second group, a positive third group, and a fourth group, and the power of the third group is reduced for compactness. Japanese Patent Application Laid-Open No. 178421/1983 shows an example in which the spherical aberration and astigmatism that occur at that time are corrected by an aspheric surface.

[Problem to be solved by the invention]

However, in the former case, the telephoto ratio at the wide-angle end is 3.
6, and the power of the second group has already been particularly strong, so if the power is increased to further downsize, various aberrations will deteriorate.

Furthermore, in the latter case, various aberrations such as spherical aberration and astigmatism are corrected at the same time using a single aspherical surface, so there is a limit to the correction of each aberration, so it is necessary to make it more compact. If the power of each group is increased, aberrations cannot be corrected completely.

Furthermore, since both are zoom lenses with a four-group configuration, the frame structure becomes complicated.

The present invention was made with attention to these problems, and by effectively using aspherical surfaces, it is possible to create a zoom lens that is high-performance, has all aberrations well corrected, and is sufficiently compact. The purpose is to provide.

[Failure to solve the problem]

In order to achieve the above object, the zoom lens according to the present invention has a positive first lens group, a negative second lens group, and an aperture in order from the object side, and has a positive lens group as a whole consisting of one or more lens groups. When zooming from the wide-angle side to the telephoto side, the distance between the second lens group and the second lens group increases, and the distance between the second lens group and the second lens group increases. A zoom lens in which the distance between the diaphragm and the diaphragm decreases, the zoom lens having at least a first aspherical surface on a surface near the aperture, and a second aspherical surface on a surface near the image plane of the imaging lens group, satisfying the following conditions. zoom lens.

However, the formula for the aspheric surface is χ-cy (1+f-yo1♂[15+azy2+ aa
When y' + abV6 is set as 10, ×; Coordinate y in the optical axis direction from the apex of the aspheric surface; Coordinate R in the normal direction of the optical axis; Paraxial radius of curvature 8! + 84+ aa-""---'-; Aspherical coefficient A
4i Aspherical coefficient a4B4 of the first aspherical surface; aspherical coefficient a4 of the second aspherical surface.

In addition, when a zoom lens has a four-group configuration, from the object side the positive 11th lens group, the negative second lens group, the positive third lens group, the diaphragm, and the positive fourth lens group. When zooming from the wide-angle side to the telephoto side, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group decreases, and the distance between the third lens group and the third lens group increases. A zoom lens in which the distance between the fourth lens group is reduced, the fourth lens group having at least one aspherical surface, and satisfying the following conditions.

0.1 xlO-'<IC41< 0.1
xlO"' -+21 However, the formula of the aspheric surface is
84V”a 6y 6 +−−−−−−°゛−, then, This effect can be obtained by setting al+86'-'-''-.-; aspherical coefficient C4; aspherical coefficient 84.

Furthermore, when the zoom lens has a three-group configuration, in order from the object side, a positive first lens group, a negative second lens group, at least one biquad lens, and a lens disposed closest to the image plane. It consists of three groups: an imaging lens group having a positive meniscus lens convex to the object side, and at least one surface of the positive meniscus lens is an aspherical surface, and the positive effect weakens as the shape of the aspherical surface moves away from the optical axis. A zoom lens that has a shape that satisfies the following conditions.

0, I Xl0-'< l D4.1 <
0. I Xl0-3−−−−−−・−−−−−+3
) However, the formula of the aspheric surface is x=cy' (1+, /TTc"7 + azY2+
aay' + a 6y 6 + ----- ~ ゛, then X; Coordinate y in the optical axis direction from the apex of the aspheric surface; Coordinate R in the normal direction of the optical axis; Paraxial radius of curvature aZ+ 84t ah- ``'-'': Aspherical coefficient D4; By setting the spherical coefficient to 84, this effect can be obtained.

In the case where two aspherical surfaces are used as described above, it is more preferable that the image-side aspherical surface of the two aspherical surfaces satisfies the following conditions because astigmatism can be well corrected.

0.1 x 10-5 < l B4 i < 0.
１ It is important to carry out the distribution, especially in order to obtain a compact lens system (J, hereafter
It is preferable to satisfy the condition O--.

0, 4 < f * w / f u < 0
, 8 −−−−−−−−−−−−−−−−−−−−−−−
(510,15<ett/fw<0.75-----
−−−−−(6) However, 9 is the focal length of the entire system at the wide-angle end +
flll+1 is the focal length at the wide-angle end of the imaging lens group (in the case of a 4-group zoom lens, the composite group of the 3rd and 4th groups corresponds, and in the case of a 3-group zoom lens, the 3rd group corresponds), and eZT is the focal length at the telephoto end. is the distance between the rear principal point of the second group and the front principal point of the imaging lens group.

Further, when the first lens group is composed of a negative meniscus lens with a convex surface facing the object side, a biconvex lens, or a cemented lens thereof, and a positive meniscus lens with a convex surface facing the object side, and focusing is performed with the first lens group, Assuming that the radius of curvature of the layer image side surface of the first lens group is R, it is preferable that the following conditions are satisfied.

1.5 < R/ f t, < 3.5 ---
-------- (71 Furthermore, by making the most object side surface of the second group convex toward the object side and also making the layer image side surface convex toward the object side, the incident angle and exit of the off-axis rays to the second group By making the angle smaller, it is possible to reduce fluctuations in off-axis aberrations due to zooming.At this time, in a four-group structure, this second lens group is sequentially constructed from the object side with one negative meniscus lens convex toward the object side. concave lens.

It is more preferable to use a cemented positive lens or to include two positive lenses.

Further, by including both a positive lens and a negative lens in each lens group, chromatic aberration can be corrected well. At this time, it is preferable to use a plurality of negative lenses because the second group has a strong shield power.

In addition, due to the lens barrel configuration, if the second group, which has a strong power, is fixed during zooming, it is easier to achieve stable performance. Furthermore, if the first group and the fourth group are used as a body for zooming, the lens barrel structure can be simplified.

[For production]

Next, the effects of the conditions (11 to (6)) will be explained.

When considering correcting astigmatism using an aspherical surface, it is desirable to arrange the aspherical surface as close as possible to the image plane than the aperture. However, since the aspherical surface also changes the spherical aberration, if the astigmatism is simply corrected using the aspherical surface, the spherical aberration will worsen. Furthermore, in consideration of reducing the diameter of the lens on the image side of the lens system, it is desirable to bring the exit pupil closer to the image plane. However, if the aperture is brought closer to the image plane for this reason, the ability to correct astigmatism becomes weaker and the change in spherical aberration increases. Spherical aberration worsens. Since the spherical aberrations generated by the aspherical surfaces as described above include higher-order aberrations, it is difficult to correct them using a spherical system.

Now, when an aspherical surface is placed near the aperture, as described above, the variation in astigmatism becomes small and the variation in spherical aberration becomes large. Therefore, if an aspherical surface for correcting spherical aberration is provided here in addition to the aspherical surface for correcting astigmatism mentioned above,
It is possible to correct spherical aberration including the above-mentioned higher-order aberrations without affecting astigmatism.

Considering the above points, an aspherical surface is placed near the image plane mainly for astigmatism correction, and an aspherical surface is placed near the aperture stop mainly for spherical aberration correction including the spherical aberration that occurs here. The above-mentioned condition (1) is a condition for properly correcting each aberration by appropriately combining these two aspheric surfaces. If the upper limit of this condition is exceeded, the spherical aberration caused by the aspherical surface on the image side cannot be corrected by the aspherical surface on the aperture side. If the lower limit is exceeded, spherical aberration on the aspherical surface on the aperture side becomes excessive.

Next, to explain condition (2), this means that when a zoom lens has a four-group configuration, by appropriately using aspherical surfaces, the overall length can be shortened and compacted by at least one aspherical surface, and each aberration can be reduced. This is a condition for good correction. This condition is based on the fact that by using an aspherical surface near the image plane of the fourth group, the light beams at each image height tend to separate, the angle of incidence on the aspherical surface increases, and the axial ray height increases. This is to take advantage of the fact that the aberration is lower and to effectively correct coma aberration and astigmatism while reducing the influence on spherical aberration.

If the upper limit of this condition is exceeded, coma aberration and astigmatism will be overcorrected, and axial rays will also be affected, resulting in a decrease in spherical aberration. If the lower limit is exceeded, the effect of the aspheric surface becomes too weak, making it difficult to correct aberrations.

Note that even when using the two aspherical surfaces described above, the action of the aspherical surface on the image side has many surfaces that are common to the explanation of condition (2) above, and therefore, by satisfying the condition (4) above, Astigmatism can be better corrected. If the upper limit of this condition is exceeded, astigmatism and spherical aberration will be overcorrected. If the lower limit is exceeded, both will be under-corrected.

Furthermore, condition (3) is a conditional expression regarding the shape of the aspheric surface provided on the image side when the zoom lens has a three-group configuration. The conditional expression itself is the same as condition (2), and furthermore,
The same goes for the tendency to exceed the lower limit. However, if the imaging lens group is
Since it is composed of a lens group, if the field curvature generated in this imaging lens group is corrected by this aspheric surface, spherical aberration and:
Since one muff flare cannot be completely corrected, this is corrected by providing a biconcave lens in the imaging lens group. Further, as with the fourth group, it is also possible to further provide an aspherical surface near the diaphragm for correction.

Now, as mentioned above, conditions (5) and (6) are conditions for determining a perfect power distribution, and if both exceed the upper limit, the overall length of the lens becomes longer and compactness cannot be achieved.

If the lower limit is exceeded, the power of each BY becomes too strong, and it becomes difficult to correct each aberration even if the above-mentioned aspherical surface is used.

Condition (7) is a condition for obtaining better performance in consideration of focusing as described above. When the upper limit is exceeded, fluctuations in distortion due to zooming become large.

If the lower limit is exceeded, the spherical aberration will fluctuate greatly during focusing, making it difficult to align good image positions at the center and periphery.

〔Example〕

Examples 1 and 2.4 have a four-group configuration of positive, negative, positive, and positive, as shown in the cross-sectional view of the wide-angle end in Fig. 1 and the telephoto end in Fig. 2.
This is a zoom lens that uses two aspherical surfaces. Example 3.5
As shown in FIG. 3, which is a cross-sectional view at the wide-angle end, this zoom lens has the same four-group configuration of positive, negative, positive, and positive as described above, and uses two aspheric surfaces. In Examples 1 to 5, the aspheric surfaces are provided on the image side surface of the lens of the third lens group closest to the image side and on the object side surface of the lens of the fourth lens group closest to the image side near the aperture stop.

Embodiment 6 is a zoom lens having a three-group configuration of positive, negative, and positive, as shown in cross-sectional views at the wide-angle end in FIG. 4 and at the telephoto end in FIG. 5, and using two aspheric surfaces.

Embodiment 7 is a zoom lens, as shown in FIG. 6, which is a cross-sectional view at the wide-angle end, and has a three-group structure of pressure, negative, and positive lenses, and uses two aspheric surfaces, as in Embodiment 6. In these embodiments 6 and 7, the aspherical surfaces are provided on the object side of the lens closest to the object side of the third lens group and on the image side of the lens closest to the image side of the third lens group near the aperture stop.

Examples 8 and 10 are zoom lenses having a positive, negative, positive, and positive four-group configuration, as shown in cross-sectional views at the wide-angle end in FIGS. 7 and 9, respectively, and using one aspheric surface.

In these Examples 8 and 10, the aspheric surface is provided on the object side of the lens closest to the image side of the fourth lens group. Example 9 is Example 8 and 10 as shown in FIG. 8, which is a cross-sectional view at the wide-angle end.
It is a zoom lens that uses one aspherical surface and has a four-group configuration (pressure, negative, positive, positive). Here, the aspherical surface is provided on the image side surface of the lens closest to the image side of the fourth lens group. Example II, 1
2 is Example 1 as shown in FIG. 10, which is a cross-sectional view at the wide-angle end.
Like the 0, it is a zoom lens with a three-group configuration of pressure, negative, and positive groups, and one aspherical surface. Here, the aspherical surface is provided on the image side surface of the positive meniscus lens, which is the lens closest to the image side of the third lens group.

Numerical data for each example is shown below.

Example I f=35.9+u+~101.0mm, F/3.57~
4.852ω-62,0°~24.2°r,, 291.13679 d+=2.5000 n+・1.80518 ν,
=25.43rz= 67.6668 d2=6.8000 nz=1.65160 1
'2=58.52rs=-173,7374 d3・0.2000 r4・39.1397 d4゜4.3000 r+3=1.65160 1
' -=58.52rs=94.3469 d,・(variable) rb=361.1701 cL=1.7293 n4=1.77250
v -=49.66rf=22.8024 d7・4.8000 r8・−32°6627 ds=1.7000 n5=1.74100
v,=52.68r9. 27.9925 dql=0.5000 r+o= 28.1629 c+,,=4.2000 na=1.80518
v , =25.43r,,, -46,7666 d++-1,4000n7=1.80400 Schiff=46.57r1□-145,0476 Lz= (variable) r+*= 45.6029 d, s□ 2.4509 ne=1.56873
=63.16r+4=-99.9305 dl 4=0.4200 r+s" 38.9381 d+s=4.3500 r+q=1.48749
v 9=70.2Or, 6=-20,6778 d+b□1.2000 rzo□1.67270
ν1O=32.1 Orat·−162,4476 (aspherical surface) dl'l·i, ooo.

'I11: Aperture 6+11・ (variable) r+q=42.3383 d+q□2.240o r+++=1. ．． 6127
2 shi++=58.75r2°. -7900,61
78 dzo・0.2000 r2□・35.8796 dz+=3.400O□n, 2=1.60311 1
'1z・raO,'/0rzz=-67,9577 dzt=2.5000 r2 knee-117,6327 dz3・1.8537 r++, I=1.59551
,, =39.21rt--24,7948 dz4=3.0000 rzs=-117,2207 (aspherical surface) dzs=2.5
000 nz=1.72B25 u 14=2
8.46rt-=-126,3532 Aspherical lens data (aspherical coefficient) r+f; az=o+ a<=0.10492 X
10-5゜ab=0.56608Xl0-", a
e=-0,12893Xl0-IOa 1o=-0,2
1888X 10-'”rts: ax-0+ a
a=-0,23442X 10-'.

a6 y 0.46934 x 10-', ae=-0
,32520X 10-9ago・0.18599
Xl0-"fll fenemy Example 2 f・35.9 fl ~ 101.0 m wealth, F/3.58 ~ 4.852 ω = 62
．． 0°~24.2°r+-312,2405 dl, 2.5000 n1=1.805], 8 shi, =25.43r2= 68.8465 dz=6.8000 nz□1.65160 v
2□58.52rs=-174,8560 d3=0.2000 r i・39.7352 d4.4.4500 n5=1.65830 1'
3□57.33rs= 98.8411 d5・ (variable) r-= 383.5690 d6=1.730on,=1.77250 p
, =49.66r7=23.2093d? =4.8000 ra=-34,7608 ds=1.6000 n5=1.74100
p5=52.68r--31,2002 d9J, 9600 rIo=31.0006 d+o=4.3500 n6=1.80518
v 6=25.43r days・-42,9177 dz=1.2500 nt□1.80400 1
' ? =46.57rIt・102.9517 dth = (variable) rr! □ 38.9895 drs= 2.6000 na=1.56873
1/5=63,16rI4=-102,4423 d l4=0.2000 r+s= 41.0031 d,,=4.450On,+=1.48749 v
q=10.2Or+6=-21,8964 d+a・1.2000 r++o=1.67270
v +o=32.10rl'7・-223,143
1 (aspherical surface) d17・1.0000 r18; Aperture dllll・ (variable) r19・ 37.8825 d+q=2.5500 rz+=1.61272
ν l+=! 58.75r2゜・1311.355
8 dto・0.2000 r! I= 34.0968 dz+=3.3000 rxz=1.60311
1' +z=60.70r2□--74.9584 d2□-1,6800 rz3・-183,6979 dz:+=1.8537 r++*=1.5955
1 ν +3□39.21rz-= 22.34
95 dzn=3.0000 rZs・-100,2426 (aspherical surface) dzs=2.4
00on, a=1.72825 v +a=
28.46rg6=-126,3532 Aspheric lens data (aspheric coefficient) r+? ; a*=o, a<=0.26934 X 1
0-'.

a6=o, 64609 Xl0-”, as=-0,4
4736XIO 0a1゜=-0,22335x 10
Tatami 2rts: at=o, aa□-0,24366X
10-'.

ah =-0,52701X 10-', a-=-0
, 52501X 1O-9a+a= 0.14229
×1Q-11 Example 3 f = 35.9mm ~101. Ot*, F/3
．． 56~4.852ω-62,0°~24.2°r++ 295.3209 d+=2.5000 n,=1.80518
y +=25.43r2=68.0618 dz=7.0000 n mini 1.65160
V 2・5B, 52r3=-178,5938 d3=0.2000 ra" 38.9905 da, 4.5000 n5-1.651 (io
v s, 5B, 52r5, 94.5204 d, (variable) r6 363.5847 d6=1.7293 n4=1.77250
v a=49.6Gr, 22.6581 d, =4.8000 r-=-33,2807 da=1.7000 ns□1.74]00
5 = 52.68 rq = 34.5108 d9 = 0.5000 r,, = 32.7693 d, o = 4.2000 na = 1.80518
White = 25.43r1 + = -36.6247 d,, = 1.4000 n, y = 1.80400
v, = 46.57rth = 125.9131 dl2・ (variable) r1ko・ 47.6517 dl:+□ 2.4509 na=1.5687
3 Shi! =63.16r14=-96,5400 d+a=0.4213 rl5・36.4698 d+s=4.3082 nq=1.48749
9 q□70.2Or+6=-21,1809 dl b=0.1000 rl, □-20,5037 d+t□1.200o nto=1.67270
v +a□32.10r1a=493.0274
(Aspherical surface) dls=1. ooooo.

r-9: Aperture dl, (variable) rto□40.9151 dgo, = 2.6729 n++ = 1.61272
v z=58.75rz+=-538,9577 d, l・0.2000 r2□= 31.3769 dzz=2.968on, z=1.60311
v 1z=GO, 10rz3□-65,9045 d2322.5000 rza=-77,8686 dza□1.8537 n+3□1.66998
' +z□39.27rzs424.8812 dzs=3. ooooo.

rtb・-183,3897 (aspherical surface) dza=2.5
00On+a・1.72825 νz□28.4(i
r17・-126,3532 Aspheric lens data (aspheric coefficient) rlm; az=0. an=-0,66216X10
-6゜a6=0.43521 Xl0-', ae・-
0,96779Xl0-”a +o--0.1120
8 X 10-”rzhi az=o, a4=
-0,25648×IO-'+ab=-0.47710
X 10-', as□-0, 19456X 1O
-9a+o=-0,30097X 10-"Example 4 f=36.0m1~101.Otm, P/3.62
~4.852ω-62,0°~24.2°rlm 306.6968 d+=2.5000 n1=1.80518 1'
1=25.43rt= 68.8581 dz-6,7000nz=1.65160 sig=5
8.52ra=-176.6059 d3・0.2000 r4= 39.8074 d,,, 4.6200 n==1.65830
y -=57.331J* 98.9843 d5- (variable) r6= 385.2105 da=1.7300 n4・1.77250
y −=49.66r7= 23.0232 d,=4.8000 re=−33,9586 de=1.6000 n5=1.74100
v 5 = 52.68 rq - 30,8857 dq = 0.9600 rl. = 30.8824 d lo・4.3500 na=1.80518
νa・25.43r,・−42,2395 d++□1.2500 ny=1.80400
9, =46.57r+2-106.4430 d1□-(variable) r1*= 38.1326 dl, I= 2.6000 n mini 1.5687
3 ν 6゜6:(,1,6rI 4--95.1
425 dl 4=0.2000 rl5・42.9543 d, S=4.4500 n, =1.48749
v ,,70.20r,6=-21,5600 dz,=1.2000 r++o□1.67270
ν ,,=32.1.0rlff・−223,1
585 (aspherical surface) dz, ・1.0000 "18; Aperture d+s= (variable) r+q-39,1051 054d1.5500 nz□1.61272
v z=58.75r2゜・2166.2549 d2゜・0.2000 rz+= 35.0493 dz+□3.3000 n+z=1.60311
shi+z=60.70rtz=-69.0344 d2□・1.6800 rts--1"14.3032 dzi□1.8537 n1s□1.59551
ν 1*=39.21rt4・23.1442 dz4=3. ooooo.

rz5=-100,0752 (aspherical surface) r26-426
．． 3532 Aspheric lens data (aspheric coefficient) r+7i az=o+ i14. = 0.29092
X 10-'.

ab=0.10818×10-”, ag7-0.
36492 X IQ-t.

al.・-〇, 29267 Xl0-”rzs;az=
o+ a4・-0,23987X 10-'.

a6=-0,52191XlO-', ae=-0,4
6119Xl0-98+o, 0.11852 X 10
-”Example 5 f=36.o Iris ~101.0 heavy electric, F/3.58~4
．． 852ω・62.0° ~ 24.2°rl, 252.0551 d+=2.5000 n1=1.80518
νI=25.43rz=65.1512 dz=7. oooo nz=1.65160
v z□5B, 52r3=-161,9672 d3=0.2000 r4= 37.5457 dt-4,5000ni□1.65160 νz=
58.52r5= 78.9480 d,・ (variable) r6・ 532.5586 d6=1.7293 n4=1.77250
v 4 = 49.66r f = 22.4685 dt・4.8000 r, yaw 29.7002 da = 1.7000 n, = 1.74100 1
'5=52.68rq-45,4110dt・0.5000rl. = 40.6119 d+o=4.2000 16=1.80518
νb・25.43r+ 11−−29.9067 dz=1.4000 r+v=1.80400
v, r=46.51r+2” 192.424
8 d, t- (variable) 1'+3" 40.9001 dz, = 2.4509 na = 1.56873
shi = 63.1 Cir mouth・-51,4228 dz=0.4213 r15= 46.2648 d+s=4.3082 nq-4,48749 shi,
=70.2Or, 6=-22,4313 dt6・0.5000 rl7・−19,8955 dz7=1.200Onto・1.67270 ν
+o"32.10rIo=-382,3099 (aspherical surface) d18・1.0000 rl9; aperture dt9・ (variable) r2゜・65.3181 dzo=2.6729 1'l+ +=1.6127
2 ν + , =58.75rffi1・-113
,4383 dz+-0,2000 r2□= 33.7189 dzz=2.968o n+z=1.60311
1' +2=60.70rzs=-71,5852 d2z=2.5000 rzs=-114,3990 dzn・1.8537 n+i=1.66998
11 +z=39.27rts-25,0369 dzs=3.0000 r26=-313,9246 (aspherical surface) dza=2.5
00o r++4=1.72825 1' +4
=28.46r27--126.3532 Aspherical lens data (aspherical coefficient) r+e; at=0. an--0,2721,7Xl
O-5+a6=o, 50299 x 10-',
a,=-0,18210x 1O-9alO=-0,5
0016X 10-”rzb: a2=0.an--
0,18698X 10-'.

ab=0.12978×10-7. aa=-0
,90959X Io-'a+o=0.32874
X 10-” Example 6 f=36.3m~102.0m, F/3.50
-4.842ω= 61.6°~24,0°rl= 393.7230 d+=2.5500 rx=1.8051B y
+=25.43r2= 77.2250 dz4.0100 nz=1.6031L z□
60.7゜r3・-118,4586 d3-0゜1000 r, = 40.5790 d,,, 4.250On*=1.69680
v, = 55.52r, 78.3661 d, - (variable) rb-174,9416 da-1,3000n4 = 1.80610 v,
, =40.95r7=20.1043 dt=4.8000 re--61,2914 da=1.1000 n5=1.83481
v s・42.72r,,66.7247 dq-0,3600 r,,-32,6794 M. Deception 3.7900 n6=1.80518
Shiro・25.43rl +--38,1815 dl l=L! 5'7o.

rth = -24,4385 d,, = 1.000On, = 1.80400
shi, =46.57r+3=-231.5781 dls-(variable) r,4; aperture d+a=1.1000 r,s=25.0368 (aspherical) d,,=2.
410On,=],65016y,=39.3
9r1b=-908,3515 dl b=0.1000 TI7= 19.9465 d+t=2.7600 119=1.65830
Shi9=57.33r+ 5=-264,0968 d Iso, 1200 r+v=724.5317 dl, □6.700 Onto=1.80518 Shi,, =25.43r2゜・13.5026 d2゜・2.1000 rzl =-63,3761 d,, =2.2800 nz=1.60311
,,=60.70r2□--35.4653 d2□-0,8600 rz*= 24.2857 dz3,3', 290Or++z=1.53172
ν, □, 48.90rta= 63.0831 (
Aspherical surface) Aspherical lens data (aspherical coefficient) rls; at=o, a4□-0,88864X 1
0-5゜a6=-0, 20553X10-', aa=-
0.16039 Xl0-”.

aIo=0.36641X10-” rtal at=0. aa=o, 11255 x 1
0-'.

a68-0.10349 X 10-7. ae=-
0,46647X 10” 'o.

a+o, -0,31622X10-” f 9 f11 Example 7 r= 36.3mm~102.Oxs, F/3.5
0-4.852ω・61.6°~24.0°r yi・-351,1978 d,, 2.5500 n,=1.80518 v
, =25.43d, -7,010On, =1.6031
1 ν 2=60.70r3=-155,4196 d,=0.1000 r4= 49.8532 L= 4.2500 r++□1.6968
0 9 :I=55.52rs=272.3
135 d,・(variable) rb=202.5582 d6=1.300on,=1.80610
v 4 = 40.95 r7 = 18.6630 d, = 4.8000 r, = -123,1804 d8 = 1.100 On, = 1.8348] v ,
=42.72rq-65,1293 d, =0.3600 rl+1・28.4356 d, a=5. (iooOna=1.80518 1'
6" 25.43rd rth = -40,4334 d, I = 1.5700 r + z = -27,4208 d + t - 1,0000 n7 = 1.80400 Schiff = 46.51r + 3" 1198.1331 d1 co = (variable) r14; Aperture dz=1. Iooo rls-15,5915 (aspherical surface) d+s1.1000 ne=1.65016
L'a=39.39r+-□-81,3885 d+ b-0,1000 r+7= 37.3048 d+tJ, 4000 n, =1.65830
p q=51.33r+ a=-68,3920 dIll・0.1200 r19・-76,1286 d+q#4.500o n+o=1.80518
1' +o=25.43rta=11.4644 dto=2.1000 r,,=15.7645 dz+=3.2900 nz=1.53172
νz=48.90r2□-51,3460 (aspherical surface) Aspherical lens data (aspherical coefficient) r+s+ 81・0. an=-0,25760X 10
-'+aa=-0.10071 X 1.0-6. a
s=-0,24203X 10-9°a,.・0.21
849 x 10-' ”rBi az=o+ am
= 0.39273 x 10-'.

ab=0.11228×10-”, an=-0
,54087X 10-9゜alo=-0,31204
X 10-”A41 Example 8 f=36.0mm~101.0**, F/3.
55~4.852ω-62,0'~2i,2゜r, = 302.6384 =42-1d, =2.1578 n1=1.76182
ν,=26.52j2=49.5172 d,・0.0019 r*=48.3934 d3=7.4999 n24.66672
νz・48.32r4=-178,2271 d,, 0.2028 r511 37.1977 ds= 4.4000 r++=1.65160
1' = □58.52r6゜ 83.5369 d6・ (variable) r,・ 287.6988 dq□1.1680 n4=1.6400
v 4=60.09r8・21.8080 d,=5.0029 rv=-38,0524 a,=2.4000 ns□1.80518
1' 5=25.43rth=-18,4836 d+o=1.1707 ni,=1.72916
shi, =54.68rll-39,0369 dll・1.9989 rl== 26.1346 d+z= 2.4000 117=1.80518
1'7=25.41rlff" 29.7372 dl,・ (variable) r1s=98.'1)06 dl4= 2.4509 ns・], 56873
ν,,=(i3.16r1s=-64,5651 dis・0.2870 r+1.-21.7173 d, b=4.500on,=1.48149
v, =70.2Or+7・-24,0000 dl7=1.3000 nlo□], 72000
shi,o=/13.7Or+a" 236.2274 d,,-1,oooO r19; Aperture dl9゜(variable) r2゜= 28.6431 dzo=2.'120Or+++=1.56873
Shiz□63. Hirz+-1066,5050 dt+=0.2000 r2□= 49.1304 dgz=3.2097 n+z=1.62041
1' +2=60.27rzz--101,,439
6 dts=2.5000 rz4--594.4244 dt4=1.8476 r+++=1.6644
6 shi, 3=35.81r2s=28.377
9 (hs・1.6246 rt== 457.2996 (aspherical surface) dza=2.
5000 r++a=1.72B25 y +a
=28.46rz, = Lens 3.8581 Aspherical lens data (aspherical coefficient) red; ax=0+ am・-0, 33217Xl0-
'.

ah"-0°10545 X 10-6. aa=-0
,25371X 10-9゜a+o=-0,12G35
X 10-” Example 9 r=36.Om++~102.O weight, F/3.
68~4.822ω=62.0°~24.0°r+= 181.7590 d1=2.0000 n1=1.78470 shi,
=26.22r2・45.9183 dz=7.0000 nz=1.72600 νg
□53.5(ir3・-627,4269 d, = 0.2000 r, = 37.9932 da-4,0000n3=1.72000 1/ a=
50.25r5= 87.8571 d, = (variable) r6= 1261.1377 d6=1.2000 n4=1.78590 ν,
=44.18-46=ry=18.0110 d,・5.0000 ra=−33,4090 de・2. oooo n5=1.80518
v s□25.43r9=-20,9855 d,=1.2000 rl. ,, -20,4225 d1o=1.2000 na□1.77250
1/ a=49.66rth=24.5290 d+ +=2.5000 n7=1.80518
v 7=25.43r1□・76.8874 d+t=1.5000 r+i・38.0892 d+i=2.0000 na=1.69895
1/ e=30.12r14・85.9796 d+4・(variable) rl8・42.7340 d+s=2.500On,=1.51633 y
9=64.15r16・-63,4158 d+640.2000 d+7=4.5000 r++o=1.51633
1/ +oJ4. ]5r1a=-19.6426 d+a=1.3000 nz=1.6B250
νz"44.65r+q= 206.3415 d19= 0.5000 r2°; Aperture d2o= (variable) r21= 112.0861 dz+-3,000On+z=], 52249 1g□59.79rt2=-32,4239 dz z- 0,2000 r2ff= 27.6866 dz:+-7,0000r++x=1.51633
ν+z2[i4.15rza・-22,8333 dza・2.000On+a=1.80440 1
1 +4□39.58rzs=33.6584 (Aspherical surface) Aspherical lens data (aspherical coefficient) r□; at, 0. aa=0.27831X
10-'.

ab=0.29941X10-', aa=-0
,38690X 1O-I08+o=-0,13006
X 10-"-f- Example 10 f 36.On~101.0 Iris weight, F/3.68~
4.832ω = 62.0° ~ 24.2° r1 = 278.0571 d+ = 2.2109 r++ = 1.80518 p
+=25.43r2・64.2523 dz=7.3000 nz=1.61405 p
t・54.95r:+=-145.3627 d, :0.2028 r4= 33.9610 d4- 4.4000 nz=], 65]60
1/3=58.52r5=73.4447 d,・(variable) r6=227.2921 d-=1.168On==1.64000 shi,=60.09r7° 16.8484 dt=4.9951 ra= -36,9833 dll=2.4551 n5=1.846(i6
Shi! , =23.78rq=-24.1831d, =1. oooO r+o=-21,2347 dz+=1.1707 n6=1.72916
Si v = 54.6Or,, = 48.3081 d,, = 0.4884 r, 2- 29.8490 d,, = 3.0000 n mini 1.84666
Schiff=23.78r13=54.3309 d+x= (variable) r14・69.6586 d+4=2.5000 na=1.51728
She=69.56r+5=-40.4085 d+a=0.2000 rlb=23.5987 d+a=4.5000 nq=1.51728
v9=69.56r1. =-26,5000 d+t=1.300On,,=1.70154 ν
,. , 41.24rre= 118.1083 d+a=1. oooo '+9+ Aperture d19・ (variable) r2゜・32.4240 dzo□3. oooo n++=1.60311
1' z□60.70rz+□-96,68I3 dz+=0.2000 r2□= 48.7873 dzz=3.000o n+□=1.56873
し＋z□63.16ruff・968.9901 d23・2.0000 r24・−41,9955 dz4=1.9097 rxy=1.12041
ν Iz-34,12r25・27.4776 d2s・2.6164 r26. Heat 709.3440 (Aspherical surface) dz6=2
．． 600On+n=1.61293 1' 14-
37.0Or2t2-36.5500 Aspherical lens data (aspherical coefficient) rza; az=o, a4-0.1+l953X1θ
-4゜a6-0.65576 X]0-7. au-0
,15217XIO9alO・0.36986 x 1
10-12f f, 1 Example 11 f=36.3n~102. Otm, P/3.56~
4.872ω, 61.6°~24.0°r+=2157.3510 d,=2.550On+□1.80518 shi,=2
5.43r2yo77.2250dz・7. oloo nz□1.60311 +'
z・60.70r3=-97,6780 d,・0.1000 r4. = 42.1265 d4.4.2500 n5=1.69680 9-=
55.52r, ・84.5493 ds= (variable) r6・227.9828 d, = 1.300on, = 1.80610 v
, =40.95r7=19.0366 d, =4.8000 r, -59,0564 do=1. l000 n5=1.83481
C-42, F2rq=52.1969 d,=0.3600 rth-31,3963 dlo-3,7900n6"1.80518 C,=25.43r,,=-45.6222 d,・1.5700 r1□--23, lens 7 d1z= 1.0000 n7=1.80400
shi, =46.57rI-=-76,2904 d+s= (variable) r,; Aperture dz=1.1000 rIs= 39.8324 d+s,-2,4100n mini 1.65016 ν,
=39.39r16・-251,3243 d+6・0.1000 rl? = 27.1172 d, □-2! ,76oo ng=1.65830
νq□51.33r+l+= Lens. 5496 d + a = 0.1200 rl9・ 34.7864 d + q = 3.830 On + o = 1.60311 v
+o□60.70r2゜=1489.2406 d2゜-2,0400 rz+=-70,2050 d2+=6.7000 r+++=1.80518
z−25.43rtt= 18.3645 d2□・2.1000 rz*=−156,1180 dzs・2.280On+z=1.60311 ν
12=60.7゜r, -34,1925 dzg=0.8600 rzs・23.2912 dzs=3.290o n+z=1.53172
1' +:+=48.9Or2b・63.3541
(Aspherical surface) Aspherical lens disk (aspherical coefficient) r2b: a2=(L a4・0.15029 X 1
0-'.

a6・0.17717 X 10-', aa=0.
26414 X 10''"'a+o=-0,305
85X 10-” Example 12 f = 36.3mm~102.0mm F/3.
68~4.872ω-61.6°~24.0' r1=-3951,1688 d,=2.550On,=1.80518v,=
25.43r2・77°2250 dz=7.010on,=1.60311v
, =60.70rz=-99,3398 ds=0.1000 r4= 43.5530 d4.4.2500 n5=1.69680 1/
3=55.52r5・107.1875 d,・(variable) rb=lens. 2378 da=1.3000 n mini 1.80610
v ,,=40.95r7・19.6682 d7=4.8000 rs=-58,5154 ds=1.1000 n5=1.83481
5 = 42.72 rq = 49.4487 d, = 0.3600 rl. = 31.4924 d+o=3.7900 na=1.80518
White=25.43rl +=-39.8707 d,=1.5700 r+g・-22,9601 d+z□ 1.0000 n7=1.80400
1't-46,57r13・-103,9685 d13・(variable) r14: Aperture d14・1.1000 rl, = 39.7399 ~ 57- d1s=2.4100 no=1.65016
ν,=39.39r 0. =-220,6437 d+a=0.1000 f'+,=25.3782 d+t=2.7600 nq=1.65830
νq・51.33r+s= 237.5652 d+ s=0.1200 rlq= 35.4197 d+q=3.8300 r++o=1.60311
siIG=60.70r2゜=961.7115 d2゜=2.0400 rz+=-63,3939 az+=6.7000 n mini 1.80518
νz=25.43rz=-16,9825 d2□=2.1000 r23 two 58.9277 d23=2.2800 r++z81.60311
+' +z=(io, 70rzn=-31,0354 d, 4=0.8600 r2.= 24.8572 dzs=3.2900 r+++=1.53172
1/+5=48.90rth=183.997
6 (Aspherical surface) Aspherical lens data (aspherical coefficient) rtb; azJ, aa= 0.12308 X 1
0-'.

a6・0.13270 xlo-', ae=0.3
7489 Xl0-”al.=-0,29362x 1
0-" However, f; Focal length of the entire system F; ; From the object side, the refractive index of each lens is d lin + 7, ν8; From the object side, each lens' a, -5 number f, .
Focal length of the entire system at the wide-angle end f□; Focal length e 2 T of the imaging lens group at the wide-angle end; Distance R between the rear principal point of the second group and the front principal point of the imaging lens group at the telephoto end; The radius of curvature of the most image side surface of the lens group, and the aspheric surface used in the above embodiment, is x = cy” (1+, 7 + a2y2−+
It is expressed as asy4 + a6y6 →-c=-□. However, az+aa+a6+ """'-
is the aspheric coefficient.

In addition, A4; aspherical coefficient a4B4i of the first aspherical surface
Aspherical coefficient a4Ca, D4 for the second aspherical surface; aspherical coefficient 84.

〔Effect of the invention〕

As is clear from the aberration curve diagrams of the respective examples, according to the present invention, a zoom lens is provided that has a high performance in which each aberration is well corrected, and is sufficiently compact.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of the lens configuration at the wide-angle end and telephoto end of Example 1°2.4 of the present invention, and FIG. 3 is a cross-sectional view of the lens configuration at the wide-angle end of Example 3.5. , Figures 4 and 5
The figure is a cross-sectional view of the lens configuration at the wide-angle end and the telephoto end of Example 6. Figures 6.7 and 8.9 are each an example. , 8.9.1
A cross-sectional view of the lens configuration at the wide-angle end of 0, FIG. 10 is Example 1
1.12 cross-sectional views of the lens configuration at the wide-angle end, FIGS. 11 to 13, FIGS. 14 to 16, and FIGS. 17 to 19
20 to 22, and 23 to 25. Figures 26 to 28, Figures 29 to 31, and 32
Figures to 34, Figures 35 to 37, Figures 38 to 40, Figures 41 to 43, Figures 44 to 46
The figures show Examples 1 to 12 at the wide-angle end and at intermediate magnification. It is an aberration curve diagram at the telephoto end.

Claims (1)

[Claims] (1) Consisting of, in order from the object side, a positive first lens group, a negative second lens group, and an overall positive imaging lens group that has an aperture and one or more lens groups. , a zoom lens in which the distance between the first lens group and the second lens group increases and the distance between the second lens group and the imaging lens group decreases when zooming from the wide-angle side to the telephoto side, and at least the aperture A zoom lens having a first aspherical surface on a surface near the image forming lens group and a second aspherical surface on a surface near the image plane of the imaging lens group, and satisfying the following conditions. 1<|B_4|/|A_4|<100………………(1
) However, if the formula of the aspheric surface is ▲ There are mathematical formulas, chemical formulas, tables, etc. Radius of curvature a_2, a_4, a_6......; aspherical coefficient A_4; aspherical coefficient a_4B_4 in the first aspherical surface; aspherical coefficient a_4 in the second aspherical surface. (2) Consisting of a positive first lens group, a negative second lens group, a positive third lens group, an aperture, and a positive fourth lens group in order from the object side, when zooming from the wide-angle side to the telephoto side The distance between the first lens group and the second lens group increases, and the distance between the first lens group and the second lens group increases.
A zoom lens in which the distance between the lens group and the third lens group is reduced and the distance between the third lens group and the fourth lens group is reduced, the fourth lens group having at least one aspherical surface, and the following: A zoom lens that satisfies the following conditions. 0.1×10^-^4＜｜C_4｜＜0.1×10^-
＾３…………(2) However, if the formula of the aspherical surface is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, then x; coordinate in the optical axis direction from the top of the aspherical surface y; Coordinates R in the normal direction; paraxial radii of curvature a_2, a_4, a_6...; aspheric coefficient C_4; aspheric coefficient a_4. (3) Imaging that includes, in order from the object side, a positive first lens group, a negative second lens group, at least one biconcave single lens, and a positive meniscus lens that is convex on the object side and is located closest to the image plane. A zoom lens consisting of three lens groups, wherein at least one surface of the positive meniscus lens is an aspherical surface, the shape of the aspherical surface is such that the positive effect weakens as the distance from the optical axis increases, and the zoom lens satisfies the following conditions. . 0.1×10^-^4<|D_4|<0.1×10^-
＾３…………(3) However, if the formula of the aspherical surface is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, then x; coordinate in the optical axis direction from the top of the aspherical surface y; Coordinates R in the normal direction; paraxial radii of curvature a_2, a_4, a_6...; aspherical coefficient D_4; aspherical coefficient a_4.