JP6406929B2 - Eyepiece, observation device having the same, and imaging device - Google Patents

Description

  The present invention relates to an eyepiece and an observation apparatus and an imaging apparatus having the same, and is suitable for observing an image displayed on an image display element in an electronic viewfinder used in, for example, a video camera, a still camera, and a broadcast camera. Is.

  2. Description of the Related Art Conventionally, an electronic viewfinder used in an optical apparatus such as a video camera or a broadcast camera is provided with an eyepiece lens for magnifying and observing an image displayed on a liquid crystal screen provided in the camera.

  2. Description of the Related Art In recent years, electronic viewfinders that have a wide field of view and can display a large image have been demanded with the enhancement of functions of imaging devices. As a method for realizing such a demand, there are a method of enlarging an image display surface such as a liquid crystal screen and a method of increasing the observation magnification of the eyepiece.

  Here, when the image display surface is enlarged, the size of the finder is increased. Therefore, in order to reduce the size of the finder as a whole, it is preferable to increase the observation magnification of the eyepiece. In order to increase the observation magnification of the eyepiece, it is necessary to increase the positive refractive power of the eyepiece. Here, if an eyepiece lens is configured only with a lens having a positive refractive power (positive lens), many axial chromatic aberrations, lateral chromatic aberrations and the like are generated, and it is difficult to correct them. Therefore, in order to obtain a high-definition observation image while increasing the observation magnification of the eyepiece, it is preferable to configure the eyepiece using a lens having a negative refractive power (negative lens) in addition to the positive lens. Thereby, an observation image in which the longitudinal chromatic aberration and the lateral chromatic aberration are corrected well can be obtained.

  There is also a need for a finder with a long eye relief that can be used even when the user is wearing glasses.

  Patent Document 1 discloses an eyepiece lens in which a positive lens is disposed on the most image display surface side and on the most observation side (eye point side), and a plurality of negative lenses are disposed. By appropriately setting the focal length of the entire eyepiece lens system, an eyepiece lens having good telecentric characteristics on the image display surface side and having various aberrations corrected satisfactorily is achieved.

JP 2013-88632 A

  As described above, in order to realize an eyepiece having a long eye relief and a wide viewing angle, an eyepiece composed of five lenses as a whole is known, using at least one positive lens and one negative lens. ing.

  In the eyepiece of Patent Document 1, the refractive power of the lens arranged closest to the observation side is weak, and there is a possibility that the effective diameter of the eyepiece increases when the viewing angle is enlarged.

  An object of the present invention is to provide an eyepiece having a long eye relief, a wide viewing angle, and high optical performance, and an observation apparatus and an imaging apparatus having the eyepiece.

The eyepiece of the present invention is an eyepiece having five or more lenses including two or more negative refractive power lenses, the lens arranged closest to the object side and the lens arranged closest to the observation side. Are both positive refracting power, f is the focal length of the eyepiece lens, and fe is the focal length of the lens arranged closest to the observation side,
0.58 <fe / f <0.95
When the Abbe number based on the d-line of an arbitrary negative refractive power lens included in the eyepiece lens is νdn, at least two negative refractive power lenses are satisfied.
5.0 <νdn <29.2
The following conditional expression is satisfied .
Further, another eyepiece of the present invention includes a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, arranged in order from the object side to the observation side. An eyepiece composed of a fourth lens having a refractive power of 5 and a fifth lens having a positive refractive power, where f is the focal length of the eyepiece and fe is the focal length of the fifth lens.
0.58 <fe / f <0.95
The following conditional expression is satisfied.
In addition, another eyepiece of the present invention includes a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a negative refractive power, arranged in order from the object side to the observation side. An eyepiece composed of a fourth lens having a refractive power of 5 and a fifth lens having a positive refractive power, where f is the focal length of the eyepiece and fe is the focal length of the fifth lens.
0.58 <fe / f <0.95
The following conditional expression is satisfied.
In addition, another eyepiece of the present invention includes a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a negative refractive power, arranged in order from the object side to the observation side. An ocular lens composed of a fourth lens having a refractive power of 5, a fifth lens having a negative refractive power, and a sixth lens having a positive refractive power, wherein the focal length of the eyepiece is f and the focus of the sixth lens When the distance is fe,
0.58 <fe / f <0.95
The following conditional expression is satisfied.

  According to the present invention, an eyepiece having a long eye relief, a wide viewing angle, and high optical performance can be obtained.

1 is a cross-sectional view of an eyepiece lens according to Example 1 of the present invention. Each aberration diagram of the eyepiece of Example 1 of the present invention Sectional view of eyepiece of Example 2 of the present invention Each aberration diagram of the eyepiece of Example 2 of the present invention Lens cross-sectional view of the eyepiece of Example 3 of the present invention Each aberration diagram of the eyepiece of Example 3 of the present invention Lens cross section of the eyepiece of Example 4 of the present invention Each aberration diagram of the eyepiece lens of Example 4 of the present invention Lens cross section of the eyepiece of Example 5 of the present invention Each aberration diagram of the eyepiece lens of Example 5 of the present invention Lens cross section of the eyepiece of Example 6 of the present invention Each aberration diagram of the eyepiece lens of Example 6 of the present invention Lens cross section of the eyepiece of Example 7 of the present invention Each aberration diagram of the eyepiece lens of Example 7 of the present invention Schematic diagram of main parts of an imaging apparatus of the present invention Relationship between refractive power arrangement of optical system and optical path Relationship between principal point position of optical system and optical path

  Hereinafter, an eyepiece of the present invention, an observation apparatus having the same, and an imaging apparatus will be described in detail with reference to the accompanying drawings. The eyepiece of the present invention has a positive lens on the most object side (image display surface side) and the most observation side (eye point side), and has one or more negative lenses.

  Specifically, the eyepieces of Examples 1 to 4 are, in order from the object side to the observation side, a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, The lens is composed of a fourth lens having a negative refractive power and a fifth lens having a positive refractive power.

  In the eyepiece of Example 5, the first lens having a positive refractive power, the second lens having a negative refractive power, the third lens having a negative refractive power, and the fourth lens having a positive refractive power are sequentially arranged from the object side to the observation side. The lens is composed of a fifth lens having a positive refractive power.

  In the eyepiece of Example 6, the first lens having a positive refractive power, the second lens having a positive refractive power, the third lens having a negative refractive power, and the fourth lens having a negative refractive power are sequentially arranged from the object side to the observation side. The lens is composed of a fifth lens having a positive refractive power.

  In the eyepiece of Example 7, the first lens having a positive refractive power, the second lens having a negative refractive power, the third lens having a negative refractive power, and the fourth lens having a positive refractive power are sequentially arranged from the object side to the observation side. The lens includes a fifth lens having a negative refractive power and a sixth lens having a positive refractive power.

  FIG. 1 is a lens cross-sectional view when the diopter of the eyepiece of Example 1 is −2.0 diopter (reference state), 2.5 diopter, and −6.0 diopter. FIG. 2 is an aberration diagram of the eyepiece of Example 1 in the reference state. FIG. 3 is a lens cross-sectional view when the diopter of the eyepiece of Example 2 is −2.0 diopter (reference state), 0.7 diopter, and −3.3 diopter. FIG. 4 is an aberration diagram of the eyepiece of Example 2 in the reference state.

  FIG. 5 is a lens cross-sectional view when the diopter of the eyepiece of Example 3 is −2.0 diopter (reference state), 2.0 diopter, and −4.0 diopter. FIG. 6 is an aberration diagram of the eyepiece lens of Example 3 in the reference state. FIG. 7 is a lens cross-sectional view when the diopter of the eyepiece of Example 4 is −2.0 diopter (reference state), 2.0 diopter, and −4.0 diopter. FIG. 8 is an aberration diagram of the eyepiece of Example 4 in the reference state.

  FIG. 9 is a lens cross-sectional view when the diopter of the eyepiece lens of Example 5 is −2.0 diopter (reference state), 2.0 diopter, and −4.0 diopter. FIG. 10 is an aberration diagram of the eyepiece lens of Example 5 in the reference state. FIG. 11 is a lens cross-sectional view when the diopter of the eyepiece of Example 6 is −2.0 diopter (reference state), 2.5 diopter, and −6.0 diopter. FIG. 12 is an aberration diagram of the eyepiece lens of Example 6 in the reference state.

  FIG. 13 is a lens cross-sectional view when the diopter of the eyepiece of Example 7 is −2.0 diopter (reference state), 2.5 diopter, and −6.0 diopter. FIG. 14 is an aberration diagram of the eyepiece lens of Example 7 in the reference state.

  FIG. 15 is a schematic diagram of a main part of an imaging apparatus including the eyepiece of the present invention. FIG. 16 is a diagram showing that the optical path changes depending on the refractive power arrangement of the optical system. FIG. 17 is a diagram showing that the optical path changes due to the change in the principal point position of the optical system.

  The eyepiece of each embodiment is used for an electronic viewfinder of an imaging apparatus such as a digital camera or a video camera. In the lens cross-sectional view, the left side is the image display surface side (object side), and the right side is the observation side. In the lens cross-sectional view, L is an eyepiece. I is an image display surface of an image display element such as a liquid crystal element or an organic EL element. EP is an eye point for the user to observe an image displayed on the display surface.

  A plate for protecting the image display surface and the lens may be provided between the image display surface I and the lens surface on the image display surface side of the lens disposed closest to the image display surface. Further, a plate or the like for protecting the lens may be provided between the eyepiece lens L and the eye point EP. Here, the eye point EP may be moved in the optical axis direction as long as the off-axis light beam emitted from the image display surface I can pass through the pupil of the observer.

  Each aberration diagram shows aberrations that occur in the eyepieces of the examples when the finder diopter is in the reference state.

  In the spherical aberration diagram, spherical aberrations with respect to d-line (wavelength 587.6 nm) and g-line (wavelength 435.8 nm) are shown. In the astigmatism diagram, S is a sagittal image plane, and M is a meridional image plane. Distortion is shown for the d-line. The chromatic aberration diagram shows the chromatic aberration at the g-line.

  Next, the relationship between the refractive power arrangement of the eyepiece and the path of the light beam that passes through the eyepiece will be described with reference to FIGS. 16 and 17.

  First, referring to FIG. 16, the path of the light beam in the optical system in which the positive lens is disposed closest to the image display surface of the eyepiece and the path of the light beam in the optical system in which the negative lens is disposed closest to the image display surface of the eyepiece. Compare FIG. 16A shows a path of light rays in an optical system in which a positive lens is arranged closest to the image display surface of the eyepiece. FIG. 16B shows a path of light rays in an optical system in which a negative lens is disposed on the most image display surface side of the eyepiece.

  As shown in FIGS. 16A and 16B, the effective diameter of a lens (hereinafter, referred to as an image display surface side lens) arranged closest to the image display surface among the eyepieces is Depends on size. Further, the effective diameter of a lens (hereinafter referred to as an observation side lens) arranged most on the observation side among the eyepiece lenses is determined by the eye point EP, the viewing angle ω, and the eye relief length. Thus, the effective diameters of the image display surface side lens and the observation side lens are determined according to the specifications of the viewfinder.

  Further, when the eyepiece is used in an electronic viewfinder, it is preferable that the angle of light (image emission angle) emitted from the image display surface and incident on the image display surface side lens is as small as possible. This is because the light emitted obliquely from the image display surface such as a liquid crystal tends to decrease in luminance.

  On the other hand, the effective diameter of a lens (hereinafter referred to as an intermediate lens) disposed between the image display surface side lens and the observation side lens changes according to the refractive power arrangement of the optical system. As shown in FIG. 16A, when the image display surface side lens and the observation side lens are positive lenses, the light emitted from the image display surface becomes convergent light in the image display surface side lens. Therefore, the effective diameter of the intermediate lens is This is smaller than the effective diameter of the image display surface side lens and the observation side lens. On the other hand, as shown in FIG. 16B, when the image display surface side lens and the observation side lens are negative lenses, light emitted from the image display surface becomes divergent light in the image display surface side lens. As a result, the effective diameter of the intermediate lens is larger than the effective diameters of the image display surface side lens and the observation side lens.

  As described above, in order to reduce the effective diameter of the intermediate lens, it is preferable to configure the optical system so that the refractive powers of the image display surface side lens and the observation side lens are positive.

  Next, with reference to FIG. 17, it will be described that the height of the off-axis ray at the observation side principal point position changes as the observation side principal point position of the optical system changes. FIG. 17 schematically shows an optical system in which a first lens having a positive refractive power, a second lens having a negative refractive power, and a third lens having a positive refractive power are arranged in order from the image display surface side to the observation side. ing. FIG. 17A shows an optical path when parallel light is incident in an optical system in which the refractive power of the third lens is stronger than the refractive power of the first lens. FIG. 17B shows an optical path when parallel light is incident in an optical system in which the refractive power of the third lens is weaker than the refractive power of the first lens. In FIGS. 17A and 17B, the eye relief and the viewing angle are the same.

  Comparing FIGS. 17A and 17B, by making the refractive power of the third lens weaker than the refractive power of the first lens, the observation-side principal point position of the optical system moves to the image display surface side, It can be seen that the height of the light beam at the observation side principal point position is increased.

  As described above, by strengthening the refractive power of the positive lens arranged on the observation side, the observation-side principal point position of the optical system can be moved to the observation side. Thereby, the height of the light beam at the observation side principal point position can be reduced, and the effective diameter of the lens arranged in the vicinity of the observation side principal point position can be reduced.

  In addition, since the eyepiece lens having a positive refractive power as a whole can collect light rays gently, the number of positive lenses can be increased to suppress the occurrence of higher-order aberrations. Here, when an eyepiece lens is configured with only a positive lens, it is difficult to sufficiently correct axial chromatic aberration and lateral chromatic aberration. Therefore, it is preferable to dispose a negative lens in the eyepiece lens.

  As a configuration in which the negative lens is arranged while increasing the number of positive lenses, it is conceivable that an eyepiece lens is configured by three lenses of two positive lenses and one negative lens. However, in order to realize an eyepiece having a long eye relief and a wide viewing angle and having good optical performance, it is necessary to further increase the number of lenses constituting the eyepiece. Therefore, in the eyepiece lens of the present invention, the eyepiece lens is configured by using five or more lenses. In particular, when the eyepiece has two or more negative lenses, it is possible to correct axial chromatic aberration and lateral chromatic aberration more satisfactorily.

In each embodiment, when the focal length of the lens arranged closest to the observation side among the lenses constituting the eyepiece lens is fe and the focal length of the entire eyepiece lens system is f,
0.58 <fe / f <0.95 (1)
The following conditional expression is satisfied.

  Conditional expression (1) defines the ratio between the focal length f of the entire eyepiece lens system and the focal length fe of the lens arranged closest to the observation side among the lenses constituting the eyepiece lens.

  If the upper limit of conditional expression (1) is exceeded and the focal length fe of the lens arranged closest to the observation side among the lenses constituting the eyepiece lens becomes long, the refractive power of the lens arranged closest to the observation side becomes weak. Too much. As a result, the observation-side principal point position of the optical system moves to the image display surface side, and the effective diameter of the lens arranged near the observation-side principal point position increases, which is not preferable.

  When the lower limit of conditional expression (1) is exceeded and the focal length fe of the lens arranged closest to the observation side among the lenses constituting the eyepiece becomes short, the refractive power of the lens arranged closest to the observation side becomes strong. Too much. As a result, many high order aberrations such as coma are generated in the lens arranged closest to the object side, which is not preferable.

In each embodiment, it is preferable to set the numerical range of conditional expression (1) as follows.
0.59 <fe / f <0.92 (1a)

More preferably, the numerical range of conditional expression (1) is set as follows.
0.61 <fe / f <0.90 (1b)

Furthermore, in each embodiment, it is more preferable to satisfy one or more of the following conditional expressions.
1.17 <ff / fe <4.71 (2)
5.0 <νdn <29.2 (3)
−3.30 <Rf2 / Re1 <−0.48 (4)

  Here, the focal length of the lens arranged closest to the object among the lenses constituting the eyepiece lens is ff, and the Abbe number based on the d-line of the material of the negative lens constituting the eyepiece lens is νdn. Also, let Rf2 be the radius of curvature on the paraxial axis of the observation-side lens surface of the lens that constitutes the eyepiece lens that is disposed closest to the object side. Further, Re1 is the radius of curvature of the paraxial surface of the object-side lens surface of the lens that constitutes the eyepiece lens that is disposed closest to the observation side.

In conditional expression (3), when the Abbe number νd is NF, NC, and Nd, respectively, the refractive indices of the materials for the F-line (486.1 nm), C-line (656.3 nm), and d-line (587.6 nm) ,
νd = (Nd−1) / (NF−NC)
It is a numerical value represented by

  Conditional expression (2) defines the ratio between the focal length fe of the lens arranged closest to the observation side and the focal length ff of the lens arranged closest to the object side. When the upper limit of conditional expression (2) is exceeded and the focal length fe of the lens arranged closest to the observation side becomes short, the refractive power of the lens arranged closest to the observation side becomes too strong. As a result, it is difficult to sufficiently correct spherical aberration, which is not preferable.

  When the lower limit of conditional expression (2) is exceeded and the focal length ff of the lens arranged closest to the object side becomes short, the refractive power of the lens arranged closest to the object side becomes too strong. As a result, it is difficult to sufficiently correct the astigmatic difference, which is not preferable.

  Conditional expression (3) is a conditional expression that defines the Abbe number νdn with reference to the d-line of the material of the negative lens constituting the eyepiece. Chromatic aberration is favorably corrected by disposing a negative lens using a highly dispersed material in an ocular lens having a positive refractive power as a whole.

  If the Abbe number νdn increases beyond the upper limit of conditional expression (3), it is difficult to sufficiently correct chromatic aberration in the eyepiece lens, which is not preferable. If the Abbe number νdn becomes smaller than the lower limit value of the conditional expression (3), chromatic aberration is excessively corrected, which is not preferable. Moreover, since the material which can be selected as a lens material will be limited, it is not preferable.

  Conditional expression (4) defines the ratio between the curvature radius Rf2 of the lens surface on the observation side of the lens disposed closest to the object side and the curvature radius Re1 of the lens surface on the object side of the lens disposed closest to the observation side. Is. When the absolute value of the radius of curvature Rf2 becomes smaller than the upper limit value of the conditional expression (4), the refractive power of the lens surface on the observation side of the lens arranged closest to the object side becomes too strong, and astigmatism or spherical surface Since it becomes difficult to reduce aberration, it is not preferable.

  When the absolute value of the radius of curvature Re1 becomes smaller than the lower limit value of the conditional expression (4), the refractive power of the lens surface on the object side of the lens arranged closest to the observation side becomes too strong, which is accompanied by diopter adjustment. It is not preferable because it is difficult to reduce the fluctuation of coma aberration.

In each embodiment, it is preferable to set the numerical ranges of conditional expressions (2) to (4) as follows.
1.20 <ff / fe <4.50 (2a)
10.0 <νdn <28.0 (3a)
−3.15 <Rf2 / Re1 <−0.50 (4a)

More preferably, the numerical ranges of the conditional expressions (2) to (4) are set as follows.
1.25 <ff / fe <4.30 (2b)
15.0 <νdn <26.8 (3b)
−3.10 <Rf2 / Re1 <−0.52 (4b)

Further, when the eyepiece L of each embodiment is used in an observation apparatus for observing an image displayed on the image display surface I, the following conditional expression should be satisfied.
0.52 <H / f <0.91 (5)

  Here, the diagonal length of the image display surface I is H.

  Conditional expression (5) is a conditional expression that defines the ratio between the diagonal length H of the image display surface I and the focal length f of the eyepiece.

  If the lower limit of conditional expression (5) is exceeded and the focal length f of the eyepiece becomes too long, the viewing angle becomes too narrow, which is not preferable.

  If the focal length f of the eyepiece is too short beyond the upper limit of conditional expression (5), many off-axis aberrations such as distortion and astigmatism occur, which is not preferable.

In each embodiment, it is preferable to set the numerical range of conditional expression (5) as follows.
0.56 <H / f <0.87 (5a)

More preferably, the numerical range of conditional expression (5) should be set as follows.
0.60 <H / f <0.85 (5b)

  Here, in the eyepiece lens L of each embodiment, diopter adjustment can be performed by moving all the lenses integrally in the optical axis direction. By moving each lens integrally, fluctuations in coma due to diopter changes can be reduced.

  Next, numerical examples 1 to 7 corresponding to the first to seventh embodiments of the present invention will be described. In each numerical example, i indicates the order of the optical surfaces from the image display surface side. ri is the radius of curvature of the i-th optical surface (i-th surface), di is the distance between the i-th surface and the i + 1-th surface, and ndi and νdi are the refractions of the material of the i-th optical member with respect to the d-line, respectively. Indicates the rate and Abbe number. r1 represents an image display surface, and r2 represents a surface on the observation side of the plate for protecting the image display surface. The most observation side surface shows the eye point EP in the reference state of the eyepiece lens of each example.

Further, when K is the eccentricity, A4, A6, and A8 are aspherical coefficients, and the displacement in the optical axis direction at the position of the height h from the optical axis is x with respect to the surface vertex, the aspherical shape is
x = (h ² / R) / [1+ [1− (1 + K) (h / R) ² ] ^1/2 ] + A4h ⁴ + A6h ⁶ + A8h ⁸
Is displayed. Where R is the paraxial radius of curvature. A surface with * on the right side of the surface number indicates an aspheric surface. The display of “e-Z” means “10 ^−Z ”.

[Numerical Example 1]
Unit mm
Surface data surface number rd nd νd
1 ∞ 0.70 1.51000 60.0
2 ∞ (variable)
3 -65.737 3.95 2.00069 25.5
4 -22.170 3.52
5 * -14.334 3.00 1.63550 23.8
6 * 110.330 0.30
7 * 48.492 6.84 1.53110 55.9
8 * -21.874 1.20
9 * 128.789 1.41 1.63550 23.8
10 * 22.276 1.20
11 39.057 8.21 1.83481 42.7
12 -39.057 27.00
13 (Eyepoint)
Aspheric data 5th surface
K = -7.28787e-001 A 4 = -6.03675e-005 A 6 = 1.77471e-007
6th page
K = 4.51650e + 001 A 4 = -1.11796e-005 A 6 = -6.19143e-008
7th page
K = -4.38548e + 000 A 4 = -2.38798e-005 A 6 = -2.65742e-008
8th page
K = -1.22703e + 000 A 4 = -4.69821e-006 A 6 = 3.91413e-008
9th page
K = -2.69921e + 002 A 4 = -1.52881e-007 A 6 = -4.63945e-009
10th page
K = -4.63925e + 000 A 4 = 4.39848e-006 A 6 = 5.19693e-010
Various data diopters [diopter] -2.0 +2.5 -6.0
Focal length 28.56 28.56 28.56
d 2 9.12 12.79 5.80

[Numerical Example 2]
Unit mm
Surface data surface number rd nd νd
1 ∞ 0.70 1.51000 60.0
2 ∞ (variable)
3 -65.913 3.14 2.00069 25.5
4 -48.248 10.11
5 -34.250 3.19 1.76182 26.5
6 -1000.301 1.69
7 * -4010.368 6.95 1.58313 59.4
8 * -44.146 1.21
9 * 161.388 5.20 1.63550 23.8
10 * 44.387 1.20
11 64.814 8.88 1.83481 42.7
12 -64.313 27.00
13 (Eyepoint)
Aspheric data 7th surface
K = 1.33592e + 004 A 4 = -7.84416e-006 A 6 = 7.50739e-009
8th page
K = -6.98689e-001 A 4 = 3.30466e-006 A 6 = -8.53288e-009
9th page
K = -2.65944e + 002 A 4 = -3.33664e-006 A 6 = -9.10796e-009
10th page
K = -9.09514e + 000 A 4 = -5.30646e-006 A 6 = 3.91499e-009
Various data diopters [diopter] -2.0 +0.7 -3.3
Focal length 61.32 61.32 61.32
d 2 21.46 31.12 17.55

[Numerical Example 3]
Unit mm
Surface data surface number rd nd νd
1 ∞ 0.70 1.51000 60.0
2 ∞ (variable)
3 -158.559 2.41 2.00069 25.5
4 -77.911 20.00
5 -30.833 8.00 1.95906 17.5
6 -72.834 3.39
7 188.533 7.00 1.83481 42.7
8 -56.340 1.20
9 40.450 1.71 1.84666 23.8
10 23.822 1.20
11 25.956 4.79 1.91082 35.3
12 64.549 27.00
13 (Eyepoint)
Various data diopters [diopter] -2.0 +2.0 -4.0
Focal length 52.34 52.34 52.34
d 2 11.05 21.99 6.18

[Numerical Example 4]
Unit mm
Surface data surface number rd nd νd
1 ∞ 0.70 1.51000 60.0
2 ∞ (variable)
3 * -98.827 11.19 1.85135 40.1
4 * -71.371 20.00
5 * -49.765 3.00 1.63550 23.8
6 * -407.575 1.11
7 * -1171.461 7.94 1.49171 57.4
8 * -82.367 1.20
9 * 219.883 3.76 1.63550 23.8
10 * 74.863 1.23
11 * 95.021 8.12 1.80610 40.7
12 * -92.616 27.00
13 (Eyepoint)
Aspheric data 3rd surface
K = 4.54099e-001 A 4 = 3.40725e-008 A 6 = 7.53032e-011 A 8 = -1.51639e-013
4th page
K = 3.40970e-001 A 4 = 8.48720e-008 A 6 = -4.76459e-011 A 8 = 1.79616e-014
5th page
K = 3.53841e-001
6th page
K = -1.00057e + 003
7th page
K = -2.99780e + 003 A 4 = -5.75156e-006 A 6 = 7.03535e-009
8th page
K = -1.18365e + 000 A 4 = 4.34382e-006 A 6 = -5.53385e-009
9th page
K = 1.75400e + 001 A 4 = -2.52412e-006 A 6 = -7.75632e-009
10th page
K = -1.05760e + 001 A 4 = -6.88282e-006 A 6 = 3.02568e-009
11th page
K = 3.83428e + 000
12th page
K = 1.63448e + 000
Various data diopters [diopter] -2.0 +2.0 -4.0
Focal length 91.98 91.98 91.98
d 2 31.59 66.08 20.00

[Numerical Example 5]
Unit mm
Surface data surface number rd nd νd
1 ∞ 0.70 1.51000 60.0
2 ∞ (variable)
3 * 85.611 7.93 1.63278 23.3
4 * -73.248 11.44
5 * -38.173 2.99 1.63550 23.8
6 ∞ 2.00
7 -50.000 2.00 1.63550 23.8
8 * 63.180 1.08
9 80.000 3.73 1.83481 42.7
10 -120.000 3.63
11 * 44.916 11.36 1.53110 55.9
12 * -38.064 27.00
13 (Eyepoint)
Aspheric data 3rd surface
K = -3.90666e + 001 A 4 = 1.18895e-005 A 6 = -1.59624e-008
4th page
K = 1.15096e + 001 A 4 = 8.63593e-006 A 6 = -4.12233e-009
5th page
K = -1.92831e + 000 A 4 = -7.44051e-006 A 6 = -6.66949e-008
8th page
K = 6.40443e + 000 A 4 = -1.12216e-005 A 6 = -5.11268e-008
11th page
K = 6.47203e-001 A 4 = -1.83397e-005 A 6 = -3.67313e-008
12th page
K = -4.15340e + 000 A 4 = -1.79314e-005 A 6 = 8.95990e-009
Various data diopters [diopter] -2.0 +2.0 -4.0
Focal length 52.35 52.35 52.35
d 2 12.84 23.84 7.81

[Numerical Example 6]
Unit mm
Surface data surface number rd nd νd
1 ∞ 0.70 1.51000 60.0
2 ∞ (variable)
3 * -38.535 14.01 1.63278 23.3
4 * -29.517 1.20
5 * 24.703 7.75 1.53110 55.9
6 * -192.936 1.07
7 * -230.075 4.76 1.63550 23.8
8 * 18.027 8.01
9 * 37.444 3.24 1.63550 23.8
10 * 30.304 3.65
11 * 53.230 10.15 1.53110 55.9
12 * -35.174 27.00
13 (Eyepoint)
Aspheric data 3rd surface
K = -2.22441e + 000
4th page
K = -1.18255e + 000
5th page
K = -1.32449e + 000 A 4 = 7.79653e-006 A 6 = -2.68440e-008
6th page
K = 2.37035e + 001 A 4 = 5.59136e-006 A 6 = 2.14521e-008
7th page
K = 1.36735e + 002 A 4 = 8.57582e-006 A 6 = 1.39697e-008
8th page
K = -1.09087e + 000 A 4 = 4.16185e-005 A 6 = -1.08061e-007
9th page
K = -1.50678e + 001 A 4 = 8.86960e-006 A 6 = 1.79036e-008
10th page
K = -1.08863e + 001 A 4 = -3.03939e-006 A 6 = 3.51421e-008
11th page
K = -1.20352e + 000
12th page
K = 3.09095e-001
Various data diopters [diopter] -2.0 +2.5 -6.0
Focal length 52.34 52.34 52.34
d 2 15.82 28.22 5.80

[Numerical Example 7]
Unit mm
Surface data surface number rd nd νd
1 ∞ 0.70 1.51000 60.0
2 ∞ (variable)
3 -52.901 3.89 2.00069 25.5
4 -21.121 3.61
5 * -13.287 2.00 1.63550 23.8
6 -295.010 0.20
7 112.818 1.52 1.49171 57.4
8 * 109.641 0.30
9 * 48.133 6.44 1.53110 55.9
10 * -21.455 1.20
11 * 395.724 1.20 1.63550 23.8
12 * 22.567 1.20
13 39.762 8.07 1.83481 42.7
14 -39.762 27.00
15 (eye point)
Aspheric data 5th surface
K = -7.56869e-001 A 4 = -5.88991e-005 A 6 = 2.21474e-007
8th page
K = 4.38705e + 001 A 4 = -1.19423e-005 A 6 = -6.22491e-008
9th page
K = -4.78924e + 000 A 4 = -2.40504e-005 A 6 = -2.98503e-008
10th page
K = -1.90079e + 000 A 4 = -1.90004e-007 A 6 = 3.37043e-008
11th page
K = -3.09759e + 003 A 4 = -8.85806e-007 A 6 = -7.73712e-010
12th page
K = -4.48834e + 000 A 4 = 3.15962e-006 A 6 = 1.14086e-009
Various data diopters [diopter] -2.0 +2.5 -6.0
Focal length 28.56 28.56 28.56
d 2 9.12 12.78 5.80

  Subsequently, the numerical values of the conditional expressions described above in the respective numerical examples are shown in Table 1. Here, with respect to νdn, the Abbe numbers of the materials of the first negative lens, the second negative lens, and the third negative lens from the object side are written in order from the top.

  Next, an embodiment of a video camera using the eyepiece shown in each example will be described with reference to FIG.

  In FIG. 15, 10 is a video camera body, 11 is an image pickup optical system for forming a subject image on an image pickup device (not shown), and 12 is a sound collecting microphone. Reference numeral 13 denotes an observation apparatus (electronic viewfinder) for observing a subject image displayed on an image display element (not shown) through the eyepiece of the present invention. The image display element is constituted by a liquid crystal panel or the like, and an object image or the like formed by the photographing optical system 11 is displayed on the image display element.

  As described above, by applying the eyepiece of the present invention to an imaging apparatus such as a video camera, an imaging apparatus having a long eye relief, a wide viewing angle, and high optical performance can be obtained.

L Eyepiece I Image display surface EP Eyepoint

Claims (12)

An eyepiece having five or more lenses, including two or more negative refractive power lenses,
The lens arranged closest to the object side and the lens arranged closest to the observation side both have a positive refractive power,
When the focal length of the eyepiece lens is f and the focal length of the lens arranged closest to the observation side is fe,
0.58 <fe / f <0.95
Satisfy the conditional expression,
When the Abbe number based on the d-line of any negative refractive power lens included in the eyepiece lens is νdn, at least two negative refractive power lenses are:
5.0 <νdn <29.2
An eyepiece that satisfies the following conditional expression: A first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, a fourth lens having a negative refractive power, and a positive refraction, which are arranged in order from the object side to the observation side. An eyepiece composed of a fifth lens of force,
When the focal length of the eyepiece is f and the focal length of the fifth lens is fe,
0.58 <fe / f <0.95
An eyepiece that satisfies the following conditional expression: A first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, and a positive refraction, which are arranged in order from the object side to the observation side. An eyepiece composed of a fifth lens of force,
When the focal length of the eyepiece is f and the focal length of the fifth lens is fe,
0.58 <fe / f <0.95
An eyepiece that satisfies the following conditional expression: A first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a negative refractive power, a fourth lens having a positive refractive power, and a negative refraction, which are arranged in order from the object side to the observation side. An eyepiece composed of a fifth lens of power and a sixth lens of positive refractive power,
When the focal length of the eyepiece is f and the focal length of the sixth lens is fe,
0.58 <fe / f <0.95
An eyepiece that satisfies the following conditional expression: When the focal length of the lens arranged on the most object side among the lenses constituting the eyepiece is ff,
1.17 <ff / fe <4.71
Eyepiece according to any one of claims 1 to 4, characterized by satisfying the conditional expression. Rf2 is the radius of curvature of the lens surface on the observation side of the lens that is the closest to the object side among the lenses that constitute the eyepiece lens, and the object side of the lens that is the closest to the observation side among the lenses that constitute the eyepiece lens . When the radius of curvature of the lens surface is Re1,
-3.30 <Rf2 / Re1 <−0.48
The eyepiece according to any one of claims 1 to 5 , wherein the following conditional expression is satisfied. It has an image display element provided with the image display surface which displays an image, and the eyepiece lens as described in any one of Claims 1 thru | or 6 provided in the image display surface side of the said image display element. Observation device. When the diagonal length before Symbol image display surface was H,
0.52 <H / f <0.91
The observation apparatus according to claim 7 , wherein the following conditional expression is satisfied. 9. The observation apparatus according to claim 7, wherein all the lenses constituting the eyepiece lens move as a unit during diopter adjustment. An image sensor for capturing an image;
An image display element comprising an image display surface for displaying an image captured by the image sensor;
The eyepiece according to any one of claims 1 to 6 , provided on the image display surface side of the image display element;
An imaging device comprising: When the diagonal length of the image display surface is H ,
0.52 <H / f <0.91
The imaging apparatus according to claim 10 , wherein the following conditional expression is satisfied. The image pickup apparatus according to claim 10 or 11, wherein all the lenses constituting the eyepiece lens move together as a diopter adjustment.

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