CN115917392A - Variable-power objective lens and photometry colorimeter provided with same - Google Patents

Variable-power objective lens and photometry colorimeter provided with same Download PDF

Info

Publication number
CN115917392A
CN115917392A CN202180042744.8A CN202180042744A CN115917392A CN 115917392 A CN115917392 A CN 115917392A CN 202180042744 A CN202180042744 A CN 202180042744A CN 115917392 A CN115917392 A CN 115917392A
Authority
CN
China
Prior art keywords
lens group
lens
variable power
objective lens
group
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202180042744.8A
Other languages
Chinese (zh)
Inventor
植田真由
金野贤治
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Konica Minolta Inc
Original Assignee
Konica Minolta Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Konica Minolta Inc filed Critical Konica Minolta Inc
Publication of CN115917392A publication Critical patent/CN115917392A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00Optical objectives specially designed for the purposes specified below
    • G02B13/18Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B15/00Optical objectives with means for varying the magnification
    • G02B15/14Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective
    • G02B15/16Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group
    • G02B15/20Optical objectives with means for varying the magnification by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective with interdependent non-linearly related movements between one lens or lens group, and another lens or lens group having an additional movable lens or lens group for varying the objective focal length

Abstract

Provided are a variable power objective lens capable of changing a measurement diameter while reducing variation in an F value on an image side, and a photometer and colorimeter provided with the variable power objective lens. The variable power objective lens (21) forms an intermediate image at a position conjugate to the image plane, and has, in order from the object side: a1 st lens group (G1) as a variable power group; a 2 nd lens group (G2) as a variable power group; and a 3 rd lens group (G3) which is not substantially changed in magnification. When the magnification is varied, the distance between two adjacent lens groups among the 1 st lens group (G1), the 2 nd lens group (G2), and the 3 rd lens group (G3) is varied. The intermediate image is formed between the 1 st lens group (G1) and the 2 nd lens group (G2). The 3 rd lens group (G1) has an aperture Stop (STO), and the aperture Stop (STO) is arranged such that a conjugate image of the aperture Stop (STO) is located on the object side of the 1 st lens group (G1).

Description

Variable-power objective lens and photometry colorimeter provided with same
Technical Field
The present invention relates to a variable power objective lens and a photometer and colorimeter including the same.
Background
In quality control of display products, a luminance meter, a color luminance meter, a spectrocolorimeter, and the like are used. These devices are devices that measure the optical characteristics of the display and are used to manage or adjust the brightness and chromaticity of the display. One of such optical characteristic measuring apparatuses is an optical characteristic measuring apparatus disclosed in international publication No. 2015/182571 (patent document 1).
Examples of the display include a micro OLED (Organic Light Emitting Diode), a micro LED (Light Emitting Diode), a smart phone display, and a television receiver (e.g., a 4K television, an 8K television, etc.). The size of the display is various according to the kind of the display. If the size of the display to be measured is small, the measurement range of the luminance and chromaticity of the colorimeter needs to be reduced, and vice versa. Therefore, a colorimeter having an objective lens capable of varying a measurement diameter (diameter of a measurement region) while measuring luminance and chromaticity in any display has been demanded.
Patent document 1 discloses an optical characteristic measuring device for measuring the luminance and chromaticity of a light-emitting body. The measuring device has a1 st optical system and a 2 nd optical system. The 1 st optical system performs spectroscopic measurement in a predetermined measurement range in a measurement region of an object to be measured. The 2 nd optical system can perform two-dimensional measurement of the object to be measured with a tristimulus value simultaneously with the measurement by the 1 st optical system. The 2 nd optical system has only one variable magnification group, and thus can make the measurement diameter on the image side variable. In particular, in the 2 nd optical system, the condensed measurement light is guided to the sensor through a filter (filter) having a spectral sensitivity that approximates to the CIE color matching function. The luminance and chromaticity of the object are calculated based on the tristimulus values.
Documents of the prior art
Patent document
Patent document 1: international publication No. 2015/182571
Disclosure of Invention
Problems to be solved by the invention
In recent years, there has been an increasing demand for measurement of luminance and chromaticity of a light emitter having a small size for a display such as a micro OLED or a micro LED. Further, since the width (dynamic range) of the luminance of the display is wide, the measurement of the luminance on the low luminance side is also emphasized in the γ adjustment of the display.
For example, in the case of measuring the brightness of a display using an objective lens having no zoom function, the measurement diameter can be changed by changing the amount of extension of the lens. However, in this method, the F value on the image side fluctuates with a change in the measurement diameter. Therefore, the amount of light taken into the sensor of the measuring device may decrease with a change in the measurement diameter.
In the case where the luminance of the display is low, if the sensor of the measuring device cannot receive light of a sufficient amount of light required for measurement, the accuracy of measurement of the luminance on the low luminance side is lowered. For example, the SN ratio in the measurement of brightness decreases. Therefore, the dynamic range of the measuring instrument becomes narrow. Since the dynamic range of the measuring device is narrow, it is assumed that the dynamic range of the display product is measured to be narrower than the original performance. Furthermore, it is difficult to make the measurement diameter vary greatly by only one variable magnification system.
The optical system disclosed in patent document 1 has one variable magnification group. In the optical system, the measurement diameter is variable. But the measurement angle changes with the change in the measurement diameter. The incident angle of light incident on the filter changes due to the change in the measurement angle. In the measuring apparatus, the closer the spectral sensitivity is to the color matching function, the closer the measured value is to the true value (the value calculated from the color matching function), and therefore it is important that the spectral sensitivity of the optical filter is closer to the color matching function. As such a filter, an interference film filter is generally used. When the incident angle of light incident on the interference film filter changes, the optical path difference in the interference film changes. As a result, a wavelength shift occurs in the transmittance characteristic of the optical filter, and the spectral sensitivity of the optical characteristic measurement device deviates from the color matching function. Therefore, there is a possibility that the accuracy of measurement of the luminance and chromaticity of the object to be measured is lowered.
Therefore, when the measurement diameter is variable by the objective lens, it is important that the variation of the F value on the image side be as small as possible.
The present invention has been made in view of the above problems, and provides a variable power objective lens capable of changing a measurement diameter while reducing variation in F value on the image side, and a photometer including the variable power objective lens.
Means for solving the problems
A variable power objective lens according to an aspect of the present invention is a variable power objective lens that forms an intermediate image at a position conjugate to an image plane, and includes, in order from an object side: a1 st lens group as a variable power group; a 2 nd lens group as a variable power group; and a 3 rd lens group which is substantially not variable in magnification, wherein, in the variable magnification, an interval between two adjacent lens groups among the 1 st lens group, the 2 nd lens group, and the 3 rd lens group is changed, an intermediate image is formed between the 1 st lens group and the 2 nd lens group, and the 3 rd lens group has an aperture stop arranged such that a conjugate image of the aperture stop is located on the object side of the 1 st lens group.
A photometry colorimeter according to an aspect of the present invention includes the above-described variable magnification objective lens.
Effects of the invention
According to the present invention, it is possible to provide a variable power objective lens capable of changing a measurement diameter while reducing a variation in F value on the image side, and a photometer and colorimeter including the variable power objective lens.
Drawings
Fig. 1 is a block diagram showing an example of a photometric/colorimetric device on which a variable magnification objective lens according to an embodiment of the present invention is mounted.
Fig. 2 is a lens configuration diagram showing a configuration of the variable power objective lens according to embodiment 1.
Fig. 3 is a lens configuration diagram showing the configuration of the variable power objective lens according to embodiment 2.
Fig. 4 is a lens configuration diagram showing a configuration of the variable power objective lens according to embodiment 3.
Detailed Description
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a block diagram showing an example of a photometric/colorimetric device on which a variable magnification objective lens according to an embodiment of the present invention is mounted. The photometry colorimeter 10 according to the present embodiment is used in, for example, an inspection process of a display production line, and measures a brightness (luminance) and chromaticity of a display surface 12 of a display.
For example, the photometry colorimeter 10 according to the present embodiment (hereinafter, also simply referred to as "colorimeter 10") is implemented as a tristimulus-value type colorimeter. As shown in fig. 1, the colorimeter 10 includes a probe (probe) section 14 and a measuring instrument main body section 16. The measurement probe unit 14 and the measurement instrument main unit 16 are integrally formed.
The measurement probe unit 14 is disposed opposite to the display surface 12 of the display as the measurement object by a predetermined distance (for example, 3 cm). The measurement probe unit 14 photoelectrically converts light from the display surface 12 of the monitor into an electric signal (analog signal), and transmits the electric signal to the measurement instrument main unit 16.
The measurement probe unit 14 includes a measurement optical system 27 and a light receiving system 28. The measurement optical system 27 includes the variable power objective lens 21 and the beam splitting member 24 according to the present embodiment. The variable power objective lens 21 is provided as an incident portion on which light from the measurement target enters. In fig. 1, the variable power objective lens 21 is illustrated as a single lens in order to illustrate a case where the colorimeter 10 has the variable power objective lens 21. The detailed configuration of the variable power objective lens 21 according to the present embodiment will be described later.
The light flux dividing member 24 is provided as a light guide portion that guides light incident through the variable power objective lens 21. The beam splitting member 24 splits the light beam transmitted through the variable magnification objective lens 21 into three light beams.
The light receiving system 28 includes a filter unit 23, a photoelectric conversion unit 25, and an amplification unit 26. The light flux split by the light flux splitting member 24 passes through the filter unit 23 and enters the photoelectric conversion unit 25. The photoelectric conversion portion 25 has a light receiving sensor (not shown) for converting incident light into an electric signal. The filter unit 23 includes a spectral sensitivity correction filter (not shown) for making the light receiving sensor of the photoelectric conversion unit 25 have spectral sensitivity of a standard observer defined by CIE. The spectral sensitivity correction filter is a filter having a spectral sensitivity close to the color matching function. As the spectral sensitivity correction filter, an interference film filter can be used. The amplifier 26 amplifies an electric signal (voltage) output from the light receiving sensor of the photoelectric conversion unit 25 to a predetermined level.
The measurement instrument main body portion 16 converts an electric signal (analog signal) input from the measurement probe portion 14 into a digital signal, and performs predetermined arithmetic processing. The measurement instrument main unit 16 calculates tristimulus values (X, Y, Z), xyY (chromaticity coordinates and luminance) defined by CIE (international commission on illumination), T Δ uvY (correlated color temperature, chromatic aberration from the black body locus, luminance), and the like by the calculation processing, and displays the calculation results on the display unit 34.
The measurement instrument main unit 16 includes an a/D conversion unit 31, a data memory 32, a display unit 34, an operation unit 35, a control unit 36, and a power supply unit 37. The a/D converter 31 converts the light reception signal input from the measurement probe unit 14 into a digital signal (hereinafter, referred to as measurement data). The data memory 32 stores the measurement data output from the a/D conversion unit 31. The control unit 36 controls the measurement operation by collectively controlling the operation of the measurement probe unit 14 and the operation of each unit in the measurement instrument main body unit 16. The control unit 36 calculates tristimulus values (X, Y, Z), xyY and T Δ uvY defined by CIE, and the like using the measurement data stored in the data memory 32.
The display unit 34 displays the calculation result in the control unit 36. Various information related to the measurement (an instruction for measurement, setting of a display mode, a measurement range, and the like) is input to the operation unit 35. The power supply unit 37 transforms a voltage of power supplied from an external AC adapter (not shown) and supplies the power to each component element via the control unit 36.
Although the example of the tristimulus-value type colorimeter is described, the photometry colorimeter 10 according to the present embodiment may be a spectrocolorimeter. In the case of a spectrocolorimeter, the filter section 23 shown in fig. 1 is replaced with a spectroscopic section. The light emitted from the display surface 12 of the display is partially split by the spectroscopic portion and enters the photoelectric conversion portion 25. The control unit 36 obtains a tristimulus value by numerical calculation based on the spectral characteristics indicated by the signal output from the photoelectric conversion unit 25.
In the present embodiment, the diameter (measurement diameter) of the measurement region AR on the display surface 12 of the display can be changed by the variable power objective lens 21. This allows the same colorimeter 10 to measure the brightness (luminance) and chromaticity of displays of various sizes. Further, in the present embodiment, even if the measurement diameter is changed, the F value on the image side can be kept constant. This enables accurate measurement of the luminance on the low luminance side of the display.
In the present embodiment, the variable power objective lens 21 is a variable power objective lens that forms an intermediate image at a position between the image plane and the conjugate position, and includes, in order from the object side: a1 st lens group as a variable power group; a 2 nd lens group as a variable power group; and a 3 rd lens group which is substantially not variable in magnification, wherein, in the variable magnification, an interval between two adjacent lens groups among the 1 st lens group, the 2 nd lens group, and the 3 rd lens group is changed, an intermediate image is formed between the 1 st lens group and the 2 nd lens group, and the 3 rd lens group has an aperture stop disposed such that a conjugate image of the aperture stop is located closer to the object side than the 1 st variable magnification group.
According to the above configuration, an afocal (afocal) system is configured by the 1 st lens group and the 2 nd lens group as variable power groups, and an intermediate image is formed between the respective groups, thereby providing an optical system that facilitates bringing a conjugate image of the aperture to the object side. In the present embodiment, the "afocal system" refers to an optical system configured such that the combined focal length of two variable power groups is 2 times or more of the focal length of the entire optical system.
The image-side F value can be fixed at all zoom positions by the 3 rd variable magnification group which does not change magnification and the aperture stop whose position and aperture diameter are fixed. Therefore, when the optical characteristics are measured at each measurement diameter, the shift of the spectral sensitivity with respect to the color matching function can be reduced. This enables accurate measurement of luminance and chromaticity. Further, even when the measurement diameter is small, optical characteristics such as luminance can be measured without narrowing the dynamic range. The aperture stop may be disposed in front of the 3 rd lens group (on the object side of the most object side lens in the 3 rd lens group).
Further, since the conjugate image of the aperture stop is located on the object side of the 1 st lens group, the brightness unevenness of the object is not reflected on the image plane (light receiving surface of the light receiving sensor). This makes it possible to construct an optical system that is not affected by variations in the measurement target. In the case where the object plane and the image plane are in a conjugate relationship as in the imaging optical system, the luminance unevenness of the measurement object is also directly reflected on the image plane, and thus the measurement accuracy is lowered. On the other hand, according to the present embodiment, such a problem can be prevented. Further, the aperture stop and the object plane may be in a conjugate relationship.
Further, according to the present embodiment, the variable power objective lens has two variable power groups. This can widen the magnification variation range.
In the present embodiment, it is preferable that-0.5 < η < 0.5 when the focal length of the entire optical system of the variable power objective lens 21 is FL and η = FL/f12, where f12 is the combined focal length of the 1 st lens group and the 2 nd lens group at the d-line.
As described above, in the present embodiment, the "afocal system" refers to an optical system configured such that the combined focal length f12 of the two variable power groups is 2 times or more the focal length FL of the entire optical system. The above-described conditions are conditions for configuring the two variable power groups (the 1 st lens group and the 2 nd lens group) into the afocal system in the present embodiment. The 1 st lens group and the 2 nd lens group constitute an afocal system, and thus light rays incident on the 3 rd lens group approach parallel light. This makes it possible to simplify correction of aberration on the image plane by the 3 rd lens group.
In the present embodiment, the 1 st lens group preferably includes, in order from the object side: an 11 th lens group having a negative refractive power; and a 12 th lens group having a positive power.
With the above configuration, the 1 st lens group as a whole can have positive refractive power. Thus, a telephoto system can be configured in which an intermediate image is formed between the 1 st lens group and the 2 nd lens group.
In the present embodiment, the 2 nd lens group preferably includes, in order from the object side: a 21 st lens group having a positive refractive power; and a 22 nd lens group having a negative power.
With the above configuration, the 2 nd lens group as a whole can have positive optical power. Thus, a telephoto system can be configured in which an intermediate image is formed between the 1 st lens group and the 2 nd lens group.
In the present embodiment, it is preferable that when the magnification β 1 of the 1 st lens group is defined as β 1= ft1/fw1 by the focal length ft1 at the telephoto end of the 1 st lens group and the focal length fw1 at the wide-angle end of the 1 st lens group, and the magnification β 2 of the 2 nd lens group is defined as β 2= ft2/fw2 by the focal length ft2 at the telephoto end of the 2 nd lens group and the focal length fw2 at the wide-angle end of the 2 nd lens group, the magnification β 1 of the 1 st lens group is 1 < β 1 < 2.5, and the magnification β 2 of the 2 nd lens group is 0.2 < β 2 < 0.8.
According to the above configuration, since the light emitted from the aperture stop is made parallel on the measurement surface side, the 1 st lens group and the 2 nd lens group which are variable power groups constitute the afocal system. By forming an intermediate image between the 1 st lens group and the 2 nd lens group, the variable magnification ratio of each of the 1 st lens group and the 2 nd lens group, which are variable magnification groups, can be reduced.
It is desirable that the magnification of the 1 st lens group is 1.5. Ltoreq. Beta. Ltoreq.2 and the magnification of the 2 nd lens group is 0.5. Ltoreq. Beta. Ltoreq.0.7.
When the magnification of the 1 st lens group is 2 < β 1, the distance from the 1 st lens group to the intermediate image becomes shorter, and therefore aberration correction in the 2 nd lens group becomes more difficult. On the other hand, in the case of 1 < β 1 < 1.5, the variable range of the focal length of the 1 st lens group is narrowed, and therefore the variable magnification range of the entire optical system is narrowed. Similarly, when the magnification of the 2 nd lens group is β 2 < 0.5, the distance from the 2 nd lens group to the intermediate image becomes short, and therefore aberration correction in the 1 st lens group becomes difficult. On the other hand, in the case of 0.8 < β 2, β 2 becomes equal power as it approaches 1, and therefore, the variable range of the focal length of the 2 nd lens group is narrowed as in the case of the 1 st lens group. This narrows the range of magnification variation of the entire optical system. When the magnification β 1 of the 1 st lens group is 1.5 β 1 or more and 2 or less and the magnification β 2 of the 2 nd lens group is 0.5 or more and β 2 or less and 0.7 or less, the distance from the front group of the 1 st lens group to the object side can be secured at the wide-angle end, and therefore the incident angle to each variable power group becomes small. Therefore, aberration correction becomes easy. Further, the range of the magnification variation of the entire optical system can be widened.
In the present embodiment, it is preferable that the zoom ratio γ is 0.5 ≦ γ ≦ 1.5 when γ = β 1 ×. β 2 is defined as the magnification β 1 of the 1 st lens group and the magnification β 2 of the 2 nd lens group.
With the above configuration, each lens group has a zoom ratio, and therefore, the configuration and mechanism for zooming can be simplified, and the range of the zoom ratio of the measurement diameter can be widened.
It is desirable that 1. Ltoreq. Gamma. Ltoreq.1.2. When γ is 1. Ltoreq. γ. Ltoreq.1.2, the focal lengths of the respective variable power groups become equal or almost equal to each other, and therefore aberration correction becomes easy.
In the present embodiment, it is preferable that the absolute value | Fno | of the F value Fno on the image side at each zoom position of the variable power objective lens satisfies 1 < | Fno | < 6, and the difference between the F values Fno at each zoom position is 3.5 or less.
With the above configuration, a decrease in the amount of light on the image plane due to a decrease in the measurement diameter can be suppressed. Therefore, even if the measurement diameter changes, the dynamic range in which measurement is performed can be fixed.
In the present embodiment, the incident angle of the principal ray on the image surface side is preferably 5 degrees or less.
With the above configuration, the incident angle to the image plane can be fixed at any angle of view, and thus a decrease in the light quantity of the light guided to the image side due to a change in the angle of view can be suppressed.
In the present embodiment, the aperture system of the aperture stop is variable. With this configuration, the measurement diameter can be further reduced. In the present embodiment, the measurement diameter can also be reduced to
Figure BDA0004000670720000071
Thus, exampleFor example, it is possible to measure the luminance and chromaticity of a light emitter used for a display of a small size such as a micro OLED or a micro LED.
In the present embodiment, the photometry colorimeter includes any of the zoom objective lenses described above. This makes it possible to realize a photometric colorimeter capable of changing the measurement diameter while reducing the variation in the F value on the image side.
Examples
Specific examples of the variable power objective lens according to the present invention will be described below with reference to fig. 2 to 4 and tables. Fig. 2 to 4 are lens configuration diagrams showing configurations of the variable power objective lens 21 according to embodiments 1 to 3, respectively. In fig. 2 to 4, examples 1 to 3 are denoted by "EX1", "EX2", and "EX3", respectively.
In fig. 2 to 4, "AX" represents an optical axis, "STO" represents an aperture stop, "I11" represents a position of an intermediate image, "IM" represents an imaging surface or an image surface of a light receiving sensor, and "AR" represents a position of a measured region.
In the following description, Z1 to Z4 each represent a zoom position. In each of fig. 2 to 4, (Z1), (Z2), and (Z3) show lens cross-sectional views at the telephoto end, the intermediate focal length state, and the wide-angle end, respectively. (Z4) shows a lens cross-sectional view at the same zoom position as (Z3) and with the aperture stop diameter reduced. The measurement diameters in (Z1) to (Z4) were 10mm, 5mm, 2.5mm and 1mm, respectively.
[ example 1]
As shown in fig. 2, the variable power objective lens 21 is an objective lens that forms an intermediate image at a position conjugate to the image plane IMG. The variable power objective lens 21 includes, in order from the object side, a1 st lens group G1 as a variable power group, a 2 nd lens group G2 as a variable power group, and a 3 rd lens group G3 which is not substantially variable in power. When the magnification is changed, the interval between two adjacent lens groups among the 1 st lens group G1, the 2 nd lens group G2, and the 3 rd lens group G3 is changed. Specifically, the 3 rd lens group G3 is fixed, and the 1 st lens group G1 and the 2 nd lens group G2 move along the optical axis AX.
The 1 st lens group G1 includes, in order from the object side: an 11 th lens group G11 having a negative refractive power; and a 12 th lens group G12 having positive refractive power. The 11 th lens group G11 is composed of one negative lens L1. The 12 th lens group G12 is composed of two positive lenses L2 and L3. Thus, the 1 st lens group G1 has positive refractive power as a whole.
The 2 nd lens group G2 is composed of, in order from the object side, a 21 st lens group G21 having positive refractive power and a 22 nd lens group G22 having negative refractive power. The 21 st lens group G21 is composed of one positive lens L4. The 22 nd lens group G22 is composed of one negative lens L5. Thereby, the 2 nd lens group G2 has positive refractive power as a whole.
The 3 rd lens group G3 has an aperture stop STO, a positive lens L6, and a positive lens L7 in this order from the object side.
The 1 st lens group G1 and the 2 nd lens group G2 constitute an afocal system, and an intermediate image is formed at an imaging position I11 between the 1 st lens group G1 and the 2 nd lens group G2. The conjugate image of the aperture stop STO is located closer to the object side than the 1 st lens group G1. The 3 rd lens group G3 is not magnified and the position of the aperture stop STO is fixed. Further, in the zoom positions Z1 to Z3, the aperture diameter of the aperture stop STO is fixed. Thus, the F value on the image side does not change at the zoom positions Z1 to Z3. The variable power objective lens 21 can reduce the measurement diameter by reducing the aperture diameter of the aperture stop STO from the state shown in (Z3) (refer to (Z4)).
The structure of example 1 will be described in more detail by referring to the structure (constraint) data and the like. The definitions described below are also applied to examples 2 and 3.
In the configuration data, as surface data, surface numbers (OBJ: object surface, STO: aperture stop, IMG: image surface), a curvature radius r, an on-axis distance d, a refractive index nd with respect to a d-line (wavelength 587.56 nm) of a lens material, an Abbe (Abbe) number vd with respect to the d-line of the lens material, and an effective diameter eff.dia.. The surface with surface number i is an aspherical surface, and the aspherical shape is represented by the following "expression 1" in which the vertex of the surface is the origin, the optical axis direction is the X axis, and the height in the direction perpendicular to the optical axis is h.
[ mathematical formula 1]
Figure BDA0004000670720000091
Wherein the content of the first and second substances,
ai: the coefficient of the aspherical surface is given by the order of i,
r: the radius of curvature of the sheet is such that,
k: the conic constant.
The basic wavelength of the lens of each example was 587.56nm (d-line), and the unit of the surface shape such as the radius of curvature was mm. Furthermore, a power of 10 (e.g., 2.5 × 10) -002 ) E (e.g., 2.5E-002) is used. Table 1 shows lens data of the variable power objective lens according to example 1.
[ Table 1]
TABLE 1
r d nd vd eff.dia
OBJ INF INF
1 INF 0.00 9.713
2 INF a1 9.713
3 -13.667 0.26 1.7530 27.67 13.867
4 -406.167 a2 15.098
5* -128.756 2.85 1.6723 51.99 16.021
6 -11.906 6.23 16.132
7 14.599 6.77 1.5639 63.67 18.698
8 47.357 a3 16.906
9 8.534 4.63 1.6135 60.69 9.834
10* -8.563 a4 9.038
11 -7.246 0.12 1.6611 32.74 5.653
12 26.731 a5 5.477
STO INF 1.00 5.418
14 -21.253 1.55 1.4875 70.41 5.548
15 -5.772 6.88 5.864
16 8.516 0.42 1.4875 70.41 5.515
17 29.698 0.00 5.493
18 INF 5.98 5.528
IMG INF 0.00 3.893
Table 2 below shows the surface pitch of the lens surfaces of the variable power objective lens according to example 1. In table 2, Z1 to Z4 correspond to Z1 to Z4 shown in fig. 2, and a1 to a5 correspond to a1 to a5 shown in table 1.
[ Table 2]
TABLE 2
a1 a2 a3 a4 a5
Z1 25.84 1.213 41.07 2.517 1.686
Z2 25.84 1.213 47.02 1.009 0.200
Z3 9.925 7.131 40.14 1.009 0.200
Z4 9.925 7.131 40.14 1.009 0.200
Table 3 and table 4 show aspheric coefficients of lens surfaces of the variable power objective lens according to example 1 as aspheric data. In addition, the coefficient of an item having no mark in the aspherical surface data is 0.
[ Table 3]
TABLE 35 th plane
K 1.00000.E+00
A4 -2.86253.E-05
A6 -1.02826.E-06
A8 1.89460.E-08
A10 -1.17538.E-10
[ Table 4]
TABLE 4 side 10
K --2.47895.E+00
A4 4.46173.E-04
A6 3.92978.E-06
A8 -3.62224.E-07
A10 6.08063.E-09
Table 5 shows the characteristics of the variable power objective lens according to example 1. FL denotes a focal length of the entire variable power objective lens system, fno denotes an image side F value, BF denotes a back focal length (back focus), TL denotes an entire system length, ymax denotes a radius of the beam dividing member, F12 denotes a combined focal length of the 1 st lens group G1 and the 2 nd lens group G2 at the d-line, and η is defined by FL/F12. The units of FL, BF, TL, ymax, f12 are mm. It can be understood from table 5 that the image-side F value is constant among the positions Z1, Z2, and Z3.
[ Table 5]
TABLE 5
FL Fno BF TL Ymax f12 η
Z1 -20.8382 -2.27 5.98 109.019 1.9 -1663.6 0.013
Z2 -14.0747 -2.27 5.98 111.977 1.9 -540.82 0.026
Z3 -9.02765 -2.27 5.98 95.1031 1.9 -516.11 0.017
Z4 -9.02765 -5.68 5.98 95.1031 1.9 -516.12 0.017
Table 6 shows lens data of a single lens constituting the variable power objective lens of example 1. The lens numbers 1 to 7 correspond to the reference numerals L1 to L7 shown in fig. 2, respectively.
[ Table 6]
TABLE 6
Lens numbering Noodle numbering Focal length
1 3~4 -18.7877
2 5~6 19.3239
3 7~8 34.8306
4 9~10 7.7671
5 11~12 -8.61068
6 14~15 15.7373
7 16~17 24.3319
[ example 2]
As shown in fig. 3, the variable power objective lens 21 is an objective lens that forms an intermediate image at a position conjugate to the image plane IMG. The variable power objective lens 21 includes, in order from the object side, a1 st lens group G1 as a variable power group, a 2 nd lens group G2 as a variable power group, and a 3 rd lens group G3 which is not substantially variable in power. When the magnification is varied, the interval between two adjacent lens groups among the 1 st lens group G1, the 2 nd lens group G2, and the 3 rd lens group G3 is varied. Specifically, the 3 rd lens group G3 is fixed, and the 1 st lens group G1 and the 2 nd lens group G2 move along the optical axis AX.
The 1 st lens group G1 includes, in order from the object side: an 11 th lens group G11 having a negative refractive power; and a 12 th lens group G12 having positive refractive power. The 11 th lens group G11 is composed of one negative lens L1. The 12 th lens group G12 is composed of two positive lenses L2 and L3. Thus, the 1 st lens group G1 has positive refractive power as a whole.
The 2 nd lens group G2 is composed of, in order from the object side, a 21 st lens group G21 having positive refractive power and a 22 nd lens group G22 having negative refractive power. The 21 st lens group G21 is composed of one positive lens L4. The 22 nd lens group G22 is composed of one negative lens L5. Thereby, the 2 nd lens group G2 has positive refractive power as a whole.
The 3 rd lens group G3 has an aperture stop STO, a positive lens L6, and a positive lens L7 in this order from the object side.
The 1 st lens group G1 and the 2 nd lens group G2 constitute an afocal system, and an intermediate image is formed at an imaging position I11 between the 1 st lens group G1 and the 2 nd lens group G2. The conjugate image of the aperture stop STO is located closer to the object side than the 1 st lens group G1. The 3 rd lens group G3 is not magnified and the position of the aperture stop STO is fixed. Further, in the zoom positions Z1 to Z3, the aperture diameter of the aperture stop STO is fixed. Thus, the F value on the image side does not change at the zoom positions Z1 to Z3. The variable power objective lens 21 can reduce the measurement diameter by reducing the aperture diameter of the aperture stop STO from the state shown in (Z3) (refer to (Z4)).
Table 7 shows lens data of the variable power objective lens according to example 2.
[ Table 7]
TABLE 7
r d nd vd eff.dia
OBJ INF INF
1 INF 0.00 10.826
2 INF a1 10.826
3 -13.027 0.12 1.7550 27.59 14.818
4 -139.428 a2 16.247
5* -184.274 3.24 1.6716 52.08 17.667
6 -12.717 0.30 17.766
7 14.683 6.83 1.5649 63.61 19.115
8 55.846 0.00 17.312
9 INF a3 17.634
10 INF a4 8.415
11 INF 19.01 7.130
12 8.522 3.32 1.6145 60.63 10.707
13* --8.329 a5 10.608
14 --7.347 0.12 1.6652 32.44 5.725
15 18.253 a6 5.538
STO INF 1.00 5.343
17 --24.943 1.65 1.4875 70.41 5.780
18 --5.609 7.31 6.108
19 14.504 5.98 1.4875 70.41 5.893
20 -156.446 0 5.875
IMG INF 0 4.404
Table 8 below shows the surface interval of the lens surfaces of the variable power objective lens according to example 2. In table 8, Z1 to Z4 correspond to Z1 to Z4 shown in fig. 3, and a1 to a6 correspond to a1 to a6 shown in table 7.
[ Table 8]
TABLE 8
a1 a2 a3 a4 a5 a6
Z1 28.05 1.505 19.57 0.354 3.559 1.621
Z2 28.05 1.505 19.57 9.608 1.000 0.200
Z3 2.900 11.41 11.95 9.608 1.000 0.200
Z4 2.900 11.41 11.95 9.608 1.000 0.200
Table 9 and table 10 show aspheric coefficients of lens surfaces of the variable power objective lens according to example 2 as aspheric data. In addition, the coefficient of an item having no mark in the aspherical surface data is 0.
[ Table 9]
TABLE 9 side 5
K 1.00000.E+00
A4 --2.46076.E-05
A6 -1.06487.E-06
A8 1.78673.E-08
A10 -1.02549.E-10
[ Table 10]
Table 10 item 13
K -2.45682.E+00
A4 4.48111.E-04
A6 4.44592.E-06
A8 -3.54971.E-07
A1 0 5.28416.E-09
Table 11 shows the characteristics of the variable power objective lens according to example 2. It can be understood from table 11 that the image-side F value is constant among the positions Z1, Z2, and Z3.
[ Table 11]
TABLE 11
FL Fno BF TL Ymax f12 η
Z1 --24.544 --2.27 5.98 75.9412 1.9 406.92 --0.060
Z2 -12.888 --2.27 5.98 81.2155 1.9 258.43 --0.050
Z3 -6.4586 -2.27 5.98 83.5013 1.9 125.38 -0.052
Z4 -6.4586 -5.68 5.98 83.5013 1.9 125.38 -0.052
Table 12 shows lens data of a single lens constituting the variable power objective lens according to example 2. The lens numbers 1 to 7 correspond to the reference numerals L1 to L7 shown in fig. 3, respectively.
[ Table 12]
TABLE 12
Lens numbering Noodle numbering Focal length
1 3~4 -19.041
2 5~6 20.186
3 7~8 33.271
4 12~13 7.4104
5 14~15 -7.8607
6 17~18 14.440
7 19~20 27.251
[ example 3]
As shown in fig. 4, the variable power objective lens 21 is an objective lens that forms an intermediate image at a position conjugate to the image plane IMG. The variable power objective lens 21 includes, in order from the object side, a1 st lens group G1 as a variable power group, a 2 nd lens group G2 as a variable power group, and a 3 rd lens group G3 which is not substantially variable in power. When the magnification is changed, the interval between two adjacent lens groups among the 1 st lens group G1, the 2 nd lens group G2, and the 3 rd lens group G3 is changed. Specifically, the 3 rd lens group G3 is fixed, and the 1 st lens group G1 and the 2 nd lens group G2 move along the optical axis AX.
The 1 st lens group G1 includes, in order from the object side: an 11 th lens group G11 having a negative refractive power; and a 12 th lens group G12 having positive refractive power. The 11 th lens group G11 is composed of one negative lens L1. The 12 th lens group G12 is composed of two positive lenses L2 and L3. Thus, the 1 st lens group G1 has positive refractive power as a whole.
The 2 nd lens group G2 is composed of, in order from the object side, a 21 st lens group G21 having positive refractive power and a 22 nd lens group G22 having negative refractive power. The 21 st lens group G21 is composed of one positive lens L4. The 22 nd lens group G22 is composed of one negative lens L5. Thus, the 2 nd lens group G2 has positive refractive power as a whole.
The 3 rd lens group G3 has an aperture stop STO, a positive lens L6, and a positive lens L7 in this order from the object side.
The 1 st lens group G1 and the 2 nd lens group G2 constitute an afocal system, and an intermediate image is formed at an imaging position I11 between the 1 st lens group G1 and the 2 nd lens group G2. The conjugate image of the aperture stop STO is located closer to the object side than the 1 st lens group G1. The 3 rd lens group G3 is not magnified and the position of the aperture stop STO is fixed. Further, in the zoom positions Z1 to Z3, the aperture diameter of the aperture stop STO is fixed. Thus, the F value on the image side does not change at the zoom positions Z1 to Z3. The variable power objective lens 21 can reduce the measurement diameter by reducing the aperture diameter of the aperture stop STO from the state shown in (Z3) (refer to (Z4)).
Table 13 shows lens data of the variable power objective lens according to example 3.
[ Table 13]
Watch 13
r d nd vd eff.dia
OBJ INF 〔NF
1 INF a1 11.131
2 -15.302 0.12 1.7546 28.12 15.013
3 91.743 a2 16.385
4* 176.128 3.03 1.6698 52.32 17.166
5 -14.034 0.30 17.252
6 14.590 6.99 1.5531 64.44 19.855
7 73.323 1.43 18.411
8 INF a3 18.009
9 INF a4 9.318
10 INF 20.36 7.378
11 9.957 a5 1.5964 55.36 9.567
12* --7.551 3.29 9.430
13 --7.695 a6 1.6892 30.85 5.665
14 12.049 2.38 5.570
Diaphragm INF 1.23 5.361
16 -146.882 2.45 1.4911 70.01 6.252
17 -5.893 10.17 6.851
18 364.407 0.82 1.5319 66.10 6.728
19 -10.263 6.18 6.726
IMG INF 0.00 4.002
Table 14 below shows the surface interval of the lens surfaces of the variable power objective lens according to example 3. In table 14, Z1 to Z4 correspond to Z1 to Z4 shown in fig. 4, and a1 to a6 correspond to a1 to a6 shown in table 13.
[ Table 14]
TABLE 14
a1 a2 a3 a4 a5 a6
Z1 30.98 1.000 19.43 0.5941 3.292 2.378
Z2 30.98 1.000 19.43 9.529 1.000 0.200
Z3 2.900 10.73 9.44 9.529 1.000 0.200
Z4 2.900 10.73 9.44 9.529 1.000 0.200
Table 15 and table 16 show the aspherical coefficients of the lens surfaces of example 3 as aspherical data. In addition, the coefficient of an item not marked in the aspherical surface data is 0.
[ Table 15]
TABLE 15 item 4
K 1.00000.E+00
A4 -2.43373.E-05
A6 -9.90736.E-07
A8 1.83871.E-08
A10 -1.21416.E-10
[ Table 16]
TABLE 16 side 12
K -2.16781.E+00
A4 3.94170.E-04
A6 2.90743.E-06
A8 -3.69111.E-07
A1 0 7.28811.E-09
Table 17 shows the characteristics of the variable magnification objective lens of example 3. It can be understood from table 17 that the image-side F value is fixed among the positions Z1, Z2, and Z3.
[ Table 17]
TABLE 17
FL Fno BF TL Yma× f12 η
Z1 -23.2501 --2.27 6.180 82.76 1.9 55.1962 --0.421
Z2 -14.0271 -2.27 6.180 87.22 1.9 34.1424 -0.411
Z3 -6.35250 -2.27 6.180 86.96 1.9 15.2975 -0.415
Z4 -6.35250 -5.68 6.180 86.96 1.9 15.2975 -0.415
Table 18 shows lens data of a single lens constituting the variable power objective lens according to example 3. The lens numbers 1 to 7 correspond to the reference numerals L1 to L7 shown in fig. 4, respectively.
[ Table 18]
Watch 18
Lens numbering Noodle numbering Focal length
1 2~3 -17.3701
2 4~5 19.5316
3 6~7 31.5903
4 11~12 7.68781
5 13~14 -6.79669
6 16~17 12.4303
7 18~19 18.7789
Next, table 19 shows the conditional expression correspondence values of the respective examples. In Table 19, η of each example max The expression represents the value of η whose absolute value is the largest among the values of η at positions Z1 to Z4 (see table 5, table 11, and table 17). In example 1,. Eta. max Is the value of η at position Z2, in examples 2 and 3, η max Is the value of η in position Z1.
[ Table 19]
Watch 19
Figure BDA0004000670720000181
While the embodiments and examples of the present invention have been described, the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and all changes that come within the meaning and range equivalent to the claims are intended to be embraced therein.
Description of the reference numerals
10: a light and color meter; 12: a display surface; 14: measuring the probe head; 16: a measuring instrument main body; 21: a zoom objective lens; 23: a filter section; 24: a beam splitting member; 25: a photoelectric conversion unit; 26: an amplifying part; 27: a measurement optical system; 28: a light receiving system; 31: an A/D conversion unit; 32: a data storage; 34: a display unit; 35: an operation unit; 36: a control unit; 37: a power supply unit; AR: a measured area; AX: an optical axis; g1: a1 st lens group; g2: a 2 nd lens group; g3: a 3 rd lens group; g11: an 11 th lens group; g12: a 12 th lens group; g21: a 21 st lens group; g22: a 22 nd lens group; i11: the imaging position of the intermediate image; l1, L5: a negative lens; l2, L3, L4, L6, L7: a positive lens; z1 to Z4: a zoom position.

Claims (10)

1. A variable power objective lens, in which an intermediate image is formed at a position conjugate to an image plane,
the object side sequentially has:
a1 st lens group as a variable power group;
a 2 nd lens group as a variable power group; and
a 3 rd lens group which is not substantially changed in magnification,
in the magnification variation, the interval between two adjacent lens groups among the 1 st lens group, the 2 nd lens group, and the 3 rd lens group is changed,
the intermediate image is formed between the 1 st lens group and the 2 nd lens group,
the 3 rd lens group is provided with an aperture diaphragm,
the aperture stop is disposed such that a conjugate image of the aperture stop is located on the object side of the 1 st lens group.
2. Variable power objective lens according to claim 1, wherein,
the combined focal length of the 1 st lens group and the 2 nd lens group at the d-line is set as f12,
the focal length of the entire optical system of the variable power objective lens is set to FL,
let η = FL/f12,
then eta is more than-0.5 and less than 0.5.
3. Variable power objective lens according to claim 1 or 2,
the 1 st lens group includes, in order from the object side:
an 11 th lens group having a negative refractive power; and
and a 12 th lens group having a positive refractive power.
4. Variable power objective lens according to any one of claims 1 to 3,
the 2 nd lens group includes, in order from the object side:
a 21 st lens group having a positive refractive power; and
and a 22 nd lens group having a negative refractive power.
5. Zoom objective lens according to any one of claims 1 to 4,
defining a magnification β 1 of the 1 st lens group as β 1= ft1/fw1 by a focal length ft1 at a telephoto end of the 1 st lens group and a focal length fw1 at a wide-angle end of the 1 st lens group,
and the focal length ft2 at the telephoto end of the 2 nd lens group and the focal length fw2 at the wide-angle end of the 2 nd lens group define the magnification β 2 of the 2 nd lens group as β 2= ft2/fw2,
the magnification beta 1 of the 1 st lens group is 1 < beta 1 < 2.5,
the magnification β 2 of the 2 nd lens group is 0.2 < β 2 < 0.8.
6. Zoom objective lens according to claim 5,
when a zoom ratio γ is defined as γ = β 1 [. Beta.2 ] by the magnification ratio β 1 of the 1 st lens group and the magnification ratio β 2 of the 2 nd lens group,
gamma is more than or equal to 0.5 and less than or equal to 1.5.
7. Zoom objective lens according to any one of claims 1 to 6,
the absolute value | Fno | of the F value Fno on the image side in each zoom position of the variable power objective lens satisfies 1 < | Fno | < 6,
the difference between the F values Fno between the zoom positions is 3.5 or less.
8. Zoom objective lens according to any one of claims 1 to 7,
the incident angle of the principal ray to the image plane is 5 degrees or less.
9. Zoom objective lens according to any one of claims 1 to 8,
the aperture system of the aperture stop is variable.
10. A photometry colorimeter includes:
zoom objective lens according to any one of claims 1 to 9.
CN202180042744.8A 2020-06-19 2021-03-30 Variable-power objective lens and photometry colorimeter provided with same Pending CN115917392A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2020-106186 2020-06-19
JP2020106186 2020-06-19
PCT/JP2021/013654 WO2021256049A1 (en) 2020-06-19 2021-03-30 Variable magnification objective lens and photometric colorimeter provided therewith

Publications (1)

Publication Number Publication Date
CN115917392A true CN115917392A (en) 2023-04-04

Family

ID=79267826

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202180042744.8A Pending CN115917392A (en) 2020-06-19 2021-03-30 Variable-power objective lens and photometry colorimeter provided with same

Country Status (3)

Country Link
JP (1) JPWO2021256049A1 (en)
CN (1) CN115917392A (en)
WO (1) WO2021256049A1 (en)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000122110A (en) * 1998-10-14 2000-04-28 Canon Inc Relay optical system and camera system provided therewith
JP4061152B2 (en) * 2002-08-08 2008-03-12 オリンパス株式会社 Zoom photography optics
US7283309B2 (en) * 2004-08-20 2007-10-16 Panavision International, L.P. Wide-range, wide-angle, rotatable compound zoom
US7227682B2 (en) * 2005-04-08 2007-06-05 Panavision International, L.P. Wide-range, wide-angle compound zoom with simplified zooming structure
JP6570493B2 (en) * 2016-08-30 2019-09-04 富士フイルム株式会社 Zoom lens, projection display device, and imaging device

Also Published As

Publication number Publication date
JPWO2021256049A1 (en) 2021-12-23
WO2021256049A1 (en) 2021-12-23

Similar Documents

Publication Publication Date Title
US20180329200A1 (en) Eyepiece optical system, optical apparatus and method for manufacturing eyepiece optical system
US9664886B2 (en) Microscope tube lens, microscope apparatus and image pickup optical system
KR102242464B1 (en) Imaging lens and imaging apparatus
US9482852B2 (en) Zoom lens and image pickup apparatus having the same
JP4869813B2 (en) Image reading lens, image reading optical system, and image reading apparatus
US20130208173A1 (en) Tele-side converter lens and image pickup apparatus including the same
US8194329B2 (en) Variable magnification optical system and imaging apparatus
US11054630B2 (en) Camera lens system for an endoscope, method for producing a camera lens system and an endoscope
JP2018066978A (en) Imaging lens
KR20200089235A (en) Photographic objective having at least six lenses
US11199699B2 (en) Camera lens assembly
EP2610662B1 (en) Microscope optical assembly and microscope system
CN111522132B (en) Visible light near-infrared wide-spectrum apochromatic image telecentric lens and application thereof
CN107430260A (en) Strabismus objective lens optical system and the strabismus endoscope for possessing the strabismus objective lens optical system
CN113447119B (en) Line spectrum confocal sensor
CN115917392A (en) Variable-power objective lens and photometry colorimeter provided with same
JP2011028009A (en) Lens for image acquisition
US7154683B1 (en) Five-element optical device
JP2006276609A (en) Imaging lens
US20200412921A1 (en) Optical apparatus and imaging system having the same
TWI683090B (en) Optical system for measurement, color luminance meter and color meter
US20150043063A1 (en) Catadioptric system and image pickup apparatus including the system
JP2020118779A (en) Far-infrared zoom optical system
CN112987270A (en) Optical lens and method for manufacturing the same
WO2024058090A1 (en) Imaging lens and imaging device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination