WO2022220069A1

WO2022220069A1 - Pupil module and inspection device

Info

Publication number: WO2022220069A1
Application number: PCT/JP2022/014392
Authority: WO
Inventors: 隆史小原; 敦彦和食; 孝義小野; 大樹堤
Original assignee: 株式会社インターアクション
Priority date: 2021-04-15
Filing date: 2022-03-25
Publication date: 2022-10-20
Also published as: TW202246744A; TWI817427B; JP2022164665A; JP2022164061A; JP7128403B1; JP7388766B2

Abstract

This pupil module that allows inspection light from a light source device to pass toward a solid-state imaging element comprises a peripheral surface and a pinhole. The peripheral surface surrounds the optical axis so as to follow the same and is capable of reflecting light. The pinhole is positioned on the emission side of the peripheral surface in a direction following the optical axis.

Description

Pupil module and inspection device

The present disclosure relates to a pupil module that passes inspection light from a light source device toward a solid-state imaging device, and an inspection device that includes the pupil module.

A pupil module that passes inspection light from a light source device toward a solid-state imaging device is known (for example, Patent Document 1). Such pupil modules serve, for example, for illumination homogenization and/or solid angle adjustment. The pupil module of Patent Document 1 has a cylindrical member (lens barrel) with a pinhole formed on one end face, and has a lens and a diffusion plate inside the cylindrical member. This pupil module is arranged so that the pinhole faces the solid-state imaging device. The pinhole adjusts, for example, the solid angle (diffuse angle from another point of view) of light irradiated to the solid-state imaging device. The lens converges on the pinhole the light that has entered the cylindrical member from the end opposite to the pinhole. The diffuser plate is positioned between the lens and the pinhole to diffuse the light (or, from another point of view, equalize the intensity of the light across the cross section of the optical path).

Japanese Patent Application Laid-Open No. 2004-266250

Pupil modules and inspection devices that can improve at least some performance (eg, light transmittance and/or diffusion function) are awaited.

A pupil module according to an aspect of the present disclosure is a pupil module that passes inspection light from a light source device toward a solid-state imaging device, surrounds an optical axis, and is capable of reflecting light. and a pinhole located on the output side of the peripheral surface in the direction along the optical axis.

An inspection apparatus according to an aspect of the present disclosure includes the pupil module, a probe card on which the pupil module is mounted, and the light source device.

According to the above configuration, the performance of at least part of the pupil module is improved.

FIG. 2 is a schematic cross-sectional view showing the configuration of the essential parts of the inspection apparatus according to the first embodiment; FIG. 2 is a schematic perspective view of a pupil module included in the inspection apparatus of FIG. 1; 3 is a schematic cross-sectional view of the pupil module of FIG. 2; FIG. FIG. 5 is a schematic cross-sectional view showing a light pipe according to a modification; FIG. 5 is a schematic cross-sectional view of a pupil module according to a second embodiment; FIG. 8 is a schematic cross-sectional view of a pupil module according to a third embodiment; FIG. 11 is a schematic cross-sectional view of a pupil module according to a fourth embodiment; Typical sectional drawing which shows the pinhole which concerns on a modification. FIG. 11 is a schematic cross-sectional view of a pupil module according to a fifth embodiment; FIG. 11 is a schematic cross-sectional view of a pupil module according to a sixth embodiment; 9 is a schematic cross-sectional view showing a pinhole according to a modification different from FIG. 8. FIG.

A plurality of aspects (embodiments and modifications) according to the present disclosure will be described below with reference to the drawings. Note that, in the description of aspects other than the first embodiment, basically, only points of difference from the previously described aspects will be described. Matters not particularly mentioned may be the same as the previously described aspects, or may be inferred from the previously described aspects. In addition, for the sake of convenience, the same reference numerals may be given to configurations that correspond to each other in a plurality of aspects even if there are differences.

The drawings are schematic. Therefore, for example, the dimensional ratios do not necessarily match the actual ones, and they may not match between drawings showing the same members. Also, for example, details of the shape of the member may be omitted.

In the description of the embodiments, the "diameter" may be the diameter or equivalent circle diameter unless otherwise specified. Unless otherwise specified, the “reflectance” may be the reflectance for visible light (for example, wavelengths of 380 nm to 780 nm) at an incident angle of 0°. Unless otherwise specified, the "angle of diffusion" may be the full-width (FWHM: Full Width at Half Maximum) of the half value of the central illuminance. The term "light pipe" may be interpreted broadly and may be synonymous with "rod integrator".

<First embodiment>
(Inspection device)
FIG. 1 is a schematic cross-sectional view showing the configuration of main parts of an inspection apparatus 1 according to the first embodiment. Note that any direction of the inspection apparatus 1 may be upward. However, in the following description, for the sake of convenience, the upper side of FIG. 1 may be expressed assuming that the actual upper side.

The inspection apparatus 1 inspects the imaging device 103 by irradiating the imaging device 103 with light. The imaging element 103 is a solid-state imaging element such as a CCD (Charge Coupled Device) image sensor and a CMOS (Complementary Metal Oxide Semiconductor) image sensor. In the illustrated example, the inspection apparatus 1 inspects the imaging device 103 included in the wafer 101 . However, unlike the illustrated example, the inspection apparatus 1 may inspect individualized imaging elements 103 . In the following description, for the sake of convenience, expressions may be made assuming that the inspection apparatus 1 inspects the wafer 101 .

The imaging element 103 may be intended to detect light in a predetermined wavelength range (for example, visible light wavelength range), or ideally to detect light having one wavelength such as laser light. may be intended. In the former case, the light with which the imaging device 103 is irradiated by the inspection apparatus 1 is, for example, light having power (or relatively high power light) over the entire wavelength range that the imaging device 103 is to detect. ), or light having power within a specific width within the wavelength band. In the latter case, the light that the inspection apparatus 1 irradiates the imaging device 103 has, for example, light having a wavelength that the imaging device 103 is to detect (strictly speaking, it is in a narrow wavelength range including the wavelength). light having power).

The type of light intended to be detected by the imaging device 103 (in another aspect, the product including the imaging device 103) (in another aspect, the type of light irradiated to the imaging device 103 by the inspection apparatus 1) is arbitrary. is. For example, the light to be detected may be visible light (an example of the wavelength range has already been described) or invisible light. Examples of invisible light include infrared rays, which have longer wavelengths than visible light, and ultraviolet rays, which have shorter wavelengths than visible light. The detection target may be light in a wavelength range that is more finely classified than visible light, infrared rays, or ultraviolet rays. Conversely, light over two or more wavelength ranges of visible light, infrared light, and ultraviolet light may be detected. It was previously stated that the “reflectance” may refer to visible light. When possible, the reflectance of that non-visible light may be applied to the following description.

The inspection device 1 has, for example, the following components. Table 3 holding wafer 101; A light source device 5 that generates light for inspection. One or more (four in the illustrated example) pupil modules 7 for passing light from the light source device 5 to the image sensor 103 . A probe card 9 electrically connected to the imaging element 103 . A computing unit 11 that controls the table 3 and the light source device 5 and controls and diagnoses the imaging element 103 via the probe card 9 .

Except for the configuration of the pupil module 7, the configuration of the inspection device 1 may be various configurations, for example, it may be a known configuration (of course, it may be a new configuration). In the description of the embodiment, the description of the configuration other than the pupil module 7 will be omitted as appropriate. In the following, first, the configuration other than the pupil module 7 will be briefly described, and then the pupil module 7 will be described.

The table 3 has an appropriate type of chuck such as a vacuum chuck or an electrostatic chuck, and holds the wafer 101 on its upper surface. The table 3 can move, for example, along each of the three axes of the orthogonal coordinate system. Thereby, for example, it is possible to position the pupil module 7 and the probe card 9 with respect to the imaging device 103 (relative movement from another point of view).

For example, the light source device 5 has at least a light source, although not particularly shown, and may have a lens, diaphragm, filter and/or mirror located on the optical path from the light source, if necessary. The light source device 5 irradiates the pupil module 7 with light, for example, with the vertical direction in FIG. 1 as a direction parallel to the optical axis. The light emitted by the light source device 5 may be, for example, uniform in intensity in the cross section and telecentric.

The probe card 9 includes, for example, one or more circuit boards. Since FIG. 1 is a schematic diagram, all of the various members (including one or more circuit boards) constituting the probe card 9 are given the same hatching. In addition, in FIG. 1, not only the body portion of the probe card 9 (the portion mainly composed of the circuit board) but also the portion fixed to the body portion (for example, the portion contributing to the support of the pupil module 7) is the probe card 9. is considered as part of When conceptualized in this way, the overall shape of the probe card 9 does not necessarily have to be card-like.

The probe card 9 has, for example, one or more (a plurality in the illustrated example, more specifically four) openings 9h through which the light that has arrived from the light source device 5 via the pupil module 7 passes through to the imaging element 103. have. For example, one aperture 9h is provided for one imaging element 103 . However, it is also possible to provide one aperture 9h for two or more imaging elements 103 . Further, the probe card 9 has pins 9 a that contact pads (not shown) of one or more (four in the illustrated example) imaging elements 103 . The number of pins 9a provided for one imaging device 103 may be set as appropriate.

The computing unit 11 is configured including, for example, a computer. The calculation unit 11 , for example, controls a driving unit (not shown) of the table 3 to position the imaging device 103 and the probe card 9 . Further, the calculation unit 11 controls the light source of the light source device 5 and the like to irradiate the imaging device 103 with light from the light source device 5 via the pupil module 7 and the opening 9h of the probe card 9 . The computing unit 11 is electrically connected to the imaging element 103 via the probe card 9 , controls the imaging element 103 , and acquires signals from the imaging element 103 . Then, the calculation unit 11 diagnoses whether the imaging element 103 is good or bad based on the acquired signal.

(Outline of pupil module)
FIG. 2 is a perspective view schematically showing four pupil modules 7 shown in FIG.

As shown in FIGS. 1 and 2, the pupil module 7 has, for example, a substantially cylindrical outer shape, and allows light from the light source device 5 to pass through in its axial direction. In other words, the pupil module 7 has a first end 8A and a second end 8B, which are both ends in the axial direction, and causes light incident from the first end 8A to exit from the second end 8B. In the process, the pupil module 7 adjusts the light intensity distribution in the cross section of the light (e.g., homogenizes the intensity) and/or adjusts the solid angle and/or the diffusion angle of the light illuminating the image sensor 103 . to adjust.

The specific shape of the outer shape of the pupil module 7 is arbitrary. For example, the outer shape of the pupil module 7 may be straight columnar (illustrated example) or oblique columnar. However, in the description of the embodiments, a straight columnar shape is mainly taken as an example, and expressions based on the straight columnar shape may be used. Further, the outer shape of the pupil module 7 may be cylindrical or prismatic. The length of the pupil module in the axial direction (the direction parallel to the optical axis) may be longer than the diameter (example shown) or shorter. In the illustrated example, the outer shape of the pupil module 7 is a substantially cylindrical shape with a flange 8C provided on the first end 8A side.

In the example of FIG. 1, the pupil module 7 is supported by the probe card 9. Specifically, the pupil module 7 is inserted through a hole (reference numeral omitted; the concept may include the opening 9h) penetrating the probe card 9 vertically, and the flange 8C is attached to the upper surface of the probe card 9. engaged. Furthermore, the flange 8C and the probe card 9 may be fixed with screws (not shown). Unlike the illustrated example, the pupil module 7 may be supported by a member separate from the probe card 9 or may be movably supported by a drive mechanism relative to the probe card 9 .

An arbitrary number of pupil modules 7 may be provided for one probe card 9 (the inspection apparatus 1 from another point of view; the same shall apply hereinafter). For example, the number of pupil modules 7 arranged in one probe card 9 may be one, or may be plural (example shown). In the latter case, the number of pupil modules 7 may be the same as the number of imaging elements 103 included in the wafer 101, or may be different (for example, it may be less as in the illustrated example).

When the number of pupil modules 7 is plural, their arrangement is also arbitrary. For example, the pupil modules 7 may be arranged in one row (the example shown), or in two or more rows. The number of columns is arbitrary, and the number of columns may be the same or different. The pitch of the pupil modules 7 may be, for example, the same as the pitch of the imaging elements 103 within the wafer 101, or may be an integer multiple.

(Internal structure of pupil module)
FIG. 3 is a cross-sectional view of pupil module 7 .

The pupil module 7 has, for example, a cylindrical member 13 and optical components held by the cylindrical member 13 . The optical components are two dimming filters 15 and a light pipe 17 in the example shown. The cylindrical member 13 contributes, for example, to holding the optical components and to reducing the influence of unintended light from outside the pupil module 7 . The light control filter 15 contributes to, for example, adjustment of the amount of light. The light pipe 17 contributes, for example, to improving the transmittance of the pupil module.

Note that the optical axis LA is shown in FIG. The illustrated optical axis LA may be regarded as the optical axis of the pupil module 7 or may be regarded as the optical axis of each part of the pupil module 7 such as the light pipe 17 . The optical axis LA is, for example, a virtual ray representative of the luminous flux passing through the pupil module 7 or each part.

(cylindrical member)
The tubular member 13 is, as its name suggests, a tubular member. The tubular member 13 has a tubular body 13a around the axis and an end surface portion 13b that closes the second end 8B side of the tubular body 13a. The first end 8A side of the cylinder main body 13a is open, and an opening 19 is formed. A pinhole 21 is opened in the end surface portion 13b. Light from the light source device 5 enters the aperture 19 and exits from the pinhole 21 .

Since FIG. 3 is a schematic diagram, the entire cylindrical member 13 is indicated by one hatching. The actual cylindrical member 13 may be integrally formed as a whole as shown in the drawing, or may be constructed by combining a plurality of members unlike the drawing.

The specific shape of the tubular member 13 is arbitrary. For example, the outer shape of the cylindrical member 13 constitutes most of the outer shape of the pupil module 7 , and the above description of the outer shape of the pupil module 7 may be used for the outer shape of the cylindrical member 13 . The shape of the inner surface (in other words, the inner space) of the cylindrical member 13 is, for example, a substantially straight columnar shape similar to the outer shape, and more specifically, a columnar or prismatic shape, for example. The outer shape and inner surface shape of the cylindrical member 13 may be similar (from another point of view, the thickness of the cylindrical member 13 may be substantially constant), or may be completely different shapes. Note that the similarity here is not limited to strict similarity in mathematics.

The shape of the opening 19 is arbitrary. For example, the shape of the opening 19 when viewed in the direction of the optical axis LA may be the same shape as most of the inner space of the cylindrical member 13, or may be a different shape. Polygon. In the illustrated example, the opening 19 has a slightly larger diameter than most of the internal space of the cylindrical member 13 for the placement of the light control filter 15 . However, such a diameter expansion may not be performed, and conversely, the diameter may be made smaller than most of the inner space of the tubular member 13 .

The shape of the pinhole 21 is arbitrary. For example, the shape of the cross section of the pinhole 21 (the cross section perpendicular to the optical axis LA) may be circular or polygonal. The shape of the cross section of the pinhole 21 (diameter in another point of view) may be constant (the example shown in the figure) or may vary in the penetrating direction of the pinhole 21 . As the latter, a part or the whole of the pinhole 21 in the penetrating direction may have a shape that expands or contracts downward.

Various dimensions (for example, the diameter of the opening 19, the diameter of the pinhole 21, the distance from the opening 19 to the pinhole 21) in the cylindrical member 13 are required for the size of the image pickup device 103 and inspection of the image pickup device 103. It may be appropriately set according to the illuminance or the like. The diameter of pinhole 21 is smaller than the diameter of opening 19 . Note that the diameter here may be a diameter that substantially contributes to the transmission of light. For example, in the illustrated example, when telecentric light from the light source device 5 is incident on the light control filter 15, the amount of light passing through the pupil module 7 is hardly increases. In such a case, the diameter of the portion below the enlarged diameter portion is regarded as the diameter of the opening 19, or the diameter of the light beam that can reach the pinhole 21 near the opening 19 is regarded as the diameter of the opening 19. You can

Give an example of dimensions. The diameter of the pinhole 21 may be 0.1 mm or more and 5 mm or less, or 0.5 mm or more and 2 mm or less. On the premise that the diameter of the opening 19 is larger than the diameter of the pinhole 21, the diameter may be 1 mm or more and 50 mm or less, or 5 mm or more and 10 mm or less. The diameter of the opening 19 may be 2 to 20 times or 4 to 10 times the diameter of the pinhole 21 . The distance from the aperture 19 (incident side surface) to the pinhole 21 (output side surface) may be 5 mm or more and 60 mm or less, or 10 mm or more and 30 mm or less. Also, the distance may be 5 times or more and 60 times or less, or 10 times or more and 30 times or less, the diameter of the pinhole 21 .

The cylindrical member 13 has a light shielding property, and prohibits the entrance and exit of light from portions other than the opening 19 and the pinhole 21 . The cylindrical member 13 may be entirely made of a light-shielding material, or may be mostly made of a non-light-shielding material with a film made of a light-shielding material on the surface (for example, the inner surface). and/or outer surface).

The surface of the cylindrical member 13 may have a low or high light reflectance. For example, the reflectance of the cylindrical member 13 may be less than 10%, 10% or more and less than 50%, or 50% or more or 80% or more. Such a reflectance may be realized by the reflectance of the material that constitutes most or all of the cylindrical member 13, or by forming a film that reduces or increases the reflectance on the inner surface of the cylindrical member 13. may be implemented.

In general, the inner surface of the lens barrel of an optical device has a low reflectance. For example, the inner surface of the lens barrel is coated with black paint (in other words, a film that reduces reflection is formed). The reflectance of black paint is, for example, 6% or less, and there are some that are 1% or less. The inner surface of the cylindrical member 13 may have a relatively low reflectance as described above by being coated with black paint or the like, like a general lens barrel, or may have a reflectance that is lower than the reflectance described above. may also have high reflectance.

Any material can be used for the tubular member 13 . For example, the material that constitutes most (for example, other than the surface) or all of the cylindrical member 13 may be resin, metal, or ceramic. Further, as described above, a suitable film may be formed on the surface of the cylindrical member 13, and the material of this film is also arbitrary. Also, the film may be made of one material, or may be a laminate of two or more layers made of different materials. Materials for the film include, for example, paint of any color (eg, black). In addition, as described in the embodiments described later, metals (and dielectrics) can also be used as the material of the film.

The inside of the tubular member 13 may or may not be sealed. The sealing may be airtight or may be of a level that reduces the intrusion of foreign matter. In the case where the cylinder member 13 is airtightly sealed, the inside of the cylinder member 13 may be in a vacuum (strictly speaking, a state in which the pressure is reduced below the atmospheric pressure), or may be in a state in which an appropriate gas is enclosed. good.

(dimmer filter)
The light control filter 15 includes, for example, a glass substrate, and adjusts the amount of transmitted light depending on the presence or absence of an AR (anti-reflection) coat. In a mode in which a plurality of pupil modules 7 are provided for one probe card 9, this adjustment of the amount of transmitted light may reduce the difference in the amount of light between the pupil modules 7 . The size and position of the dimmer filter 15 may be set, for example, so that all the light that enters the light pipe 17 is light that has passed through the dimmer filter 15 . In the illustrated example, the light control filter 15 is provided so as to close the opening 19 .

Note that the light control filter 15 may not be provided. In the illustrated example, the dimmer filter 15 also contributes to sealing the inside of the tubular member 13 . If the chromatic filter 15 is not provided, the sealing of the pupil module 7 may be done by a transparent member which has another optical function or merely allows light to pass through.

(light pipe)
The light pipe 17 is made of, for example, translucent material. Also, the light pipe 17 is, for example, a solid rod-shaped member. In other words, the light pipe has a peripheral surface 17a that is a cylindrical surface that spreads around the optical axis LA, and an entrance surface 17b and an exit surface 17c that are end surfaces that intersect the optical axis LA on both sides of the peripheral surface 17a. and The entrance surface 17b is a surface on the opening 19 side, and the exit surface 17c is a surface on the pinhole 21 side.

At least part of the light incident on the entrance surface 17b is reflected once or more by the peripheral surface 17a and guided to the exit surface 17c. Thereby, for example, the light absorbed by the inner surface of the cylindrical member 13 is reduced, and the transmittance of the pupil module 7 is improved. From another point of view, the light is diffused by reflection on the peripheral surface 17a (from another point of view, the intensity of the light is made uniform). Further, in the light pipe 17 of the illustrated example, the tapered shape or the like allows light to be collected from the opening 19 to the pinhole 21, to improve the above-described diffusion action, and to adjust the diffusion angle (or the solid angle from another point of view). be. In a mode in which the light control filter 15 is not provided, the light pipe 17 may have the function of sealing the inside of the tubular member 13 .

The refractive index of the light pipe 17 is higher than that of its surroundings (vacuum or gas). From another point of view, the peripheral surface 17a constitutes an interface between media having different refractive indices. A portion of the light incident on the incident surface 17b and reaching the peripheral surface 17a is reflected by the peripheral surface 17a, and the other portion is transmitted through the peripheral surface 17a. Also, when the incident angle with respect to the peripheral surface 17a becomes smaller than a certain amount, so-called total reflection occurs. Thus, the peripheral surface 17a reflects light. As can be understood from this embodiment, when the peripheral surface 17a can reflect light, the reflectance of the peripheral surface 17a does not necessarily have to be high.

The material (refractive index from another point of view) of the light pipe 17 may be set appropriately. For example, the material of the light pipe 17 may be glass or resin. As the refractive index of the light pipe 17 increases, total reflection is more likely to occur on the peripheral surface 17a. The refractive index (absolute refractive index) of the material of the light pipe 17 may be, for example, 1.4 or more.

The specific shape of the light pipe 17 is arbitrary. In the illustrated example, the shape of the light pipe 17 (in other words, the peripheral surface 17a; hereinafter, the same applies in this paragraph and the next paragraph) is a tapered shape in which the cross section (the cross section perpendicular to the optical axis LA) becomes smaller toward the output side. (In other words, it has a frustum shape). Unlike the illustrated example, the shape of the light pipe 17 may be a constant columnar shape (for example, a straight columnar shape) regardless of the position of the optical axis LA, or may be a frustum. It may be a combination with a columnar body.

A more specific shape of the frustum or column in the light pipe 17 is also arbitrary. For example, the cross-sectional shape of the frustum or cylinder may be circular or polygonal. In other words, the shape of the light pipe 17 may be a truncated cone, a truncated pyramid, a cylinder, or a prism. The truncated cone shape may be a rotationally symmetrical shape with the optical axis LA as an axis of symmetry (example shown in the figure), or may not be so. In the longitudinal section of the frustum (the section parallel to the optical axis LA), the side surface of the frustum (peripheral surface 17a) may be straight or curved.

The inclination angle θ of the peripheral surface 17a with respect to the optical axis LA when the light pipe 17 is frustum-shaped may be appropriately set. For example, the inclination angle θ (when the peripheral surface 17a is not linear in the longitudinal section, for example, the inclination angle of an approximate straight line) may be greater than 0°, 1° or more, 3° or more, or 5° or more, and less than 45°. , 30° or less, or 15° or less, and the above lower and upper limits may be combined appropriately. For example, the tilt angle θ may be 5° or more and 15° or less.

The shapes of the entrance surface 17b and the exit surface 17c are also arbitrary. The shape of the cross section of the light pipe 17 (peripheral surface 17a) may be used for the planar shape of these surfaces. In the illustrated example, the incident surface 17b has a curved surface that bulges outward (in other words, a convex curved surface). Moreover, the exit surface 17c is planar. However, unlike the illustrated example, the incident surface 17b may be planar or concave curved. Further, the output surface 17c may be convex or concave. Combinations of the shapes (curved or flat) of the entrance surface 17b and the exit surface 17c are also arbitrary.

The curved surfaces of the entrance surface 17b and/or the exit surface 17c may be spherical or aspherical. Also, the radius of curvature or the focal length may be set appropriately. For example, when the entrance surface 17b is a convex curved surface, its center of curvature and/or focal point may be located within the light pipe 17. It may be located on the incident side of the center.

The surface properties of the peripheral surface 17a, the entrance surface 17b, and the exit surface 17c are arbitrary. For example, these surfaces are smooth surfaces. For example, the arithmetic mean roughness Ra of these surfaces may be 100 nm or less, 10 nm or less, or 1 nm or less. However, some or all of these surfaces may be intentionally roughened for the purpose of diffusion. In other words, the arithmetic mean roughness Ra may be larger than the above upper limit.

The dimensions of the light pipe 17 are arbitrary. For example, the dimensions exemplified as the dimensions of the cylindrical member 13 in the description of the cylindrical member 13 may be referred to as the dimensions of the frustum-shaped light pipe 17 instead of the dimensions of the cylindrical member 13 . Just to be sure, the diameter of the exit surface 17c may be 0.1 mm or more and 5 mm or less, or 0.5 mm or more and 2 mm or less. The diameter of the incident surface 17b may be 1 mm or more and 50 mm or less, or 5 mm or more and 10 mm or less, on the premise that it is larger than the diameter of the exit surface 17c. The diameter of the entrance surface 17b may be two to twenty times or four to ten times the diameter of the exit surface 17c. The length from the entrance surface 17b to the exit surface 17c on the optical axis LA may be 5 mm or more and 60 mm or less, or 10 mm or more and 30 mm or less. In addition, the distance may be 5 times or more and 60 times or less, or 10 times or more and 30 times or less, the diameter of the output surface 17c.

The position of the light pipe 17 with respect to the cylindrical member 13 may be set appropriately. In the illustrated example, the peripheral surface 17a is basically separated from the tubular member 13 (for example, the inner surface of the tubular main body 13a) except for a portion on the entrance surface 17b side and a portion on the exit surface 17c side. Further, the incident surface 17b is positioned inside the cylindrical member 13 . The exit surface 17c is located inside the pinhole 21 (more specifically, in the illustrated example, in the middle of the penetrating direction). When it is said that the peripheral surface 17a is separated from the tubular member 13, for example, the peripheral surface 17a may be separated from the tubular member 13 by 1/2 or more or 4/5 or more of the area.

Unlike the illustrated example, the peripheral surface 17a and the inner surface of the cylindrical member 13 may have the same shape and be in contact with each other. As a mode in which both have the same shape, for example, in the illustrated example, a mode in which the light pipe 17 is deformed into a straight columnar shape, or a mode in which the inner surface of the cylinder main body 13a is deformed into a frustum shape. can be mentioned. Also, in a mode in which the light control filter 15 is not provided inside the cylindrical member 13 , the incident surface 17 b may be positioned at the same position as the opening 19 or positioned outside the opening 19 . The exit surface 17c may be positioned above the pinhole 21 or below the pinhole 21. As shown in FIG.

The method of fixing the light pipe 17 to the tubular member 13 may be any appropriate method. In the illustrated example, a portion of the light pipe 17 on the output surface 17c side is fitted into a portion of the pinhole 21 (in contact with the inner surface of the pinhole 21). Also, a portion of the incident surface 17 b side is in contact with the inner surface of the cylindrical member 13 . Thereby, the light pipe 17 is fixed to the tubular member 13 . An adhesive interposed between the light pipe 17 and the cylindrical member 13 may be provided (or may not be provided) at the portion where the light pipe 17 and the cylindrical member 13 are in contact with each other.

Unlike the illustrated example, a portion may be provided that protrudes from the inner surface of the cylindrical member 13 and abuts on an appropriate position of the peripheral surface 17a. The cylindrical member 13 may be provided with a portion that abuts from above on a portion of the entrance surface 17b on the outer edge side. The cylindrical member 13 may be provided with a portion that abuts from below on a part of the exit surface 17c on the outer edge side.

As described above, the pupil module 7 that passes the inspection light from the light source device 5 toward the solid-state imaging device (imaging device 103) has the peripheral surface 17a and the pinhole 21. The peripheral surface 17a surrounds the optical axis LA and can reflect light. The pinhole 21 is positioned on the output side of the peripheral surface 17a in the direction along the optical axis LA.

Therefore, for example, the transmittance of the pupil module 7 is improved. Specifically, in a mode in which the peripheral surface 17 a is not provided, part of the light that enters the cylindrical member 13 through the opening 19 is deviated from the optical path toward the pinhole 21 and is absorbed by the inner surface of the cylindrical member 13 . be. In this embodiment, at least part of such light can be guided to the pinhole 21 by reflection on the peripheral surface 17a to improve the transmittance. As a result, for example, the illuminance in the image sensor 103 can be improved. From another point of view, the power consumption of the light source device 5 can be reduced and/or the size of the light source device 5 can be reduced.

When the pinhole 21 is located on the output side of the peripheral surface 17a in the direction along the optical axis LA, as understood from the above description of the pinhole 21 on the output surface 17c, With respect to the positional range in the direction along, part or all of the pinhole 21 may or may not overlap with the exit-side portion of the peripheral surface 17a. For example, if it can be reasonably said that the light passing through the area surrounded by the peripheral surface 17a passes through the pinhole 21, the pinhole 21 is positioned on the exit side of the peripheral surface 17a. It can be taken as Further, for example, the opening surface on the output side of the pinhole 21 is 1/5 of the length of the peripheral surface 17a in the direction parallel to the optical axis LA from the end surface (output surface 17c) on the output side of the peripheral surface 17a to the incident side. Alternatively, when the pinhole 21 is located on the exit side of the position separated by a distance of 1/10, it may be understood that the pinhole 21 is located on the exit side of the peripheral surface 17a.

The pupil module 7 may have a light shielding cylinder member 13 . The cylindrical member 13 may have an opening 19 into which light is incident at one end and a pinhole 21 having a smaller diameter than the opening 19 at the other end. The peripheral surface 17 a may be positioned inside the tubular member 13 .

In this case, for example, the probability that unintended light enters the area surrounded by the peripheral surface 17a and/or the pinhole 21 from the outside of the pupil module 7 is reduced. As a result, the light emitted from the pupil module 7 is stabilized.

The pupil module 7 may have a solid or hollow (solid in this embodiment) light pipe 17 having a peripheral surface 17a inside the tubular member 13, which is a separate member from the tubular member 13.

In this case, for example, theory and/or know-how related to the light pipe 17 can be used, which facilitates design. Also, for example, by using a commercially available light pipe 17, the pupil module 7 having the peripheral surface 17a can be realized at low cost. In addition, for example, the properties of emitted light required of the pupil module 7 differ depending on the type of the image pickup device 103, etc., but it is possible to change the design of only one of the light pipe 17 and the cylindrical member 13 to deal with this. .

The outer peripheral surface (surrounding surface 17a) of the light pipe 17 and the inner peripheral surface of the cylindrical member 13 may be separated. In this case, the peripheral surface 17a may be locally in contact with the inner peripheral surface of the cylindrical member 13, as understood from the illustrated example.

When the peripheral surface 17a and the cylindrical member 13 are separated from each other, for example, the light pipe 17 and the cylindrical member 13 can be designed separately. Moreover, since the surroundings of the peripheral surface 17a are in a vacuum or a gas, the conditions for causing total reflection are likely to be met. Moreover, the inconvenience that the joint state between the peripheral surface 17a and the cylindrical member 13 affects the reflection on the peripheral surface 17a is reduced.

The light pipe 17 may be solid, or may be curved such that the end surface (incident surface 17b) on the side where the light from the light source device 5 is incident bulges outward.

In this case, for example, the direction in the light pipe 17 of the luminous flux incident on the incident surface 17b can be adjusted. More specifically, for example, when telecentric light is incident on the incident surface 17b, the inclination angle of the light beam with respect to the optical axis LA can be increased to increase the light beam reaching the peripheral surface 17a. As a result, the light diffusion effect of the light pipe 17 is improved.

The peripheral surface 17a may have a smaller diameter toward the pinhole 21 side.

In this case, for example, the light pipe 17 contributes to collecting (condensing) the light incident on the incident surface 17b with a relatively large diameter onto the output surface 17c with a relatively small diameter. This reduces, for example, the need for a condenser lens on the entrance side of the pupil module 7 . By not providing a condenser lens (however, a mode in which a condenser lens is provided is also included in the technology according to the present disclosure), the size and simplification of the pupil module 7 and/or cost reduction can be achieved.

Furthermore, since the diameter is smaller toward the pinhole 21 side, for example, the light passing through the light pipe 17 is diffused according to the etendue law. Specifically, the diffusion angle (solid angle from another point of view) of the light beam emitted from the exit surface 17c (exit) is the entrance diameter/output It is multiplied by the aperture ratio. Therefore, the diffusion action of the peripheral surface 17a is improved.

Also, unlike the present embodiment, when the incident surface 17b is not convexly curved, when telecentric light is incident on the incident surface 17b, this light travels in the light pipe 17 parallel to the optical axis AL. At this time, the circumferential surface 17a, which has a smaller diameter toward the pinhole 21 side, reflects the light beam away from the optical axis AL among the telecentric light. This action also improves the diffusion action of the peripheral surface 17a.

The length parallel to the optical axis AL of the peripheral surface 17a may be greater than the diameter.

In this case, for example, compared to a mode in which the length of the peripheral surface 17a is shorter than the above (this mode may also be included in the technology according to the present disclosure), it is easier to increase the number of reflections by the peripheral surface 17a. As a result, the diffusion effect of the peripheral surface 17a is improved.

<Modified example of light pipe>
FIG. 4 is a cross-sectional view showing a light pipe 23 according to a modification.

While the light pipe 17 of the embodiment has a solid rod shape, the light pipe 23 according to the modified example has a hollow cylindrical shape. The light pipe 23 has a peripheral surface 23a surrounding the optical axis LA, an entrance 23b into which light enters, and an exit 23c from which light exits. A peripheral surface 17 a that reflects the light within the light pipe 17 was formed by the outer peripheral surface of the light pipe 17 . On the other hand, the peripheral surface 23 a that reflects the light inside the light pipe 23 is formed by the inner peripheral surface of the light pipe 23 .

The peripheral surface 17a of the light pipe 17 according to the embodiment has translucency. On the other hand, the peripheral surface 23a of the light pipe 23 according to the modification may function as a reflecting surface (for example, a mirror) that reflects light without substantially transmitting the light regardless of the incident angle. The reflectance of the peripheral surface 23a may be appropriately set. For example, the reflectance of the peripheral surface 23a may be 50% or more, 80% or more, or 90% or more.

In terms of materials, the configuration of the light pipe 23 is arbitrary. For example, although not shown, the light pipe 23 may have a base that forms most of the light pipe 23 and a reflective film that overlaps the inner peripheral surface of the base and forms a peripheral surface 23a. The substrate may be composed of one or more materials. Each of the one or more materials may be opaque or translucent. Materials for the base include, for example, glass, resin, and metal. Also, the reflective film may be composed of one material, or may be composed of layers of different materials. More specifically, for example, the reflective film may be a metal film, or may be a metal film overlaid with a dielectric layer having translucency. Alternatively, the light pipe 23 may be constructed entirely of a single, relatively highly reflective material (eg, metal).

For the shape and dimensions of the peripheral surface 23a and/or the outer peripheral surface of the light pipe 23, the description of the peripheral surface 17a of the light pipe 17 may be used as appropriate. The thickness of the light pipe 23 is, for example, generally constant throughout the light pipe 23 . In other words, the peripheral surface 23a and the outer peripheral surface of the light pipe 23 are similar. However, unlike the illustrated example, the thickness of the light pipe 23 may not be constant. For example, the shape of the peripheral surface 23a may be substantially the same as the peripheral surface 17a of the first embodiment (frustum shape), while the shape of the outer peripheral surface may be a columnar shape that fits into the tubular member 13. .

The light pipe 23 according to such a modified example may be used in place of the light pipe 17 in the first embodiment and other embodiments having the light pipe 17 (described later). Even when the light pipe 23 is used instead of the light pipe 17, the same effects as those of the embodiment can be obtained.

<Second embodiment>
FIG. 5 is a cross-sectional view showing the configuration of a pupil module 207 according to the second embodiment, and corresponds to FIG. 3 of the first embodiment.

A pupil module 207 according to the second embodiment is obtained by adding a diffusion plate 25 to the pupil module 7 according to the first embodiment. The diffuser plate 25 diffuses the light while transmitting the light. Thereby, for example, the light emitted from the pupil module 207 has a more uniform intensity in the cross section. It should be noted that, in the first embodiment, the transmittance of the pupil module is higher than in the second embodiment.

The diffusion plate 25 is positioned on the incident side with respect to the light pipe 17 (peripheral surface 17a). More specifically, the diffuser plate 25 is located inside the cylindrical member 13 and, from another point of view, is located between the light control filter 15 (or the opening 19 from another point of view) and the light pipe 17. there is Note that, unlike the illustrated example, the diffusion plate 25 can also be positioned outside the cylindrical member 13 . For example, the diffusion plate 25 may overlap the upper end of the cylindrical member 13 so as to close the opening 19 from the outside, or may be arranged at a position spaced upward from the upper end of the cylindrical member 13 (opening 19). . In the direction parallel to the optical axis LA, the distance between the aperture 19 and the diffusion plate 25 and the distance between the diffusion plate 25 and the light pipe 17 are arbitrary.

The shape and size (and position) of the diffuser plate 25 may be set, for example, so that substantially all light entering the light pipe 17 is light that has passed through the diffuser plate 25 . For example, in the illustrated example, the diffusing plate 25 is disposed inside the cylindrical member 13 and has a width covering the entire cross section of the inner space of the cylindrical member 13, whereby the above light relationship has been realized. Unlike the illustrated example, in a mode in which the diffuser plate 25 is spaced upward from the opening 19, the above light relationship is realized by making the area of the diffuser plate 25 sufficiently large with respect to the area of the opening 19. may be

The specific material, shape, dimensions, etc. of the diffusion plate 25 may be set as appropriate. For example, the material of the entire diffuser plate 25 or the base material of the diffuser plate 25 is a translucent material such as glass or resin. The diffuser plate 25 may have a plate shape with a substantially constant thickness. The thickness of the diffuser plate 25 may be appropriately set according to the required action and the like.

In a mode in which the diffusion plate 27 is positioned inside the cylindrical member 13 as in the illustrated example, the shape and dimensions of the diffusion plate 25 in a plan view are, for example, the shape and dimensions of the cross section of the internal space of the cylindrical member 13 . A description of dimensions may be used. Further, in a mode in which the diffusion plate 27 is positioned outside the cylindrical member 13 , the diffusion plate 25 may have an area larger than the internal space of the cylindrical member 13 or the cross section of the entirety.

In the illustrated example, the diffusion plate 25 is wider than the incident surface 17b and includes the incident surface 17b when viewed parallel to the optical axis LA. However, the diffusion plate 25 may have the same width as the incident surface 17b, or may be narrower than the incident surface 17b. The latter aspect may occur, for example, due to the convenience of the portion of the tubular member 13 that holds the diffuser plate 25 and/or the light pipe 17 .

The diffusion plate 25 may have various configurations for diffusing light. For example, the diffusion plate 25 may have unevenness on one surface or both surfaces. The light passing through the diffusion plate 25 is diffused by being refracted by the unevenness of the surface. The surface roughness Ra of the uneven surface may be, for example, 200 nm or more, 1 μm or more, 10 μm or more, or 100 μm or more. The diffusing plate 25 having unevenness on the surface may be regarded as having randomly arranged microlenses having different sizes. Further, the diffuser plate 25 may have fine particles inside instead of or in addition to the irregularities on the surface. Light passing through the diffuser plate 25 may be diffused by being reflected by these minute particles.

The transmittance and diffusion angle of the diffusion plate 25 may be set arbitrarily. In this embodiment, the light pipe 17 has a diffusion effect. Therefore, the diffusion plate 25 may have a relatively high transmittance and/or a low diffusion effect compared to the diffusion plate of the conventional pupil module. For example, the diffuser plate 25 may have a transmittance of 70% or more, 80% or more, or 90% or more. Also, the diffusion angle of the diffusion plate 25 may be 40° or less, 30° or less, or 20° or less.

The method of fixing the diffusion plate 25 to the cylindrical member 13 may be an appropriate method. In the illustrated example, the inside of the cylindrical member 13 has a larger diameter on the opening 19 side than on the pinhole 21 side. Then, the diffuser plate 25 is inserted from the opening 19 side and engages with the step formed by the diameter expansion. Thereby, the diffusion plate 25 is held by the cylindrical member 13 . An adhesive may be interposed between the diffuser plate 25 and the cylindrical member 13 (it may not be interposed). Unlike the illustrated example, for example, when the cylindrical member 13 is composed of two or more members, the diffusing plate 25 can be inserted from the pinhole 21 side or can be inserted into the cylindrical member 13 appropriately in the direction of the optical axis LA. It may be sandwiched between parts.

As described above, in this embodiment, the diffusion plate 25 is provided on the incident side of the peripheral surface 17a. In this case, for example, the diffusion effect of the pupil module 207 is improved, as already mentioned. Furthermore, since the light diffused by the diffusion plate 25 is incident on the light pipe 17, the luminous flux that reaches the peripheral surface 17a of the light pipe 17 and is reflected tends to increase. As a result, the diffusion effect of the light pipe 17 is improved. In other words, the combination of the diffuser plate 25 on the incident side and the light pipe 17 produces a synergistic effect rather than a mere additive effect.

<Third Embodiment>
FIG. 6 is a cross-sectional view showing the configuration of a pupil module 307 according to the third embodiment, and corresponds to FIG. 3 of the first embodiment.

A pupil module 307 according to the third embodiment is obtained by changing the position of the diffusion plate with respect to the pupil module 207 according to the second embodiment. That is, in the pupil module 207 , the diffuser plate 25 is positioned on the incident side of the light pipe 17 , whereas in the pupil module 307 the diffuser plate 27 is positioned on the exit side of the light pipe 17 .

A more detailed position of the diffusion plate 27 may be set as appropriate. For example, the diffusion plate 27 is positioned inside the cylindrical member 13 . However, the diffuser plate 27 may be positioned outside the tubular member 13 . For example, the diffusion plate 27 may overlap the lower end of the cylindrical member 13 so as to close the pinhole 21 from the outside, or may be arranged at a position spaced downward from the lower end of the cylindrical member 13 (the pinhole 21). good too. The distance between the light pipe 17 and the diffusion plate 27 and the distance between the diffusion plate 27 and the pinhole 21 are arbitrary in the direction parallel to the optical axis LA.

The shape and dimensions (and position) of the diffuser plate 27 are, for example, such that substantially all light emitted from the exit surface 17c of the light pipe 17 enters the diffuser plate 27 and/or passes through the pinholes 21. It may be set so that substantially all the light that passes through diffuser plate 27 . In the illustrated example, the diffuser plate 27 overlaps the entire surface of the exit surface 17c and closes the pinhole 21, thereby realizing the above light relationship. Unlike the illustrated example, for example, in a mode in which the diffusion plate 27 is spaced downward from the pinholes 21 , the area of the diffusion plate 27 is made sufficiently large with respect to the area of the pinholes 21 so that the pinholes 21 substantially all light passing through the diffuser plate 27 .

The specific material, shape, dimensions, and configuration for diffusing light of the diffuser plate 27 may be set as appropriate. The description of the material, shape, dimensions, and configuration for diffusing light of the diffuser plate 25 may be applied to the diffuser plate 27 as long as there is no contradiction. In the illustrated example, the diffuser plate 27 is narrower than the cross section of the internal space of the cylindrical member 13 when viewed parallel to the optical axis LA. However, the diffuser plate 27 may have a width covering the entire cross section of the internal space of the cylindrical member 13 . Further, in a mode in which the diffusion plate 27 is positioned outside the cylindrical member 13 , the diffusion plate 27 may have an area wider than the internal space of the cylindrical member 13 or the cross section of the entirety.

The transmittance and diffusion angle of the diffusion plate 27 may be set arbitrarily. As in the second embodiment, the light pipe 17 has a diffusing effect, so that the diffusing plate 25 can have a relatively high transmittance and/or a low diffusing effect. Therefore, for example, the lower limit of the transmittance and the upper limit of the diffusion angle exemplified in the second embodiment may be applied to the present embodiment. However, unlike the diffuser plate 25 of the second embodiment, the diffuser plate 27 of this embodiment does not have the effect of increasing the light flux that reaches the peripheral surface 17a and is reflected. Therefore, instead of the diffuser plate 25, the diffuser plate 27 may have a lower transmittance or a larger diffusion angle. For example, the diffusion angle of the diffusion plate 27 may be 70° or more and 90° or less.

The method of fixing the diffusion plate 27 to the cylindrical member 13 may be an appropriate method. In the illustrated example, a concave portion (reference numeral omitted) having a diameter larger than that of the pinhole 21 is formed on the inner surface (upper surface) of the end surface portion 13b of the tubular member 13 . The diffuser plate 27 is fitted in the recess. An adhesive may be interposed between the diffuser plate 27 and the cylindrical member 13 (it may not be interposed). Unlike the illustrated example, for example, a diffusing plate 27 having the same diameter as the inner diameter of the cylindrical member 13 may be fitted to the cylindrical member 13, or the outer surface (lower surface) of the end surface portion 13b may be arranged closer to the pinhole 21 than the pinhole 21. A concave portion having a large diameter is formed and the diffusion plate 27 is fitted in the concave portion, the diffusion plate 27 is adhered to the upper surface or the lower surface of the end face portion 13b without forming a concave portion, or two or more cylindrical members 13 are used. The diffusion plate 27 may be sandwiched between appropriate portions of the cylindrical member 13 in the direction of the optical axis LA.

As described above, in this embodiment, the diffusion plate 27 is provided on the emission side of the peripheral surface 17a. In this case, for example, the diffusion effect of the pupil module 307 is improved, as already mentioned. Since the diffusion plate 27 is positioned on the pinhole 21 side, the area can be reduced, for example, compared to the diffusion plate 25 of the second embodiment. As a result, the cost of the pupil module can be reduced, for example, if the

diffusers

25 and 27 are expensive.

<Fourth Embodiment>
FIG. 7 is a cross-sectional view showing the configuration of a pupil module 407 according to the fourth embodiment, and corresponds to FIG. 3 of the first embodiment.

In the first embodiment, the light pipe 17 is provided as a separate member from the cylindrical member 13. On the other hand, in the fourth embodiment, the inner surface of the cylindrical member 413 is configured to be able to reflect light. Further, in the fourth embodiment, a condensing lens 29 is provided for condensing light incident from the opening 19 side to the pinhole 21 side. Furthermore, in the fourth embodiment, similarly to the third embodiment, a diffusion plate 27 is provided adjacent to the pinhole 21 . For the diffuser plate 27, the description in the third embodiment may be used.

(cylindrical member)
The cylindrical member 413 can be regarded as a further modified example of the light pipe 23 according to the modified example described with reference to FIG. Therefore, the description of the light pipe 23 may be applied to the tubular member 413 as appropriate. For example, the tubular member 413 has a peripheral surface 413a surrounding the optical axis LA. Like the peripheral surface 23a of the light pipe 23, the peripheral surface 413a may function as a reflecting surface (for example, a mirror) that reflects light without substantially transmitting light regardless of the incident angle. The reflectance exemplified in the description of the peripheral surface 23a may be applied to the peripheral surface 413a.

In terms of materials, the tubular member 413 may have the base 31 and the reflective film 33 overlapping the inner surface of the base 31, like the light pipe 23 according to the modification. As for the materials of the base 31 and the reflective film 33, the description of the base and the reflective film (both not shown) of the light pipe 23 may be used. Also, unlike the illustrated example, the cylindrical member 413 may be entirely made of a single material with relatively high reflectance (for example, metal).

For the outer shape (shape of the outer surface) of the cylindrical member 413, the description of the outer shape of the cylindrical member 13 in the first embodiment may be used. Most of the inner surface of the cylindrical member 413 is constituted by a peripheral surface 413a. For the shape of the peripheral surface 413a, the description of the peripheral surface 17a of the light pipe 17 in the first embodiment may be used. In the illustrated example, the shape of the inner surface of the cylindrical member 413 is composed of a frustum formed by the peripheral surface 413a, a column positioned below the frustum, and two columns positioned above the frustum. have. The lower columnar body is a part where the diffusion plate 27 is arranged (for example, fitted). The upper two pillars are portions where the condenser lens 29 and the light control filter 15 are arranged (for example, fitted). Unlike the illustrated example, the pillars may not be formed. Moreover, as described in the description of the first embodiment, the shape of the peripheral surface 413a may include a columnar body.

As can be understood from the range of the reflective film 33, in the illustrated example, of the inner surface of the cylindrical member 413, the side surface of the frustum (from another point of view, the portion between the condenser lens 29 and the diffuser plate 27) is The entire surface is a reflective surface. Moreover, not only the side surfaces of the frustum, but also the side surfaces and end surfaces of the columnar body (from another point of view, the portion where the diffuser plate 27 is arranged) and the inner surface of the pinhole 21 are used as reflecting surfaces.

Unlike the illustrated example, at least one of the side surfaces and end surfaces of the pillar and the inner surface of the pinhole 21 may not be a reflective surface. Moreover, it is not necessary to make all the side surfaces of the frustum a reflecting surface. For example, regarding the length in the direction parallel to the optical axis LA, the length of the reflective surface is the length of the frustum, or the length from the aperture 19 to the pinhole 21 (including the aperture 19 and the pinhole 21). 1/2 or more, 4/5 or more, or 9/10 or more. Contrary to the above, at least one of the side surfaces and the end surfaces of the upper two pillars (from another point of view, the portion where the condenser lens 29 and the light control filter 15 are arranged) may be a reflective surface.

In various aspects including the illustrated example, the reflective peripheral surface 413a surrounding the optical axis LA is the surface of the portion of the inner peripheral surface of the cylindrical member 13 where the optical components (diffusion plate 27, etc.) are arranged. may be defined within an area excluding the area, or may be defined within an area including the surface of the above portion. In the description of this embodiment, the former is used for convenience.

(Condenser lens)
The focal point of the condenser lens 29 may be set at an appropriate position. For example, the focal point may be set within, in front of, or behind the pinhole 21 . In this case, for example, telecentric light incident on the aperture 19 is condensed on the pinhole 21 or before and after it. The peripheral surface 413a is more efficient in condensing and diffusing light than in an aspect in which the condensing lens 29 is not provided (as understood from the above-described embodiments, this aspect is also included in the technology according to the present disclosure). , and contributes to the effective use of light that has not been condensed (conventionally, light that has been absorbed by the inner surface of the cylindrical member).

Also, for example, the focal point may be located inside the peripheral surface 413a (frustum), similar to the focal point of the incident surface 17b of the light pipe 17 in the first embodiment. In this case, for example, the condensing lens 29 contributes to increasing the luminous flux that reaches the peripheral surface 413a and is reflected in the same way as the incident surface 17b. contributes to the improvement of the action of

The shape and size (and position) of the condensing lens 29 may be set, for example, so that substantially all the light that enters the peripheral surface 413 a passes through the condensing lens 29 . In the illustrated example, the condensing lens 29 closes the opening of the peripheral surface 413a on the incident side, thereby realizing the above light relationship.

The specific shape and material of the condenser lens 29 (convex lens) may be appropriate. For example, the condenser lens 29 may be a plano-convex lens (example shown), a bi-convex lens, or a convex meniscus lens. The convex side of the plano-convex lens or convex meniscus lens as the condenser lens 29 may face either the opening 19 side or the pinhole 21 side. The condenser lens 29 may be a single lens, or may be a group of lenses. The material of the condenser lens 29 may be glass or resin, for example.

As described above, the pupil module 407 also has the peripheral surface 413a and the pinhole 21 in this embodiment. The peripheral surface 413a surrounds the optical axis LA and can reflect light. The pinhole 21 is positioned on the output side of the peripheral surface 413a in the direction along the optical axis LA.

Therefore, the same effects as in the first embodiment are achieved. For example, it is possible to effectively utilize the light that has conventionally been absorbed by the inner surface of the cylindrical member. and/or the diffusing action of the peripheral surface 413a reduces the need for a diffuser plate. These improve the transmittance.

As shown in this embodiment, the reflecting film 33 may overlap the inner surface of the cylindrical member 413 to form the peripheral surface 413a as described above.

In this case, for example, the entire cylindrical member 413 is made of metal, and the inner surface is not coated with black paint, so that the peripheral surface 413a that reflects light is configured (this aspect is also the technology according to the present disclosure). ), the flexibility of the material of the cylindrical member 413 is improved. Moreover, since the light pipe 17 separate from the tubular member is not required, the configuration is simplified.

The reflective film 33 may contain a metal film.

In this case, for example, it is easy to increase the reflectance of the peripheral surface 413a. As a result, the action of condensing and/or diffusing light by the peripheral surface 413a is improved. The metal film also functions as a light shielding film. Therefore, the metal film also contributes to reducing interference of light from or to the outside of pupil module 407 . From another point of view, the flexibility of the material of the substrate 31 is further improved. As a result, for example, it is possible to use an inexpensive resin with low light shielding properties as the material of the base 31 .

As shown in the present embodiment, the pupil module 407 may further have a condenser lens 29 for condensing light to the pinhole 21 side on the incident side of the peripheral surface 413a.

In this case, as described above, for example, in a mode in which light is basically focused on the pinhole 21 by the condenser lens 29, the peripheral surface 413a can be used as a portion for reflecting the leaked light, and the transmittance is improved. do. Alternatively, similarly to the convex curved incident surface 17b of the first embodiment, the light flux that reaches the peripheral surface 413a and is reflected by the condenser lens 29 is increased, and the peripheral surface 413a diffuses and/or condenses light. can be improved.

<First modification of pinhole>
FIG. 8 is a cross-sectional view showing a pinhole 21A according to a modification, and corresponds to an enlarged view of the pinhole 21 and its surroundings in FIG.

So far, the shape of the pinhole 21 has been illustrated as a straight column (for example, a cylinder or a square column). In FIG. 8, as the shape of the pinhole 21A, a shape having a frustum (incident side portion 21s) whose diameter decreases downward and a straight column (output side portion 21t) continuing below the frustum is shown. there is Note that the shape of the pinhole 21 shown in various drawings other than FIG. It may be understood as a shape shown in a simplified form. In another aspect, the shape of pinhole 21A may be applied to any embodiment.

The specific shape and dimensions of the pinhole 21A according to the modification may be set as appropriate. For example, the description of the pinhole 21 in the embodiment may be applied to the pinhole 21A according to the modified example as long as there is no contradiction. In the pinhole 21A, the shape of the cross section of the frustum (the cross section orthogonal to the optical axis LA) and the shape of the cross section of the column may be the same (similar) or different. The inclination angle θ2 of the side surface of the frustum with respect to the optical axis LA is arbitrary. For example, the inclination angle θ2 may be 10° or more, 30° or more, or 50° or more, and may be 80° or less or 70° or less, and the above lower limit and upper limit may be appropriately combined. Regarding the length in the direction parallel to the optical axis LA, either the frustum or the straight pillar may be large. In the illustrated example, the latter is shorter than the former.

In FIG. 8, the pupil module 407 of the fourth embodiment (FIG. 7) is taken as an example of the pupil module having the pinhole 21A according to the modification. In this case, as described in the description of the fourth embodiment, the reflective film 33 (in other words, the reflective surface) may be formed over part or all of the pinhole 21A (illustrated example), does not have to be formed

As described above, the pinhole 21A may have a portion (incidence side portion 21s of the frustum) whose diameter becomes smaller toward the exit side.

In this case, for example, the luminous flux incident on the pinhole 21A can be increased. More specifically, compared to the aspect (this aspect is also included in the technology according to the present disclosure) in which the straight columnar output side portion 21t constitutes the entire pinhole 21, the outer peripheral side (in the illustrated example, the diffusion plate 27) can be easily transmitted to the output side (downward in the figure). Thereby, the transmittance of light can be improved. Furthermore, since the light from the outer peripheral side (the outer peripheral edge side of the diffusion plate 27) can be easily transmitted to the output side as described above, the light transmitted to the output side is inclined at a certain angle with respect to the optical axis LA. the proportion of light that is As a result, the angle of incidence on the image sensor 103 can be increased. In addition, when the thickness of the cylindrical member 413 is large from the viewpoint of strength (when the length of the pinhole 21A in the penetrating direction is long), the possibility of excessively affecting the diffusion angle of the emitted light from the pinhole 21A is reduced. be. In the aspect in which the side surface of the frustum is a reflecting surface, the pinhole 21A is also expected to have a function of condensing and/or diffusing light.

The above effects are likely to be enhanced as the length of the pinhole 21A parallel to the optical axis LA or the length of the straight columnar portion (incidence side portion 21s in this modified example) parallel to the optical axis LA is shorter. . On the other hand, from the viewpoint of the strength of the tubular member 413, these lengths are set to a certain extent or more. The above length can be shortened by securing the strength by optical components (for example, a lens 35 to be described later) or the like provided in front of and behind the pinhole 21A. Considering these circumstances, the above length may be set as appropriate. For example, the length of the pinhole 21A parallel to the optical axis LA may be 0.4 mm or more and 0.6 mm or less. When the strength can be ensured by the optical component, the length of the pinhole 21A parallel to the optical axis LA may be 0.2 mm or more and 0.4 mm or less. The length of the straight columnar portion may be, for example, 0.05 mm or more and 0.15 mm or less.

<Fifth Embodiment>
FIG. 9 is a cross-sectional view showing the configuration of a pupil module 507 according to the fifth embodiment, and corresponds to FIG. 3 of the first embodiment.

A pupil module 507 according to the fifth embodiment differs from the pupil module 407 according to the fourth embodiment in the shape of the cylindrical member (in other words, the peripheral surface). Specifically, the peripheral surface 413a (inner peripheral surface) of the tubular member 413 according to the fourth embodiment has a frustum shape, whereas the peripheral surface 513a (inner peripheral surface) of the tubular member 513 according to the fifth embodiment has a frustum shape. peripheral surface) is straight columnar. For the shape of the peripheral surface 513a, the description of the shape of the inner surface of the cylindrical member 13 in the first embodiment may be used.

Also in this embodiment, the pupil module 507 has a peripheral surface 513 a and a pinhole 21 . The peripheral surface 513a surrounds the optical axis LA and can reflect light. The pinhole 21 is positioned on the output side of the peripheral surface 513a in the direction along the optical axis LA.

<Sixth embodiment>
FIG. 10 is a cross-sectional view showing the configuration of a pupil module 607 according to the sixth embodiment, and corresponds to FIG. 3 of the first embodiment.

A pupil module 607 according to the sixth embodiment is obtained by adding a lens 35 (the term "lens" includes a group of lenses) on the exit side of the pinhole 21 to the pupil module 7 according to the first embodiment. is. By adding the lens 35, for example, various incident angles (for example, CRA: Chief Ray Angle) with respect to the image sensor 103 can be obtained without changing the design of most of the pupil module 607 (for example, everything other than the lens 35). can be realized. It should be noted that the illustrated shape, dimensions, etc. of the lens 35 do not reflect the actual one.

The material and shape of the lens 35 are arbitrary. For example, the lens 35 may be a single lens or a lens group (example shown). The material of the lens 35 (strictly speaking, one or more lenses included in the lens 35; hereinafter the same) may be glass or resin. Lens 35 may be a spherical lens or an aspherical lens. The lens 35 may be a convex lens, a concave lens, more particularly a bi-convex lens, a plano-convex lens, a convex meniscus lens, a bi-concave lens, a plano-concave lens or a concave meniscus lens, for example. A lens that is asymmetric with respect to a plane perpendicular to the optical axis may be oriented convex or concave on either the entrance side or the exit side. Combinations of shapes of a plurality of lenses constituting lens 35 as a lens group are also arbitrary.

As described above, the pupil module 507 may have the lens 35 on the output side of the pinhole 21 .

In this case, as described above, by changing the design of the lens 35, it is possible to realize various incident angles with respect to the image sensor 103. As a result, it is possible to inexpensively respond to various specifications of one or more users who use the pupil module.

Here, a lens 35 is provided for the pupil module 7 of the first embodiment. However, the lens 35 may be applied not only to the first embodiment but also to any other embodiment. For example, as in the fourth embodiment (FIG. 7) and the fifth embodiment (FIG. 9), the lens 35 may be provided in the mode in which the reflecting film 33 is provided on the inner surface of the base 31 of the cylindrical member.

<Second modification of pinhole>
FIG. 11 is a cross-sectional view showing a pinhole 21B according to a modification, and corresponds to an enlarged view of the pinhole 21 and its periphery in FIG.

Note that, as described above, the lens 35 described with reference to FIG. 10 may be applied to any embodiment. FIG. 11 is a diagram in which a lens 35 is provided in the fifth embodiment (FIG. 9).

In the pinhole 21A according to the modified example described with reference to FIG. 8, the incidence side portion 21s has a frustum shape that expands in diameter toward the incidence side. On the other hand, in the pinhole 21B according to the modified example shown in FIG. 11, contrary to the pinhole 21A, the incident side portion 21s has a straight columnar shape and the outgoing side portion 21t has a frustum shape. The output side portion 21t is formed so as to increase in diameter toward the output side.

It should be noted that, like the pinhole 21A, the pinhole 21B may be applied to any embodiment. For example, it may be applied to a mode having the light pipe 17 or to a mode having no lens 35 .

The specific shape and dimensions of the pinhole 21B may be set as appropriate. For example, the description of the pinhole 21A may be incorporated into the description of the pinhole 21B by appropriately replacing the terms of incident side and exit side. For example, similarly to the pinhole 21A, the inclination angle θ2 (not shown) of the side surface of the frustum with respect to the optical axis LA is arbitrary, and may be, for example, 10° or more, 30° or more, or 50° or more. ° or less or 70° or less. Also, for example, similarly to the pinhole 21A, either the frustum or the straight column may be large in terms of the length in the direction parallel to the optical axis LA. Further, for example, similar to the pinhole 21A, the specific size of the pinhole 21B is arbitrary and may be 0.4 mm or more and 0.6 mm or less.

When the pinhole 21B is applied to the aspect having the reflective film 33, the arrangement range of the reflective film 33 with respect to the pinhole 21B is arbitrary, similarly to the pinhole 21A. For example, the reflective film 33 may be formed over the entire pinhole 21B (example shown), may be formed over only a portion of the pinhole 21B, or may be formed entirely over the pinhole 21B. It doesn't have to be. As a mode in which the reflecting film 33 is formed on a part of the pinhole 21B, for example, there is a mode in which the reflecting film is formed only on the incident side portion 21s of the incident side portion 21s and the emitting side portion 21t. can.

As described above, the pinhole 21B may have a portion (the exit side portion 21t of the frustum) whose diameter becomes smaller toward the entrance side.

In this case, for example, the same effect as the pinhole 21A can be obtained. Specifically, for example, light from the outer peripheral side (the outer peripheral edge side of the diffuser plate 27 in the illustrated example) can be easily transmitted through the pinhole 21B, the transmittance is improved, and the incident angle to the image sensor 103 is increased. can be made

The technology according to the present disclosure is not limited to the above embodiments and modifications, and may be implemented in various ways.

For example, the various embodiments described above may be combined as appropriate. For example, a configuration in which no diffusion plate is arranged (FIG. 3) or a configuration in which a diffusion plate is arranged only on the incident side (FIG. 5) is applied to embodiments in which a reflecting surface is formed on the inner surface of the cylindrical member (FIGS. 7 and 9). may be Condensing lenses (FIGS. 7 and 9) may be applied in embodiments with light pipes (FIGS. 3, 5 and 6), or conversely in configurations where no condensing lenses are arranged (FIGS. 3 and 5). 5 and 6) may be applied to the aspect (FIGS. 7 and 9) in which the reflecting surface is formed on the inner surface of the tubular member. Thus, presence/absence of a diffusion plate on the incident side, presence/absence of a diffusion plate on the output side, presence/absence of a condenser lens, presence/absence of a lens on the output side of the pinhole, and aspects of the peripheral surface (reflecting surface) surrounding the optical axis, etc. Any combination of

In the embodiment, as a peripheral surface that surrounds the optical axis and can reflect light, an outer peripheral surface of a solid light pipe (FIG. 3, etc.) as a member separate from the cylindrical member, and a member separate from the cylindrical member The inner peripheral surface of the hollow light pipe (FIG. 4) and the reflective film (FIG. 7, etc.) overlapping the inner surface of the cylindrical member are shown. As mentioned in the description of the embodiments, the circumferential surface surrounding the optical axis and capable of reflecting light may be realized by forming the entire cylindrical member from a material capable of reflecting light. However, even in the prior art, strictly speaking, the inner surface of the cylindrical member does not reflect light at all. Therefore, regarding the aspect in which the entire cylindrical member is formed of a material that can reflect light, the reflectance of the peripheral surface that can reflect light is higher than the reflectance of the conventional black inner surface. shall refer to a high configuration. Such reflectance can include, for example, 50% or more or 80% or more.

A reflective film that reflects the light inside the light pipe may be provided on the outer peripheral surface of the solid light pipe. A reflective film may be viewed as a hollow light pipe. In another aspect, a translucent material may be placed inside the hollow light pipe.

Diffusion plates, condensing lenses, light control filters, etc., placed on the incident side or the exit side of a peripheral surface that can reflect light (peripheral surface of a solid light pipe, etc.) can be generalized as optical components. Also, the optical components arranged on the incident side or the exit side of the peripheral surface may be various types other than those exemplified in the embodiments.

For example, in the fourth embodiment (FIG. 7), the condensing lens 29 (in other words, convex lens) is illustrated as an optical component, but a concave lens may be provided instead of the convex lens. In this case, for example, the light emitted from the concave lens diverges and the light is more likely to enter the peripheral surface 413a (or the peripheral surface in another embodiment). As a result, the effect of diffusing light by the peripheral surface 413a is improved. The specific shape of the concave lens may be made appropriate. For example, the concave lens may be a biconcave lens, a plano-concave lens, or a concave meniscus lens.

1... Inspection device, 7... Pupil module, 17a... Peripheral surface (of pupil module), 21... Pinhole, 103... Imaging device (solid-state imaging device), LA... Optical axis.

Claims

A pupil module that passes inspection light from a light source device toward a solid-state imaging device,
a peripheral surface surrounding the optical axis and capable of reflecting light;
a pinhole located on the output side of the peripheral surface in the direction along the optical axis;
A pupil module having a
a light-shielding cylindrical member having an opening for the light to enter at one end and the pinhole having a smaller diameter than the opening at the other end;
The pupil module according to claim 1, wherein the peripheral surface is positioned inside the cylindrical member.
3. The pupil module according to claim 2, wherein a reflecting film overlaps an inner surface of the tubular member to form the peripheral surface.
4. Pupil module according to claim 3, wherein the reflective film comprises a metal film.
5. A pupil module according to claim 3 or 4, wherein the peripheral surface is straight columnar.
5. The pupil module according to claim 3, wherein said peripheral surface has a smaller diameter toward said pinhole.
3. A pupil module according to claim 2, further comprising a solid or hollow light pipe having said peripheral surface, which is separate from said tubular member and which is inside said tubular member.
8. The pupil module according to claim 7, wherein the outer peripheral surface of the light pipe and the inner peripheral surface of the tubular member are separated.
9. The pupil module according to claim 7, wherein the light pipe is solid, and has a curved surface in which the end face on the side on which the light from the light source device is incident bulges outward.
The pupil module according to any one of claims 7 to 9, wherein the peripheral surface has a smaller diameter toward the pinhole.
The pupil module according to any one of claims 1 to 10, wherein the peripheral surface has a length parallel to the optical axis greater than a diameter.
The pupil module according to any one of claims 1 to 11, further comprising a diffusion plate on the output side of the peripheral surface.
The pupil module according to any one of claims 1 to 12, further comprising a diffusion plate on the entrance side of said peripheral surface.
Pupil module according to any one of claims 1 to 11, wherein no diffuser plate is located on both the exit side and the entrance side of the peripheral surface.
The pupil module according to any one of claims 1 to 14, further comprising a condensing lens on the incident side of the peripheral surface for condensing the light to the pinhole side.
Pupil module according to any one of claims 1 to 15, comprising a lens on the output side of the pinhole.
The pupil module according to any one of claims 1 to 16, wherein the pinhole has a portion with a smaller diameter toward the exit side or toward the entrance side.
a pupil module according to any one of claims 1 to 17;
a probe card on which the pupil module is mounted;
the light source device;
inspection device.