TWI817427B - Pupil module and inspection device - Google Patents

Abstract

The pupil module that passes inspection light from the light source device toward the solid-state imaging element has a peripheral surface and a pinhole. The peripheral surface surrounds the optical axis around the axis and can reflect light. The pinhole is located along the direction of the optical axis and on the exit side of the peripheral surface.

Description

Pupil module and inspection device

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

A pupil module is known that allows inspection light from a light source device to pass toward a solid-state imaging element (for example, Patent Document 1). Such a pupil module is useful, for example, in uniformizing the illumination and/or adjusting the solid angle. The pupil module of Patent Document 1 has a barrel member (lens barrel) with a pinhole formed on one end surface, and has a lens and a diffusion plate inside the barrel member. The pupil module is configured such that the pinhole faces the solid-state imaging element. The pinhole adjusts, for example, the solid angle (from another point of view, the diffusion angle) of the light irradiated to the solid-state imaging element. The lens condenses the light incident on the cylindrical member from the end opposite to the pinhole system into the pinhole. The diffusion plate is located between the lens and the pinhole to diffuse the light (according to another point of view, it makes the intensity of the light uniform across the cross section of the light path). [Prior patent documents] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2004-266250

[Problem to be solved by the invention]

What is desired is a pupil module and an inspection device that can improve at least part of the performance (such as light transmittance and/or diffusion function). [Means used to solve problems]

A pupil module according to one aspect of the present disclosure is a pupil module that allows inspection light from a light source device to pass toward a solid-state imaging element, and has: a peripheral surface that surrounds the optical axis and can reflect the light; and The pinhole is located along the direction of the optical axis and on the exit side of the peripheral surface.

An inspection device in one form of the present disclosure includes: the pupil module; a detection card equipped with the pupil module; and the light source device. [Invention effect]

According to the above structure, the performance of at least part of the pupil module will be improved.

Hereinafter, a plurality of aspects (embodiments and modifications) of the present invention will be described with reference to the drawings. In addition, the description of the modes other than the first embodiment basically explains only the differences from the previously described modes. Regarding matters not specifically mentioned, they are in the same form as those previously explained, or can be deduced by analogy from those previously explained. In addition, there are differences in the corresponding structures of plural forms, and the same symbols may be added for expediency.

The picture is a pattern. Therefore, for example, dimensional proportions may not be consistent with reality, and drawings showing the same member may not be consistent with each other. Also, for example, details of the shape of the member may be omitted.

In the description of the embodiment, "diameter" can be regarded as a diameter or a diameter equivalent to a circle unless otherwise specified. "Reflectance" refers to the reflectance of visible light (for example, wavelength 380nm or more and 780nm or less) when the incident angle is 0∘ unless otherwise stated. The "diffusion angle" can be regarded as the full width at half maximum (FWHM: Full Width at Half Maximum) of the central illumination unless otherwise specified. The term "light tube" is open to interpretation and may be considered synonymous with "rod integrator". <First Embodiment> (Inspection device)

FIG. 1 is a schematic cross-sectional view showing the structure of the main parts of the inspection device 1 according to the first embodiment. In addition, the inspection device 1 may regard any direction as upward. However, in the following description, for the sake of expediency, expressions may be used that assume that the top in Figure 1 is the actual top.

The inspection device 1 irradiates light to the imaging element 103 and inspects the imaging element 103 . 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 example shown in the figure, the inspection device 1 is configured to inspect the imaging element 103 contained in the wafer 101 . However, the inspection device 1 may be different from the example shown in the figure, and the individual imaging elements 103 may be inspected. In the following description, expressions may be used based on the premise that the inspection device 1 inspects the wafer 101 for expediency.

The imaging element 103 may be designed to detect light in a predetermined wavelength range (for example, the wavelength range of visible light), or may be designed to detect light that ideally has one wavelength like laser light. In the former case, the light that the inspection device 1 irradiates onto the imaging element 103 may be, for example, light having power in the entire wavelength region of the detection target of the imaging element 103 (or light with relatively high power, the same applies below). It may also be light with power within a specific range within the wavelength region. In the latter case, the light system that the inspection device 1 irradiates onto the imaging element 103 can be, for example, light having a wavelength that is a detection target in the imaging element 103 (strictly speaking, light having power in a narrow wavelength range including the wavelength). Light).

The type of light to be detected by the imaging element 103 (from another perspective, the product including the imaging element 103) (from another perspective, the type of light irradiated to the imaging element 103 by the inspection device 1) is arbitrary. For example, the light system of the detection object may be visible light (examples of the wavelength range are already mentioned) or invisible light. Examples of invisible light include infrared rays with a longer wavelength than visible light and ultraviolet rays with a shorter wavelength than visible light. Visible light, infrared light and ultraviolet light in more subdivided wavelength regions can also be detected. Conversely, light in two or more wavelength regions of visible light, infrared rays, and ultraviolet rays may be the detection target. As explained above, "reflectivity" can mean the reflectivity of visible light. However, when the light that can specify the detection target of the imaging element 103 (or the light irradiated by the inspection device 1 on the imaging element 103) is invisible light, , this reflectance of invisible light can also be applied to the following description.

The inspection device 1 has, for example, the following components. The workbench 3 holds the wafer 101; the light source device 5 generates light for inspection; and one or more (four in the example shown) pupil modules 7 directs the light from the light source device 5 to the imaging element. 103 passes; the detection card 9 is electrically connected to the imaging element 103; and the computing unit 11 controls the workbench 3 and the light source device 5, and controls and diagnoses the imaging element 103 via the detection card 9.

In addition to the structure of the pupil module 7, the inspection device 1 may have various structures, such as a well-known structure (of course, a new structure may also be used). The description of the embodiment relates to the structure other than the pupil module 7, and the description is appropriately omitted. In the following, the structure other than the pupil module 7 will be briefly described first, and then the pupil module 7 will be described.

The workbench 3 has a suitable chuck such as a vacuum chuck or an electrostatic chuck, and holds the wafer 101 thereon. The worktable 3 is movable in directions along each of the three axes of the rectangular coordinate system, for example. Thereby, the pupil module 7 and the detection card 9 can be positioned (relatively moved according to other viewpoints) to the imaging element 103 .

For example, although not specifically shown, the light source device 5 at least has a light source, and may have a lens, an aperture, a filter and/or a reflector located on the light path from the light source as needed. For example, the light source device 5 regards the up and down direction in FIG. 1 as a direction parallel to the optical axis, and irradiates the pupil module 7 with light. The light emitted by the light source device 5 may be, for example, uniform in intensity in cross section and telecentric.

The detection card 9 is configured to include one or more circuit boards, for example. In addition, since FIG. 1 is a schematic diagram, the same hatching is added to the entirety of various components (including one or more circuit boards) constituting the detection card 9 . In addition, in Figure 1, not only the body part of the detection card 9 (the part mainly composed of the circuit board), but also the parts fixed on the body part (for example, the part that helps to support the pupil module 7) are also Conceptually regarded as part of the detection card 9. In the case of this concept, it can also be detected that the overall shape of the card 9 is not necessarily card-like.

The detection card 9 has, for example, one or more (in the example shown in the figure, there are a plurality of openings, and in more detail, four openings 9h), which allow the light arriving from the light source device 5 through the pupil module 7 to Passes toward the imaging element 103 . For example, one opening 9h is provided for each imaging element 103 . However, one opening 9h may be provided for two or more imaging elements 103. In addition, the detection card 9 has pins 9a that are in contact with pads (not shown) of one or more (in the example shown, four) imaging elements 103. The number of pins 9a provided for one imaging element 103 can be set appropriately.

The computing unit 11 is configured to include a computer, for example. The arithmetic unit 11 controls, for example, a driving unit (not shown) of the workbench 3 to position the imaging element 103 and the detection card 9 . In addition, the calculation unit 11 controls the light source of the light source device 5 and irradiates the light from the light source device 5 to the imaging element 103 through the pupil module 7 and the opening 9 h of the detection card 9 . The computing unit 11 is electrically connected to the imaging element 103 via the detection card 9 , performs control of the imaging element 103 , and obtains signals from the imaging element 103 . Furthermore, the calculation unit 11 diagnoses the quality of the imaging element 103 based on the acquired signal. (Outline of the pupil module)

FIG. 2 is a perspective view schematically showing the four pupil modules 7 shown in FIG. 1 .

As shown in FIGS. 1 and 2 , the pupil module 7 has, for example, a substantially cylindrical 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 opposite ends in the axial direction, and causes the light incident from the first end 8A to be emitted from the second end 8B. In the process, the pupil module 7 adjusts the intensity distribution of the light in the cross-section of the light (for example, making the intensity uniform), and/or adjusts the solid angle and/or the diffusion angle of the light irradiated to the imaging element 103 .

The specific shape of the pupil module 7 is arbitrary. For example, the shape of the pupil module 7 can also be a straight column (the example shown in the figure) or an oblique column. However, in the description of the embodiment, the straight column is mainly used as an example, and expressions based on the straight column are sometimes used. In addition, the shape of the pupil module 7 may also be cylindrical or prism-shaped. The length of the pupil module 7 in the axial direction (the direction parallel to the optical axis) may be longer than the diameter (the example shown in the figure) or shorter. In the example shown in the figure, the outer shape of the pupil module 7 is substantially cylindrical, and is formed in a shape in which a flange 8C is provided on the first end 8A side.

In the example of Figure 1, the pupil module 7 is supported by the detection card 9. Specifically, the pupil module 7 is inserted into a hole that penetrates the detection card 9 up and down (the symbol is omitted, it may also conceptually include the opening 9h), and the flange 8C is engaged with the upper surface of the detection card 9 . Furthermore, the flange 8C and the detection card 9 can be fixed by screws not shown in the figure. Different from the example shown in the figure, the pupil module 7 can also be supported by a component separate from the detection card 9, or the pair of detection cards 9 can be supported movable by a driving mechanism.

The pupil module 7 can be set to any number for one detection card 9 (the inspection device 1 from another point of view. The same applies below). For example, the number of pupil modules 7 configured on one detection card 9 can be one or a plurality (the example shown in the figure). 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, as in the example shown in the figure, it may be smaller).

When the number of pupil modules 7 is plural, their arrangement is also arbitrary. For example, the pupil module series 7 can also be arranged in one row (the example shown in the figure), or in two or more rows. The number of each row is arbitrary, and the numbers in each row can be the same or different. The distance between the pupil modules 7 is, for example, the distance between the imaging elements 103 in the wafer 101, and may be the same or an integer multiple. (Internal structure of pupil module)

Figure 3 is a cross-sectional view of the pupil module 7.

The pupil module 7 has, for example, a barrel member 13 and an optical element held by the barrel member 13 . In the example shown in the figure, the optical components are two dimming filters 15 and a light pipe 17 . The barrel member 13 is, for example, helpful in retaining the optical elements and in reducing the influence of unintended light from outside the pupil module 7 . The dimming filter 15 helps, for example, in adjusting the amount of light. The light pipe 17 contributes to, for example, improving the transmittance of the pupil module.

In addition, in Fig. 3, the optical axis LA is shown. The optical axis LA shown in the figure can also be understood as the optical axis of the pupil module 7 , and can also be understood as the optical axis of each part of the light pipe 17 and other components that constitute the pupil module 7 . The optical axis LA is, for example, a virtual light ray, which is a representative of the light beam passing through the pupil module 7 or each part. (tube member)

The cylindrical member 13 is a cylindrical member as its name indicates. The cylindrical member 13 has a cylindrical body 13a around an axis, and an end surface 13b that blocks the second end 8B side of the cylindrical body 13a. The first end 8A side of the barrel body 13a is opened to form an opening 19. The pinhole 21 is opened in the end portion 13b. The light from the light source device 5 enters the opening 19 and then exits from the pinhole 21 .

Since FIG. 3 is a schematic diagram, the entire cylindrical member 13 is shown with hatching. The actual cylindrical member 13 may be integrally formed as shown in Fig. 3 , or may be composed of a plurality of members, unlike the one shown in Fig. 3 .

The specific shape of the cylindrical member 13 is arbitrary. For example, the outer shape of the barrel member 13 constitutes most of the outer shape of the pupil module 7 , and the description of the outer shape of the pupil module 7 can be based on the outer shape of the barrel 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 column shape like the outer shape. To be more detailed, it is, for example, a cylindrical shape or a square prism shape. The shape of the outer shape and the inner surface of the cylindrical member 13 may be similar (according to another point of view, the thickness of the cylindrical member 13 may be substantially constant), or may be completely different shapes. In addition, the similarity here is not limited to strict mathematical similarity.

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 internal space of the cylindrical member 13 , or may be a different shape, such as a circle or a polygon. In the example shown in the figure, the diameter of the opening 19 is slightly larger than that of most of the internal space of the cylindrical member 13 in order to arrange the dimming filter 15 . However, such a diameter expansion system does not need to be performed, and conversely, the diameter may be smaller than most of the internal space of the cylindrical 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 orthogonal to the optical axis LA) may be circular or polygonal. The cross-sectional shape (diameter from another point of view) of the pinhole 21 depends on the penetrating direction of the pinhole 21, and may be a fixed value (example shown in the figure) or may be changed. As the latter, a series is exemplified by a shape in which part or all of the pinhole 21 in the penetrating direction expands or contracts in diameter as it goes downward.

Various dimensions of the cylindrical member 13 (for example, the diameter of the opening 19, the diameter of the pinhole 21, the distance from the opening 19 to the pinhole 21) are determined according to the required size of the imaging element 103 and the inspection requirements of the imaging element 103. The illumination, etc. can be set appropriately. The diameter of the pinhole 21 is smaller than the diameter of the opening 19 . In addition, the diameter referred to here only needs to be a diameter that substantially contributes to the transmission of light. For example, in the example shown in the figure, when telecentric light enters the dimming filter 15 from the light source device 5, the diameter of the portion where the dimming filter 15 is arranged becomes too large, and the amount of light passing through the pupil module 7 is also reduced. Almost no increase. In this case, the diameter of the portion below the enlarged portion may be 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 may be regarded as the diameter of the opening 19 .

Give examples of dimensions. The diameter of the pinhole 21 can be made to 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 opening 19 is premised on being larger than the diameter of the pinhole 21, and 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 is relative to the diameter of the pinhole 21, and can be made to be more than 2 times and less than 20 times, or more than 4 times and less than 10 times. The distance from the opening 19 (surface on the incident side) to the pinhole 21 (surface on the emission side) 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 pinhole 21.

The cylindrical member 13 has light-shielding properties and prohibits the entry and exit of light from parts 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 on one side, and may be made of a light-shielding material on the surface (for example, the inner surface and/or the outer surface). membrane formed.

The surface of the cylindrical member 13 may have a low or high light reflectivity. For example, the reflectivity of the tube member 13 may be less than 10%, may be 10% or more and less than 50%, may be 50% or more, or may be 80% or more. This reflectivity can also be achieved by the reflectivity of most or all of the materials constituting the cylindrical member 13 , or by forming a film on the inner surface of the cylindrical member 13 that reduces or increases the reflectivity.

Generally, the inner surface of the lens barrel of an optical machine is designed to have low reflectivity. For example, the inner surface of the lens barrel is coated with black paint (in other words, a film that reduces reflection is formed). There are also cases where the reflectivity of black paint is, for example, 6% or less or 1% or less. The inner surface of the barrel member 13 is the same as a general lens barrel. It can also have a relatively low reflectivity as shown above by coating it with black paint, or it can also have a higher reflectivity than the above. Rate.

The material of the tube member 13 is arbitrary. For example, resin, metal, and ceramics may be used as a material constituting most (eg, except for the surface) or all of the cylindrical member 13 . Moreover, as already mentioned, a suitable film can be formed on the surface of the cylindrical member 13, and the material of this film can also be arbitrary. In addition, the film system may be composed of one kind of material, or may be two or more laminated layers composed of mutually different materials. Examples of materials for the film include paints of any color (for example, black). In addition, as described in the embodiments described below, the material of the film may also include metal (and dielectric).

The inside of the cylindrical member 13 may be sealed or not. The sealing system can also be airtight and can also reduce the level of intrusion of foreign matter. In the case of airtight sealing, the inside of the cylindrical member 13 may be in a vacuum (strictly speaking, a state in which the pressure is lower than atmospheric pressure), or may be in a state in which an appropriate gas is sealed. (Dimming filter)

The dimming filter 15 includes, for example, a glass substrate, and adjusts the amount of transmitted light by the presence or absence of an AR (anti-reflection) coating. In the case where one detection card 9 is provided with a plurality of pupil modules 7, the difference in light intensity between the pupil modules 7 can be reduced by adjusting the amount of transmitted light. The size and position of the dimming filter 15 can be set, for example, so that all the light incident on the light pipe 17 becomes the light passing through the dimming filter 15 . In the example shown in the figure, the dimming filter 15 is arranged to block the opening 19 .

In addition, the dimmable filter 15 may not be provided. In the example shown in the figure, the dimming filter 15 also helps to seal the inside of the cylindrical member 13 . In the case where the dimming filter 15 is not provided, the sealing system of the pupil module 7 can be implemented by a transparent member, which has other optical functions, or simply allows light to pass through. (light pipe)

The light pipe 17 is made of a translucent material, for example. In addition, the light pipe 17 is, for example, a solid rod-shaped member. In other words, the light pipe system has: the peripheral surface 17a, which is a cylindrical surface that expands around the optical axis LA; and the incident surface 17b and the emission surface 17c, which are end surfaces that intersect the optical axis LA on both sides of the peripheral surface 17a. The incident surface 17b is a surface on the opening 19 side, and the emission surface 17c is a surface on the pinhole 21 side.

At least part of the light incident on the incident surface 17b is guided to the emission surface 17c after being reflected at least once by the peripheral surface 17a. Thereby, for example, the light absorbed by the inner surface of the tube member 13 is reduced, and the transmittance of the pupil module 7 is increased. Furthermore, 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). Furthermore, in the light pipe 17 in the example shown in the figure, the light is condensed from the opening 19 to the pinhole 21 by a tapered shape, etc., the above-mentioned diffusion effect is improved, and the diffusion angle (from another point of view is the solid angle) adjustment. In addition, in the form where the dimming filter 15 is not provided, the light pipe 17 may also serve as a function of sealing the inside of the cylindrical member 13 .

The refractive index of the light pipe 17 is higher than the refractive index of its surroundings (vacuum or gas). According to another point of view, the peripheral surface 17a constitutes an interface between media having different refractive indexes. Furthermore, part of the light system that enters the incident surface 17b and reaches the peripheral surface 17a is reflected by the peripheral surface 17a, and the other part is transmitted through the peripheral surface 17a. In addition, when the incident angle to the peripheral surface 17a is smaller than a certain level, so-called total reflection occurs. In this way, the peripheral surface 17a reflects light. As can be understood from this embodiment, when the peripheral surface 17a can reflect light, the reflectivity of the peripheral surface 17a does not necessarily need to be high.

The material (refractive index from another point of view) of the light pipe 17 can be set appropriately. For example, the light pipe 17 may be made of glass or resin. Because the greater the refractive index of the light pipe 17 is, the easier it is for total reflection to occur on the peripheral surface 17a. Therefore, as the material of the light pipe 17, a material with a high refractive index can be selected. The refractive index (absolute refractive index) of the material of the light pipe 17 can be, for example, 1.4 or more.

The specific shape of the light pipe 17 is arbitrary. In the example shown in the figure, the shape of the light pipe 17 (in other words, the peripheral surface 17a. Hereinafter, the same applies to this paragraph and the next paragraph) is a cone shape (in other words, a truncated cone shape). The smaller the cross section (the cross section orthogonal to the optical axis LA). Different from the example shown in the figure, the shape of the light pipe 17 may be a fixed cylindrical shape (for example, a straight cylinder), the cross-sectional shape of which is independent of the position of the optical axis LA, or it may be a combination of a truncated cone and a cylinder. .

The more specific shape of the frustum or cylinder of the light pipe 17 is also arbitrary. For example, the shape of the cross section of the frustum or cylinder may be circular or polygonal. In other words, the shape of the light pipe 17 can be made into a truncated cone, a truncated pyramid, a cylinder and a corner prism. The truncated cone may be a rotationally symmetric shape with the optical axis LA as the axis of symmetry (the example shown in the figure), or it may not be. In the longitudinal section of the truncated cone (the section parallel to the optical axis LA), the side surface (peripheral surface 17a) of the truncated cone may be linear or curved.

In the case where the light pipe 17 has a truncated cone shape, the inclination angle θ of the peripheral surface 17a with respect to the optical axis LA can be appropriately set. For example, the inclination angle θ (in the longitudinal section, when the circumferential surface 17a is not linear, it is an inclination angle that is approximately a straight line) may be more than 0∘, 1∘ or more, 3∘ or more, and 5∘ or more, and may be Below 45∘, below 30∘ and below 15∘, the above lower limit and upper limit can be combined appropriately. For example, the inclination angle θ may be 5∘ or more and 15∘ or less.

The shapes of the incident surface 17b and the emission surface 17c are also arbitrary. In addition, as for the planar shape of these surfaces, the cross-sectional shape of the above-mentioned light pipe 17 (peripheral surface 17a) can be used. In the example shown in the figure, the incident surface 17b has a curved surface shape that bulges outward (in other words, a convex curved surface shape). In addition, the injection surface 17c is flat. However, unlike the example shown in the figure, the incident surface 17b may also be a flat surface or a concave curved surface. In addition, the injection surface 17c may have a convex curved surface shape or a concave curved surface shape. The combination of the shapes (curved surface or flat surface) of the incident surface 17b and the emission surface 17c is also arbitrary.

The curved surface of the incident surface 17b and/or the exit surface 17c may also be a spherical surface or an aspherical surface. In addition, the radius of curvature or focal length can be set appropriately. For example, when the incident surface 17b is a convex curved surface, its center of curvature and/or focus system may be located within the light pipe 17. To explain in more detail, for example, it may be located within the length of the optical axis LA of the light pipe 17. The center is closer to the incident side.

The surface properties of the peripheral surface 17a, the incident surface 17b, and the emission surface 17c are arbitrary. For example, these faces are smooth faces. For example, the arithmetic mean roughness Ra of these surfaces can be 100 nm or less, 10 nm or less, or 1 nm or less. However, these surfaces may be connected to part or all of them for the purpose of spreading, and concavities and convexities may be formed intentionally. In other words, the arithmetic mean roughness Ra may be larger than the above-mentioned upper limit.

The size of the light pipe 17 is arbitrary. For example, in the description of the cylindrical member 13 , the dimensions listed as the dimensions of the cylindrical member 13 are not the dimensions of the cylindrical member 13 but refer to the dimensions of the truncated cone-shaped light pipe 17 . For the sake of caution, the diameter of the injection 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 entrance surface 17b is assumed to be larger than the diameter of the exit surface 17c, and 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 incident surface 17b is the diameter of the exit surface 17c, and may be 2 times or more and 20 times or less, or 4 times or more and 10 times or less. The length from the incident surface 17b to the emitting surface 17c on the optical axis LA can 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 emission surface 17c.

The position of the light pipe 17 of the barrel member 13 can be set appropriately. In the example shown in the figure, the peripheral surface 17a is basically separated from the cylindrical member 13 (for example, the inner surface of the cylindrical body 13a) except for a part on the incident surface 17b side and a part on the ejection surface 17c side. Moreover, the incident surface 17b is located in the cylindrical member 13. The emission surface 17c is located within the pinhole 21 (to explain in more detail, in the example shown in the figure, it is halfway in the penetration direction). In addition, when the peripheral surface 17a is separated from the cylindrical member 13, for example, the peripheral surface 17a is separated from the cylindrical member 13 by 1/2 or 4/5 or more of its area.

Different from the example shown in the figure, 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 form in which both have the same shape, for example, in the example shown in the figure, the light pipe 17 is deformed into a straight column, or the inner surface of the barrel body 13a is deformed into a truncated cone. In addition, in the case where the dimming filter 15 is not provided in the cylindrical member 13 , the incident surface 17 b may be located at the same position as the opening 19 , or may be located further outside than the opening 19 . The emission surface 17 c may be located above the pinhole 21 or below the pinhole 21 .

The light pipe 17 can be fixed to the tube member 13 by an appropriate method. In the example shown in the figure, a part of the light pipe 17 on the side of the emission surface 17c is fitted with a part of the pinhole 21 (abuts against the inner surface of the pinhole 21). Moreover, a part on the incident surface 17b side is in contact with the inner surface of the cylindrical member 13 . Thereby, the light pipe 17 is fixed to the cylindrical member 13. At the portion where the light pipe 17 and the barrel member 13 are in contact, an adhesive may be provided between them (or not).

Different from the example shown in the figure, a portion protruding from the inner surface of the cylindrical member 13 and coming into contact with an appropriate position of the peripheral surface 17a may be provided. The cylindrical member 13 may be provided with a portion that comes into contact with a portion of the incident surface 17 b on the outer edge side from above. The tube member 13 may be provided with a portion that comes into contact with a portion of the emission surface 17 c on the outer edge side from below.

As described above, the pupil module 7 has the peripheral surface 17a and the pinhole 21, and allows the inspection light from the light source device 5 to pass toward the solid-state imaging element (the imaging element 103). The peripheral surface 17a surrounds the optical axis LA around the axis and can reflect light. The pinhole 21 is located on the emission 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 the form where the peripheral surface 17 a is not provided, part of the light incident into the cylindrical member 13 from the opening 19 deviates from the optical path toward the pinhole 21 and is absorbed by the inner surface of the cylindrical member 13 . In this embodiment, at least part of the light is guided to the pinhole 21 by reflection on the peripheral surface 17a, thereby improving the transmittance. As a result, for example, the illumination at the imaging element 103 can be increased. From another viewpoint, it is possible to reduce the power consumption of the light source device 5 and/or to downsize the light source device 5 .

In addition, in the case where the pinhole 21 is located on the exit side of the peripheral surface 17a in the direction along the optical axis LA, as can be understood from the description of the pinhole 21 on the exit surface 17c, regarding the pinhole 21 along the exit surface 17c, In the position range in the direction of the optical axis LA, part or all of the pinhole 21 may or may not overlap the part on the emission side of the peripheral surface 17a. For example, when thinking rationally, it can be said that light passing through the area surrounded by the peripheral surface 17a passes through the pinhole 21, the pinhole 21 can be understood to be located on the emission side of the peripheral surface 17a. For example, the opening surface on the exit side of the pinhole 21 is located 1/1 of the length from the exit side end surface (emission surface 17c) of the peripheral surface 17a in the direction parallel to the optical axis LA from the peripheral surface 17a to the incident side. When the position of /5 or 1/10 is closer to the emission side, the pinhole 21 can be understood as being located on the emission side of the peripheral surface 17a.

The pupil module 7 is a tube member 13 that can have light-shielding properties. The barrel member 13 may have an opening 19 through which light enters at one end, and may have a pinhole 21 with a smaller diameter than the opening 19 at the other end. The peripheral surface 17a may be located inside the barrel member 13.

In this case, for example, the possibility of unexpected light entering 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 becomes stable. .

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

In this case, for example, theory and/or expertise related to the light pipe 17 can be utilized, and the design becomes easy. Also, for example, by using a commercially available light pipe 17, the pupil module 7 having the peripheral surface 17a can be realized cheaply. Furthermore, for example, the properties of the emitted light required by the pupil module 7 vary depending on the type of the imaging element 103 and the like. This can be solved by changing the design of only one of the light pipe 17 and the barrel member 13 .

The outer peripheral surface (peripheral surface 17a) of the light pipe 17 and the inner peripheral surface of the cylindrical member 13 are separable. In addition, in this case, as can be understood from the example shown in the figure, the peripheral surface 17a may be partially in contact with the inner peripheral surface of the cylindrical member 13.

In the case where the peripheral surface 17a is separated from the cylindrical member 13, for example, since the light pipe 17 and the cylindrical member 13 are designed to be separable, the above-mentioned easiness of design and the like are improved. In addition, since the circumferential surface 17a is surrounded by vacuum or gas, conditions for total reflection to occur are easily satisfied. In addition, defects such as the influence of the joining state of the peripheral surface 17a and the cylindrical member 13 on the reflection on the peripheral surface 17a are also reduced.

The light pipe 17 may be solid, and the end surface (incident surface 17b) on the side where the light from the light source device 5 is incident may be in the shape of a curved surface bulging outward.

In this case, for example, the direction of the light beam incident on the incident surface 17b in the light pipe 17 can be adjusted. To explain in more detail, 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, thereby increasing the amount of light beam that reaches 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 as it approaches the pinhole 21.

In this case, for example, the light pipe 17 helps to concentrate (concentrate) the light incident on the incident surface 17b with a relatively large diameter toward the exit surface 17c with a relatively small diameter. Thereby, for example, the necessity of providing a condenser lens on the incident side of the pupil module 7 is reduced. Moreover, by not providing a condenser lens (however, the form of providing a condenser lens is also included in the technology of the present disclosure), the pupil module 7 is intended to be miniaturized, simplified and/or reduced in cost.

Furthermore, since the diameter is smaller on the side closer to the pinhole 21, for example, the light passing through the light pipe 17 is diffused according to Etendue's law. Specifically, the divergence angle (solid angle from another point of view) of the light beam emitted from the exit surface 17c (exit) is the divergence angle of the light beam incident on the incident surface 17b (entrance) multiplied by the entrance diameter/exit diameter ratio. Therefore, the diffusion effect of the peripheral surface 17a is improved.

In addition, unlike this embodiment, when the incident surface 17b is not convexly curved, when telecentric light is incident on the incident surface 17b, the light advances parallel to the optical axis LA in the light pipe 17. At this time, the peripheral surface 17a, which has a smaller diameter on the side closer to the pinhole 21, reflects the light beam deviated from the optical axis LA among the telecentric light. By this effect, the diffusion effect of the peripheral surface 17a is also improved.

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

In this case, for example, compared with a form in which the length of the circumferential surface 17a is shorter than the above (this form may also be included in the technology of the present disclosure), the number of reflections by the circumferential surface 17a is likely to increase. As a result, the diffusion effect of the peripheral surface 17a is enhanced.

<Modification of light pipe>

FIG. 4 is a cross-sectional view showing a light pipe 23 according to a modified example.

While the light pipe 17 of the embodiment has a solid rod shape, the light pipe 23 of the modified example has a hollow cylindrical shape. The light pipe 23 has a peripheral surface 23a surrounding the optical axis LA, an entrance port 23b through which light enters, and an exit port 23c through which light exits. The peripheral surface 17a that reflects light in the light pipe 17 is composed of the outer peripheral surface of the light pipe 17. In contrast, the peripheral surface 23a that reflects the light in 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 of the embodiment is light-transmissive. In contrast, the peripheral surface 23a of the light pipe 23 in the modified example can function as a reflective surface (for example, a reflector) that reflects light, and does not substantially transmit light regardless of the incident angle. The reflectivity of the peripheral surface 23a can be set appropriately. For example, the reflectivity of the peripheral surface 23a can be set to 50% or more, 80% or more, or 90% or more.

The structure of the light pipe 23 is arbitrary from a material point of view. For example, although not particularly illustrated, the light pipe 23 may have a base body constituting the majority of the light pipe 23 and a reflective film overlapping the inner peripheral surface of the base body to form the peripheral surface 23a. The base system can be composed of one or more than two materials. Each material system of more than one material may have light-shielding properties or light-transmitting properties. Examples of the material of the base include glass, resin and metal. In addition, the reflective film system may be composed of one kind of material, or may be composed of layers of different materials. To explain in more detail, for example, the reflective film may be a metal film, or a light-transmissive dielectric layer and a metal film may be overlapped. Different from the above system, the light pipe 23 may also be made of a single material with a relatively high reflectivity (such as metal).

Regarding the shape and size 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 can be appropriately applied. The thickness of the light pipe 23 is, for example, substantially constant throughout the light pipe 23 . In other words, the peripheral surface 23a is made similar to the outer peripheral surface of the light pipe 23. However, unlike the example shown in the figure, the thickness of the light pipe 23 may not be fixed. For example, the shape of the peripheral surface 23a may be substantially the same as the peripheral surface 17a of the first embodiment (truncated cone shape), and the shape of the outer peripheral surface may be a cylindrical shape to be fitted with the cylindrical member 13.

The light pipe 23 of this modified example can be used in place of the light pipe 17 in the first embodiment and other embodiments (described later) including the light pipe 17. Even when the light pipe 23 is used instead of the light pipe 17, the same effect as in the embodiment is achieved. <Second Embodiment>

FIG. 5 is a cross-sectional view showing the structure of the pupil module 207 of the second embodiment, and corresponds to FIG. 3 of the first embodiment.

The pupil module 207 of the second embodiment adds a diffusion plate 25 to the pupil module 7 of the first embodiment. The diffusion plate 25 diffuses light while transmitting it. Thereby, for example, the intensity of the light emitted from the pupil module 207 becomes more uniform across the cross-section. In addition, the transmittance of the pupil module in the first embodiment is higher than that in the second embodiment.

The diffusion plate 25 is located on the incident side with the light pipe 17 (peripheral surface 17a). To explain in more detail, the diffusion plate 25 is located within the cylindrical member 13 and, from another perspective, between the dimming filter 15 (from another perspective, the opening 19 ) and the light pipe 17 . In addition, unlike the illustrated example, the diffuser plate 25 may be located outside the cylindrical member 13 . For example, the diffusion plate 25 may be overlapped with the upper end of the cylindrical member 13 to block the opening 19 from the outside, or may be disposed above the secondary cylindrical member 13 The position where the end (opening 19) leaves upward. In the direction parallel to the optical axis LA, the distance between the opening 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 diffusion plate 25 can be set, for example, so that all the light incident on the light pipe 17 substantially passes through the diffusion plate 25 . For example, in the illustration In this example, the diffusion plate 25 is disposed inside the cylindrical member 13, and has the internal space of the cylindrical member 13 being as wide as the entire cross-section, thereby realizing the above-mentioned light relationship. It is different from the example shown in the figure. The diffuser plate 25 is separated upward from the opening 19 by making the area of the diffuser plate 25 much larger than the area of the opening 19, so that the above-mentioned light relationship can be achieved.

The specific material, shape and size of the diffusion plate 25 can be appropriately set. For example, the overall material of the diffusion plate 25 or the material that becomes the base of the diffusion plate 25 It is a translucent material, and can be made of glass or resin. The diffusion plate 25 can be formed into a plate shape with a substantially constant thickness. The thickness of the diffusion plate 25 can be appropriately set according to the required functions and the like.

As shown in the example in the figure, when the diffuser plate 25 is located inside the cylindrical member 13, the shape and size of the diffuser plate 25 in plan view can be, for example, used. Description of the cross-sectional shape and size of the internal space of the cylindrical member 13. In addition, in the form where the diffusion plate 25 is located outside the cylindrical member 13, the diffusion plate 25 may have a larger cross section than the internal space or the entire diameter of the cylindrical member 13. Wider area.

In the example shown in the figure, 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 diffuser plate 25 series can also be used with The incident surface 17b may be equally wide or narrower than the incident surface 17b. The latter state may occur, for example, due to the portion of the cylindrical member 13 holding the diffuser plate 25 and/or the light pipe 17 .

The diffusion plate 25 may have various structures for diffusing light. For example, the diffusion plate 25 may have unevenness on one side or both sides. The light that passes through the diffusion plate 25 is diffused by being refracted by the unevenness of the surface. The surface roughness Ra of the surface on which the unevenness is formed can be, for example, 200 nm or more, 1 μm or more, 10 μm or more, or 100 μm or more. The diffusion plate 25 having unevenness on the surface can be understood as a form in which micro lenses of different sizes are randomly arranged. In addition, the diffusion plate 25 can also replace the uneven surface, or have tiny particles inside. The light passing through the diffusion plate 25 can be diffused by being reflected by the tiny particles.

The transmittance and diffusion angle of the diffusion plate 25 can be set arbitrarily. In this embodiment, the light pipe 17 has a diffusion function. Therefore, as the diffusion plate 25 , one with a higher transmittance and/or a lower diffusion effect than the diffusion plate of the conventional pupil module may be used. For example, the transmittance of the diffusion plate 25 may be above 70%, above 80%, or above 90%. In addition, the diffusion angle of the diffusion plate 25 may be 40∘ or less, 30∘ or less, or 20∘ or less.

The diffuser plate 25 can be fixed to the cylindrical member 13 by an appropriate method. In the example shown in the figure, the inner portion of the cylindrical member 13 on the opening 19 side has a larger diameter than the portion on the pinhole 21 side. Furthermore, the diffusion plate 25 is inserted from the opening 19 side and engages with the step formed by the diameter expansion. Thereby, the diffuser plate 25 is held by the cylindrical member 13 . The adhesive may be interposed between the diffusion plate 25 and the cylindrical member 13 (or not). Different from the example shown in the figure, for example, the tube member 13 may be composed of two or more members. The diffuser plate 25 is inserted from the pinhole 21 side, or is inserted by the tube member 13 in the direction of the optical axis LA. Clamp it at the appropriate location.

As described above, in this embodiment, the diffuser plate 25 is provided on the incident side of the peripheral surface 17a. In this case, for example, as already described, the diffusion effect of the pupil module 207 is increased. Furthermore, since the light diffused by the diffusion plate 25 enters the light pipe 17, the amount of light beams that reaches the peripheral surface 17a of the light pipe 17 and is reflected tends to increase. As a result, the diffusion efficiency of the light pipe 17 is improved. That is, the combination of the diffuser plate 25 and the light pipe 17 on the incident side not only has a simple additive effect, but also has a multiplicative effect. <Third Embodiment>

FIG. 6 is a cross-sectional view showing the structure of the pupil module 307 of the third embodiment, and corresponds to FIG. 3 of the first embodiment.

The pupil module 307 of the third embodiment is the pupil module 207 of the second embodiment by changing the position of the diffusion plate. That is, in the pupil module 207 , the diffusion plate 25 is located on the incident side of the light pipe 17 , whereas in the pupil module 307 , the diffusion plate 27 is located on the exit side of the light pipe 17 .

The more detailed position of the diffuser plate 27 can be set appropriately. For example, the diffuser plate 27 is located inside the barrel member 13 . However, the diffusion plate 27 may be located outside the cylindrical member 13 . For example, the diffusion plate 27 overlaps the lower end of the cylindrical member 13 so as to block the pinhole 21 from the outside, or it may be disposed at a position downwardly separated from the lower end (pinhole 21) of the cylindrical member 13. In the direction parallel to the optical axis LA, 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.

The shape and size (and position) of the diffusion plate 27 can be set, for example, so that substantially all the light emitted from the emission surface 17 c of the light pipe 17 enters the diffusion plate 27 and/or all the light passes through the pinhole 21 substantially through the diffuser plate 27 . In the example shown in the figure, the diffusion plate 27 overlaps the entire surface of the emission surface 17c and blocks the pinhole 21, thereby realizing the above-mentioned light relationship. Different from the example shown in the figure, for example, when the diffuser plate 27 is separated downward from the pinhole 21, by making the area of the diffuser plate 27 much larger than the area of the pinhole 21, the entire area passing through the pinhole 21 can be made. The light substantially passes through the diffuser plate 27 .

The specific material, shape, size, and structure for diffusing light of the diffusion plate 27 can be appropriately set. For example, the description about the material, shape, size, and structure for diffusing light of the diffusion plate 25 can be applied to the diffusion plate 27 as long as there is no contradiction. In the example shown in the figure, the diffusion 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 an internal space that is wider than the entire cross-section of the cylindrical member 13 . Moreover, in the form where the diffuser plate 27 is located outside the cylindrical member 13, the diffuser plate 27 may have an area wider than the internal space of the cylindrical member 13 or the overall cross-section.

The transmittance and diffusion angle of the diffusion plate 27 can be set arbitrarily. Like the second embodiment, since the light pipe 17 has a diffusion effect, a diffuser plate 25 having a relatively high transmittance and/or a low diffusion effect can be used. Therefore, for example, the lower limit value of the transmittance and the upper limit value of the diffusion angle exemplified in the second embodiment can also be applied to this embodiment. However, the diffusion plate 27 of this embodiment is different from the diffusion plate 25 of the second embodiment, and does not have the effect of increasing the amount of light beams that reach the peripheral surface 17a and are reflected. Therefore, the diffusion plate 27 may be used instead of the diffusion plate 25 so that the transmittance becomes low or the diffusion angle becomes large. For example, the diffusion angle of the diffusion plate 27 may be 70∘ or more and 90∘ or less.

The diffuser plate 27 can be fixed to the cylindrical member 13 by an appropriate method. In the example shown in the figure, a recessed portion (symbol omitted) with a larger diameter than the pinhole 21 is formed on the inner surface (upper surface) of the end portion 13b of the cylindrical member 13. Furthermore, the diffusion plate 27 is fitted into this recessed portion. The adhesive may be interposed between the diffusion plate 27 and the cylindrical member 13 (or not). Different from the example shown in the figure, for example, the diffuser plate 27 having the same diameter as the inner diameter of the cylindrical member 13 is fitted to the cylindrical member 13, or a pinhole 21 with a diameter smaller than that of the cylindrical member 13b is formed on the outer side (lower surface) of the cylindrical member 13b. A larger recess is formed, and the diffuser plate 27 is fitted into the recess, or the diffuser plate 27 is adhered without forming a recess on the upper or lower surface of the end surface 13b, or the cylindrical member 13 is composed of two or more members, etc. The diffusion plate 27 may be sandwiched at an appropriate position of the cylindrical member 13 in the direction of the optical axis LA.

As described above, in this embodiment, the diffuser plate 27 is provided on the emission side of the peripheral surface 17a. In this case, for example, as already described, the diffusion effect of the pupil module 307 is increased. Since the diffusion plate 27 is located on the pinhole 21 side, the area can be made smaller compared to the diffusion plate 25 of the second embodiment. As a result, for example, where diffuser plates 25 and 27 are expensive, the cost of the pupil module can be reduced. <Fourth Embodiment>

FIG. 7 is a cross-sectional view showing the structure of the pupil module 407 of the fourth embodiment, and corresponds to FIG. 3 of the first embodiment.

In the first embodiment, the light pipe 17 is provided as a member separate from the tube member 13 . On the other hand, in the fourth embodiment, the inner surface of the cylindrical member 413 is configured to reflect light. Furthermore, in the fourth embodiment, a condenser lens 29 is provided to condense the light incident from the opening 19 side onto the pinhole 21 side. Furthermore, in the fourth embodiment, like the third embodiment, the diffusion plate 27 is provided adjacent to the pinhole 21 . Regarding the diffusion plate 27, the same description as in the third embodiment can be applied. (tube member)

The tube member 413 can be understood as a further modification of the light pipe 23 of the modification described with reference to FIG. 4 . Therefore, the description of light pipe 23 applies to barrel member 413 as appropriate. For example, the cylindrical member 413 has a peripheral surface 413a surrounding the optical axis LA. This circumferential surface 413a is the same as the circumferential surface 23a of the light pipe 23. It does not substantially transmit light regardless of the incident angle, and can function as a reflective surface (for example, a reflector) that reflects light. The reflectivity exemplified in the description of the peripheral surface 23a can be applied to the peripheral surface 413a.

From the viewpoint of materials, the cylindrical member 413 may have a base 31 and a reflective film 33 overlapping the inner surface of the base 31, just like the light pipe 23 of the modified example. Regarding the materials of the base body 31 and the reflective film 33, the description of the base body and the reflective film of the light pipe 23 (neither shown in the figure) can be followed. In addition, unlike the example shown in the figure, the cylindrical member 413 may be entirely made of a single material with a relatively high reflectivity (for example, metal).

Regarding the outer shape (outer shape) of the cylindrical member 413, the description of the outer shape of the cylindrical member 13 in the first embodiment can be applied. The inner surface of the cylindrical member 413 is mostly composed of the peripheral surface 413a. Regarding the shape of the peripheral surface 413a, the description of the peripheral surface 17a of the light pipe 17 in the first embodiment can be applied. In the example shown in the figure, the shape of the inner surface of the cylindrical member 413 has: a truncated cone, which is composed of the peripheral surface 413a; a cylinder located below the truncated cone; and two cylinders located below the truncated cone. above. The lower column system serves as a location where the diffusion plate 27 is arranged (for example, fitted). The two upper column systems serve as locations where the condenser lens 29 and the light-adjusting filter 15 are disposed (for example, fitted). Different from the example shown in the figure, the column does not need to be formed. Furthermore, as described in the description of the first embodiment, the shape of the peripheral surface 413a may include a column.

As can be understood from the range of the reflective film 33, in the example shown in the figure, it is a truncated cone in the inner surface of the cylindrical member 413 (from another point of view, it is the portion from the condenser lens 29 to the diffusion plate 27) The side surface is formed as a reflective surface as a whole. In addition, not only the side surfaces of the truncated cone, but also the side surfaces and end surfaces of the cylinder below it (from another point of view, the part where the diffusion plate 27 is disposed), and the inner surface of the pinhole 21 are formed as reflective surfaces.

Different from the example shown in the figure, at least one surface of the side and end surfaces of the cylinder and the inner surface of the pinhole 21 may not be made into a reflective surface. In addition, it is not necessary to make the entire side surface of the truncated cone a reflective surface. For example, regarding the length in the direction parallel to the optical axis LA, the length of the reflective surface may be the length of a truncated cone, or more than 1/2 of the length from the opening 19 to the pinhole 21 (including the opening 19 and the pinhole 21). 4/5+ and 9/10+. Contrary to the above, at least one of the side surfaces and end surfaces of the two upper cylinders (according to another point of view, the portion where the condenser lens 29 and the dimming filter 15 are disposed) may be made into a reflective surface.

In addition, the example shown in the figure also includes various forms. The reflective peripheral surface 413a surrounding the optical axis LA is provided on the inner peripheral surface of the cylindrical member 13. In addition to arranging the optical element (diffusion plate 27, etc.), It can be defined in an area outside the face of a part, or it can be defined in an area including the face of the part. The description of this embodiment is based on the former for expediency. (concentrating lens)

The focus of the condenser lens 29 can be set at an appropriate position. For example, the focus system can be set inside the pinhole 21 or before and after it. In this case, for example, the light incident on the far center of the opening 19 is condensed on the pinhole 21 or before and after the pinhole 21 . Compared with the form in which the condenser lens 29 is not provided (as understood from the above-described embodiments, this form is also included in the technology of the present disclosure), the peripheral surface 413a does not actively have the functions of condensing and diffusing light. This contributes to the effective use of unconcentrated light (light that has been absorbed by the inner surface of the tube member in the past).

Furthermore, for example, the focal point is the same as the focal point on the incident surface 17b of the light pipe 17 in the first embodiment, and may be located inside the peripheral surface 413a (truncated cone). In this case, for example, the condenser lens 29, like the incident surface 17b, helps to increase the light beam that reaches the peripheral surface 413a and is reflected, and further, helps to condense and/or diffuse the light by the peripheral surface 413a. Improvement of effect.

The shape and size (and position) of the condenser lens 29 can be set, for example, so that all the light incident on the peripheral surface 413 a substantially passes through the condenser lens 29 . In the example shown in the figure, the condenser lens 29 blocks the opening surface on the incident side of the peripheral surface 413a, thereby realizing the above-mentioned light relationship.

The specific shape and material of the condenser lens 29 (convex lens) can be appropriately selected. For example, the condenser lens 29 may be a plano-convex lens (example shown in the figure), a biconvex lens, or a convex meniscus lens. A plano-convex lens or a convex meniscus lens that can also be used as the condenser lens 29 has its convex side facing either the opening 19 side or the pinhole 21 side. The condenser lens 29 may be a single lens or a plurality of lens groups. The material of the condenser lens 29 can be, for example, glass or resin.

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

Therefore, it has the same function as the first embodiment. For example, light that has conventionally been absorbed by the inner surface of the cylindrical member can be effectively utilized. And/or, by utilizing the diffusion effect of the peripheral surface 413a, the necessity of installing a diffusion plate is reduced. Thereby, the transmittance is improved.

As shown in this embodiment, the reflective film 33 overlaps with 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 formed of metal, and no black paint is applied to the inner surface, thereby forming a form of the peripheral surface 413a that reflects light (this form may also be included in the technology of the present disclosure). In comparison, the degree of freedom of the material of the tube member 413 is improved. Furthermore, since there is no need for the light pipe 17 that is separate from the tube member, the structure is simplified.

The reflective film 33 may include a metal film.

In this case, for example, it is easy to increase the reflectivity of the peripheral surface 413a. Furthermore, the effect of condensing and/or diffusing light by the peripheral surface 413a is improved. In addition, the metal film system also functions as a light-shielding film. Therefore, the metal film system also helps to reduce the interference of light from or to the outside of the pupil module 407 . According to another point of view, the degree of freedom of the material of the base 31 is further increased. As a result, for example, an inexpensive resin with low light-shielding properties can be used as the material of the base 31 .

As shown in this embodiment, the pupil module 407 is on the incident side of the peripheral surface 413a, and may further include a condenser lens 29 that condenses light on the pinhole 21 side.

In this case, as described above, for example, in a form based on focusing light on the pinhole 21 by the condenser lens 29, the peripheral surface 413a can be used as a portion to reflect the leaked light, thereby improving the transmittance. Alternatively, like the convexly curved incident surface 17b in the first embodiment, the condenser lens 29 can increase the amount of light beams that reach the peripheral surface 413a and be reflected, thereby improving the diffusion and/or condensing effects of the peripheral surface 413a. ＜First variation of pinhole＞

FIG. 8 is a cross-sectional view showing the pinhole 21A of the modified example, and is equivalent to an enlarged view of the pinhole 21 and its surroundings in FIG. 7 .

So far, as the shape of the pinhole 21, a straight column (for example, a cylinder or a corner prism) has been shown. In FIG. 8 , the shape of the pinhole 21A represents a shape having a truncated cone (incidence side portion 21 s) with a diameter that becomes smaller toward the bottom, and a straight column (ejection side portion) continuous with the bottom of the truncated cone. 21t). In addition, the shape of the pinhole 21 shown in various figures other than Fig. 8 can also be understood as the shape of the actual pinhole 21, and the actual shape of the pinhole 21 (not the shape of a straight column) can also be understood as Pattern the represented shape. From another viewpoint, the shape of the pinhole 21A can be applied to any embodiment.

The specific shape and size of the pinhole 21A in the modified example can be set appropriately. For example, the description of the pinhole 21 in the embodiment can be applied to the pinhole 21A in the modified example as long as no contradiction occurs. In the pinhole 21A, the cross-sectional shape of the frustum (a cross-section perpendicular to the optical axis LA) and the cross-sectional shape of the cylinder may be the same (similar) or different. The inclination angle θ2 of the side surface of the truncated cone relative 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. The above lower limit and upper limit can be combined appropriately. Regarding the length in the direction parallel to the optical axis LA, any square length of a truncated cone or a straight cylinder may be used. In the example shown, the tie rod is shorter than the truncated cone.

In FIG. 8 , the pupil module 407 of the fourth embodiment (FIG. 7) is taken as an example as a pupil module having a pinhole 21A of a modified example. In this case, as described in the fourth embodiment, the reflective film 33 (in other words, the reflective surface) may be formed on part or all of the pinhole 21A (the example shown in the figure), or may not be formed at all.

As shown above, the pinhole 21A may have a portion (incident side portion 21s of the truncated cone) with a smaller diameter as it approaches the exit side.

In this case, for example, the number of light beams entering the pinhole 21A can be increased. To explain in more detail, compared with the form in which the straight cylindrical injection side portion 21t constitutes the entire pinhole 21 (this form is also included in the technology of the present disclosure), the radiation from the outer peripheral side (in the example shown in the figure is diffused Light from the outer peripheral edge side of the plate 27 is easily transmitted toward the emission side (lower side in the figure). Thereby, the light transmittance can be improved. Furthermore, as described above, since the light from the outer peripheral side (outer peripheral edge side of the diffuser plate 27) is easily transmitted toward the emission side, the light transmitted toward the emission side is light inclined at a certain angle with respect to the optical axis LA. proportion increased. Thereby, the incident angle to the imaging element 103 can be enlarged. In addition, from the viewpoint of strength, when the thickness of the cylindrical member 413 is thick (when the length of the pinhole 21A in the penetrating direction is long), the possibility that the pinhole 21A will excessively affect the diffusion angle of the emitted light is reduced. A reflective surface is formed on the side of the truncated cone, and the pinhole 21A is also expected to have functions of condensing and/or diffusing light.

The effect shown above is that the shorter the length parallel to the optical axis LA of the pinhole 21A or the length of the straight cylindrical portion (in this modification, the incident side portion 21s) parallel to the optical axis LA, the easier it is to increase. On the other hand, from the viewpoint of the strength of the cylindrical member 413, these lengths are set to a certain level or more. The strength can be ensured by optical elements (such as the lens 35 described below) provided before and after the pinhole 21A, thereby shortening the above-mentioned length. Taking these matters into consideration, the above length can be set appropriately. For example, the length of the pinhole 21A parallel to the optical axis LA can be set to 0.4 mm or more and 0.6 mm or less. When the strength can be ensured by optical elements, the length of the pinhole 21A parallel to the optical axis LA can be set to 0.2 mm or more and 0.4 mm or less. The length of the straight columnar part can be set to 0.05mm or more and 0.15mm or less. <Fifth Embodiment>

FIG. 9 is a cross-sectional view showing the structure of the pupil module 507 of the fifth embodiment, and corresponds to FIG. 3 of the first embodiment.

The pupil module 507 of the fifth embodiment is different from the pupil module 407 of the fourth embodiment in the shape of the cylindrical member (in other words, the peripheral surface). Specifically, whereas the circumferential surface 413a (inner circumferential surface) of the cylindrical member 413 in the fourth embodiment is a truncated cone, the circumferential surface 513a (inner circumferential surface) of the cylindrical member 513 in the fifth embodiment is a straight column. . Regarding 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 can be applied.

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

Therefore, it has the same function as the first embodiment. For example, light that has conventionally been absorbed by the inner surface of the cylindrical member can be effectively utilized. And/or, by utilizing the diffusion effect of the peripheral surface 413a, the necessity of installing a diffusion plate is reduced. Thereby, the transmittance is improved. <Sixth Embodiment>

FIG. 10 is a cross-sectional view showing the structure of the pupil module 607 of the sixth embodiment, and corresponds to FIG. 3 of the first embodiment.

The pupil module 607 of the sixth embodiment is the pupil module 7 of the first embodiment, in which a lens 35 (the term "lens" is deemed to include a lens group) is added to the exit side of the pinhole 21. By adding the lens 35, for example, various incident angles (for example, CRA: Chief Ray Angle) to the imaging element 103 can be realized without changing the design of the structure of most parts of the pupil module 607 (for example, all except the lens 35). In addition, the shape, size, etc. shown in the figure of the lens 35 reflect actual ones.

The shape and size of the lens 35 are arbitrary. For example, the lens 35 may be a single lens or a lens group (example shown in the figure). The material of the lens 35 (if strictly expressed, the lens 35 includes one or more lenses. The same applies below) can be glass or resin. The lens 35 series may be a spherical lens or an aspherical lens. The lens 35 may be a convex lens or a concave lens. To explain in more detail, for example, a biconvex lens, a plano-convex lens, a convex meniscus lens, a biconcave lens, a plano-concave lens and a concave meniscus lens can be used. Lenses that are asymmetrical to the plane orthogonal to the optical axis may be convex or concave toward either the incident side or the emitting side. The combination of the shapes of the plurality of lenses constituting the lens 35 as the lens group is also arbitrary.

As shown above, the pupil module 607 has the lens 35 on the exit side of the pinhole 21 .

In this case, as already mentioned, various incident angles to the imaging element 103 can be realized by changing the design of the lens 35 . Furthermore, the system can cope with the use of pupil at low cost. Hole module in various sizes for more than one user.

Here, the lens 35 is provided for the pupil module 7 of the first embodiment. However, the lens 35 system is applicable not only to the first embodiment but also to any other practical applications. Shi form. For example, as shown in the fourth embodiment (FIG. 7) and the fifth embodiment (FIG. 9), the reflective film 33 may be provided on the inner surface of the base 31 of the cylindrical member, and the lens 35 may be provided.

<Second Variation of Pinhole>

FIG. 11 is a cross-sectional view showing the pinhole 21B of the modified example, and is equivalent to an enlarged view of the pinhole 21 and its surroundings in FIG. 9 .

In addition, as already mentioned, the lens 35 described with reference to FIG. 10 can be applied to any embodiment. Figure 11 shows the fifth embodiment (Figure 9) in which a lens is installed. 35 picture.

In the pinhole 21A of the modified example described with reference to FIG. 8 , the incident side portion 21 s is formed into a truncated cone shape in which the diameter increases as it approaches the incident side. On the other hand, the change shown in Figure 11 The pinhole 21B of this example is opposite to the pinhole 21A. The incident side part 21s is formed into a straight column shape, and the emission side part 21t is formed into a truncated cone shape. The injection side portion 21t is formed in such a manner that its diameter increases as it approaches the injection side.

In addition, like the pinhole 21A, the pinhole 21B can be applied to any embodiment. For example, it can also be applied to a form with a light pipe 17, or it can be applied to a form without a light pipe 17. The shape of the lens 35.

The specific shape and size of the pinhole 21B can be set appropriately. For example, the description of pinhole 21A replaces the words incident side and exit side appropriately, and can be used for pinholes. 21B. For example, like the pinhole 21A, the inclination angle θ2 (not shown) of the side surface of the truncated cone with respect to the optical axis LA is arbitrary. For example, it can be 10° or more, 30° or more, 50° or more, and it can be 80° or less. or 70° or more Down. For example, as with the pinhole 21A, any one of the truncated cone and the straight column may be longer in length in the direction parallel to the optical axis LA. Furthermore, for example, like the pinhole 21A, the specific size of the pinhole 21B is arbitrary, and can be 0.4 mm or more and 0.6 mm or less.

When the pinhole 21B is used in the form of the reflective film 33, the arrangement range of the reflective film 33 relative to the pinhole 21B is arbitrary, as in the case of the pinhole 21A. For example, the reflective film 33 may be formed on the entire pinhole 21B (the example shown in the figure), may be formed on only a part of the pinhole 21B, or may not be formed on the pinhole 21B at all. An example of forming the reflective film 33 on a part of the pinhole 21B includes forming the reflective film only on the incident side portion 21s among the incident side portion 21s and the emitting side portion 21t.

As shown above, the pinhole 21B may have a portion (the exit side portion 21t of the truncated cone) with a smaller diameter as it approaches the incident side.

In this case, for example, it has the same effect as the pinhole 21A. Specifically, for example, light from the outer peripheral side (in the example shown in the figure, the outer peripheral edge side of the diffusion plate 27 ) easily passes through the pinhole 21B, thereby increasing the transmittance and increasing the incident angle on the imaging element 103 .

The technology of the present disclosure is not limited to the above embodiments and modifications, and can be implemented in various forms.

For example, the various embodiments described above can be combined appropriately. For example, the configuration without a diffuser plate (Fig. 3) or the configuration with a diffuser plate only on the incident side (Fig. 5) can also be applied to the configuration in which a reflective surface is formed on the inner surface of the cylindrical member (Figs. 7 and 9) . The condenser lens (Fig. 7 and Fig. 9) can also be used in a configuration with a light pipe (Fig. 3, Fig. 5 and Fig. 6). On the contrary, it is not equipped with a condenser lens (Fig. 3, Fig. 5 and Fig. 6). It can also be applied to a configuration in which a reflective surface is formed on the inner surface of the cylindrical member (Fig. 7 and Fig. 9). In this way, the presence or absence of the diffuser plate on the incident side, the presence or absence of the diffuser plate on the exit side, the presence or absence of the condenser lens, the presence or absence of the lens on the exit side of the pinhole, and the shape of the peripheral surface (reflecting surface) surrounding the optical axis, etc. The combination is arbitrary.

In the embodiment, the outer circumferential surface of the solid light pipe (Fig. 3, etc.), which is a member separate from the cylindrical member, is shown as a circumferential surface that surrounds the optical axis and can reflect light. Among the components, the inner peripheral surface of the hollow light pipe (Fig. 4), and the reflective film overlapping the inner surface of the cylindrical member (Fig. 7, etc.). As mentioned in the description of the embodiment, this can also be achieved by forming the entire cylindrical member with a light-reflecting peripheral surface surrounding the optical axis. However, in the conventional technology, strictly speaking, the inner surface of the tube member is not completely non-reflective. Therefore, when the entire cylindrical member is made of a light-reflective material and has a circumferential surface that can reflect light, it is deemed to mean that the reflectivity of the circumferential surface is higher than that of the conventional black-coated inner surface. Higher rate composition. Examples of such reflectivity include 50% or more or 80% or more.

A reflective film that reflects the light in the light pipe can also be provided on the outer peripheral surface of the solid light pipe. The reflective film system can also be understood as a hollow light tube. According to another point of view, a light-transmitting material can also be arranged inside the hollow light tube.

The diffuser plate, condenser lens, and dimming filter arranged on the incident or emitting side of the peripheral surface that can reflect light (the outer peripheral surface of a solid light pipe, etc.) can be conceptualized as optical elements at a higher level. In addition, the optical elements arranged on the incident side or the emitting side of the peripheral surface may be of various types other than those exemplified in the embodiments.

For example, in the fourth embodiment ( FIG. 7 ), the condenser lens 29 (in other words, a convex lens) is exemplified as the optical element. However, 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 easily enters the peripheral surface 413a (or the peripheral surface of other embodiments). As a result, the light diffusion effect by the peripheral surface 413a is improved. The specific shape of the concave lens can be appropriately selected. For example, the concave lens system may use biconcave lenses, plano-concave lenses, and concave meniscus lenses.

1: Check the device 7: Pupil module 17a: (Pupillary module) peripheral surface 21: Pinhole 103: Camera element (solid-state camera element) LA: optical axis

FIG. 1 is a schematic cross-sectional view showing the structure of the main parts of the inspection device according to the first embodiment. FIG. 2 is a schematic perspective view of a pupil module included in the inspection device of FIG. 1 . FIG. 3 is a cross-sectional view of the pupil module in FIG. 2 . FIG. 4 is a schematic cross-sectional view showing a light pipe according to a modified example. FIG. 5 is a schematic cross-sectional view of the pupil module of the second embodiment. FIG. 6 is a schematic cross-sectional view of the pupil module according to the third embodiment. Fig. 7 is a schematic cross-sectional view of the pupil module according to the fourth embodiment. FIG. 8 is a schematic cross-sectional view showing a pinhole according to a modified example. Fig. 9 is a schematic cross-sectional view of the pupil module according to the fifth embodiment. Fig. 10 is a schematic cross-sectional view of the pupil module according to the sixth embodiment. FIG. 11 is a schematic cross-sectional view of a pinhole showing a modified example different from that shown in FIG. 8 .

7: Pupil module

8A: End 1

8B:End 2

8C:Flange

13: Tube component

13a: Barrel body

13b: End face

15: Dimming filter

17:Light pipe

17a: (Pupillary module) peripheral surface

17b:Incidence surface

17c: Shoot out the face

19:Open your mouth

21: Pinhole

θ:tilt angle

LA: optical axis

Claims (16)

A pupil module that allows inspection light from a light source device to pass toward a solid-state imaging element, wherein It has: a peripheral surface that surrounds the optical axis and can reflect light; a pinhole that is located along the direction of the optical axis and is located on the exit side of the peripheral surface; and a cylindrical member with light-shielding properties that is Having this light at one end The injection opening has a pinhole with a smaller diameter than the opening at the other end; the reflective film overlaps with the inner surface of the cylindrical member to form the peripheral surface; the reflective film contains a metal film. A pupil module is a pupil module that allows inspection light from a light source device to pass toward a solid-state imaging element, and has: A surface that surrounds the optical axis and can reflect light; a pinhole that is located along the direction of the optical axis and is located on the exit side of the peripheral surface; and a light-shielding tube member that has a The opening that the light enters The other end has a pinhole with a smaller diameter than the opening; the reflective film overlaps with the inner surface of the cylindrical member to form the peripheral surface; and the reflectivity of the reflective film is above 50%. For example, the pupil module of claim 1 or 2, wherein the peripheral surface is straight cylindrical. For example, the pupil module of claim 1 or 2, wherein the diameter of the circumferential surface is smaller as it is closer to the side of the pinhole. A pupil module is a pupil module that allows inspection light from a light source device to pass toward a solid-state imaging element, and has: The surface surrounds the optical axis and can reflect light; the pinhole is along the direction of the optical axis and is located on the exit side of the peripheral surface; and A cylindrical member with light-shielding properties, which has an opening through which the light enters at one end, and a pinhole with a smaller diameter than the opening at the other end; wherein there is a solid or hollow light inside the cylindrical member Tube, It is a component separate from the barrel component and has the peripheral surface. The pupil module of claim 5, wherein the outer peripheral surface of the light pipe is separated from the inner peripheral surface of the barrel member. The pupil module of claim 5, wherein the light pipe is solid, and the end on the side where the light from the light source device is incident is bulging outward. The curved surface shape. For example, the pupil module of claim 5, wherein the diameter of the circumferential surface becomes smaller as it approaches the side of the pinhole. The pupil module of claim 1, 2, 5, 6, 7 or 8, wherein the length of the peripheral surface parallel to the optical axis is greater than the diameter. The pupil module of claim 1, 2, 5, 6, 7 or 8, wherein there is a diffusion plate on the exit side of the peripheral surface. The pupil module of claim 1, 2, 5, 6, 7 or 8, wherein there is a diffusion plate on the incident side of the peripheral surface. For example, the pupil module of claim 1, 2, 5, 6, 7 or 8, wherein the diffusion plate is not located on both the exit side and the entrance side of the peripheral surface. For example, the pupil module of claim 1, 2, 5, 6, 7 or 8 further has a condenser lens on the incident side of the circumferential surface, which converts the light The light is focused on the pinhole side. The pupil module of claim 1, 2, 5, 6, 7 or 8, wherein there is a lens on the exit side of the pinhole. The pupil module of claim 1, 2, 5, 6, 7 or 8, wherein the pinhole has a diameter closer to the exit side or closer to the entrance side. The smaller the part. An inspection device having: a pupil module according to any one of claims 1 to 15; a detection card equipped with the pupil module; and the light source device.

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