JP2008152010A - Method for manufacturing sharpening element - Google Patents

Abstract

A method of manufacturing a sharpening element capable of increasing the alignment accuracy between a microlens and an aperture is provided.
Laser light L1, L2 is irradiated onto two microlenses 3a separated in the longitudinal direction. The reflection directions of the reflected lights R1 and R2 reflected from the upper surface 3f of the micro lens array (MLA) 3 are detected, and the position of the MLA 3 is corrected so that the laser beams L1 and L2 are orthogonal to the upper surface 3f. The apertures corresponding to the microlenses 3a irradiated with the laser beams L1 and L2 are imaged by the cameras 41a and 41b from the lower surface side of the aperture array (APA) 4, respectively. Based on the captured image, MLA3 and APA4 are aligned so that the centers of the laser beams L1 and L2 that have passed through the aperture coincide with the centers of the apertures, and MLA3 and APA4 are combined with a UV curable adhesive. 6 and the spacer 5.
[Selection] Figure 6

Description

  The present invention relates to a method for manufacturing a sharpening element for an exposure image formed by combining a microlens array and an aperture array, and more particularly to a method for manufacturing a sharpening element used in a maskless digital exposure apparatus.

  In recent years, a digital exposure apparatus that performs image exposure on an exposed member such as a printed circuit board by a light beam modulated in accordance with image data using a spatial modulation element such as a digital micromirror device (DMD). Development of a multi-beam exposure apparatus is also underway.

  The DMD is a mirror device in which a large number of micromirrors (micromirrors) whose reflection surface angle changes according to a control signal are two-dimensionally arranged on a semiconductor substrate, and are stored in a memory cell provided for each micromirror. The angle of the reflecting surface of the micromirror is changed by the electrostatic force applied.

  In this digital exposure apparatus, a light beam emitted from a light source is collimated (parallelized) by a lens system, and each DMD micromirror arranged at the focal position of the lens system is generated according to image data or the like. The light beam is modulated by on / off control based on the signal, and the modulated light beam is collected by a lens system having an optical element such as a microlens array (MLA) that collects each modulated light beam with one lens for each pixel. It has been proposed to perform exposure with high resolution by forming an image with a reduced spot diameter on the exposure surface of the exposure member (see, for example, Patent Document 1).

In order to further increase the resolution, in the same type of digital exposure apparatus, an aperture array (APA) having a pinhole-like aperture (opening) corresponding to each microlens of the MLA is arranged on the rear side of the MLA, It has been proposed that only the light beam that has passed through the corresponding microlens passes through the aperture (see, for example, Patent Documents 2 and 3). With this configuration, the light beam is prevented from entering each aperture of the APA from the adjacent microlens that does not correspond to the aperture, and the exposure image is sharpened.
JP 2001-305663 A JP 2004-122470 A JP 2005-216950 A

  By the way, the MLA and the APA need to be adjusted and fixed so that the focal position of the microlens and the center position of the aperture exactly coincide with each other, but the diameters of the microlens and the aperture are very small. Since it is enormous, it is very difficult to accurately align MLA and APA.

  MLA and APA are fixed by an ultraviolet (UV) curable adhesive via a spacer or the like, and incorporated into a digital exposure apparatus as a sharpening element. The alignment of MLA and APA at the time of manufacture of this sharpening element is currently performed based on the alignment marks and the end faces of each, and alignment is performed based on these. Even so, there is a possibility that the microlens and the aperture are misaligned, and there is a possibility that the misalignment will occur after the alignment due to slight vibration. Since this misalignment cannot be determined in real time, production defects cannot be prevented.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a sharpening element that can improve the alignment accuracy between a microlens and an aperture.

  In order to achieve the above object, a method of manufacturing a sharpening element according to the present invention includes a microlens array having a flat upper surface and a plurality of convex microlenses formed on the lower surface, and a lower surface side of the microlens array. In the method of manufacturing a sharpening element comprising an aperture array that is disposed and has an aperture corresponding to each of the microlenses, the microlens is disposed on at least two microlenses of the plurality of microlenses. Laser light is irradiated from the upper surface side of the array, the reflection direction of the laser light reflected from the upper surface of the microlens array is detected, and each laser beam is orthogonal to the upper surface of the microlens array Correction is performed, and the aperture corresponding to the microlens irradiated with each laser beam is changed to the aperture array. The microlens array and the aperture array are aligned so that the center of the laser beam that has been imaged from the lower surface side of each of the apertures coincides with the center of the aperture, and the microlens array and the The aperture array is fixed.

  The alignment is performed in a state where the microlens array and the aperture array are temporarily attached through a spacer coated with a photocurable adhesive, and predetermined light is irradiated to the photocurable adhesive. It is preferable that the microlens array and the aperture array are fixed to each other.

  Moreover, it is preferable that the said photocurable adhesive is an ultraviolet curable adhesive hardened | cured by irradiation of an ultraviolet-ray.

  In the alignment, it is preferable to perform alignment by fixing the microlens array and moving the aperture array.

  The aperture array is preferably spaced from the microlens array so that the aperture is positioned at the focal point of the corresponding microlens.

  Further, the microlenses are arranged in a matrix in a rectangular lens forming region, and the laser light is irradiated to two microlenses that are maximally separated in the long side direction of the lens forming region. It is preferable to do.

  In the sharpening element manufacturing method of the present invention, alignment is performed while actually observing the laser beam transmitted through the aperture, so that the alignment accuracy between the microlens and the aperture can be increased. Further, since the microlens array and the aperture array are fixed while performing alignment, it is possible to prevent a positional shift at the time of fixing caused by vibration or the like.

  FIG. 1 shows a configuration of a digital exposure apparatus 10 in which a sharpening element 2 is incorporated. The fiber array light source 11 has a plurality of optical fiber emitting ends (light emitting points) arranged in a matrix and emits a substantially rectangular (rectangular) laser beam. The lens system 12 includes a condensing lens 13 that condenses the laser light B as illumination light emitted from the fiber array light source 11, a rod-shaped optical integrator 14 that collimates the light that has passed through the condensing lens 13, and an optical integrator. 14 and an imaging lens 15 that forms an image on the DMD 18 with the laser beam B arranged on the emission side. The lens system 12 causes the laser beam B to enter the DMD 18 as a light beam that is close to parallel light and has a uniform beam cross-sectional intensity.

  The mirror 16 reflects the laser beam B emitted from the lens system 12 and irradiates the DMD 18 via a TIR (total reflection) prism 17. The DMD 18 is a mirror device in which micromirrors that constitute pixels (pixels) are supported by pillars and are tiltable on SRAM (Static Random Access Memory) cells arranged in a lattice pattern. Each micromirror changes the angle of the reflecting surface according to the digital signal written in the SRAM cell. Therefore, by controlling the tilt of the micromirror in each pixel of the DMD 18 according to the image data to be exposed, the laser light B incident on the DMD 18 is reflected in the direction according to the tilt of each micromirror.

  The first imaging optical system 19 includes lenses 20 and 21, and enlarges an image generated by reflecting the laser beam B by the DMD 18 to a predetermined magnification, and forms an image on the MLA 3 of the sharpening element 2. To do. In the sharpening element 2, MLA3 and APA4 are separated and fixed via a spacer 5, and UV light (wavelength: 300) is provided between the spacer 5 and MLA3 and between the spacer 5 and APA4. It is bonded by a UV curable adhesive 6 that is cured by irradiation of ˜380 nm. Note that the adhesive 6 is not limited to the UV curable type, and may be one that is cured by visible light, and may be at least a photo curable type adhesive.

  As will be described in detail later, the MLA 3 has a flat upper surface 3f and a number of microlenses 3a arranged two-dimensionally on the lower surface 3g. The microlens 3a has a propagation direction of laser light B (downward in the figure). ) Toward the surface. Each microlens 3a forms an image by reducing the incident image at a predetermined magnification. In the APA 4, a plurality of circular apertures 4a are two-dimensionally arranged on a light-shielding member, and each aperture 4a is arranged to correspond to each microlens 3a on a one-to-one basis. Further, the APA 4 is separated from the MLA 3 so that the aperture 4a is positioned at the imaging position (focal point) 3h of the micro lens 3a. Since light is prevented from entering each aperture 4a of the APA 4 from the adjacent microlens 3a that does not correspond to the aperture 4a, the incidence of stray light on the adjacent pixels is suppressed, and the sharpness (resolution) of the exposure image is improved.

  The second imaging optical system 22 includes lenses 23 and 24, and enlarges an image output from the sharpening element 2 to a predetermined magnification or enters the prism pair 25 at an equal magnification. The prism pair 25 can adjust the focus of the image on the exposed member 26 by moving in the vertical direction in the drawing. The exposed member 26 is specifically a printed circuit board, and is sub-scan fed by a transport device (not shown).

  2A to 2C show the configuration of MLA3. As shown in FIG. 2A, the MLA 3 is composed of a quartz-made rectangular translucent plate 3b, and a rectangular lens forming region 3c in which microlenses 3a are arranged in a matrix is formed at the center. Is formed. The MLA 3 has an outer shape of about 21 mm in the X direction and about 52 mm in the Y direction, and has a thickness of about 1 mm. At the four corners outside the lens formation region 3c of the MLA 3, alignment marks 3d are formed by forming light shielding films made of chromium (Cr) in a cross pattern.

As shown in FIG. 2 (B), the lens forming region 3c along the long side direction (X direction) and the short side direction (Y-direction), the micro lenses 3a of the diameter D _M is at a constant pitch P It is arranged. Specifically, D _M = 34 μm and P = 41 μm, and a total of about 260,000 microlenses 3a are arranged in the lens formation region 3c, with 1024 in the X direction and 256 in the Y direction.

  As shown in FIG. 2C, the microlens 3a is a convex lens having a spherical lens surface, and is formed by performing dry etching on the flat light-transmitting plate 3b and transferring the lens shape. Is. A light shielding mask 3e made of chromium (Cr) is formed between the outer edge of the microlens 3a and the adjacent microlens 3a.

  3A to 3C show the configuration of APA4. As shown in FIG. 3A, the APA 4 is provided with a light-shielding film 4e (see FIG. 3C) in which a circular aperture 4a is formed on a lower surface 4f of a quartz-shaped rectangular translucent plate 4b. It will be. The APA 4 has substantially the same shape as the MLA 3, and the aperture formation region 4c is formed at the same position as the lens formation region 3c. At the four corners outside the aperture formation region 4c of the APA 4, alignment marks 4d formed by patterning light shielding films 4e in a cross shape are arranged. The alignment mark 4d is disposed at the same position as the alignment mark 3d of the MLA 3.

As shown in FIG. 3B, the aperture forming region 4c has the same number (1024 in the X direction) at the same position and at the same pitch P so as to correspond to the microlenses 3a of the MLA 3 on a one-to-one basis. , 256 in the Y direction, about 260,000 in total). Apertures 4a are arranged. The diameter D _{A of the} aperture 4a is smaller than the diameter D _{M of the} microlens 3a. Specifically, D _A = 14 μm.

  As shown in FIG. 3C, the aperture 4a is a light transmitting hole in which a light shielding film 4e made of chromium (Cr) is formed on the lower surface 4f of the light transmitting plate 4b. The APA does not have to have a light shielding film attached to the light transmitting plate, and may have a physical hole (pin hole) formed in the light shielding plate. Further, the planar shape of the aperture does not have to be circular, and may be, for example, a quadrangle.

  Hereinafter, a method for manufacturing the sharpening element 2 by fixing the MLA 3 and the APA 4 configured as described above will be described. As shown in FIG. 4, the spacer 5 is a quadrangular prism-shaped member made of quartz, and the length in the longitudinal direction (X direction) is shorter than the length in the X direction of MLA3 and APA4 (for example, 15 mm). The length is about 200 μm. The MLA 3 and the APA 4 are overlapped so that the alignment marks 3d and 4d substantially coincide with each other with the pair of spacers 5 interposed therebetween. The spacer 5 separates the MLA 3 and the APA 4 so that the aperture 4a is positioned at the focal position of the micro lens 3a. Note that the adhesive 6 described above is applied to the upper surface 5a and the lower surface 5b of each spacer 5, and the upper surface 5a is outside the lens forming region 3c on the lower surface of the MLA 3 (between two alignment marks 3d spaced apart in the X direction). 5b is attached to the outside of the aperture formation region 4c on the upper surface of the APA 4 (between two alignment marks 4d spaced apart in the X direction). Since the adhesive 6 is not cured until the UV light is irradiated, the MLA 3 and the APA 4 are not completely fixed and are temporarily attached before the UV light irradiation.

  FIG. 5 shows the alignment of the sharpening element 2 in a state where the MLA 3 and the APA 4 are temporarily attached by the adhesive 6 through the spacer 5 so that the focal position of the microlens 3a coincides with the center position of the aperture 4a ( The assembly (assembly) apparatus 30 which adheres MLA3 and APA4 while performing concentric adjustment is shown. In the sharpening element 2, the MLA 3 and the APA 4 are temporarily attached as described above, the MLA 3 is fixed by the fixing jig 31, and the APA 4 is held movably by the moving mechanism 32.

  The fixing jig 31 includes a substantially L-shaped fixing frame that abuts two adjacent side surfaces of the four side surfaces of the MLA 3 and a pressing member that presses the MLA 3 against the fixing frame. The pressing member is an operator. Can be operated. The moving mechanism 32 includes a fixing jig similar to the fixing jig 31, a stage to which the fixing jig is fixed, and the stage in the X, Y, and Z directions and the θx, θy, and θz directions (X, Y, and Z directions). It consists of a 6-axis drive unit that drives in the rotation direction with each direction as an axis (see FIG. 6). The controller 33 controls the moving mechanism 32 and adjusts the relative position between the MLA 3 and the APA 4.

An autocollimator 34 and a laser branching device 35 are provided immediately above the sharpening element 2 held in this way. The autocollimator 34 is a well-known inclination measuring device that measures the inclination degree of an object by irradiating the object with laser light and detecting the deviation of the reflected light, and has a measurement accuracy of about 0.004 ° ( Angular resolution). Specifically, the autocollimator 34 reflects the laser beam L emitted from the light source 36 in a right-angle direction toward the target object and also from the target object. Of the reflected light (returned light) R ₁ and a two-dimensional image sensor 38 that receives the reflected light R ₁ that has passed through the beam splitter 37 and detects the reflection direction of the reflected light R ₁ . Position of the reflected light R ₁ incident is changed to the image sensor 38 in accordance with the tilt of the object.

The laser branching device 35 includes two half mirrors 39a and 39b. The first half mirror 39a branches the laser light L emitted from the autocollimator 34 into two paths. That is, a part of the laser beam L is allowed to pass and a part is reflected in the right-angle direction. The laser beam L ₁ having passed through the first half mirror 39a, it is emitted towards the sharpening element 2 as an object. The laser beam L ₂ reflected by the first half mirror 39a, is reflected at a right angle by the second half mirror 39 b, and is emitted toward the sharpening element 2. The half mirrors 39a and 39b are arranged so that the laser beams L ₁ and L ₂ emitted from the laser branching device 35 are parallel to each other.

The laser beams L ₁ and L ₂ emitted from the laser branching device 35 are irradiated almost perpendicularly to the flat upper surface 3f of the MLA 3. The irradiation positions of the laser beams L ₁ and L ₂ are on the two microlenses 3 a that are maximally separated in the X direction. Part of the laser beams L ₁ and L ₂ is condensed by the microlens 3a and enters the corresponding aperture 4a. A part of the light is reflected by the upper surface 3f of the MLA 3, and returns to the laser branching device 35 as reflected light R ₁ and R ₂ . The reflected lights R ₁ and R ₂ pass through the half mirrors 39a and 39b, respectively. The reflected light R ₁ passes through the first half mirror 39 a and is returned into the autocollimator 34, but the reflected light R ₂ is not returned into the autocollimator 34.

The reflected light R ₁ returned into the autocollimator 34 passes through the beam splitter 37 and enters the image sensor 38 as described above. A light reception image by the image sensor 38 is displayed on the display 40. The operator can confirm the orthogonality (perpendicularity) of the laser beams L ₁ and L ₂ with respect to the upper surface 3f of the MLA _{3 according to} the position of the reflected light R ₁ in the received light image, and when it is not orthogonal Can adjust the position of the MLA 3 by operating the fixing jig 31 to perform correction.

Cameras 41a and 41b are respectively provided below the two apertures 4a through which the laser beams L ₁ and L ₂ pass, and the cameras 41a and 41b respectively capture the respective apertures 4a. The cameras 41 a and 41 b are independently movable in the X, Y, and Z directions by the moving mechanism 42, and the moving mechanism 42 is controlled by the controller 33. The cameras 41a and 41b are provided with a magnifying optical system (for example, 50 times) in order to image a minute aperture 4a such as 14 μm.

The cameras 41 a and 41 b capture an image including the shape of the aperture 4 a through which the laser beams L ₁ and L ₂ pass and the luminance distribution of the laser beams L ₁ and L ₂ , and input the captured images to the controller 33. The controller 33 moves the APA 4 by controlling the moving mechanism 32 so that the luminance peak positions of the laser beams L ₁ and L ₂ are located at the centers of the respective apertures 4a. Since the position of the aperture 4a moves with the movement of the APA 4, the controller 33 simultaneously controls the moving mechanism 42 to move the cameras 41a and 41b in the XY directions and adjust the visual field positions of the cameras 41a and 41b. Further, the controller 33 controls the moving mechanism 42 to move the cameras 41a and 41b in the Z direction, and focuses on the aperture 4a. Furthermore, the images captured by the cameras 41a and 41b are displayed on the display 43 so that the operator can confirm them.

  The UV irradiation device 44 includes a UV light source and an optical fiber, and performs UV light irradiation based on control from the controller 33. As described above, the controller 33 controls the movement mechanism 32 to align the APA 4 with the MLA 3, and when the alignment accuracy is within the standard (for example, 1 μm or less) and the adjustment is completed, the controller 33 controls the UV irradiation device 44. Then, UV irradiation is performed on the UV curable adhesive 6 applied to the spacer 5. The controller 33 continues the positioning of the APA 4 with respect to the MLA 3 by controlling the moving mechanism 32 even during the UV irradiation. Thereby, it is possible to prevent positional deviation caused by vibration during UV irradiation and maintain alignment accuracy.

FIG. 6 shows the irradiation positions of the laser beams L ₁ and L ₂ irradiated from the laser branching device 35 to the upper surface 3f of the MLA 3 in more detail. The laser beams L ₁ and L ₂ are irradiated on the two microlenses 3a farthest in the X direction in the lens formation region 3c. Moreover, this irradiation part is located in the substantially center regarding the Y direction. In this way, two points that are maximally separated in the long side direction (X direction) are set as the irradiation positions of the laser beams L ₁ and L ₂ , so that the θz direction of MLA 3 and APA 4 (rotation around the Z direction as an axis) (Direction) appears significantly as a deviation between the luminance peak positions of the laser beams L ₁ and L ₂ and the centers of the respective apertures 4a, so that the alignment can be performed with high accuracy in the θz direction.

  Next, a series of procedures for assembling and manufacturing the sharpening element 2 will be described based on the flowchart of FIG. First, MLA3, APA4, and spacer 5 are prepared (step S1). Next, a UV curable adhesive 6 is applied to the upper surface 5 a and the lower surface 5 b of the spacer 5, and the MLA 3 and the APA 4 are temporarily attached via the pair of spacers 5 so that the formation surface of the microlens 3 a faces the APA 4. (Step S2). The alignment between the MLA 3 and the APA 4 at the time of the temporary attachment is performed by the alignment marks 3d and 4d respectively described, and each spacer 5 is directed in the X direction (long side direction of the MLA 3 and the APA 4), respectively. Are arranged in parallel in the Y direction. The spacer 5 separates the APA 4 so as to be positioned on the focal plane of the MLA 3.

The sharpening element 2 at the stage where temporary attachment is performed in this manner is set in the assembly apparatus 30 (step S4). The MLA 3 is fixed by the fixing jig 31 and the APA 4 is held by the moving mechanism 32 to be movable. In this state, the autocollimator 34 is operated to start laser emission (step S5). The autocollimator 34 emits a laser beam L. The laser beam L is branched into parallel laser beams L ₁ and L ₂ by a laser branching device 35 and irradiated on the upper surface 3f of the MLA 3 as shown in FIG. . Of the reflected light R ₁ and R ₂ from the upper surface 3 f of the MLA 3, the reflected light R ₁ is returned to the autocollimator 34, and the reflection direction of the reflected light R ₁ is detected by the image sensor 38.

At this time, the received light image of the image sensor 38 is displayed on the display screen 50 of the display 40 as shown in FIG. 51 shows the incident position of the reflected light _{R 1.} When the laser beams L ₁ and L ₂ are perpendicularly incident (orthogonal) on the upper surface 3f of the MLA 3, the point 51 is positioned at the center 52 of the screen. The amount of deviation of the point 51 from the center 52 represents the degree of inclination of the MLA 3 with respect to the laser beams L ₁ and L ₂ . The operator operates the fixing jig 31 and adjusts the position of the MLA 3 so as to move the point 51 to the center 52 of the screen (step S6).

Next, images including the aperture 4 a through which the laser beams L ₁ and L ₂ pass are captured by the cameras 41 a and 41 b and input to the controller 33. The controller 33 obtains the centers of the laser beams L ₁ and L ₂ from the luminance information of the input image, and detects the amount of deviation between each center and the center of the corresponding aperture 4a (step S7). The controller 33 determines whether or not the deviation amount is within a standard (for example, 1 μm or less) (step S8). If the deviation amount is out of the standard, the controller 33 controls the moving mechanism 32 to determine the position of the APA4. Adjustment is performed (step S9).

At this time, the captured image of the camera 41a is displayed on the display screen 60 of the display 43 as shown in FIG. Since the captured image of the camera 41b is the same, it is omitted. 61, the laser beam L ₁ indicates the shape of the aperture 4a to pass (the image of the laser beam L ₁ is to prevent complication, not shown.). 62, the center determined from the image of the laser beam L ₁ (luminance information) (luminance peak) is located. Cross lines 63a and 63b and a virtual circle 64 are displayed with the center 62 as a reference. Controller 33, so that the aperture 4a is a virtual circle 64 concentric, i.e., so that the center 65 of the aperture 4a coincides with the center 62 of the laser beam _{L 1} adjusts the position of APA4. At the same time, the position adjustment of APA4 so that the center of the aperture 4a of the laser beam L ₂ passes matches the center of the laser beam L ₂ is performed.

As a result of this position adjustment, when the amount of deviation between the center of the laser beams L ₁ and L _{2 and} the center of the corresponding aperture 4 a is within the standard, the UV irradiation device 44 performs UV irradiation on the application region of the adhesive 6. (Step S10). When the adhesive 6 is irradiated with UV light, the adhesive 6 is cured and the MLA 3 and the APA 4 are fixed to the spacer 5. Even during this UV irradiation, the alignment operation in steps S7 to S9 is performed, and the position of the APA 4 is corrected one by one.

  When the MLA 3 and the APA 4 are fixed, the sharpening element 2 is completed. Thereafter, the sharpening element 2 is removed from the assembly apparatus 30, and an appearance inspection or the like is appropriately performed.

In the above embodiment, only the reflected light R ₁ is used out of the reflected light R ₁ and R ₂ in order to detect the degree of inclination of the MLA 3 with respect to the laser light L ₁ and L ₂ . limited not, reflected light _R 1, both _{R 2} or may be used only the reflected light _{R 2,.}

  In the above embodiment, the alignment is performed by irradiating the laser beams on the two microlenses 3a. However, the present invention is not limited to this, and the laser beams are irradiated on the three or more microlenses 3a. Then, the alignment may be performed, which further improves the alignment accuracy.

  In the above embodiment, the moving mechanism 32 drives the APA 4 in the six directions of the X, Y, and Z directions and the θx, θy, and θz directions. However, the present invention is not limited to this, and the X, Y, It is good also as four directions, Z direction and (theta) z direction. When the APA 4 is placed on a flat stage, the inclination in the θx and θy directions can be ignored, and sufficient alignment accuracy can be obtained only by the movement in the four directions.

  In the above embodiment, MLA3 is fixed, APA4 is movable, and alignment is performed by controlling the movement of APA4. However, the present invention is not limited to this, and conversely, APA4 is fixed and MLA3 is fixed. May be moved and the positioning may be performed by controlling the movement of the MLA 3. Further, both MLA3 and MLA3 may be movable, and positioning may be performed by individually controlling movement of each.

It is a schematic diagram which shows the structure of a digital exposure apparatus. It is a figure which shows the structure of a micro lens array, (A) is a top view, (B) is an enlarged view in a lens formation area, (C) is sectional drawing in a lens formation area. It is a figure which shows the structure of an aperture array, (A) is a top view, (B) is an enlarged view in an aperture formation area, (C) is sectional drawing in an aperture formation area. It is a disassembled perspective view which shows the structure of a sharpening element. It is a schematic diagram which shows the structure of an assembly apparatus. It is a perspective view which shows the irradiation position of the laser beam to a sharpening element. It is a flowchart which shows the manufacture procedure of a sharpening element. It is a figure which shows the screen which displayed the image of the reflected light from a sharpening element. It is a figure which shows the screen which displayed the laser beam which passed the aperture, and the image of the aperture.

Explanation of symbols

2 Sharpening element 3a Micro lens 3b Translucent plate 3c Lens formation region 3d Alignment mark 3e Light shielding mask 4a Aperture 4b Translucent plate 4c Aperture formation region 4d Alignment mark 4e Light shielding film 5 Spacer 6 Adhesive 10 Digital exposure device 30 Assembly device 31 Fixing jig 32 Moving mechanism 33 Controller 34 Auto collimator 35 Laser branching device 36 Light source 37 Beam splitter 38 Two-dimensional image sensor 39a, 39b Half mirror 41a, 41b Camera 42 Moving mechanism 43 UV irradiation device

Claims (6)

A microlens array having a flat upper surface and a plurality of convex microlenses formed on the lower surface, and an aperture disposed on the lower surface side of the microlens array, each aperture corresponding to each microlens. In a method of manufacturing a sharpening element comprising an array,
At least two microlenses of the plurality of microlenses are irradiated with laser light from the upper surface side of the microlens array, and the reflection direction of the laser light reflected from the upper surface of the microlens array is detected. , Correction is performed so that the laser beams are orthogonal to the upper surface of the microlens array, and apertures corresponding to the microlenses irradiated with the laser beams are respectively imaged from the lower surface side of the aperture array, The microlens array and the aperture array are aligned so that the center of the laser beam that has passed through the aperture coincides with the center of the aperture, and the microlens array and the aperture array are fixedly fixed. A method for manufacturing a sharpening element.   The alignment is performed in a state where the microlens array and the aperture array are temporarily attached via a spacer coated with a photocurable adhesive, and the predetermined light is irradiated to the photocurable adhesive. The method for manufacturing a sharpening element according to claim 1, wherein the microlens array and the aperture array are fixed to each other.   The method of manufacturing a sharpening element according to claim 1, wherein the photocurable adhesive is an ultraviolet curable adhesive that is cured by irradiation with ultraviolet rays.   4. The method for manufacturing a sharpening element according to claim 1, wherein the alignment is performed by fixing the microlens array and moving the aperture array during the alignment. 5.   5. The method for manufacturing a sharpening element according to claim 1, wherein the aperture array is separated from the microlens array so that the aperture is located at a focal point of the corresponding microlens. 6. .   The microlenses are arranged in a matrix within a rectangular lens formation region, and the laser light is irradiated to two microlenses that are spaced apart from each other in the longest direction of the lens formation region. The method for manufacturing a sharpening element according to any one of claims 1 to 5, wherein:

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