Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
  • G02B27/0927—Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/09—Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for
  • G02B27/0938—Using specific optical elements
  • G02B27/095—Refractive optical elements
  • G02B27/0955—Lenses
  • G02B27/0961—Lens arrays
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B3/00—Simple or compound lenses
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B3/00—Simple or compound lenses
  • G02B3/0006—Arrays
  • G02B3/0037—Arrays characterized by the distribution or form of lenses
  • G02B3/0056—Arrays characterized by the distribution or form of lenses arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses

Definitions

• the present invention relates to an optical element, an optical system device, and a method for manufacturing an optical system device.
• Three-dimensional measurement sensors using the time-of-flight (TOF) method are about to be adopted in mobile devices, cars, robots, etc.
• This method measures the distance to an object based on the time it takes for the light irradiated from the light source to the object to be reflected and returned. If a predetermined area of the object is uniformly irradiated with light from a light source, the distance at each irradiated point can be measured and the three-dimensional structure of the object can be detected.
• the above sensor system includes an irradiation section that irradiates light, an optical element that controls the light from the irradiation section to a predetermined light distribution, a camera section that detects the light reflected from each point on the object, and the camera section that receives the light. It consists of a calculation unit that calculates the distance to the object from the signal. Since existing VCSEL, CMOS imager, CPU, etc. can be used for the irradiation section, camera section, and calculation section, the unique part of the above system is the optical element.
• TOF has the need for long-distance measurement, and the intensity of the irradiated light must be strong enough to enable long-distance measurement.
• randomly arranged microlens arrays are unsuitable for long-distance measurements because the intensity of the irradiated light is low due to the high uniformity of the irradiated light.
• the present invention relates to an optical element that can be easily packaged with other components, an optical system device using the optical element, and a method for manufacturing the optical system device.
• the optical element of the present invention provides an interface between a first medium layer having a first refractive index and a second medium layer having a second refractive index higher than the first refractive index.
• the first medium layer is a gas
• the second medium layer and the adjustment section are integrally formed of a second resin having a second refractive index.
• the second medium layer is made of a second resin having a second refractive index
• the first medium layer and the adjustment section are integrally formed of a first resin having a first refractive index. is preferred.
• the surface of the first medium layer or the second medium layer opposite to the boundary surface is planar or curved.
• an anti-reflection film is provided on a surface of the first medium layer or the second medium layer opposite to the boundary surface.
• a surface of the first medium layer or the second medium layer opposite to the boundary surface has a fine uneven structure that functions as a moth eye.
• a third medium layer may be provided on a surface of the second medium layer opposite to the boundary surface.
• the third medium layer may be made of the same material as the first medium layer.
• the first medium layer is preferably formed on a base material.
• one or more functional layers having a specific function may be provided on a surface of the base material opposite to the surface on which the first medium layer is located.
• the functional layer may be an aperture mask.
• the functional layer may be a metal wiring.
• the functional layer includes a metal wiring formed on the substrate, an insulating layer formed on the metal wiring, an aperture mask made of metal formed on the insulating layer, and a metal wiring formed on the substrate. and a conductive portion that electrically connects to the aperture mask.
• the uneven shape may be a shape in which lenses are arranged periodically.
• the optical element is capable of diffusing incident light into a predetermined diffusion range, the diffusion range being defined as the inside of a single closed curve in a predetermined plane, and the uneven shape having a plurality of irregularities having no periodicity.
• the uneven shape has a width, where ⁇ is the wavelength of the light, n 1 is the refractive index of the first medium layer, and n 2 is the refractive index of the second medium layer.
• the slope of the uneven shape does not have a part where the slope changes by 135 degrees, and the uneven shape has a slope such that the incident light is emitted to a region outside the diffusion range according to Snell's law. It is preferable that the area having the above is 5% or less of the total area.
• the uneven shape is formed such that the light distribution calculated by Snell's law is proportional to cos ⁇ n ⁇ (1 ⁇ n ⁇ 7) from the center of the diffusion range toward the boundary. .
• the optical system device of the present invention includes the above-described optical element of the present invention, and an irradiation section that is disposed on the first medium layer side of the optical element and has a light source that irradiates light to the optical element.
• the optical element and the irradiation section are stacked with the adjustment section interposed therebetween.
• the irradiation section may include a light source coating layer made of resin and covering the light source.
• a cover part that includes the optical element and the irradiation part may be provided.
• at least a portion of the cover portion may be made of a light-shielding material.
• the uneven shape is a shape in which lenses that transmit light with a wavelength ⁇ are arranged periodically, and the irradiation section has a light source that irradiates the plurality of lenses with light with a wavelength ⁇ , m and n are natural numbers of 1 or more, the focal length of the lens according to the cross-sectional shape perpendicular to the y direction is f 1 , the focal length according to the cross-sectional shape perpendicular to the x direction is f 2 , and the pitch of the lens in the x direction Assuming that the pitch is P 1 and the pitch in the y direction is P 2 , the distance L 1 between the irradiation section and the first focal plane of the lens, and the distance L 2 between the second focal plane and the Formula 2 It is preferable to satisfy the following.
• the method for manufacturing an optical system device of the present invention includes the above-described optical element of the present invention and an irradiation section that is disposed on the first medium layer side of the optical element and has a light source that irradiates the optical element with light. , comprising a laminating step of laminating layers through the adjusting portion, and a cover portion forming step of forming a cover portion that includes the optical element and the irradiation portion.
• Another method of manufacturing an optical system device of the present invention includes a first resin supplying step of supplying a first resin that is photocurable and has a first refractive index onto a substrate to which an irradiation part is fixed; 1.
• An uneven shape forming step of forming an uneven shape on the surface of a resin by an imprint method, and applying a second resin that is photocurable and has a second refractive index higher than the first refractive index on the uneven surface. It is characterized by comprising a second medium layer forming step of supplying and curing to form a second medium layer.
• the optical element of the present invention is formed with an adjustment part to maintain a certain distance from the uneven shape of the optical element, it is easy to package the optical element with the irradiation part and other components.
• FIG. 1 is a schematic cross-sectional view showing an optical system element of the present invention.
• FIG. 3 is a schematic cross-sectional view showing another optical system element of the present invention.
• FIG. 3 is a schematic cross-sectional view showing still another optical system element of the present invention.
• FIG. 2 is a schematic plan view showing functional layers of the optical system element of the present invention.
• FIG. 2 is a schematic cross-sectional view showing (a) a conventional optical system device and (b) an optical system device of the present invention. It is (a) a schematic cross-sectional view and (b) a top view which show the optical system element of this invention which has multiple functional layers.
• FIG. 1 is a schematic perspective view showing an optical element of the present invention.
• FIG. 1 is a schematic perspective view showing an optical element of the present invention.
• FIG. 1 is an enlarged sectional view showing an optical element of the present invention.
• FIG. 3 is a diagram illustrating refraction of the optical element of the present invention.
• 1 is a schematic plan view showing an optical system device of the present invention.
• FIG. 7 is a diagram showing the light intensity at the camera section when the light intensity distribution P( ⁇ ) is made proportional to cos ⁇ n ⁇ (n is 1 to 7) [P( ⁇ ) ⁇ cos ⁇ n ⁇ ].
• 1 is a schematic cross-sectional view showing an optical system device in which an optical element of the present invention is integrated with an irradiation section.
• 1 is a schematic cross-sectional view showing an optical system device of the present invention.
• FIG. 2 is a schematic cross-sectional view showing an optical system device of the present invention in which a cover portion is formed.
• FIG. 1 is a diagram for explaining an example of an optical system device of the present invention.
• FIG. 3 is a schematic plan view showing the positional relationship between the irradiation section and the optical element according to the present invention.
• 1 is a schematic cross-sectional view showing a method of manufacturing an optical system device of the present invention.
• FIG. 7 is a schematic cross-sectional view showing another method of manufacturing an optical system device of the present invention. It is a schematic sectional view showing the manufacturing method of yet another optical system device of the present invention.
• the optical element of the present invention includes a first medium layer 1 having a first refractive index and a second medium layer 2 having a second refractive index higher than the first refractive index.
• the interface 11 has a concavo-convex shape 20 that exhibits an optical function.
• an adjustment portion 7 is formed on the first medium layer 1 side from the uneven shape 20 (boundary surface 11) to provide a certain distance from the uneven shape 20.
• the certain distance means the distance in the vertical or horizontal direction that needs to be provided between the concavo-convex shape 20 and the irradiation section or other components when combining the irradiation section or other components.
• the distance in the vertical direction is preferably at least a distance that exceeds the height of the convex portion of the concavo-convex shape 20 on the first medium layer 1 side.
• the adjustment section 7 By forming the adjustment section 7, vertical and horizontal alignments can be easily and accurately performed when combining the irradiation section and other components, making it easy to perform alignments in the vertical and horizontal directions when manufacturing optical system devices. Packaging becomes easier. It is preferable that the adjusting section 7 is formed integrally with the first medium layer 1 or the second medium layer 2.
• the difference between the first refractive index and the second refractive index may be any value as long as it can at least make the concavo-convex shape 20 function optically. In order to widen the exit angle of the lens, it is better to increase the refractive index difference between the first refractive index and the second refractive index, for example, 1.8 or more, preferably 1.9 or more, and more preferably 2.0 or more. good.
• the first medium layer 1 be made of gas, as shown in FIG. Although any gas may be used, air, an inert gas, etc. may be used.
• the gas also includes gas in a reduced pressure state called vacuum.
• the second medium layer 2 may be made of a material that can transmit at least light of a predetermined wavelength ⁇ , such as a resin such as silicone resin, epoxy resin, or acrylic resin (hereinafter referred to as second resin). Can be used.
• the adjusting section 7 determines the thickness of the first medium layer 1 (the thickness of the space) by leaving a certain distance between the concavo-convex shape 20 and the periphery of the second medium layer 2. It is formed as the lower part of the side member 25.
• the side members 25 may be made of any material.
• the second medium layer and the adjustment section 7 may be integrally formed of a material having a second refractive index (for example, a second resin).
• an optical element may be manufactured in any manner, for example, it may be manufactured using an imprint method. Specifically, manufacturing may be performed by forming the uneven shape 20 on the material of the second medium layer using a mold having a pattern in which the uneven shape 20 and the adjustment portion 7 are reversed. At this time, it is also possible to manufacture a plurality of optical elements by forming a plurality of regions with the concavo-convex shape 20 and the adjusting portion 7, and then dividing each region.
• the refractive index difference between the first refractive index and the second refractive index may be reduced.
• the refractive index difference may be, for example, 0.4 or less, preferably 0.2 or less. This makes it possible to reduce the irradiation angle to 30 degrees or less while keeping the sag of the lens at 10 ⁇ m or more.
• the first medium layer 1 and the second medium layer 2 may be made of materials with a small difference in refractive index.
• the first medium layer 1 and the second medium layer 2 may be made of any material as long as it can transmit at least light of a predetermined wavelength ⁇ , but examples include silicone resin, epoxy resin, and acrylic resin. type resin etc. can be used.
• the adjusting section 7 can utilize the surface 12 of the first medium layer 1 on the opposite side to the boundary surface 11 as is, as shown in FIG. That is, the thickness of the first medium layer 1 may be set to a size that leaves a certain distance from the uneven shape 20 on the first medium layer 1 side than the uneven shape 20.
• such an optical element may be manufactured in any manner, for example, it may be manufactured using an imprint method. Specifically, after forming the concavo-convex shape 20 on the material of the first medium layer using a mold having a pattern in which the concavo-convex shape 20 and the adjustment part 7 are reversed, the material of the second medium layer is applied, or Alternatively, it may be manufactured by forming the uneven shape 20 on the material of the second medium layer and then applying the material of the first medium layer. At this time, it is also possible to manufacture a plurality of optical elements by forming the concavo-convex shape 20 in a large area or in a plurality of regions, and then dividing this.
• the surface 21 of the second medium layer 2 opposite to the boundary surface 11 can be formed into a planar shape as shown in FIG. 1(a) or FIG. 2(a). Further, the surface 21 can also be formed into a curved shape as shown in FIGS. 1(b) and 2(c) or 2(b) and 2(c).
• the term "planar” or "curved” means that the surface has no irregularities larger than the wavelength of the emitted light and is sufficiently smooth.
• layers, films, and shapes having various functions can be easily added to the surface 21.
• an antireflection film can be formed on the surface 21. Thereby, reflection when light is emitted from the second medium layer 2 can be suppressed.
• the surface 21 may be formed with a fine uneven structure that functions as a moth eye. The fine uneven structure is formed to be smaller than the wavelength of the light that passes through it.
• the third medium layer 3 may be provided on the surface 21, as shown in FIGS. 1(d) and 2(d).
• the second medium layer 2 needs to be made of a resin with a high refractive index.
• resins with high refractive index often have poor environmental performance. Therefore, by arranging the third medium layer 3 on the surface of the second medium layer 2 so as to relieve the stress of the second medium layer 2, the environmental performance of the optical element can be improved.
• the material for the third medium layer 3 may be any material as long as it can improve the environmental performance of the first medium layer 1 or the second medium layer 2.
• silicone resin, epoxy resin, acrylic resin, etc. Resin etc. can be used.
• the third medium layer 3 is preferably made of the same material as the first medium layer 1.
• the first medium layer 1 may be formed on the base material 5.
• one or more functional layers 6 having a specific function can be formed on the surface 52 of the base material 5 opposite to the surface 51 on which the first medium layer 1 is located.
• the base material 5 for example, a glass substrate or the like can be used.
• an intermediate resin layer 4A may be formed on the surface 51 of the base material 5, as shown in FIG. 3(c).
• the intermediate resin layer 4A for example, a resin layer as a base that improves the adhesion between the base material 5 and the second medium layer 2 is applicable.
• the first medium layer 1 being formed on the base material 5 means that the first medium layer 1 is in direct contact with the surface 51 of the base material 5, as shown in FIGS. 3(a) to 3(c).
• the intermediate resin layer 4B for example, a resin layer as a base that improves the adhesion between the base material 5 and the first medium layer 1 is applicable.
• the functional layer 6 may be of any material as long as it has a specific function, and for example, an aperture mask 61 as shown in FIG. 4(a) is applicable.
• the aperture mask 61 has an opening 61a and is used to block part of the light. Thereby, electromagnetic waves that become noise can be prevented from being emitted from other than the opening 61a.
• metal such as gold can be used, for example.
• a metal wiring 62 as shown in FIG. 4(b) corresponds.
• the metal wiring 62 constitutes a predetermined electric circuit or the like.
• a metal wiring 62 was formed on the lower surface 52 of the base material 5, and an uneven shape 20 such as a lens was formed on the resin layer 2A on the surface.
• the metal wiring 62 is insulated by the resin layer 2A, it is necessary to form a separate structure for conduction in order to establish conduction with the package side.
• the optical element of the present invention as shown in FIG.
• an uneven shape 20 such as a lens is formed on one surface 51 side of the base material 5, and a metal wiring 62 is formed on the other surface 52 side. Therefore, the metal terminal of the metal wiring 62 can be exposed on the surface. Therefore, there is no need for a structure for establishing electrical conduction with the package side, such as the irradiation section 8, and it is possible to connect directly to the contacts on the package side.
• the metal wiring 62 for example, ITO or the like can be used.
• the functional layer 6 may be a combination of layers having specific functions.
• the functional layer is formed by forming a metal wiring 62 such as ITO formed on the surface 52 of the base material 5, an insulating layer 63 formed on the metal wiring 62, and an insulating layer 63 formed on the surface 52 of the base material 5. It is composed of an aperture mask 61 made of metal formed above, and a conductive portion 64 that electrically connects the metal wiring 62 and the aperture mask 61.
• the optical element can be provided with eye-safe and EMI-compatible functions.
• the aperture mask 61 with metal, the connection between the contacts on the package side and the metal wiring 62 can be facilitated.
• the uneven shape 20 of the optical element may be of any shape as long as it has an optical function.
• a shape that can control and emit incident light such as a microlens array (MLA) or a diffractive optical element (DOE), is applicable.
• MLA microlens array
• DOE diffractive optical element
• the lenses of the microlens array may be arranged periodically or randomly.
• Diffusion range 91 of optical element 100 is defined as the interior of a single closed curve in a predetermined plane.
• the uneven shape 20 has a plurality of ridges and valleys without periodicity, as shown in FIG.
• the diffusion range 91 is defined as the interior of a single closed curve 92, such as a polygon or an ellipse, in a predetermined plane 90, for example.
• the predetermined plane 90 here is a plane (xy plane) perpendicular to the optical axis (z axis) of the light source that irradiates light to the optical element, and is at least the size of the light when the light source 2 emits light. It means a plane that is 100 times or more away from the optical element.
• the uneven shape 20 is formed so as to refract the incident light into the diffusion range 91 according to Snell's law. This will be explained using FIG. 9.
• Snell's law also holds true between the incident angle ⁇ 3 on the output surface 21 of the optical element and the refraction angle ⁇ 4 of the emitted light to the outside.
• n 1 sin ⁇ 1 n 2 sin ⁇ 2
• the light distribution of the emitted light that is, the intensity distribution at the outgoing angle ⁇ 4 has a one-to-one relationship with the frequency distribution at the incident angle ⁇ 1 .
• the incident angle ⁇ 1 is the same as the inclination angle ⁇ 1 (gradient) of the uneven surface of the optical element (the surface of the uneven shape 20), so the frequency distribution of the incident angle ⁇ 1 is This corresponds to the frequency distribution of the inclination angle ⁇ 1 of the uneven surface of the element.
• y yo ))) becomes.
• the uneven shape 20 may be designed by calculating the frequency distribution of the inclination angle ⁇ 1 (gradient) on the surface of the optical element.
• the uneven shape 20 when calculating according to Snell's law, has a region having a slope that causes the incident light to be emitted to a region outside the diffusion range 91 in 5% or less of the total region, preferably 3% or less, More preferably, it is designed to be 1% or less.
• the wavelength of light incident on the optical element in vacuum must be ⁇ , the refractive index of the first medium layer 1 n 1 , and the refractive index of the second medium layer 2 n 2 .
• the uneven shape 20 has a height of at least 2.5 times or more of ⁇ /(n 2 - n 1 ), preferably 5 times or more, and more preferably 10 times or more. good. Note that the height of the uneven shape 20 herein means the difference between the highest ridge and the lowest valley of the uneven shape 20.
• the inclination angle ⁇ 1 of the uneven shape 20 changes gradually.
• the uneven shape 20 is formed so that it does not have a portion where the inclination angle ⁇ 1 (gradient) of the surface changes by 135 degrees, preferably by 120 degrees, and more preferably by 90 degrees. Note that the change in the tilt angle ⁇ 1 can be ignored if the change is of a magnitude that cannot be detected by light.
• the inclination angle of the surface of the uneven shape 20 is ⁇ 1 may be calculated from the height change in the width ⁇ /(n 2 -n 1 ) from any position to any position.
• the width means the width of the uneven shape 20 in a direction perpendicular to the z-axis direction (direction parallel to the incident surface or the exit surface).
• a general sensor system mainly includes an optical element 100, an irradiation unit 8, a camera unit 300 that detects light reflected from each point on an object 10, and a camera unit 300. It consists of a calculation unit 400 that calculates the distance to the object from the received signal.
• the light intensity becomes lower as the light is reflected at a wider angle and enters the camera unit 300. Therefore, in order for the camera to better sense light incident from a wide angle, it is preferable that the intensity of the light transmitted through the optical element 100 increases as the angle ⁇ increases. That is, the light distribution in the far field from the optical element 100 is preferably such that the intensity increases as the angle ⁇ increases.
• the uneven shape 20 is preferably formed so that the light distribution calculated by Snell's law increases monotonically from the center of the diffusion range 91 toward the boundary.
• the concavo-convex shape 20 of the optical element may be designed such that the frequency distribution of the inclination monotonically increases as the inclination increases.
• the center of the diffusion range 91 means the position of the intersection of the optical axis of the light source 2 and the diffusion range 91 when the light from the light source 2 is irradiated perpendicularly to the optical element of the present invention. do. Further, the boundary of the diffusion range 91 is a portion corresponding to the closed curve 92 described above, and means the position of the maximum peak in the light intensity distribution in the cross section.
• FIG. 11 shows the light intensity distribution P( ⁇ ) in the far field from the optical element 100 in an optical system in which light transmitted through the optical element 100 is reflected on a screen and returned to the camera as cos ⁇ n ⁇ .
• This is a graph in which the intensity of light returning to the camera unit is calculated with respect to the incident angle ⁇ when the intensity of light is proportional to [P( ⁇ ) ⁇ cos ⁇ n ⁇ ] (n is 1 to 7). It can be seen that the larger the incident angle, the smaller the light intensity, but the larger n is, the smaller the difference becomes. Furthermore, it can be seen that if the light intensity distribution P( ⁇ ) is made proportional to cos ⁇ 7 ⁇ [P( ⁇ ) ⁇ cos ⁇ 7 ⁇ ], the intensity of the light returning to the camera becomes uniform with respect to the angle ⁇ .
• the uneven shape 20 of the optical element is formed such that the light distribution calculated by Snell's law is proportional to cos ⁇ n ⁇ (1 ⁇ n ⁇ 7) from the center to the boundary of the diffusion range 91. Preferably, it is formed so as to be proportional to cos ⁇ 7 ⁇ .
• the frequency distribution of the inclination angle ⁇ 1 of the concavo-convex shape 20 of the optical element is formed so as to be proportional to cos ⁇ n ⁇ 1 (1 ⁇ n ⁇ 7), and is preferably proportional to cos ⁇ 7 ⁇ 1 . formed in proportion.
• each uneven shape 20 preferably has a height of at least 5 times or more of ⁇ /(n 2 - n 1 ), preferably 10 times or more, and more preferably 25 times or more. It's better to have.
• the optical system device of the present invention as shown in FIG. 5(b), FIG. 6(a), FIG. 12, and FIG.
• An irradiation unit 8 is arranged and irradiates the optical element with light. Further, the optical element and the irradiation section 8 are stacked with the adjustment section 7 interposed therebetween.
• the irradiation unit 8 may be of any type as long as it has a light source 80 that irradiates light with a wavelength ⁇ .
• the irradiation unit 8 may be a single light source or a plurality of light sources.
• a plurality of light sources may be provided by passing light from a single light source through an aperture in which a plurality of pores are formed.
• the irradiation section 8 is composed of a plurality of light sources, it is preferable that the light sources 80 are formed on the same plane because the distance and angle between the optical element and the irradiation section 8 can be adjusted accurately.
• VCSEL Vertical Cavity Surface Emitting LASER
• VCSELs include single-emitter VCSELs that have one light source 80 that can emit light in a direction perpendicular to the light-emitting surface, and multi-emitter VCSELs that have multiple light sources 80. Further, it is preferable that a light absorption film is formed in a portion other than the light source 80 because noise due to reflected light does not enter.
• the irradiation section 8 is preferably formed integrally with the adjustment section 7 of the optical element of the present invention in contact with it.
• the optical system device can utilize the adjusting section 7 to integrally form the irradiation section 8 and the optical element so that they are at an appropriate distance.
• the irradiation unit 8 often generates heat when emitting light. If a gas with low thermal conductivity exists between the optical element and the irradiation section 8 as in the conventional case, there is a risk that the performance of the irradiation section 8 and the optical element may be deteriorated or damage may occur. Therefore, the irradiation section 8 may include a light source coating layer 85 made of resin and covering the light source 80, as shown in FIG. Since resin has higher thermal conductivity than gas, the heat dissipation of the light source can be improved. Further, since the resin can have a smaller refractive index difference with the material of the light source 80 than gas, the light extraction efficiency of the light source 80 can be improved.
• the light source 80 is covered with the light source coating layer 85, there is a low possibility that the light source 80 will be exposed even if the optical system device is damaged, which is preferable from the viewpoint of eye safety. Further, a fine uneven structure that functions as an antireflection film or a moth eye can also be formed on the surface of the light source coating layer 85. Thereby, reflection when light is emitted from the light source coating layer 85 can be suppressed.
• the resin constituting the light source coating layer 85 may be any resin as long as it can transmit at least light of wavelength ⁇ and can exhibit the optical function of the concavo-convex shape 20. For example, silicone resin, epoxy resin, acrylic resin, etc. can be used.
• the surface of the light source coating layer 85 may include a base material such as glass or a metal layer.
• the light source coating layer 85 be formed to a thickness such that the distance from the light source 80 to the surface 86 of the light source coating layer 85 is a constant distance. This makes it possible to easily and accurately perform alignment in the vertical and horizontal directions when combining optical elements and other components, making packaging easier when manufacturing optical system devices. For example, as shown in FIGS. 13(a) and 13(b), if the adjusting part 7 of the optical element and the surface 86 of the light source coating layer 85 are brought into contact with each other and formed integrally, the optical element and the irradiating part 8 can be A highly reliable optical system device in which distance, angle, etc. are adjusted can be provided.
• the first medium layer 1 and the light source coating layer 85 in common.
• the space between the concavo-convex shape 20 can be filled with only the material of the first medium layer 1, and it can be formed integrally with the optical element.
• the boundary between the first medium layer 1 and the irradiation section 7 becomes the adjustment section 7.
• the optical system device of the present invention may include a cover section 150 that includes the optical element and the irradiation section 8, as shown in FIG. Since the light source 80 is enclosed in the cover part 150, there is a low possibility that the light source 80 will be exposed even if the optical system device is damaged, which is preferable from the viewpoint of eye safety.
• the resin constituting the cover portion 150 may be any resin as long as it can transmit at least light of wavelength ⁇ and can exhibit the optical function of the concavo-convex shape 20.
• silicone resin, epoxy resin, acrylic resin, etc. can be used.
• the above-mentioned side member 25 becomes the first medium layer 1 at the periphery of the second medium layer 2 between the irradiation part 8 and the second medium layer. Formed so that gas can be sealed.
• titanium oxide TiO 2
• a light-shielding material that suppresses the transmission of light such as ultraviolet rays may be used for the material constituting at least a portion of the cover portion 150 or the material covering the cover portion 150.
• cover portion 150 may be integrally formed of the same material, or may be formed of different materials for each portion such as the top surface and side surfaces.
• the side surfaces may be made of a material that blocks light
• the top surface may be made of a material that transmits only infrared rays.
• an optical element used in an optical system device includes a first medium layer 1 having a first refractive index and a second medium layer 2 having a second refractive index higher than the first refractive index.
• FIG. 15(a) shows an optical system device in which the first medium layer 1 is gas and the second medium layer is resin
• FIG. 15(b) shows an optical system device in which both the first medium layer 1 and the second medium layer are This is an example of an optical system device in the case of resin.
• the lens 21 has a focal point at a position on the first medium layer 1 side and a predetermined distance f (f>0) away from the lens 21.
• the optical element of the present invention can improve contrast as the focal length f increases, such as 10 ⁇ m or more, 20 ⁇ m or more, 40 ⁇ m or more, or 60 ⁇ m or more.
• the position of a plane that includes the focal point of the lens 21 and is perpendicular to the optical axis of the lens will be referred to as the focal point position 25 of the optical element.
• the shape of the lens 21 can be freely designed according to the desired spread pattern of dots (hereinafter referred to as dot pattern).
• dot pattern the desired spread pattern of dots
• the shape of the lens 21 may be a spherical lens.
• the lens 21 may be an appropriately designed aspherical lens.
• the focal length differs depending on the direction.
• the focal length according to the cross-sectional shape perpendicular to the y direction is f 1
• the focal length according to the cross-sectional shape perpendicular to the x direction is f 2 (f 1 ⁇ f 2 )
• the size of the pitch in the x direction is f 1 .
• the lens shape may be a convex lens, a concave lens, or the like. In the case of a convex lens, it is preferable that the convex lens portion faces the irradiation unit 8 side.
• the periodic arrangement of the lenses 21 includes a square arrangement of square or rectangular lenses 21 in plan view, and a hexagonal arrangement of hexagonal lenses 21 in plan view.
• the lens 21 may be of any type as long as it functions as a lens; for example, a Fresnel lens, a DOE lens, a metalens, etc. can also be used.
• an anti-reflection film may be formed on the lens 21 to prevent the light from the irradiation section 8 from being reflected.
• the irradiation unit 8 includes a light source 80 that irradiates a plurality of lenses 21 with light having a wavelength ⁇ .
• the irradiation unit 8 may be a single light source or a plurality of light sources.
• a plurality of light sources 80 are included in one irradiation unit 8, it is preferable that the light sources 80 are formed on the same plane.
• one irradiation section 8 includes a plurality of light sources 80, even if each light source 80 and the optical element are moved in parallel, the number of light sources 80 for each lens 21 of the optical element in plan view must be arranged so that they are the same.
• the apparent positions of the aggregated light sources 80 may be formed to coincide with each other.
• the light sources included in the same irradiation section are arranged periodically, and the pitch P x of the light sources in the x direction is a natural number multiple or reciprocal multiple of the lens pitch P 1 , and the pitch P x of the light sources in the y direction
• the pitch P y may be configured to be a natural number multiple of the lens pitch P 2 or a reciprocal number multiple of the natural number.
• the pitches P x and P y of the light sources 80 are set to 1/2 of the pitches P 1 and P 2 of the lenses 21 of the optical element 2. Further, in FIG. 14(d), the pitches P x and P y of the light sources 80 are twice the pitches P 1 and P 2 of the lenses 21 of the optical element 2.
• the irradiation section 8 and the optical element 2 are arranged so that the optical axis direction of the light source 80 of the irradiation section 8 and the optical axis direction of the lens 21 of the optical element 2 coincide.
• the distance L 1 between the irradiation unit 8 and the first focal plane 251 of the lens 21, and the distance L 2 between the second focal plane 252 are determined by the incident light when the following formulas ⁇ and ⁇ are satisfied. can be converted into a high-contrast dot pattern.
• m and n are natural numbers greater than or equal to 1
• P1 is the pitch size of the lens 21 in the x direction
• P2 is the pitch size in the y direction
• ⁇ is the wavelength of the light incident from the irradiation part 8
• f 1 is the focal length of the lens 21 according to the cross-sectional shape perpendicular to the y direction
• f2 is the focal length of the lens 21 according to the cross-sectional shape perpendicular to the x direction
• a, b, c, and d are coefficients indicating allowable errors. do.
• the first focal plane 251 refers to a plane that is perpendicular to the optical axis (z direction) of the lens 21 and located at the focal position of the cross-sectional shape of the lens 21 perpendicular to the y direction.
• the second focal plane 252 refers to a plane that is perpendicular to the optical axis (z direction) of the lens 21 and located at the focal point of the cross-sectional shape of the lens 21 perpendicular to the x direction.
• the first focal plane 251 and the second focal plane 252 are located on the irradiation section 8 side of the lens 21 as a reference.
• the distances L 1 and L 2 mean the distance (optical path length) that light travels in a vacuum in the same time as when it travels through a medium, and if the refractive index of the medium is N and the actual distance is L, then It is expressed as their product NL.
• the values of the coefficients a, b, c, and d of the formulas ⁇ and ⁇ are preferably as small as 1, 0.5, 0.3, and 0.1.
• equations ⁇ and ⁇ become the following equations 1 and 2, respectively.
• the adjusting section 7 of the optical element of the present invention is formed so that the concavo-convex shape 20 and the illumination section can be spaced apart from each other by the predetermined distance, taking into consideration Equations 1 and 2, preferably Equations 3 and 4. is preferred.
• the pitches P 1 and P 2 become too small than the wavelength ⁇ of the light from the light source 80, it becomes difficult to cause diffraction, so it is necessary to include enough lenses 21 to cause diffraction within the light distribution angle of the light source 80.
• the pitches P 1 and P 2 should be sufficiently larger than the wavelength ⁇ of the light from the light source 80, for example, 5 times or more, preferably 10 times or more.
• the above-described optical element for irradiating a dot pattern can be used not only for irradiating a dot pattern but also as a diffuser.
• the irradiation part 8 and the optical element are arranged so that the distances L 1 and L 2 between the irradiation part 8 and the focal position 25 of the optical element do not satisfy at least formulas 1 and 2.
• the optical system device may be configured by combining or integrating the optical system.
• the irradiation section 8 and the optical element are prepared and aligned as appropriate.
• the adjustment section 25 is brought into contact with the irradiation section 8 and bonded.
• the optical system device may include one irradiation unit 8 and one optical element, but as shown in FIG. It is also possible to stack the irradiation section members integrally formed at one time. In this case, the optical element member and the irradiation part member may be laminated and bonded together, and then cut as shown in FIG. 17(c) to separate each optical system device.
• the cover part 150 that includes the optical element and the irradiation part 8
• an optical system device is first placed on the substrate, as shown in FIG. 18(a), for example.
• a fluid material for the cover section 150 is supplied and covered over the optical system device, and is solidified to form the cover section 150.
• the first medium layer 1 is a gas
• the above-mentioned side member 25 becomes the first medium layer 1 at the periphery of the second medium layer 2 between the irradiation part 8 and the second medium layer. Formed so that gas can be sealed. Thereby, it is possible to protect the space that will become the first medium layer 1 from entering the material of the cover part 150.
• cover part 150 can be formed for each optical system device, but as shown in FIG. 18, it is also possible to form the cover part 150 for a plurality of optical system devices at once. In this case, after forming the cover portion 150, it may be cut as shown in FIG. 18(c) to divide it into individual optical system devices.
• the manufacturing method includes a first resin supply step, an uneven shape forming step, and a second medium layer forming step.
• the first resin supply step is to supply the material of the first medium layer 1 onto the substrate to which the irradiation section is fixed.
• a first resin 19 that is photocurable and has a first refractive index is supplied.
• the irradiation part 8 such as VCSEL is fixed on a substrate 55 such as a lead frame by die bonding, and electrically connected by wire bonding.
• a substrate 55 on which is fixed is prepared.
• a photocurable first resin 19 may be supplied to the irradiation section 8 side of the substrate 55.
• the uneven shape forming step is to form an uneven shape 20 on the surface of the first resin 19 by an imprint method.
• a mold 50 having a pattern 20A similar to the uneven shape 20 is pressed onto the first resin 19 to form an uneven shape 20 on the first resin 19.
• the first resin 19 is cured, the mold 50 is released, and the first medium layer 1 having the first refractive index is formed.
• the second medium layer forming step is to form the second medium layer 2 by supplying a second medium layer material having a second refractive index higher than the first refractive index to the surface of the uneven shape 20. .
• a photocurable second resin 29 is applied to the surface 21 of the uneven shape 20.
• the second resin 29 is cured to form the second medium layer 2 having a second refractive index higher than the first refractive index.
• an optical system device as shown in FIG. 15(h) can be manufactured.

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• 2023
  • 2023-08-04 TW TW112129461A patent/TW202424537A/zh unknown
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