JP2008207517A - Molding die for lens array and method for producing lens array using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding die for a lens array avoiding molding defects in the lens array and having an excellent performance, and a method for producing a lens array using the same. <P>SOLUTION: The molding die for a lens array having a plurality of lenses arranged in a plane and condensing light introduced in the lens to each light axis comprises a mold main body 10 having a plurality of curved surfaces 16 formed in one surface in the vertical direction of a substrate and reflecting a shape of the lens and a through hole 18 opened to the curved surface 16 in its one end and opened to the other surface in the vertical direction of the substrate in the other end and a drawing part 19 kept in the through hole 18 in the state of being capable of being drawn out from the through hole 18. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens array mold and a method of manufacturing a lens array using the same.

Conventionally, in a casting method in which a resin is poured into a mold, the resin is cured in the mold and the molded product is taken out, there is a problem that voids enter the molded product. For example, in the case where the molded product is a lens, if there is a void inside, the lens characteristics will be significantly deteriorated. Therefore, measures such as casting a resin under a vacuum atmosphere have been taken (for example, Patent Document 1).
Japanese Patent Laid-Open No. 2001-127087

  According to Patent Document 1, when hole plate printing is performed with a squeegee under a vacuum pressure, an unfilled portion of the sealing resin generated in the mold is contracted by using a pressure difference when returning from vacuum to atmospheric pressure. Can be removed. In addition, it is described that by making the resin supply amount excessive with respect to the cavity, the surface area of the resin receiving the differential pressure is increased, and the above effect can be further exhibited. However, when this method is applied to a lens array mold, the individual lens molds are connected to each other, so that even if the amount of sealing resin supplied to each lens mold is excessive, differential pressure is received. The surface area of the sealing resin could not be increased, and it was difficult to reliably remove voids (bubbles) in the sealing resin.

  The present invention has been made in view of the above-described problems of the prior art, and provides a high-performance lens array molding die and a lens array manufacturing method using the same, which prevents defective molding of the lens array. The purpose is to do.

  In order to solve the above-described problems, a lens array mold according to the present invention has a plurality of lenses arranged in a plane, and collects light incident on each lens toward its respective optical axis. A lens array mold for forming an array, which is formed on one surface in the thickness direction of a substrate, and has a plurality of curved surface portions reflecting the shape of the lens, one end side opening to the curved surface portion, and the other end A mold body having a through hole that opens on the other surface in the thickness direction of the base material, and a drawing portion that is held in the through hole so as to be able to be pulled out from the through hole. It is characterized by.

According to the mold for lens array of the present invention, for example, even when a void (bubble) is included when supplying the sealing resin into the curved surface portion, by pulling out (retracting) the extraction portion from the through hole, The void in the curved surface portion can be drawn into the through hole. In other words, voids can be eliminated from the curved surface portion and the occurrence of unfilled portions can be prevented. The unfilled portion of the sealing resin can be easily formed at the bottom of the curved portion. Therefore, by forming a through hole in the bottom of the curved surface portion and drawing the void into the through hole, it is possible to prevent molding with the void remaining in the curved surface portion. Thereby, molding defects of the lens array can be prevented, and the yield can be improved.
Therefore, according to the lens array molding die of the present invention, the problem of reliability due to molding defects and the problem of deterioration of quality do not occur.

The through hole is located at the top of the curved surface portion.
According to such a configuration, by providing the position of the through hole at the top position of the curved surface portion, it is possible to reliably pull out a void that tends to stay at this position.

Moreover, it is also preferable that the protrusion part which protrudes inside a through-hole is provided in the boundary of a curved surface part and a through-hole.
According to such a configuration, since the opening area of the boundary portion between the curved surface portion and the through hole can be reduced, the sealing resin that has moved into the through hole together with the void is cured, and from the tip of the lens Even in the case of a protruding shape (burr), it is easy to remove a burr portion that is not necessary for the lens shape. Thereby, a desired lens shape can be easily obtained.

Moreover, it is also preferable that the mold body has a light-transmitting property and the extraction portion has a non-light-transmitting property.
According to such a structure, when the ultraviolet light which hardens sealing resin is irradiated from the drawing direction retraction side of the extraction | drawer part, light does not reach to the sealing resin which moved into the through-hole, and it does not harden | cure. On the other hand, the sealing resin in the curved surface portion is cured because the light is refracted by the shape of the curved surface portion and irradiated with ultraviolet light. Therefore, generation | occurrence | production of a burr | flash is prevented. Therefore, the removal of the sealing resin that has moved into the through hole is simplified, and the yield is improved.

Moreover, it is also preferable that the volume of the through hole is in the range of 1% to 30% with respect to the volume of the curved surface portion.
According to such a configuration, if the volume of the through-hole is 30% or more with respect to the volume of the curved surface portion, the burr becomes large and it is difficult to remove, so the yield decreases. In addition, the material is wasted and the cost is increased. On the other hand, if the volume of the through hole is 1% or less with respect to the volume of the curved surface portion, the void in the curved surface portion may not be reliably drawn into the through hole. Therefore, by setting the volume of the through hole in the range of 1% to 30% with respect to the volume of the curved surface portion, the void of the curved surface portion can be surely drawn into the through hole, and after the sealing resin is cured The deburring work becomes easier and the yield is improved.

Moreover, it is also preferable that the volume of the through hole is in the range of 1% to 10% with respect to the volume of the curved surface portion.
Such a configuration is particularly effective in terms of void removal rate and ease of deburring.

  The method of manufacturing a lens array according to the present invention includes a plurality of lenses arranged in a plane, and a method of manufacturing a lens array that collects light incident on each lens toward a respective optical axis. A plurality of curved surface portions reflecting the shape of the lens and having one end side opened in the curved surface portion and the other end side opened in the other surface in the thickness direction of the substrate. A plurality of curved surfaces in a vacuum atmosphere using a mold for a lens array that includes a mold body having a hole, and a drawing portion that is held in the through hole so as to be pulled out from the through hole. A step of supplying the sealing resin to the part, a step of increasing the pressure from the vacuum atmosphere, a step of retracting the extraction portion from the through hole to eliminate the unfilled portion in the curved surface portion, a step of curing the sealing resin, It is characterized by providing.

  According to the manufacturing method of the lens array of the present invention, even if a void is generated when supplying the sealing resin into the curved surface portion, for example, the size of the void is utilized by utilizing the differential pressure when the pressure is increased from the vacuum atmosphere. The thickness can be reduced. Further, in the present invention, all the voids in the curved surface portion can be drawn into the through hole by pulling out (retracting) the drawing portion from the through hole. In other words, voids can be eliminated from the curved surface portion and the occurrence of unfilled portions can be prevented. The drawing amount (retraction amount) of the drawing portion needs to be determined according to the size of the unfilled portion. The size of the unfilled portion varies mainly depending on the resin viscosity during printing and the printing conditions (squeegee pressure and squeegee moving speed). Therefore, by grasping the size of the unfilled part that occurs from the above-mentioned conditions and determining the minimum amount of pull-in necessary to eliminate voids from the curved part, the unfilled part in the curved part is reliably Can be erased.

Further, the unfilled portion of the sealing resin is likely to occur at the bottom of the curved portion. Therefore, by forming a through hole that communicates with the top of the curved surface portion and drawing the void into the through hole, it is possible to prevent molding with the void remaining in the curved surface portion. Thereby, molding defects of the lens array can be prevented, and the yield can be improved.
Therefore, according to the manufacturing method using the lens array molding die of the present invention, it is possible to mold a lens array which is excellent in reliability and in performance quality.

In the step of increasing the pressure from the vacuum atmosphere, it is preferable to increase the pressure to the atmospheric pressure atmosphere.
Thereby, the reduction effect of an unfilled part can be heightened.

Moreover, it is good also as a manufacturing method which has the process of removing the protrusion part of sealing resin hardened | cured in the through-hole.
According to such a manufacturing method, by performing a so-called deburring operation, the sealing resin cured in the through hole can be removed, so that a desired lens shape can be obtained. Further, since the top portion of the lens is a portion where light is not refracted, it does not necessarily have to be a curved surface. This eliminates the need for highly accurate work along other lens curved surfaces, and improves the yield.

Further, the mold body may be translucent and the extraction portion may be non-translucent.
According to such a manufacturing method, when light is irradiated from the retracted side of the extraction portion, the light does not reach the sealing resin in the through hole, so that it does not cure. On the other hand, the sealing resin in the curved surface portion is cured because the light is refracted by the shape of the curved surface portion and irradiated with ultraviolet light. Therefore, generation | occurrence | production of the burr | flash which hardens the sealing resin in a through-hole is prevented. Therefore, the removal operation of the sealing resin that has moved into the through hole is simplified, and the yield is improved.

Alternatively, the sealing resin may be a photosensitive curable resin having a higher refractive index than the mold body.
According to such a manufacturing method, light also circulates in the shadowed portion of the drawn portion in the curved surface portion, and the entire curved surface portion can be reliably and effectively cured.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[First Embodiment]
FIG. 1A is a plan view showing the overall configuration of a lens array mold according to the first embodiment of the present invention. 1B is a cross-sectional view taken along the line IB-IB shown in FIG. 1A, and FIG. 1C is an enlarged cross-sectional view of the main part of FIG. The planar shape of the lens array mold 1 is not particularly limited, and may be a circle or a polygon such as a rectangle.

  In the lens array mold 1, a transfer shape 12 and a flat surface 14 are formed on one surface side of a mold body 10 made of a glass substrate such as quartz. The transfer shape 12 is for forming a plurality of lenses of the microlens array, and is formed in the central portion (a portion avoiding the end portion). The transfer shape 12 includes a plurality of hemispherical curved surface portions 16 that are recessed in the thickness direction of the mold body 10 and is arranged at a predetermined position.

  Each curved surface portion 16 has a shape corresponding to the shape of each lens of the microlens array. When the microlens array is formed directly from the lens array mold 1, the curved surface portion 16 has a lens reversal shape. That is, when forming a convex lens, the curved surface portion 16 is a concave portion. Further, when the replica mold is manufactured by transferring the shape of the lens array mold 1 and the microlens array is manufactured by transferring the replica mold shape, at least a part of the curved surface portion 16 of the lens array mold 1 is produced. Is equal to the lens shape.

  The lens array molding die 1 of the present embodiment has a sealing resin filled in the transfer shape 12 on the back side of the mold body 10 when the surface on which the transfer shape 12 and the flat surface 14 are formed is the front surface. It has an unfilling prevention means for eliminating the voids (bubbles) inside. The unfilling prevention means is formed on the bottom side of the mold body 10 as shown in FIG. 1 (c), and includes a plurality of through holes 18 and a plurality of extraction portions 19 respectively held in the through holes 18. It is configured.

  The through-hole 18 penetrates the thickness direction of the mold body 10 from the bottom of the curved surface portion 16, and one end side opens to the bottom of the curved surface portion 16 and the other end side opens to the back surface side of the mold body 10. The through-hole 18 has its axis aligned with the top of the curved surface portion 16 and is formed with a predetermined hole diameter with respect to the diameter of the curved surface portion 16. Thus, by having the axial center of the through-hole 18 coincide with the axial center of the curved surface portion 16, a structure having a through-hole 18 that opens at the top of the curved surface portion 16 where sealing resin is likely to be unfilled is formed. Can do.

  The extraction portion 19 is made of a light transmissive material such as acrylic resin, and is inserted into each through hole 18. The extraction portion 19 is held so as to be insertable / removable (removable) with respect to the through hole 18, and has a cylindrical shape corresponding to the shape of the through hole 18. The extraction part 19 is formed with a diameter substantially equal to the through-hole 18, and the side surface of the through-hole 18 and the side surface of the extraction part 19 are always held or moved in contact with each other, so that the resin filling the curved surface part 16 is obtained. Leakage into the gap between the through hole 18 and the extraction portion 19 is prevented. Moreover, the some extraction part 19 provided in the type | mold main body 10 is set as the structure which each operate | moves interlockingly. For example, the extraction portions 19 may be connected to each other by a connecting member (not shown) or the extraction portions 19 may be operated all at once by a control system or the like.

  The plurality of curved surface portions 16 are partitioned into a plurality of groups as shown in FIG. 1A, and are partitioned into a plurality of regions (for example, substantially rectangular regions) by a part of the flat surface 14, for example. A plurality of curved surface portions 16 are arranged. A plurality of curved surface portions 16 formed in each partitioned area form individual microlens array chips (hereinafter sometimes simply referred to as microlens arrays). That is, the lens array mold 1 shown in FIG. 1A is for manufacturing a microlens array substrate in which a plurality of chips are integrally assembled, and the microlens array substrate is cut into individual pieces. Chips are obtained.

In the present embodiment, the plurality of curved surface portions 16 are arranged in a state in which the centers of the curved surface portions 16 are adjacent to each other in plan view. For example, it is good also as an arrangement | sequence which shifted | deviated predetermined pitch with respect to the curved surface part 16 of an adjacent row | line | column.
Further, the number and arrangement interval of the curved surface portions 16 to be partitioned are appropriately set according to the use of the microlens array.
Furthermore, although the extraction part 19 was set as the structure which operate | moves interlockingly, it is good also as what each act | operates separately.

[Microlens array manufacturing method]
A microlens array having a plurality of lenses is formed using the lens array mold 1 described above. FIG. 2 is a flowchart showing a method for manufacturing the microlens array of the present embodiment. 3A to 3F are process diagrams of the manufacturing method along the flowchart of FIG.

  In this embodiment, a hole plate printing method is used in which the sealing resin 3 is supplied and filled into the curved surface portion 16 of the lens array mold 1 in a vacuum atmosphere. As the sealing resin 3, an energy curable resin having a refractive index larger than that of the lens array mold 1 is used. As the resin having energy curability, it is desirable that the resin can be cured by applying one of light and heat. By using a resin that is cured by heat or light, a general-purpose exposure apparatus, a heating apparatus such as a baking furnace or a heater can be used, and thus the equipment cost can be reduced. Examples of the energy curable resin include acrylic resins and epoxy resins. Note that the stencil printing in the present embodiment is performed using a conventionally known apparatus that enables the pressure reduction and pressure increase in the chamber.

  First, the lens array mold 1 according to the present invention described above is prepared (step S1). FIG. 3A shows a cross-sectional view of the lens array mold 1 before the start of the step of filling and sealing the sealing resin 3.

  As shown in FIG. 3B, the sealing resin 3 supplied onto the lens array mold 1 is pushed and filled into the curved surface portion 16 of the lens array mold 1 by the operation of the squeegee 5 ( Step S2). At this time, a mask 15 having a predetermined thickness is formed in advance on the flat surface 14 of the lens array mold 1, and the squeegee 5 is disposed on the surface of the mask 15 at a distance from the flat surface 14. ing. The squeegee 5 is adjusted in advance so as to be positioned above the lens array molding die 1 for the excessive supply of the sealing resin 3 to the lens array molding die 1. An interval necessary for excessive supply is formed between the flat surface 14 of the mold 1 and the tip of the squeegee 5.

  FIG. 3B shows a state after the squeegee 5 pushes and fills the sealing resin 3, and a resin layer 6a (excess supply portion) including a plurality of curved surface portions 16 is formed. Further, as shown in the figure, unfilled portions 4 are generated at the bottoms of some curved surface portions 16. As a cause of the occurrence of the unfilled portion 4, it is conceivable that the sealing resin 3 is pushed by the squeegee 5 and the filling pressure is insufficient. In addition, since filling is performed in a vacuum atmosphere, it is considered that the amount of air corresponding to the degree of vacuum is confined as a void 7 in the curved surface portion 16.

Therefore, in this embodiment, first, after the filling of the sealing resin 3 under the vacuum atmosphere is completed, the ambient atmosphere is returned to the atmospheric pressure (step S3), and the unfilled portion 4 is reduced. The unfilled portion 4 is reduced by the sealing resin 3 being pushed into the unfilled portion 4 due to the differential pressure when returning from the vacuum atmosphere to the atmospheric pressure atmosphere.
In step S3, the ambient atmosphere does not have to be returned to atmospheric pressure, and the pressure is gradually increased so as to lower the vacuum degree of the vacuum atmosphere (for example, the pressure is increased to a predetermined pressure). The reduction effect of 4 can be sufficiently obtained.

  However, the unfilled portion 4 cannot be completely erased only by the differential pressure generated between the unfilled portion 4 and the outside air. Therefore, in the present embodiment, as shown in FIG. 3C, after the sealing resin 3 is filled, the extraction portion 19 is retracted from the through hole 18 by a predetermined amount toward the opposite side (outward) from the curved surface portion 16 side. (Step S4), the void 7 in the curved surface portion 16 is drawn into the through hole 18 together with the sealing resin 3. Since the unfilled portion 4 is a space sealed by the sealing resin 3 and the extraction portion 19, the void 7 or the sealing resin 3 including the void 7 is contained in the through hole 18 as the extraction portion 19 is retracted. Will be aspirated.

  Here, the retraction amount (retraction amount) of the extraction portion 19 is appropriately set according to the size of the unfilled portion 4 in order to completely erase the unfilled portion 4. The size of the unfilled portion mainly varies depending on the resin viscosity and printing conditions (squeegee pressure and squeegee moving speed). For this reason, it is important to grasp the size of the unfilled portion 4 generated from the above-described conditions and determine the minimum pull-in amount according to this. Thereby, the unfilled portion 4 in the curved surface portion 16 is completely erased, and the sealing resin 3 can be sufficiently and surely filled up to every corner of the bottom portion of the curved surface portion 16.

  In addition, by the operation | movement of the extraction part 19, while the sealing resin 3 containing the void 7 moves in the through-hole 18, the unfilled part 4 is erase | eliminated, On the upper surface side of the resin layer 6a, a recess arises. Become. Therefore, it is desirable to flatten the upper surface of the resin layer 6a before the sealing resin 3 is cured.

  Next, as shown in FIG. 3D, the sealing resin 3 is cured by heating or irradiating light (step S5). The exposure device and the heating device described above are arranged on the drawing portion 19 side in the lens array mold 1, and heat or irradiate light with a predetermined energy amount and time. In the case of irradiating UV, the lens array mold 1 including the extraction portion 19 has light transmittance, so that at least the entire transfer shape 12 is irradiated with UV, and the sealing resin 3 in the curved surface portion 16 is surely secured. To harden. In this way, the light transmissive body 6 including the resin layer 6a and the plurality of lenses 6b is configured. Note that the mask 15 provided on the flat surface 14 of the mold body 10 is appropriately removed after the sealing resin 3 is cured.

  Next, as shown in FIG. 3E, the lens array mold 1 is released from the light transmissive body 6 (step S6). The light-transmitting body 6 peeled off from the lens array mold 1 is in a state in which burrs 13 are generated at the top 6c of the lens 6b by the sealing resin 3 cured in the through hole 18. Therefore, deburring work is required for each lens 6b in order to obtain a desired lens shape (curvature).

  Therefore, a deburring operation is performed in the next process (step S7). In this deburring operation, the burr 13 may be cut with a cutter or the like, ground with sandpaper, or polished with a buff. Further, the light transmitted through the top portion 6c of the lens 6b does not necessarily have to be a curved surface because it has straightness. Therefore, the surface of the top portion 6c of the lens 6b may be a flat surface instead of finishing along the curvature of another curved surface. This shortens the work time and improves the manufacturing efficiency.

  In this way, the light transmissive body 6 as shown in FIG. 3F is formed using the lens array mold 1. Since the light transmissive body 6 is a collection of a plurality of microlens array chips (hereinafter simply referred to as a microlens array 11), each chip ( A microlens array 11) is obtained.

[Second Embodiment]
Next, a second embodiment of the lens array mold according to the present invention will be described with reference to the drawings. Here, FIG. 4A is a main part enlarged view showing a part of a curved surface portion of the transfer shape in the lens array mold, and FIG. 4B is a plan view of the curved surface portion. . In addition, in this embodiment, since it differs in the shape of the boundary part of the curved-surface part 16 and the through-hole 18 of the said 1st Embodiment, while explaining centering on this point, it demonstrated in the said 1st Embodiment. Constituent elements are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 4A and 4B, the radius of the through-hole 18 from the edge of the through-hole 18 opening in the curved-surface portion 16 is at the boundary between the curved-surface portion 16 and the through-hole 18 in the present embodiment. An annular protrusion 28 that protrudes inward in the direction is provided. The annular protrusion 28 (annular protrusion) has a communication hole 27 that allows the through hole 18 and the curved surface portion 16 to communicate with each other at the center thereof, and reduces the opening area of the through hole 18 that opens to the curved surface portion 16. It works as follows. The diameter of the communication hole 27 is such that when the extraction portion 19 is extracted (retracted) from the through hole 18, the sealing resin 3 including voids and voids can be smoothly drawn into the through hole 18 from the curved surface portion 16. Set by dimensions. The extraction portion 19 provided in the through hole 18 is held such that the upper surface thereof is in contact with the lower surface (surface opposite to the curved surface portion 16) of the annular protrusion 28.

  In this manner, the deburring operation is facilitated by reducing the opening area of the through hole 18 that communicates with the curved surface portion 16. The diameter of the curved surface portion 16, that is, the diameter of the lens is about 20 μm. Then, if the diameter of the through hole 18 is several microns, and the diameter of the central hole (communication hole 27) of the protrusion 28 is small, the diameter becomes very small. Therefore, when the mold 1 for the lens array is released from the light transmissive body, the sealing resin cured in the through hole 18 (part that becomes a burr) is removed from the light transmissive body by being bent from the top of the lens. Is done. Further, in order to completely remove the burrs from all the lenses, the deburring operation described above is performed after releasing the mold. As described above, according to the present embodiment having a configuration in which the generation of burrs is suppressed, the deburring operation for the light transmissive body becomes very simple. This shortens the work time and improves the yield.

  Note that the shape of the protruding portion is not limited to the above, and may be a protruding portion 29 protruding from the side surface of the through hole 18 as shown in FIG. The number of the protrusions 29 is not particularly limited as long as the condition that the sealing resin 3 is smoothly drawn into the through hole 18 from the curved surface portion 16 is satisfied.

[Third Embodiment]
Next, a third embodiment of the lens array mold according to the present invention will be described with reference to the drawings. Here, FIG. 6 is an enlarged view of a main part showing a part of the curved surface portion of the transfer shape in the lens array mold. In addition, in this embodiment, since it differs in the material of the extraction | drawer part 19 of the said 1st Embodiment, while it demonstrates centering on this point, the same code | symbol is given to the component demonstrated in the said 1st Embodiment. A description thereof will be omitted.

  As shown in FIG. 6, a non-light-transmissive extraction part 19 is inserted into the through hole 18 of the present embodiment. This embodiment is suitable when light (UV) is used when the sealing resin 3 is cured. Specifically, the applied UV is blocked by the extraction portion 19 so that the inside of the through hole 18 is blocked. It functions so as not to cure the sucked sealing resin 3. A part of the irradiated UV is cut off by the extraction portion 19, and the UV that has passed through the mold body 10 is refracted on the curved surface of the curved surface portion 16 to effectively cure the sealing resin 3 in the curved surface portion 16. . When the sealing resin 3 in the through-hole 18 is not irradiated with UV, that is, when the extraction part 19 is configured not to transmit UV, when the lens array mold 1 is peeled from the light transmissive body 6, A burr | flash will not be formed in the top part 6c of the lens 6b, and a deburring operation can be omitted. Thereby, the manufacturing time is shortened and the yield is improved.

  In addition, when the light-transmitting body 6 is peeled from the lens array mold 1, the liquid sealing resin 3 may adhere. In that case, the sealing resin 3 adhering to the lens surface is appropriately removed by wiping.

  In each of the above embodiments, the plurality of lenses 6b have a shape corresponding to the transfer shape 12 (specifically, a reverse shape). In other words, each lens 6b has a shape corresponding to each curved surface portion 16 (specifically, an inverted shape). Since the curved surface portion 16 is a concave portion, a convex lens is formed on the resin layer 6a.

[Display device]
FIG. 7 is a diagram showing a part of a liquid crystal projector as an example of a display device to which the microlens array according to the present invention is applied.
The liquid crystal projector 40 includes a light valve 20 incorporating the microlens array 11 manufactured by the method according to each embodiment described above, and a lamp 30 as a light source.

  The microlens array 11 is disposed so as to be concave when the lens 6 b is viewed from the lamp 30. On the microlens array 11, a light transmission layer 22, a protective layer 23, a black matrix 24, an electrode 25, and an alignment film 26 are formed in this order. Further, a TFT substrate 32 is provided with a gap from the alignment film 26. A transparent individual electrode 34 and a thin film transistor 36 are provided on the TFT substrate 32, and an alignment film 38 is formed thereon. The TFT substrate 32 is disposed with the alignment film 38 facing the alignment film 26.

  A liquid crystal 31 is sealed between the alignment films 26 and 38, and the liquid crystal 31 is driven by a voltage controlled by the thin film transistor 36.

  According to the liquid crystal projector 40, since the light 33 emitted from the lamp 30 is condensed by the lens 6b for each pixel, a bright screen can be generated.

  As a premise, it is necessary that the light refractive index na of the light transmission layer 22 and the light refractive index nb of the microlens array 11 have a relationship of na <nb. By satisfying this condition, light enters from a medium having a high refractive index to a medium having a low refractive index, and the light 33 is refracted and condensed away from the normal line of the interface between the two media. And the screen can be brightened.

  The microlens array 11 according to the present invention can be applied to an optical device other than a display device, for example, an imaging device. The imaging device has an imaging element (image sensor). Light condensed by the microlens array enters the image sensor. A CCD (Charge Coupled Device) type is an example of the imaging element.

[Embodiment of Display Device]
As an embodiment of the display device described in detail above, the overall configuration, particularly the optical configuration, of a double-plate color projector will be described. FIG. 8 is a schematic cross-sectional view of a double-plate color projector.

  In FIG. 8, a liquid crystal projector 1100, which is an example of a double-plate type color projector in the present embodiment, prepares three light valves including an electro-optical device having a drive circuit mounted on a TFT array substrate, each for RGB. It is configured as a projector used as the light valves 100R, 100G and 100B. In the liquid crystal projector 1100, when projection light is emitted from a lamp unit 1102 of a white light source such as a metal halide lamp, light components R, G, and R corresponding to the three primary colors of RGB are obtained by three mirrors 1106 and two dichroic mirrors 1108. Divided into B, the light valves are guided to the light valves 100R, 100G and 100B corresponding to the respective colors. At this time, in particular, the B light is guided through a relay lens system 1121 including an incident lens 1122, a relay lens 1123, and an exit lens 1124 in order to prevent light loss due to a long optical path. The light components corresponding to the three primary colors modulated by the light valves 100R, 100G, and 100B are synthesized again by the dichroic prism 1112 and then projected as a color image on the screen 1120 through the projection lens 1114.

[screen]
Next, the details of the above-described screen will be described.
FIG. 9 is a diagram showing a configuration of a screen to which the microlens array of the present invention is applied as a lenticular plate.

  As shown in FIG. 9A, the screen 70 is disposed between the Fresnel plate 71 that converts the angle of incident light, the transmissive lenticular plate 73, and the Fresnel plate 71 and the lenticular plate 73. And a diffusing plate 72 (light diffusing plate) for diffusing the incident light. In addition, the screen 70 includes a vibration supply unit 74 that vibrates the diffusion plate 72 as shown in FIG. An opening 77a is formed on the front surface of the housing, and the screen 70 is fitted in the opening 77a.

  The lenticular plate 73 is provided with a plurality of bowl-shaped microlens elements 73c on the light incident side on the incident surface 73a. The plurality of microlens elements 73c have a y direction (longitudinal direction in the vertical direction when the screen 70 is installed) in a plane perpendicular to the optical axis O (xy plane), and are arranged in parallel in the x direction. Yes.

  The lenticular plate 73 diffuses light incident from the incident surface 73a within a predetermined angle range and emits the light from the emission surface 73b, widens the viewing angle of the image, and shifts the screen 70 horizontally from the front. A good image can be inspected even when observed at a position.

[Line head]
10A and 10B are diagrams showing an image forming apparatus line head (exposure means) to which the microlens array according to the present invention is applied, wherein FIG. 10A is a plan view and FIG. 10B is a side view. The line head 81 is disposed to face the photosensitive drum 320.

  The line head 81 includes a light emitting element array 83A in which a plurality of organic EL elements 83 are arranged on a long and thin element substrate 82, and a drive element group including a drive element 84 that drives the organic EL elements 83; A control circuit group 85 that controls driving of these drive elements 84 (drive element groups) is integrally formed. In FIG. 10A, the organic EL elements 83 are arranged in one row, but are arranged in two rows so as to be staggered (in a state shifted by a predetermined pitch with respect to the organic EL elements 83 in adjacent rows). May be. In this case, the pitch of the organic EL elements 83 in the longitudinal direction of the line head 81 can be reduced, and the resolution of the image forming apparatus can be improved.

  As shown in FIG. 10B, a microlens array 87 having a plurality of lenses 86 is provided at the bottom of the line head 81. The microlens array 87 includes the same number of lenses 86 as the organic EL elements, and each of the lenses 86 has a one-to-one relationship with each of the organic EL elements in order to condense light from the organic EL elements and enter the SL elements. It corresponds to. The arrangement position of the microlens array 87 (lens 86) may be on the light emitting side of the organic EL element, and is not limited to the lower surface of the element substrate 82. In particular, in order to allow as much light as possible to enter the microlens from the organic EL element, it is desirable to reduce the distance between the organic EL element and the microlens array 87 (lens 86) as much as possible.

[Image forming equipment]
Next, an image forming apparatus including the line head will be described.
FIG. 11 is a view showing an image forming apparatus provided with the line head. In FIG. 11, reference numeral 80 denotes an image forming apparatus. In this image forming apparatus 80, the organic EL array line heads 101K, 101C, 101M, and 101Y, which are examples of the above-described line heads, correspond to four photosensitive drums (image carriers) 41K and 41C having the same configuration. , 41M, and 41Y, respectively, and configured as a tandem system.

  The image forming apparatus 80 includes a driving roller 91, a driven roller 92, and a tension roller 93. The intermediate transfer belt 90 is stretched around these rollers so as to circulate and drive in the direction of the arrow (counterclockwise) in FIG. Is. Photosensitive drums 41K, 41C, 41M, and 41Y are arranged at predetermined intervals with respect to the intermediate transfer belt 90. These photosensitive drums 41K, 41C, 41M, and 41Y have a photosensitive layer as an image carrier on the outer peripheral surface thereof.

Here, K, C, M, and Y in the symbols mean black, cyan, magenta, and yellow, respectively, and indicate that the photoconductors are for black, cyan, magenta, and yellow, respectively.
The meanings of these symbols (K, C, M, Y) are the same for the other members. The photosensitive drums 41K, 41C, 41M, and 41Y are driven to rotate in the arrow direction (clockwise) in FIG. 11 in synchronization with the driving of the intermediate transfer belt 90.

  Around each photosensitive drum 41 (K, C, M, Y), charging means (corona charger) 42 for uniformly charging the outer peripheral surface of the photosensitive drum 41 (K, C, M, Y), respectively. (K, C, M, Y) and rotation of the photosensitive drum 41 (K, C, M, Y) on the outer peripheral surface uniformly charged by the charging means 42 (K, C, M, Y) The organic EL array line head 101 (K, C, M, Y) of the present invention that sequentially scans the line in synchronization with each other is provided.

  Further, a developing device 44 (K) that applies toner as a developer to the electrostatic latent image formed by the organic EL array line head 101 (K, C, M, Y) to form a visible image (toner image). , C, M, Y) and a primary transfer roller 45 as transfer means for sequentially transferring the toner image developed by the developing device 44 (K, C, M, Y) to the intermediate transfer belt 90 as a primary transfer target. (K, C, M, Y) and a cleaning device 46 (K, C) as a cleaning means for removing toner remaining on the surface of the photosensitive drum 41 (K, C, M, Y) after being transferred. , M, Y).

  Here, each organic EL array line head 101 (K, C, M, Y) is installed such that each array direction is along the bus line of the photosensitive drum 41 (K, C, M, Y). Then, the emission energy peak wavelength of each organic EL array line head 101 (K, C, M, Y) and the sensitivity peak wavelength of the photosensitive drum 41 (K, C, M, Y) are set to substantially coincide with each other. Has been.

  The developing device 44 (K, C, M, Y) uses, for example, a non-magnetic one-component toner as a developer. The film thickness of the developed developer is regulated by a regulating blade, and the developing roller is brought into contact with or pressed against the photosensitive drum 41 (K, C, M, Y), whereby the photosensitive drum 41 (K, C, M, A developer is attached in accordance with the potential level of Y) and developed as a toner image.

  The black, cyan, magenta, and yellow toner images formed by the four-color single-color toner image forming station are intermediated by the primary transfer bias applied to the primary transfer roller 45 (K, C, M, Y). Primary transfer is sequentially performed on the transfer belt 90. The toner images, which are sequentially superimposed on the intermediate transfer belt 90 and become full color, are secondarily transferred to the recording medium P such as paper by the secondary transfer roller 56 and further pass through the fixing roller pair 51 that is a fixing unit. Then, the toner image is fixed on the recording medium P and then discharged onto a paper discharge tray 58 formed on the upper portion of the apparatus by a pair of paper discharge rollers 52.

  In FIG. 11, reference numeral 53 denotes a paper feed cassette in which a large number of recording media P are stacked and held, 54 denotes a pickup roller for feeding the recording media P from the paper feed cassette 53 one by one, and 55 denotes secondary transfer. A pair of gate rollers for defining the supply timing of the recording medium P to the secondary transfer portion of the roller 56; a secondary transfer roller 56 as a secondary transfer means for forming a secondary transfer portion with the intermediate transfer belt 90; A cleaning blade 57 serves as a cleaning unit for removing toner remaining on the surface of the intermediate transfer belt 90 after the secondary transfer.

  It should be noted that the technical scope of the present invention is not limited to the above-described embodiment, and includes those in which various modifications are made to the above-described embodiment without departing from the spirit of the present invention.

(A) is a top view which shows schematic structure of the shaping | molding die for lens arrays in 1st Embodiment, (b) is IB-IB cross section of (a), (c) is the principal part of FIG.1 (b). It is expanded sectional drawing. It is a flowchart which shows the manufacturing method of the micro lens array of this embodiment. (A)-(f) is process drawing of the manufacturing method in alignment with the flowchart of FIG. (A) is a principal part expanded sectional view of the shaping | molding die for lens arrays in 2nd Embodiment, (b) is a top view of a curved surface part. It is a top view which shows the other Example of the curved surface part in 2nd Embodiment. It is a principal part enlarged view of the shaping | molding die for lens arrays in 3rd Embodiment. It is a schematic block diagram which shows the display apparatus which has a microlens array obtained with the shaping | molding die for lens arrays which concerns on this invention. It is a schematic block diagram which shows embodiment of the display apparatus of FIG. It is a schematic block diagram which shows the screen which has a microlens array obtained with the shaping | molding die for lens arrays which concerns on this invention. It is a schematic block diagram which shows the line head which has a microlens array obtained with the shaping | molding die for lens arrays which concerns on this invention. It is a schematic block diagram which shows the image forming apparatus which has the line head of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Lens array shaping | molding die, 3 ... Sealing resin, 4 ... Unfilled part, 10 ... Mold main body, 11 ... Micro lens array, 16 ... Curved surface part, 18 ... Through-hole, 19 ... Extraction part

Claims (11)

A lens array molding die having a plurality of lenses arranged in a plane and forming a lens array for condensing light incident on each lens toward the respective optical axis,
A plurality of curved surface portions that are formed on one surface in the thickness direction of the base material and reflect the shape of the lens, one end side opens in the curved surface portion, and the other end side is the other in the thickness direction of the base material. A mold body having a through hole opening in the surface;
A lens array molding die having a pull-out portion that is held in the through-hole so as to be pulled out from the through-hole.   The lens array molding die according to claim 1, wherein the through hole is located at a top portion of the curved surface portion.   3. The lens array molding die according to claim 1, wherein a projecting portion that projects inward of the through hole is provided at a boundary between the curved surface portion and the through hole.   4. The lens array molding die according to claim 1, wherein the mold body has translucency, and the extraction portion has non-translucency. 5.   5. The lens array molding die according to claim 1, wherein a volume of the through hole is in a range of 1% to 30% with respect to a volume of the curved surface portion.   6. The lens array mold according to claim 5, wherein the volume of the through hole is in the range of 1% to 10% with respect to the volume of the curved surface portion. In a manufacturing method of a lens array, which has a plurality of lenses arranged in a plane, and condenses light incident on each lens toward the respective optical axis,
A plurality of curved surface portions that are formed on one surface in the thickness direction of the base material and reflect the shape of the lens, one end side opens in the curved surface portion, and the other end side is the other in the thickness direction of the base material. A mold body having a through hole opening in the surface;
In the through hole, using a lens array mold configured to have a drawing portion that is held so as to be able to be pulled out from the through hole,
Supplying a sealing resin to the plurality of curved surface portions in a vacuum atmosphere;
Increasing the pressure from a vacuum atmosphere;
Retreating the extraction portion from the through hole to eliminate an unfilled portion in the curved portion;
And a step of curing the sealing resin. In the step of increasing the pressure from the vacuum atmosphere,
8. The method of manufacturing a lens array according to claim 7, wherein the pressure is increased to an atmospheric pressure atmosphere.   The method for manufacturing a lens array according to claim 7, further comprising a step of removing a protruding portion of the sealing resin cured in the through hole.   10. The method of manufacturing a lens array according to claim 7, wherein the mold main body has translucency, and the extraction portion has non-translucency. 11.   The method for manufacturing a lens array according to claim 7, wherein the sealing resin is a photosensitive curable resin having a higher refractive index than the mold body.

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