JP4189700B2 - Planar lens manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method for manufacturing a planar lens.,In particularFor rear projection projector screens using this flat lensSuitable manufacturing methodConcerningIs a thing.
[0002]
[Prior art]
In recent years, for example, development of rear projection projectors using liquid crystal light valves and CRTs has become active as large-screen displays for HDTV (high vision) and theaters.
[0003]
FIG. 29 shows a schematic configuration of a conventional rear projection type projector.
[0004]
The illustrated example is a box-type projector, and the projection video light L from the video projection unit 101 is reflected by, for example, the reflection mirror 102 and guided to the transmission screen 105. The transmissive screen 105 includes a Fresnel lens 103 and a lenticular lens 104 that normally extends in the vertical direction. Then, the projection video light L incident from the back surface of the transmission screen 105 becomes substantially parallel light by the Fresnel lens 103 and then diffused mainly in the horizontal direction by the lenticular lens 104.
[0005]
As shown in FIGS. 30 (a) and 30 (b), the lenticular lens 104 is provided with a protrusion 104a extending in the vertical direction on the back side (light emission side) thereof, and external light is provided on the protrusion 104a. Black stripes 104b are provided to absorb the light and improve the screen contrast. For example, after the acrylic resin is molded into the shape of the lenticular lens 104 including the protruding portion 104a by extrusion molding, black printing is performed only on the protruding portion 104a to form the black stripe 104b.
[0006]
As shown in FIG. 30B, the width w of the black stripe 104b is usually 0.3 to 0.4 times the pitch p of the lenticular lens 104.
[0007]
[Problems to be solved by the invention]
However, in the transmissive screen using the lenticular lens as described above, for example, a wide viewing angle is obtained because light is diffused widely in the horizontal direction, but light is diffused only in a narrow range in the vertical direction. There was a drawback that the viewing angle in the direction was narrow. In order to overcome this drawback, there is also a structure in which a lenticular lens extending in the vertical direction and a lenticular lens extending in the horizontal direction are combined, but there is a problem that the component cost and manufacturing cost increase due to the increase in the number of components, Further, since the number of laminated screens is increased, the thickness of the screen is increased, and further, there is a problem that the influence of multiple reflection between each layer is increased.
[0008]
Further, as described above, when black stripes are provided to improve contrast, it is necessary to form a ridge for black printing on the light emission side of the lenticular lens, and this ridge is used as an obstacle to the emitted light. Since it is necessary to form in the width | variety which does not become, the area ratio of the external light absorption part by a black stripe has usually stayed at about 30 to 40%. For this reason, the effect of improving contrast was relatively poor.
[0009]
Accordingly, attention has been paid to a transmissive screen using a planar lens formed by two-dimensionally arranging transparent microspheres instead of a lenticular lens (for example, U.S. Pat. Nos. 2,378,252 and 3,552,822). , Japanese Utility Model Registration No. 2513508), research and development for practical use in large-screen high-definition displays are being conducted.
[0010]
For example, the configuration previously proposed by the present applicant as Japanese Patent Application No. 9-100590 (filed on April 17, 1997) will be described with reference to FIGS.
[0011]
FIG. 31 shows the main configuration of an open-type rear projection projector. Projected video light L from the video projection unit 21 is forwarded through a transmissive screen 10 including a Fresnel lens 22 and a flat lens 23. Is diffused. As shown in the figure, the planar lens 23 is configured by two-dimensionally packing and arranging transparent microspheres 2 such as glass beads. Accordingly, the projection image light L can be diffused in a wide range in the horizontal direction and the vertical direction by the single layer of the transparent microsphere 2.
[0012]
FIG. 32 is a box-type rear projection projector, and the projection video light L from the video projection unit 21 arranged in the housing 25 is reflected by the reflection mirror 24, and again, the Fresnel lens 22 and the transparent microlens. The light is diffused forward through a transmission screen 10 composed of a flat lens 23 constituted by a sphere 2.
[0013]
FIG. 33 shows an example of the configuration of the planar lens 23.
[0014]
In this flat lens 23, for example, a large number of transparent microspheres 2 such as glass beads are applied to the transparent adhesive layer 5 formed on the light incident side transparent substrate 4 by 50% of the diameter of each transparent microsphere 2. The degree is embedded and retained. For example, a light absorption layer (colored layer) 3 made of carbon toner or the like is formed in the gap between the transparent microspheres 2, and a region near the top of each transparent microsphere 2 on the light emission side is the light absorption layer 3. Is exposed from. Further, the transparent substrate 1 is laminated on the light emitting side of the transparent microsphere 2 via the transparent adhesive layer 6, thereby protecting the transparent microsphere 2 and the light absorption layer 3 from the outside.
[0015]
Incident light L incident through a Fresnel lens (not shown)_inAs shown in the figure, the light passes through the transparent substrate 4 and the transparent adhesive layer 5 on the incident side and is converged by the transparent microspheres 2, and the converged light passes through the region near the top of the light output side of each transparent microsphere 2. The light is transmitted through the transparent adhesive layer 6 and the transparent substrate 1 on the output side, and the output light L_outIs diffused and emitted. On the other hand, external light L incident from the transparent substrate 1 side_exMost of the light is absorbed by the light absorption layer 3, and therefore, the external light L_exThe reduction in contrast due to the reflection is reduced.
[0016]
At this time, in the planar lens 23, the area ratio of the light absorption layer 3 on the light emitting side can be set to, for example, about 80% or more._exThe reduction in contrast due to the reflection of light can be greatly reduced, and a high-contrast screen that is hardly affected by outside light can be realized.
[0017]
For example, the flat lens 23 is manufactured as follows.
[0018]
First, the transparent adhesive layer 5 is formed on the transparent substrate 4 on the light incident side, and a large number of transparent microspheres 2 are dispersed thereon. Thereafter, the transparent microspheres 2 are pressurized from above and embedded in the transparent adhesive layer 5 to about half the diameter thereof. Next, a light absorbing material such as carbon toner spread over the entire surface is pressurized with, for example, a pressure roll and filled in the gaps between the transparent microspheres 2 to form the light absorbing layer 3. Next, the light-absorbing material on the area near the top on the light emission side of each transparent microsphere 2 is removed, and a light emission portion is formed on each transparent microsphere 2. Thereafter, the transparent substrate 1 is laminated on the light emitting side via the transparent adhesive layer 6.
[0019]
However, in this manufacturing method, it is relatively difficult to uniformly fill the gaps between the transparent microspheres 2 with the light-absorbing material, and when the light emitting portion is formed in each transparent microsphere 2, the cueing area is increased. There was a problem that the variation of the was relatively large. For this reason, the transmissive screen 10 using the conventional planar lens 23 has a disadvantage that the luminance and contrast are relatively uneven.
[0020]
Further, in this manufacturing method, a step of spreading a light absorbing material such as carbon toner on the entire surface and then filling it into the gaps between the transparent microspheres 2 and the area near the top of the light emission side of each transparent microsphere 2 A process for removing the above light-absorbing material is required, and the manufacturing time is increased as a whole, resulting in an increase in cost. Furthermore, there is a problem of contamination of the process due to the removed carbon toner or the like.
[0021]
In addition, the conventional planar lens 23 has a problem in that an additional antistatic film or the like must be provided in order to prevent the charging, which increases the cost.
[0022]
  Therefore, an object of the present invention is to provide a gap between the transparent microspheres so as to expose a region near the top of each transparent microsphere.Filled inIt is an object of the present invention to provide a method for manufacturing a planar lens having a structure capable of forming a light absorbing layer effectively in a relatively short time and capable of easily preventing charging.
[0023]
[Means for Solving the Problems]
  The planar lens of the present invention that solves the above-described problemsManufacturing methodIs
    Forming an electrically insulating adhesive layer on the substrate;
    A plurality of transparent microspheres each having at least a surface portion having conductivity on the adhesive layer
  And a plurality of the plurality of transparent microspheres so as to expose a predetermined portion on the light emission side.
  Embedding the transparent microspheres in the adhesive layer to a predetermined depth;
    In an electric field with the adhesive layer exposed between the plurality of transparent microspheres having a first polarity side,
  By supplying a light absorption material in the form of a fine powder charged to a bipolar potential, the first polarity
  Sucking the light-absorbing material of the second polarity to the surface of the adhesive layer of
  The light absorbing material is selectively attached to the gaps between the plurality of transparent microspheres.
  Filling the light absorbing material, exposing a predetermined region on each light emitting side of the plurality of transparent microspheres.
  Forming a light absorption layer so as to
Have
  By this manufacturing method,A plurality of transparent microspheres distributed in a planar shape or a curved surface, and at least a surface portion of each of which is conductive, an electrically insulating adhesive layer that holds the plurality of transparent microspheres, and each of the transparent microspheres A light absorbing layer disposed in a gap between the plurality of transparent microspheres so as to expose a predetermined portion on the light emitting side ofPlanar lens can be manufactured.
[0025]
  In addition, a method for manufacturing a planar lens according to another aspect of the present invention includes:
    Forming an electrically insulating adhesive layer on the substrate;
    A plurality of transparent microspheres each having at least a surface portion having conductivity on the adhesive layer
  SupplyThe plurality of transparent microspheres are exposed to a predetermined location on the light exit side.
  Transparent microspheresEmbedding in the adhesive layer to a predetermined depth;
    Through an electrostatic screen having an electrostatic pattern latent image corresponding to the arrangement of the transparent microspheres
  AndExposed between the plurality of transparent microspheresDuring the electric field with the adhesive layer as the first polarity side,
  By supplying a light absorption material in the form of a fine powder charged to a potential of the second polarity,The first pole
  The surface of the adhesive layer by sucking the light-absorbing material of the second polarity onto the surface of the adhesive layer
  Selectively adhering the light absorbing material to theGap between the plurality of transparent microspheres
  Filled with the light absorbing material,pluralTransparent microsphereOn each light exit sidePredetermined areaTheExposure
  To letForming a light absorption layer; and
Have
[0026]
  In addition, the present inventionThe planar lens manufactured by the manufacturing method isRear projection projector screenInUseSuitable for.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described according to preferred embodiments.
[0028]
In the following embodiments, portions corresponding to those shown in FIGS. 31 to 33 are denoted by the same reference numerals as those in FIGS. 31 to 33.
[0029]
First, a planar lens according to an embodiment of the present invention will be described with reference to FIGS.
[0030]
First, as shown in FIG. 2A, the transparent adhesive layer 5 is formed on the transparent substrate 4 on the light incident side. For example, an acrylic ultraviolet (UV) curable resin with a protective film 5a is attached on the transparent substrate 4 made of an acrylic resin such as polymethyl methacrylate (PMMA). 4 a is a protective film for protecting the back side of the transparent substrate 4.
[0031]
Note that the substrate 4 and the adhesive layer 5 described above are not necessarily a complete transparent body as long as they can transmit most of the target light. Therefore, in this specification, “transparent” "Is used in a sense including transparency to a so-called translucent level.
[0032]
As the transparent substrate 4, for example, a rigid glass substrate or various plastic substrates having rigidity or flexibility can be used in addition to the above-described acrylic resin such as PMMA. Other than the acrylic resin and glass described above, for example, polycarbonate resin, polyolefin resin, vinyl chloride resin, polystyrene resin, polyethylene resin, epoxy resin, polyarylate resin, polyethersulfone resin, silicone resin, polyethylene terephthalate resin, etc. may be used. it can.
[0033]
Since the transparent adhesive layer 5 has a large number of transparent microspheres embedded therein and needs to securely fix and hold them, it has an appropriate softness before photocuring, so that the transparent microspheres can be embedded easily, and After photocuring, it is particularly preferable that the transparent microspheres are made of an acrylic ultraviolet curable resin that securely holds and holds the transparent microspheres. However, other acrylic resins such as polycarbonate resin, polyolefin resin, vinyl chloride resin, polystyrene resin, polyethylene resin, epoxy resin, polyarylate resin, polyethersulfone resin, silicone resin, polyethylene terephthalate resin, etc. Is of course good.
[0034]
Next, as shown in FIG. 2 (b), the static elimination blow 41 is performed to neutralize static electricity and the protective film 5 a is peeled from the transparent adhesive layer 5 while removing suction dust.
[0035]
Next, as shown in FIG. 2C, for example, a large number of transparent microspheres 2 are supplied onto the transparent adhesive layer 5 from the hopper 42.
[0036]
Each transparent microsphere 2 is configured such that, for example, the surface of a sphere body 2a made of glass beads is covered with a transparent conductive paint 2b as clearly shown in FIG.
[0037]
The transparent conductive paint 2b is formed to have a film thickness of about 1 μm by, for example, immersing glass beads in a solution in which ITO (indium-tin oxide) is dispersed, and then lifting and drying.
[0038]
The formed film thickness of the transparent conductive paint 2b is, for example, 0.1 to 5 μm. If the film thickness of the transparent conductive paint 2b is smaller than 0.1 μm, sufficient conductivity may not be obtained, and it is technically difficult to form a film thicker than 5 μm.
[0039]
The spherical body 2a of each transparent microsphere 2 can be made of, for example, plastic such as acrylic resin or polystyrene resin in addition to the glass described above.
[0040]
Each transparent microsphere 2 may be entirely made of conductive glass or plastic.
[0041]
The refractive index of each transparent microsphere 2 is at least such that the refractive index of the sphere body 2a is larger than the refractive index of the transparent adhesive layer 5 in contact with the transparent microsphere 2 on the light incident side, for example 1.4 or more. And
[0042]
The size of the spherical body 2a of each transparent microsphere 2 is, for example, a diameter d = 50 to 100 [μm]. If this size is too large, especially when a rear projection projector screen is constructed, the gap between the transparent microspheres 2 becomes too large, and the resolution may be lowered.
[0043]
The variation in the size of the sphere body 2a of the transparent microsphere 2 is, for example, 10% or less of the average diameter. If this variation is too large, it may be difficult to uniformly distribute the transparent microspheres 2.
[0044]
Next, as shown in FIG. 3 (a), for example, skiing is performed by the doctor plate 39, and the height of the transparent microsphere 2 is made uniform.
[0045]
Next, as shown in FIG. 3 (b), the transparent microsphere 2 is pressed from above with a pressure roll 31 such as silicone rubber, for example, and the lowermost transparent microsphere 2 is embedded in the transparent adhesive layer 5.
[0046]
The amount of the transparent microspheres 2 embedded in the transparent adhesive layer 5 is, for example, 30% or more of the diameter, more preferably about 50%. This ensures that each transparent microsphere 2 is fixed and held by the transparent adhesive layer 5 and the amount of light incident on each transparent microsphere 2 is increased. For example, when used for a rear projection projector screen, The brightness increases.
[0047]
Next, as shown in FIG. 3C, excess transparent microspheres 2 that are embedded and not held in the transparent adhesive layer 5 are removed by suction, for example, by a vacuum suction means 43.
[0048]
Next, as shown in FIG. 4A, for example, after checking the filling state of the transparent microspheres 2 with the camera 44, the ultraviolet irradiation 45 is performed to cure the transparent adhesive layer 5 made of an ultraviolet curable resin. The transparent microsphere 2 is fixed.
[0049]
Next, as shown in FIG. 4B, a so-called electrostatic screen printing technique is applied to fill the gap between the transparent microspheres 2 with fine powdery carbon toner, which is a light-absorbing material. The absorption layer 3 is formed.
[0050]
That is, as clearly shown in FIG. 1A, for example, a 100-300 mesh stainless steel screen 46 used for normal electrostatic screen printing is stretched on a screen frame 47, and toner is supplied thereon. To do. The stainless steel screen 46 may be opened in all the openings, or may be opened in a pattern roughly corresponding to the gap between the transparent microspheres 2.
[0051]
The transparent substrate 4 in which the transparent microspheres 2 are fixedly held on the transparent adhesive layer 5 is placed on a metal plate 48 which is a base of a printing machine. And, between the metal plate 48 and the screen frame 47, for example, a DC high voltage V of 1000 to 3000V._HIs applied in the illustrated direction, thereby forming an electrostatic field between the stainless steel screen 46 and the metal plate 48 with the metal plate 48 as the positive electrode side.
[0052]
Incidentally, the distance t between the stainless steel screen 46 and the upper end of the light absorption layer 3 to be finally formed.₁Is about 2 to 3 mm, for example, and the thickness t of the light absorption layer 3 to be finally formed is₂Is, for example, about 20 μm and the thickness t of the transparent adhesive layer 5_ThreeIs, for example, about 20 μm, the thickness t of the transparent substrate 4_FourIs about 2 mm, for example. Moreover, the diameter of each transparent microsphere 2 shall be about 50 micrometers, for example. In FIG. 1A, the illustration of the protective film 5a on the back side of the transparent substrate 4 is omitted.
[0053]
In this state, for example, as shown in the figure, when the toner on the stainless steel screen 46 is scraped out with a brush 49, negatively charged toner powder is supplied into the electrostatic field through the opening of the stainless steel screen 46. The negatively charged toner powder falls in an electrostatic field, is attracted to the surface of the positively charged transparent adhesive layer 5 and adheres thereto. At this time, since the surface of each transparent microsphere 2 is imparted with conductivity, the surface is not charged, and therefore toner powder hardly adheres to the surface. At this time, for example, it is preferable to reliably prevent the surface of each transparent microsphere 2 from being charged by grounding each transparent microsphere 2 through the transparent microsphere 2 arranged at the outermost peripheral position.
[0054]
Through the above process, the toner powder preferentially fills the gaps between the transparent microspheres 2 and forms the light absorption layer 3 in a state where the area near the top of each transparent microsphere 2 is exposed. Therefore, the applied voltage is turned off when the light absorption layer 3 having a desired film thickness is obtained.
[0055]
FIG. 1B shows a plan view of the light absorption layer 3 formed in a state in which the region near the top of each transparent microsphere 2 is exposed. s is the diameter of the opening 3 a of the light absorption layer 3.
[0056]
Since the opening area of each opening 3a of the light absorption layer 3 formed by the above process is basically determined only by the film thickness of the light absorption layer 3, it is formed relatively uniformly as a whole as shown in the figure. The
[0057]
When the light absorption layer 3 is formed in this way, a toner removal step for exposing the region near the top of each transparent microsphere 2 as in the prior art becomes unnecessary, so that the removed toner powder contaminates the equipment, Further, it is possible to eliminate the inconvenience that the light absorbing layer 3 is unevenly deposited by reattaching to other toner layer portions.
[0058]
Moreover, since the light absorption layer 3 can be formed from the beginning with the region near the top of each transparent microsphere 2 exposed, the final formation time of the light absorption layer 3 can be greatly shortened. As a result, the manufacturing cost of the product can be reduced.
[0059]
Even in the manufacturing method according to the above-described embodiment of the present invention, after the light absorption layer 3 is finally formed, for example, a minute amount attached to the exposed portion of each transparent microsphere 2 using a soft bristle brush. Of course, the toner powder of the transparent microspheres 2 may be more reliably formed by removing the toner powder.
[0060]
Further, when a conductive substrate is used as the transparent substrate 4 or instead, the metal plate 48 can be omitted. At this time, when an opaque substrate is used as the conductive substrate, the substrate may be peeled off after the planar lens is manufactured or at an appropriate time in the manufacturing process.
[0061]
Furthermore, when using toner powder that is positively charged, the direction of the applied voltage is reversed. In any polarity, pre-charged toner may be used.
[0062]
As shown in FIG. 4C, after the light absorption layer 3 is formed, the filling state of the light absorption layer 3 is checked by the camera 50, for example.
[0063]
Next, as shown in FIG. 5A, the protective film 6a of the transparent adhesive layer 6 formed on the transparent substrate 1 on the light emitting side is peeled off and on the transparent substrate 4 on the light incident side as described above. It laminates on the formed transparent microsphere 2 and the light absorption layer 3. 1 a is a protective film provided on the back side of the transparent substrate 1.
[0064]
As the transparent substrate 1 and the transparent adhesive layer 6 on the light emitting side, the same materials as the transparent substrate 4 and the transparent adhesive layer 5 on the light incident side described above can be used. For example, the transparent substrate 1 is made of an acrylic plate, and the transparent adhesive layer 6 is made of an acrylic ultraviolet curable resin.
[0065]
Thereafter, as shown in FIG. 5 (b), for example, pressure is applied by a pressure roll 37 and the transparent microspheres 2 and the light absorption layer 3 formed on the transparent substrate 4 are interposed via the transparent adhesive layer 6. The transparent substrate 1 is pressure bonded.
[0066]
Then, as shown in FIG.5 (c), the ultraviolet irradiation 51 is performed, the transparent adhesion layer 6 is hardened, and the adhesion | attachment is strengthened.
[0067]
If the transparent adhesive layer 5 on the light incident side sufficiently holds and holds the transparent microsphere 2 even before ultraviolet curing, the final ultraviolet curing of the transparent adhesive layer 5 is performed simultaneously in this step. Anyway.
[0068]
Thereafter, the protective films 1a and 4a are peeled off to obtain a planar lens.
[0069]
In the flat lens manufactured as described above, for example, a ground wire is connected to the transparent microsphere 2 in order to prevent electrification when used in a transmission screen. The mode is shown in FIG.
[0070]
FIG. 6A shows an example in which the ground wire 52 is connected under the transparent microsphere 2 at the outermost peripheral position in the process of FIG. 2C described above. At this time, if the transparent microsphere 2 is provided with a ground structure, the grounding of each transparent microsphere 2 can be easily performed using the ground structure in the toner filling process described with reference to FIGS. 1 (a) and 4 (b). Can be taken.
[0071]
Since the transparent microspheres 2 are finally arranged in close contact with each other, all the transparent microspheres 2 are grounded by simply connecting the ground wire 52 to the transparent microspheres 2 at the end in this way. can do. In particular, in a large-screen screen, it is preferable to ground at a plurality of positions on the end portion in order to reliably apply a ground potential to each transparent microsphere 2.
[0072]
FIG. 6 (b) shows an example in which the ground wire 52 is connected to the transparent microsphere 2 at the outermost peripheral position and is sandwiched by the transparent adhesive layer 6 on the light emitting side in the process of FIG. 5 (a). An example of fixing is shown.
[0073]
In FIG. 6C, as shown in FIG. 7, for example, a conductive tape 53 is attached to the end side surface of the finally obtained planar lens 23, and the ground wire 52 is attached to the conductive tape 53. Is an example of connecting. The ground wire 52 may be directly connected to the transparent microsphere 2 using an electrically insulating adhesive tape.
[0074]
As described above, in the planar lens 23 according to the present embodiment, at least the surface portion of each transparent microsphere 2 is configured to be conductive. When the lens 23 is used for a transmissive screen, the charging can be easily prevented. Further, since at least the surface portion of each transparent microsphere 2 is conductive, for example, there is an effect of shielding electromagnetic waves from a CRT (cathode ray tube) or the like of the video projection unit.
[0075]
FIG. 8 shows another mode for forming the light absorption layer 3.
[0076]
In this embodiment, for example, as shown in FIG. 8A, an endless photoconductive screen 61 is used and is continuously connected to a plurality of transparent substrates 4 holding a large number of transparent microspheres (not shown) as described above. A light absorbing layer is formed.
[0077]
A photoconductive screen is obtained by applying a photoconductive film to a screen. For example, when the entire surface is charged by corona discharge at a position 62, the screen is irradiated with light with an arbitrary image pattern. Then, the static electricity is neutralized and becomes uncharged, and as a result, an electrostatic latent image having a pattern corresponding to the image is formed on the screen. The charged part of the screen repels the same polarity powder and prevents its passage through the opening. On the other hand, since the non-charged portion allows the powder to pass through the opening, an adhesion image corresponding to the image is obtained when printing with the paint powder is performed through this screen.
[0078]
Therefore, in this aspect, first, an image of the target substrate 4 is captured by the imaging unit 63, and the image data is subjected to image processing by the image processing unit 64. For example, as illustrated in FIG. A binary image showing the arrangement state of the transparent microspheres on 4 is obtained. Then, an image corresponding to the binary image is projected from the image projection unit 65 onto the photoconductive screen 61, and the photoconductive screen 61 is electrostatically responded to the arrangement state of the transparent microspheres on the target substrate 4. A latent image is formed.
[0079]
Then, when the target substrate 4 is transferred to the printing stage 68 by, for example, the belt conveyor 67, the corresponding photoconductive screen 61 on which the electrostatic latent image is formed is just put on the printing stage 68. In this state, toner powder is supplied from the toner supply unit 66, and a light absorption layer is formed on the substrate 4.
[0080]
In this way, the toner powder can be supplied substantially only to the gaps between the transparent microspheres on the substrate 4, and the filling can be performed very efficiently. Further, since the toner powder corresponding to the actual arrangement state of the transparent microspheres on each substrate 4 can be supplied, the filling of the gap portion between the transparent microspheres is always accurately performed on any substrate 4. It can be carried out.
[0081]
In FIG. 8A, 69 is a cleaner for removing the toner powder adhering to the photoconductive screen 61, 70 is a bias roller for applying a bias potential to each substrate 4, and 71 is a light beam if necessary. It is a heater for heating and curing the toner of the absorption layer.
[0082]
Even in this embodiment, by imparting conductivity to the surface portion of each transparent microsphere, it becomes difficult for toner powder to adhere to the surface portion of the transparent microsphere. Even when the pattern of the electrostatic latent image and the actual pattern on the substrate 4 are slightly misaligned, the light absorption layer can be formed accurately.
[0083]
9 to 28 show various aspects of the planar lens 23.
[0084]
The example of FIG. 9 is a planar lens 23 having the most basic structure including the transparent substrate 4 on the light incident side, the transparent adhesive layer 5, the transparent microsphere 2, and the light absorption layer 3. If it is not particularly necessary to protect the transparent microspheres 2 and the light absorption layer 3 on the light emitting side, this form can be used as it is.
[0085]
In the example of FIG. 10, in the most basic structure shown in FIG. 9, a transparent adhesive layer 6 is provided on the light emitting side, and the transparent microspheres 2 and the light absorbing layer 3 are protected on the light emitting side. .
[0086]
In the example of FIG. 11, the transparent substrate 1 is provided on the light emitting side in the most basic structure shown in FIG. 9, and the transparent microspheres 2 and the light absorbing layer 3 on the light emitting side are further protected. It is. This structure is possible when the light absorbing layer 3 having an adhesive function is used.
[0087]
The example of FIG. 12 has a structure in which the transparent substrate 1 is provided on the light emitting side through the transparent adhesive layer 6 in the most basic structure shown in FIG. It is a structure manufactured by a process.
[0088]
In the example of FIG. 13, the transparent substrate 4 on the light incident side is omitted from the structure shown in FIG. This structure can be manufactured, for example, by manufacturing the structure of FIG. 11 using a peelable substrate instead of the transparent substrate 4 on the light incident side, and peeling the substrate at an appropriate time in the process. .
[0089]
Similarly, the example of FIG. 14 is obtained by omitting the light incident side transparent substrate 4 in the structure shown in FIG.
[0090]
In the example of FIG. 15, after the structure shown in FIG. 13 is manufactured, the Fresnel lens 22 is joined to the light incident side of the planar lens 23 to constitute the integral transmission screen 10.
[0091]
In the example of FIG. 16, similarly, after manufacturing the structure shown in FIG. 14, the Fresnel lens 22 is joined to the light incident side of the planar lens 23 to constitute the integral transmission screen 10. .
[0092]
In the example of FIG. 17, in the structure shown in FIG. 9, the planar lens 23 is manufactured using a peeling substrate instead of the transparent substrate 4, and after peeling off the peeling substrate, the Fresnel lens 22 is bonded to the light incident side. Thus, the integrated transmission screen 10 is configured. As described above, it is possible to ensure the shape stability of the planar lens 23 itself by bonding it to the Fresnel lens 22 without providing a substrate.
[0093]
In the example of FIG. 18, similarly, in the structure shown in FIG. 10, the planar lens 23 is manufactured using a peeling substrate instead of the transparent substrate 4, and after peeling off the peeling substrate, the Fresnel lens 22 on the light incident side Are combined to form an integral transmission screen 10.
[0094]
In the example of FIG. 19, silicon oxide (SiO 2) is respectively formed on the light incident side and the light output side of the planar lens 23 having the structure shown in FIG.₂) An antireflection film 7 such as a film is provided.
[0095]
In the example of FIG. 20, similarly, the antireflection film 7 is provided on the light incident side and the light emission side of the planar lens 23 having the structure shown in FIG.
[0096]
In the example of FIG. 21, similarly, the antireflection film 7 is provided on the light incident side and the light emission side of the planar lens 23 having the structure shown in FIG.
[0097]
In the example of FIG. 22, similarly, the antireflection film 7 is provided on the light incident side and the light emission side of the planar lens 23 having the structure shown in FIG.
[0098]
In the example of FIG. 23, similarly, the antireflection film 7 is provided on the light incident side and the light emission side of the planar lens 23 having the structure shown in FIG.
[0099]
Similarly, in the example of FIG. 24, the antireflection film 7 is provided on each of the light incident side and the light emitting side of the planar lens 23 having the structure shown in FIG.
[0100]
In the example of FIG. 25, the antireflection film 7 is provided on the light incident side of the Fresnel lens 22 and the light emission side of the planar lens 23 in the structure shown in FIG.
[0101]
Similarly, in the example of FIG. 26, the antireflection film 7 is provided on the light incident side of the Fresnel lens 22 and the light emission side of the planar lens 23 in the structure shown in FIG.
[0102]
Similarly, in the example of FIG. 27, the antireflection film 7 is provided on the light incident side of the Fresnel lens 22 and the light emission side of the planar lens 23 in the structure shown in FIG.
[0103]
Similarly, in the example of FIG. 28, the antireflection film 7 is provided on the light incident side of the Fresnel lens 22 and the light emission side of the planar lens 23 in the structure shown in FIG.
[0104]
The planar lens 23 described above is particularly suitable for use in, for example, the transmissive screen 10 for a rear projection projector shown in FIG. 31 or FIG.
[0105]
In the embodiment described above, the transparent microspheres 2 are arranged in a planar shape. However, the transparent microspheres 2 may be arranged in a curved shape along a slightly curved transparent substrate, for example. Further, the toner itself (first layer) may be used in place of the transparent adhesive layer 5.
[0106]
Further, in the above-described embodiment, the planar lens 23 is manufactured in order from the light incident side in a state where each transparent microsphere 2 is held by the transparent adhesive layer 5 on the light incident side. For example, FIG. Such a structure may be manufactured in order from the light emitting side. In this case, for example, each transparent microsphere 2 is held by a light absorbing layer 3 formed to a certain thickness on the transparent substrate 1, and further, by the electrostatic screen printing method described above. A light absorption layer 3 having a predetermined thickness is laminated.
[0107]
【The invention's effect】
  In the present inventionAccording toA plurality of transparent microspheres each having at least a surface portion having conductivity.ConfiguredPlanar lensCan be manufacturedTherefore, for example, when this flat lens is used for a screen for a rear projection projector, the screen can be easily prevented from being charged by grounding each transparent microsphere. In addition, since at least the surface portion of each transparent microsphere has conductivity, for example, an effect of shielding electromagnetic waves from a CRT or the like of the image projection unit can be obtained.
[0108]
In addition, for example, by applying an electrostatic screen printing method which is a contactless printing method, a light absorption layer can be formed uniformly between each transparent microsphere, so that particularly high brightness and contrast non-uniformity are high. A high performance rear projection projector screen can be provided.
[0109]
Furthermore, for example, the process of removing the light absorbing material on each transparent microsphere for exposing the light emitting portion of each transparent microsphere from the light absorption layer is not required, so the process is simplified and the manufacturing time is reduced. The manufacturing cost of the product can be reduced. Further, the problem of contamination of the process due to the removed toner powder or the like is eliminated.
[Brief description of the drawings]
1A and 1B are a schematic cross-sectional view and a plan view showing a method for forming a light absorption layer according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view showing a method of manufacturing a planar lens according to an embodiment of the present invention in the order of steps.
FIG. 3 is a schematic cross-sectional view showing a method of manufacturing a planar lens according to an embodiment of the present invention in the order of steps.
FIG. 4 is a schematic cross-sectional view showing a method of manufacturing a planar lens according to an embodiment of the present invention in the order of steps.
FIG. 5 is a schematic cross-sectional view showing a method of manufacturing a planar lens according to an embodiment of the present invention in the order of steps.
FIG. 6 is a schematic cross-sectional view showing how to ground a planar lens according to an embodiment of the present invention.
FIG. 7 is a perspective view showing how to ground a planar lens according to an embodiment of the present invention.
FIG. 8 is a schematic diagram showing another method of forming a light absorption layer according to an embodiment of the present invention and a schematic diagram showing a binary image of an arrangement state of transparent microspheres.
FIG. 9 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 10 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 11 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 12 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 13 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 14 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 15 shows the present invention.Obtained based on manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of the screen for rear projection type projectors.
FIG. 16 shows the present invention.Obtained based on manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of the screen for rear projection type projectors.
FIG. 17 shows the present invention.Obtained based on manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of the screen for rear projection type projectors.
FIG. 18 shows the present invention.Obtained based on manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of the screen for rear projection type projectors.
FIG. 19 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 20 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 21 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 22 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 23 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 24 shows the present invention.Obtained by manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of a planar lens.
FIG. 25 shows the present invention.Obtained based on manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of the screen for rear projection type projectors.
FIG. 26 of the present inventionObtained based on manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of the screen for rear projection type projectors.
Fig. 27 of the present inventionObtained based on manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of the screen for rear projection type projectors.
FIG. 28 shows the present invention.Obtained based on manufacturing methodIt is a schematic sectional drawing which shows the one aspect | mode of the screen for rear projection type projectors.
FIG. 29 is a schematic view showing a conventional rear projection type projector.
30A and 30B are a schematic diagram and a cross-sectional view showing a configuration of a lenticular lens in a conventional rear projection projector.
FIG. 31 is a schematic diagram showing an open-type rear projection projector using a planar lens made of transparent microspheres.
FIG. 32 is a schematic diagram showing a box-type rear projection projector using a planar lens made of transparent microspheres.
FIG. 33 is a schematic cross-sectional view showing the configuration of a planar lens made of transparent microspheres.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 4 ... Transparent substrate, 2 ... Transparent microsphere, 2a ... Sphere main-body part, 2b ... Conductive coating material, 3 ... Light absorption layer, 3a ... Opening part, 5, 6 ... Transparent adhesion layer, 7 ... Antireflection film, DESCRIPTION OF SYMBOLS 10 ... Transmission type screen, 21 ... Video projection part, 22 ... Fresnel lens, 23 ... Plane type lens, 24 ... Reflection mirror, 25 ... Case, 46 ... Stainless steel screen, 47 ... Screen frame, 48 ... Metal plate, 49 ... Brush, L ... Projected image light, L_in... incident light, L_out... emitted light, L_ex... light

Claims (12)

Forming an electrically insulating adhesive layer on the substrate;
A plurality of transparent microspheres each having at least a surface portion each having conductivity are provided on the adhesive layer, and the plurality of the plurality of transparent microspheres are exposed so as to expose predetermined portions on the light emission side of these transparent microspheres.
Embedding the transparent microspheres in the adhesive layer to a predetermined depth;
The adhesive layer exposed between said plurality of transparent microspheres in an electric field which is the first polarity side, by supplying the fine powder of the light-absorbing material is charged to a second polarity of the potential, the first polarity
Sucking the light-absorbing material of the second polarity to the surface of the adhesive layer of
Selectively depositing to the light-absorbing material, thereby filling the said light absorbing material in a gap between said plurality of transparent microspheres, exposed of the predetermined area of each light emitting side of said plurality of transparent microspheres
Forming a light-absorbing layer so as to cause a flat lens. 2. The method for manufacturing a planar lens according to claim 1 , wherein the fine powdery light-absorbing material is supplied to a gap between the plurality of transparent microspheres in a non-contact manner from the supply unit. When forming the light absorption layer, the base material is disposed on a metal plate, and the light absorbing material is supplied onto a mesh screen disposed to face the base material. In this state, the metal plate and the mesh screen are supplied. A DC voltage is applied between the first and second light-absorbing materials charged to the potential of the second polarity and supplied to the electric field through the opening of the mesh screen. The method for producing a planar lens according to claim 2, wherein the surface of the adhesive layer is selectively attracted by electrostatic attraction. The method for producing a planar lens according to claim 1 , wherein a transparent adhesive layer is formed as the adhesive layer. The method for producing a planar lens according to claim 4 , wherein a transparent substrate is used as the base material. After forming the light-absorbing layer, on which, via a second transparent adhesive layer further comprises a step of laminating a second transparent substrate, a manufacturing method of the planar lens according to claim 5. Forming an electrically insulating adhesive layer on the substrate;
A plurality of transparent microspheres each having at least a surface portion each having conductivity are provided on the adhesive layer, and the plurality of the plurality of transparent microspheres are exposed so as to expose predetermined portions on the light emission side of these transparent microspheres.
Embedding the transparent microspheres in the adhesive layer to a predetermined depth;
Through an electrostatic screen having an electrostatic pattern latent image corresponding to the arrangement of the transparent microspheres, an electric field with the adhesive layer exposed between the plurality of transparent microspheres having a first polarity side,
By supplying a light absorption material in the form of fine powder charged to a potential of the second polarity, the first electrode
The surface of the adhesive layer by sucking the light-absorbing material of the second polarity onto the surface of the adhesive layer
The light absorbing material is selectively attached to the transparent microspheres, thereby filling the gaps between the plurality of transparent microspheres with the light absorbing material to expose predetermined regions on the light emission sides of the plurality of transparent microspheres.
And a step of forming a light absorption layer so as to cause the flat lens to be produced. The method for producing a planar lens according to claim 7 , wherein the fine powdery light absorbing material is supplied from a supply part thereof to the gaps between the plurality of transparent microspheres in a non-contact manner. When forming the light absorbing layer, the plurality of transparent microspheres and the adhesive layer in which these transparent microspheres are embedded are imaged and image-processed, and the resulting image pattern is charged to the second polarity. To form an electrostatic pattern latent image corresponding to the arrangement of the plurality of transparent microspheres on the photoconductive screen, and supply the light absorbing material having the second polarity through the photoconductive screen in this state. The method for producing a planar lens according to claim 8, wherein electrostatic suction is performed on the surface of the adhesive layer having the first polarity. The method for producing a planar lens according to claim 7 , wherein a transparent adhesive layer is formed as the adhesive layer. The method for producing a planar lens according to claim 10 , wherein a transparent substrate is used as the base material. After forming the light-absorbing layer, on which, via a second transparent adhesive layer further comprises a step of laminating a second transparent substrate, a manufacturing method of the planar lens according to claim 11.

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