JP2007156032A - Rear projection type screen, rear projection type display apparatus, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rear projection type screen and a rear projection type display apparatus of high quality, and to provide a manufacturing method thereof. <P>SOLUTION: The rear projection type screen 1 includes a fresnel lens sheet 10, and a lenticular lens sheet 20 that comes in point-contact or linear-contact with the fresnel lens sheet 10 while facing the fresnel lens sheet 10, and that is stuck to the fresnel lens sheet 10 through the contact parts. The sticking area where the fresnel lens sheet 10 is stuck to the lenticular lens sheet 20 is set to 1 to 60% of the whole effective area of the screen 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rear projection screen, a rear projection display device, and a manufacturing method thereof.

  2. Description of the Related Art Conventionally, there is a rear projection type projection television as an apparatus for observing an image by enlarging and projecting an image from a video projection device on a screen from the back. A rear projection type television uses a rear projection type screen, and this rear projection type screen has a configuration in which two sheets of a Fresnel lens sheet and a lenticular lens sheet are overlapped. Therefore, various problems occur when vibration is applied to the two lens sheets during transportation of the rear projection type projection television.

For example, in a rear projection screen, a flawed lens sheet and a lenticular lens sheet that are stacked on each other collide with each other or rub against each other, thereby causing a scratch defect. In particular, since the tip of the Fresnel lens has a sharp serrated shape and the opposing lenticular lens has a bowl-like convex shape, a problem that the tip of the Fresnel lens breaks the lenticular lens is likely to occur. When the above damage problem occurs during the transportation of the projection television, resin powder is observed at the tip of the lenticular lens. Therefore, in the present invention, such a scratch defect is particularly called white powder.
The Fresnel lens sheet may be formed of a transparent resin substrate and a lens portion made of an ultraviolet curable resin such as a urethane acrylate resin. The urethane acrylate resin has a high elastic modulus at a low temperature. Therefore, when the opposing Fresnel lens and the lenticular lens collide, the white powder problem becomes prominent, especially at low temperatures.
In order to prevent this scratch defect, a method of applying a silicone oil or a fluorine-based lubricant to the lens surface has been proposed. Patent Document 1 discloses a technique for preventing scratch defects by controlling the Young's modulus of a Fresnel lens and a lenticular lens.

Further, when the lens sheet is deformed by being affected by humidity change, temperature change, etc., the distance between the lens sheets changes. At the same time, a difference occurs in the optical path book depending on the position in the sheet surface, which causes deterioration of the focus of the screen.
A technique for preventing this focus deterioration is disclosed in Patent Document 2. In the technique disclosed in Patent Document 2, a light transmissive member is provided between the Fresnel lens sheet and the lenticular lens sheet. As a result, the amount of change in the distance between sheets can be reduced and focus deterioration can be prevented.

Patent Document 3 discloses a technique for adhering a Fresnel lens sheet and a lenticular lens sheet (lenticular plate) as in Patent Document 2. In the rear projection type screen disclosed in Patent Document 3, the Fresnel lens sheet and the lenticular lens sheet are joined together by a line-shaped adhesive portion arranged at a predetermined interval in the vertical direction. Concave surfaces are formed at the upper and lower end portions that serve as the boundary surface between the joint and air. Therefore, in this rear projection type screen, the lenticular lens sheet diffuses light in the left-right direction, and the line-shaped adhesive portion diffuses light in the up-down direction at the upper and lower ends thereof. As a result, the viewing angle in the vertical direction as well as in the horizontal direction is expanded.
JP 2002-196422 A JP 2002-139800 A Japanese Patent Laid-Open No. 6-210761

As described above, the conventional rear projection screen has a problem in that it deteriorates due to an external influence because the two lens sheets are overlapped.
The present invention has been made in view of such problems, and an object thereof is to provide a high-quality rear projection type screen, a rear projection type display device, and a manufacturing method thereof.

  The rear projection screen according to the present invention has a first lens sheet having a lens surface having a lens formed on at least one surface thereof, and a point contact or a line contact in a state of facing the lens surface of the first lens sheet, A rear projection screen including a second lens sheet bonded to the first lens sheet at the contacted portion, wherein the first lens sheet and the second lens sheet are bonded together The area is 1% or more and 60% or less with respect to the entire effective area of the screen.

  Preferably, the bonding area is 3% or more and 40% or less with respect to the entire effective area of the screen.

  Furthermore, the first lens sheet has a first lens portion, the second lens sheet has a second lens portion, and the second lens sheet has the second lens portion described above. The first lens sheet is bonded to the first lens sheet in a state of facing the first lens portion.

  Furthermore, the first lens sheet has a first lens part, the second lens sheet has a second lens part and a flat surface facing the second lens part, The second lens sheet is bonded to the first lens sheet with the flat surface facing the first lens portion.

  Preferably, the first lens sheet is a Fresnel lens sheet, and the second lens sheet is a lenticular lens sheet.

  On the other hand, a rear projection screen according to the present invention includes a Fresnel lens sheet and a lenticular lens sheet disposed in a state of being opposed to the Fresnel lens sheet and having a lenticular lens portion disposed on one side. The top of the lenticular lens part is in contact with the surface of the Fresnel lens lens sheet parallel to the surface on which the lenticular lens part is disposed, and the lenticular lens sheet is in contact with the Fresnel lens. An air layer is interposed between the lenticular lens sheet and the Fresnel lens sheet in a portion other than the contacted portion that is bonded to the sheet.

  Furthermore, the Fresnel lens sheet has a Fresnel lens part on one side where the top of the lenticular lens part contacts, and is bonded to the lenticular lens sheet at the contacted part.

  Preferably, the bonding area between the Fresnel lens sheet and the lenticular lens sheet is 1% or more and 60% or less with respect to the entire effective area of the screen.

  More preferably, the bonding area is not less than 3% and not more than 40% with respect to the entire effective area of the screen.

  The rear projection display device according to the present invention includes such a rear projection screen.

  A manufacturing method of a rear projection type screen according to the present invention is a method of manufacturing a rear projection type screen having a first lens sheet and a second lens sheet made of plastic, the first lens being A step of causing the sheet and the second lens sheet to face each other and superimposing them in a point contact or line contact state, and a step of irradiating the superimposed second lens sheet with an energy ray having an energy of 4 eV or more And a step of subjecting the surface of the second lens sheet to a modification process by irradiation of the energy beam, and a step of bonding the first lens sheet and the second lens sheet. .

  Preferably, the first lens sheet is made of plastic, and in the step of irradiating the energy beam, the energy beam is irradiated to the first lens sheet together with the second lens sheet, and the modification is performed. In the quality treatment step, the surface of the first lens sheet is subjected to a modification treatment.

  The manufacturing method of the rear projection type display device according to the present invention includes a step of manufacturing a rear projection type screen by such a manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, a high quality rear projection type screen, a rear projection type display apparatus, and its manufacturing method can be provided.

Hereinafter, the best mode for carrying out the present invention will be described.
Embodiment 1 of the Invention
First, the configuration of a rear projection screen according to the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a configuration example of a rear projection type screen according to the present invention, and FIG. 2 is a schematic view showing a cross section taken along line AA ′ in FIG.
As shown in FIG. 1, the rear projection screen 1 includes a Fresnel lens sheet 10, a lenticular lens sheet 20, and a diffusion plate 30. A Fresnel lens sheet 10, a lenticular lens sheet 20, and a diffusion plate 30 are sequentially arranged from the image light projection side to the image light emission side.

  As shown in FIG. 2, the Fresnel lens sheet 10 is an example of a first lens sheet that has, for example, a sheet shape and is made of plastic. This Fresnel lens sheet 10 has a Fresnel lens portion 12 on one surface of a base material 11, and the Fresnel lens portion 12 is constituted by a sawtooth shaped Fresnel lens having a sharp tip. The Fresnel lens portion 12 is uneven toward the image light emission side.

The lenticular lens sheet 20 is an example of a second lens sheet that has, for example, a sheet shape and is made of plastic. The lenticular lens sheet 20 has a lenticular lens portion 22 on one side of a base material 21, and the lenticular lens portion 22 is formed of a bowl-shaped convex lenticular lens. The lenticular lens portion 22 is uneven toward the image light projection side. Accordingly, the lenticular lens portion 22 of the lenticular lens sheet 20 faces the Fresnel lens portion 12 of the Fresnel lens sheet 10.
The light shielding layer 23 that blocks light is arranged in parallel on a flat surface opposite to the lens surface of the lenticular lens portion 22 and is formed in a non-condensing region where video light does not pass.

As will be described later, the plastic used in the lens sheets 10 and 20 does not have tackiness or adhesiveness in advance, and has tackiness or adhesiveness when irradiated with energy rays. Therefore, examples of the plastic constituting the lens sheets 10 and 20 include polyamide, polyester, other engineering plastics, polyolefin, styrene resin, vinyl resin, and cellulose resin, but are limited to those exemplified above. It is not a thing. Further, an alloy or a blended product in which various plastics or fillers are dispersed may be used.
The diffusion plate 30 is laminated on the surface of the light shielding layer 23 via an adhesive or pressure sensitive adhesive for optical use.

In the rear projection screen 1 according to the present invention, the two lens sheets 10 and 20 are in point contact or line contact at the tops of the lens portions 12 and 22 in a state of being overlaid. Further, these lens sheets 10 and 20 are fixed at the contact portions that are in point contact or line contact. In other words, the lens tops of both lens sheets are bonded at the contact portion.
The lens sheets 10 and 20 only need to be bonded at the contact portion, and not only all the contact portions but also only a part of the contact portions may be bonded. Here, when each lens part 12 and 22 contacts, it shows that it is contacting substantially, and a contact part contains the part which adjoined so that each lens part 12 and 22 may contact.

  The rear projection type screen 1 according to the present invention has a non-contact portion that is not in contact with the lens portions 12 and 22 of both lens sheets 10 and 20 in addition to the contact portion of the top portion that is in point contact or line contact. This non-contact part is a part which is recessed in the concave shape of each lens part 12 and 22, and is not contacting. Such a non-contact portion is not fixed unlike the contact portion. That is, an air layer is interposed in the non-contact portion where the lens sheets 10 and 20 are not fixed.

In the rear projection type screen 1 according to the present invention, the two lens sheets 10 and 20 are locally bonded at the top of the lens in point contact or line contact. On the other hand, generally, these lens sheets 10 and 20 are uniformly bonded over the entire effective screen surface.
Specifically, the bonding area of the lens sheets 10 and 20 is 1% or more with respect to the entire effective area of the screen in order to secure the adhesion between the lens sheets 10 and 20 and to maintain the lens characteristics. It is preferable that it is 60% or less.

  When the bonding area is less than 1%, the adhesion is low, and both lens sheets 10 and 20 are peeled off due to the influence of temperature change, humidity change, vibration, etc., which is not preferable. Further, if the bonding area is larger than 60%, the refraction angle of the lenticular lens portion 22 of the lenticular lens 20 is lowered, so that the required horizontal viewing angle characteristics cannot be obtained. In this case, more light rays are absorbed by the black stripe 23, and the total light transmittance is lowered. Therefore, it is not preferable that the bonding area is larger than 60%.

  Further, the bonding area is preferably 3% or more and 40% or less with respect to the entire effective area of the screen. If the bonding area is less than 3%, the adhesion cannot be increased, and both lens sheets 10 and 20 may be peeled off due to the influence of temperature change, humidity change, vibration, etc., which is not preferable. Further, if the bonding area is larger than 40%, it is difficult to maintain the refraction angle of the lenticular lens portion 22 of the lenticular lens 20, so that the required horizontal viewing angle characteristics cannot be obtained. Furthermore, in this case, the amount of light absorbed by the black stripe 23 increases, and it is difficult to maintain a high total light transmittance. Therefore, it is not preferable that the bonding area is larger than 40%.

  In the case of a refractive Fresnel lens sheet, the Fresnel lens surface and the lenticular lens surface are bonded together. Therefore, 3% or more and 15% or less are more preferable from the viewpoint of maintaining the optical characteristics of the Fresnel lens. Furthermore, in the case of a Fresnel lens sheet of the total reflection type that has been attracting attention in recent years, it is preferably 3% or more and 40% or less from the viewpoint of improving the adhesion because no bonding is performed on the Fresnel lens surface. This is because the deterioration of the optical characteristics of the lens due to bonding is small and the bonding area can be increased.

Then, the manufacturing method of the rear projection type screen 1 which concerns on this invention is demonstrated.
In the present invention, the overlapped lens sheets 10 and 20 are bonded together by a so-called excimer process. The bonding method using the excimer process is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2002-268383 and 2002-268383 previously filed by the applicant of the present invention.
Specifically, the surfaces of the lens sheets 10 and 20 are not sticky or adhesive in advance in a state before being irradiated with energy rays. When such lens sheets 10 and 20 are irradiated with energy rays having an energy of 4 eV or more, the lens sheets 10 and 20 having no tackiness or adhesiveness exhibit tackiness or adhesiveness. Accordingly, the tops of the lens portions 12 and 22 of the lens sheets 10 and 20 can be bonded without using an adhesive means such as an adhesive.

  The energy ray used here is an energy ray such as an ultraviolet ray, an electron beam, or an ion beam, and its energy needs to be 4 eV or more, and preferably 7 eV or more. Among these, laser sources such as excimer laser, Ar + laser, Kr + laser, N2 laser, etc .; D2 lamp, high pressure mercury lamp, low pressure mercury lamp, Xe lamp, Hg-Xe lamp, halogen lamp, excimer lamp Or an ultraviolet lamp such as a discharge lamp obtained by arc, corona or silent discharge in air, nitrogen or other gas atmosphere. Among these, ultraviolet lamps such as D2 lamp, high pressure mercury lamp, low pressure mercury lamp, Xe lamp, Hg-Xe lamp, halogen lamp, and excimer lamp are preferably used from the viewpoint of balance of energy, intensity, irradiation range, and the like.

The energy rays may be applied to only one of the lens sheets 10 and 20 made of a plastic to be bonded, or both of the lens sheets 10 and 20 may be applied. Moreover, it is possible to irradiate different energy rays on the bonding surfaces of the lens sheets 10 and 20 or to irradiate them in different atmospheres.
Further, the temperature at which the lens sheets 10 and 20 are bonded is desirably normal temperature, but the lens sheets 10 and 20 may be bonded in a heated state at a temperature at which the lens sheets 10 and 20 do not exhibit tackiness or adhesiveness. Furthermore, it is possible to shorten the irradiation time of the energy beam by heating the lens sheets 10 and 20 before and / or during the energy beam irradiation.

  At the time of energy beam irradiation, the plastic surface can be brought into contact with the atmosphere, at least one gas of oxygen, nitrogen, ozone, water vapor, ammonia, or a mixed gas thereof, but is limited to the above gas Is not to be done. Furthermore, when the energy beam is irradiated, the plastic surface contains any one of water, hydrogen peroxide, ammonia, alcohols, organic acids and derivatives thereof, nitriles, nitro compounds, amines, and sulfur compounds. Although it is possible to make it contact with a liquid, it is not limited to the said liquid.

  Irradiation of energy rays to the plastic surface is performed in an atmosphere containing air, oxygen, ozone or water vapor, or in an atmosphere containing gaseous organic matter such as ammonia or hydrazine, or in an organic solvent such as water, hydrogen peroxide, alcohol or amines. Can be done. In this case, a hydroxyl group, an amino group, a carbonyl group is formed on the plastic surface due to the ability to cut the C—H bond, C—C bond, etc. on the plastic surface and the carbon component, oxygen component, nitrogen component, moisture, etc. in the atmosphere. It is preferable because functional groups such as carboxyl groups are formed and the hydrophilicity of the plastic surface is increased.

  Depending on conditions such as the energy beam irradiation atmosphere and irradiation time, the cutting of plastic C—H bonds and C—C bonds further proceeds. Then, oligomers, low molecular compounds, etc. are formed on the surface or surface irregularities are formed, and the tackiness and adhesiveness are more effectively expressed. The conditions at this time vary depending on the constituent materials of the lens sheets 10 and 20 and the type of energy beam.

  As described above, in the rear projection type screen 1 according to the present invention, both the lens sheets 10 and 20 are bonded together by the contact portion. Even when the lens sections 10 and 20 of the lens sheets 10 and 20 are shipped in a state of being overlapped so as to face each other, the two lens sheets 10 and 20 vibrate during transportation, so that There is no collision and no friction. Therefore, it is possible to prevent crushing (stain) at the top of the lens of the Fresnel lens sheet 10 and to obtain the rear projection type screen 1 in which scratch defects at the top of the lens of the lenticular lens sheet such as white powder are suppressed. it can.

  In the rear projection screen 1 according to the present invention, the top portions of the lens portions 12 and 22 that are in point contact or line contact are bonded. Therefore, the location and area where the lens sheets 10 and 20 are bonded can be suppressed to a range where the lens action does not substantially change. In particular, since both lens sheets 10 and 20 are bonded together in a relatively narrow area of 1% or more and 60% or less with respect to the entire clean effective area, the high-quality back surface in which the effect on the lens action due to this bonding is reduced. The projection type screen 1 can be realized.

  Furthermore, since both the lens sheets 10 and 20 are fixed, it is possible to reduce the amount of change in which the distance between the lens sheets 10 and 20 changes due to humidity change, temperature change, and the like. Therefore, it is possible to suppress the focus deterioration, and it is possible to realize the high quality rear projection screen 1 in which both the scratch defect and the focus deterioration are suppressed. Furthermore, by bonding both lens sheets 10 and 20, the rigidity of the sheet increases and the rear projection screen 1 can be easily handled.

  In the present invention, the lens sheets 10 and 20 are preferably made of plastic, but the lens sheets 10 and 20 made of a material other than plastic, such as glass, ceramics, wood, and metal (including alloys). It is also applicable to. When the plastics are bonded together, the same material plastic may be used, but different materials may be used.

  In addition, the present invention is not limited to a sheet-like material such as the lens sheets 10 and 20, but can be applied to various forms such as a film, a fiber, and a resin molded product having the lens portions 12 and 22. Further, it is not always necessary to have a form as a final product, and the shape is arbitrary. The bonding surface in the present invention is not limited to a flat surface, and the shape thereof is arbitrary.

Embodiment 2 of the Invention
In the first embodiment, the case where the lens sheets 10 and 20 are overlapped so that the lens portions 12 and 22 face each other has been described. However, the present invention is not limited to this.
FIG. 3 shows a configuration example of a rear projection type screen according to the second embodiment. As shown in FIG. 3, the Fresnel lens sheet 10 can be bonded in a state where the Fresnel lens part 12 faces the opposite side of the lenticular lens part 22 of the lenticular lens sheet 20. In this case, the top of the lenticular lens portion 22 of the lenticular lens sheet 20 is in point contact or line contact with the flat surface on the back surface of the Fresnel lens sheet 10. The top part of the lenticular lens part 22 is bonded to the back surface of the Fresnel lens sheet 10 in this state. At this time, as in the first embodiment, bonding can be performed by excimer processing. Here, the back surface of the Fresnel lens sheet 10 is a surface on the opposite side to the Fresnel lens portion 12 and is the back surface of the substrate 11.
Thus, when the top part of the lenticular lens part 22 of the lenticular lesbian sheet 20 is bonded to a flat surface, it can be attached in a more stable state.

Other Embodiments of the Invention
In the first and second embodiments, bonding is performed by excimer processing, but the present invention is not limited to this, and bonding can be performed using a transparent adhesive or the like.
As described above, when the lens portions 12 and 22 are simply bonded with an adhesive (including an adhesive), the difference between the refractive index of the adhesive and the refractive index of the lens is reduced. Therefore, the lens action changes, and the original lens action cannot be exhibited. As in Embodiments 1 and 2, paying attention to the location and area to be bonded, the apexes of the lens portions 12 and 22 are bonded by line contact or point contact by excimer processing. Accordingly, the first and second embodiments can be suppressed to a range in which the lens action does not substantially change compared to the present embodiment.

It is a perspective view which shows one structural example of the rear projection type screen which concerns on this invention. It is a cross-sectional schematic diagram which shows one structural example of the rear projection type screen which concerns on this invention. It is a cross-sectional schematic diagram which shows one structural example of the rear projection type | mold screen which concerns on this invention.

Explanation of symbols

1 ... rear projection type screen, 10 ... Fresnel lens sheet,
20 ... Lenticular lens sheet, 30 ... Diffusion plates 11, 21 ... Base material, 12 ... Fresnel lens part, 22 ... Lenticular lens part,
23 ... Light shielding layer

Claims (13)

A first lens sheet having a lens surface having a lens formed on at least one side;
A rear projection screen comprising a point contact or a line contact in a state of facing the lens surface of the first lens sheet, and a second lens sheet bonded to the first lens sheet at the contacted portion. Because
The rear projection type screen in which a bonding area between the first lens sheet and the second lens sheet is 1% or more and 60% or less with respect to the entire effective area of the screen.   The rear projection screen according to claim 1, wherein the bonding area is 3% or more and 40% or less with respect to the entire effective area of the screen. The first lens sheet has a first lens portion,
The second lens sheet has a second lens portion;
3. The back surface according to claim 1, wherein the second lens sheet is bonded to the first lens sheet in a state where the second lens portion faces the first lens portion. Projection type screen. The first lens sheet has a first lens portion,
The second lens sheet has a second lens portion and a flat surface facing the second lens portion,
3. The rear projection screen according to claim 1, wherein the second lens sheet is bonded to the first lens sheet with the flat surface facing the first lens unit. 4. . The first lens sheet is a Fresnel lens sheet,
3. The rear projection type screen according to claim 1, wherein the second lens sheet is a lenticular lens sheet. A Fresnel lens sheet,
A rear projection screen provided with a lenticular lens sheet disposed in a state facing the Fresnel lens sheet and having a lenticular lens portion disposed on one side,
The top of the lenticular lens portion is in contact with the surface of the Fresnel lens lens sheet parallel to the surface on which the lenticular lens portion is disposed,
The lenticular lens sheet is bonded to the Fresnel lens sheet at the contacted part,
A rear projection screen in which an air layer is interposed between the lenticular lens sheet and the Fresnel lens sheet in a portion other than the contacted portion.   The rear projection according to claim 6, wherein the Fresnel lens sheet has a Fresnel lens part on one side where a top part of the lenticular lens part contacts, and is bonded to the lenticular lens sheet at the contacted part. Mold screen.   8. The rear projection type screen according to claim 6, wherein a bonding area between the Fresnel lens sheet and the lenticular lens sheet is 1% or more and 60% or less with respect to the entire effective area of the screen. .   The rear projection type screen according to claim 8, wherein the bonding area is 3% or more and 40% or less with respect to the entire effective area of the screen.   A rear projection display device comprising the rear projection screen according to claim 1. A method of manufacturing a rear projection screen having a first lens sheet and a second lens sheet made of plastic,
The first lens sheet and the second lens sheet are opposed to each other and superposed in a point contact or line contact state;
Irradiating the superimposed second lens sheet with energy rays having energy of 4 eV or more;
A step of modifying the surface of the second lens sheet by irradiation with the energy beam;
A method of manufacturing a rear projection screen, comprising: bonding the first lens sheet and the second lens sheet. The first lens sheet is made of plastic,
In the step of irradiating the energy beam, the energy beam is irradiated to the first lens sheet together with the second lens sheet,
The method for manufacturing a rear projection screen according to claim 11, wherein in the step of performing the modification process, a modification process is performed on a surface of the first lens sheet.   A method for manufacturing a rear projection display device, comprising a step of manufacturing a rear projection screen by the manufacturing method according to claim 11.

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