JP2006237563A - Surface emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface emitting device capable of radiating ultraviolet rays for mainly exciting a photocatalyst by utilizing the features of back light; and moreover provide a compact and thin surface emitting device functioning as a filter allowing the transmission of a fluid by utilizing the features of the back light. <P>SOLUTION: A light emitting surface has a light source and a light guide plate with this light source arranged on the side, and at least one of the surface or the back of this light guide plate radiates light from the light source. In a surface emitting device, the faces of the light guide plate other than the light emitting surface and the side with the light source arranged are formed as light shielding surfaces. The surface emitting device radiates the light having a peak wavelength of 388 nm or less, or has the light guide plate formed as a porous body. The surface emitting device may have the light guide plate having a plurality of through holes and the light emitting surface that is the face forming the through holes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a device capable of converting a point light source or a line light source having a visible light or ultraviolet light emission function into a surface light source. In addition, the visible light or ultraviolet light converted into a surface light source is used to directly sterilize or decompose organic matter, or the photocatalyst is excited by emitted light to decompose or sterilize harmful substances. The present invention relates to a surface emitting device, and further to a filtration filter using the same.

A conventional hazardous substance decomposing apparatus using a photocatalyst, such as a conventional air cleaner, has a photocatalytic sheet formed by supporting a material having a photocatalytic function such as TiO ₂ on a porous body, and a linear light source or a point light source such as a mercury lamp or a light emitting diode. The photocatalyst is excited by irradiating with ultraviolet rays emitted from.
However, in the case of a point light source or a line light source, the entire device size becomes large because light cannot be applied to the entire photocatalyst sheet unless it is installed at an appropriate distance from the photocatalyst sheet. In the case of a liquid with high turbidity, there is also a problem that light from the light source attenuates before reaching the photocatalyst.

  On the other hand, a method of exciting a photocatalyst using a surface light emitter as a light source has been considered (see Patent Document 1). This excites a photocatalyst using an inorganic EL phosphor sheet emitting short-wavelength visible light to ultraviolet light as a light source. For example, two sheets are stacked, and harmful components in the fluid existing between them are decomposed and removed by photocatalytic action. However, in this structure, in order to process a large amount of fluid, it is necessary to increase the number of stacked layers and create a large number of flow paths, and the apparatus itself becomes very large.

  In contrast to these methods, the light emitter and the electrode itself have a porous structure, and when the fluid passes through the porous body, the porous body itself emits ultraviolet rays, and the photocatalyst supported in the porous body decomposes organic matter, or A ceramic filter having a function of sterilizing bacteria and viruses has been invented (see Patent Document 2). The luminous body is obtained by slightly sintering semiconductor particles.

However, this method has the following problems.
(1) Advanced technology is required to control the pore size and porosity of the porous light emitting layer. In particular, when used for air purification, etc., where high permeability is required, it is necessary to increase the pore size and porosity, and it is necessary to use semiconductor particles having a large particle size. Decreases. Moreover, it is difficult to obtain a light emitting layer having a high porosity by the method of sintering powder.
(2) Since the electrode is formed on the surface of the porous body by sputtering or vapor deposition, the cost increases.
(3) When a liquid, particularly a highly conductive liquid, is allowed to pass through the inside of the porous light emitting layer, an electric field cannot be efficiently applied unless the particles, electrodes, and the like constituting the porous light emitting layer are completely insulated. In some cases, this insulation process requires advanced techniques. In particular, when the constituent particle size is reduced, a more advanced technique is required and costs are increased.
(4) Inorganic EL devices generally emit light by applying an AC electric field of 100 V or higher and a frequency of several hundreds to several thousand Hz. End up.

  There is a backlight light source of a liquid crystal display as a product that converts an LED or a mercury lamp having high emission intensity into a surface light source. In this method, light from a light source is once guided to a light guide plate on a plane, and further extracted in a direction perpendicular to the surface of the light guide plate. The extracted light passes through the liquid crystal and becomes a display. The light source is disposed below or on the side of the light guide plate, but is often placed on the side for a compact and thin backlight.

However, conventional backlights are limited to liquid crystal panels, and are limited to those that emit visible light centered on white light. In particular, since liquid crystals are deteriorated by ultraviolet rays, they are limited to those that do not emit ultraviolet rays as much as possible (see Patent Document 3).
JP 2003-200043 A PCT / WO 2004/006969 JP 2002-133930 A

  The present invention provides a surface-emitting device that can emit ultraviolet light mainly for exciting a photocatalyst by utilizing the characteristics of a backlight. Furthermore, the present invention provides a compact and thin surface emitting device that functions as a filter that allows fluid to pass through by utilizing the characteristics of the backlight.

As a method for solving the above problems, the inventor has invented a thin surface emitting device having a unique structure. That is, the present invention has the following configuration.
(1) A light source and a light guide plate having the light source disposed on a side surface, and at least one of the front surface or the back surface of the light guide plate is a light emitting surface that emits light from the light source, A surface-emitting device characterized in that a surface other than a side surface on which a light source is disposed is formed as a light-shielding surface and emits light having a peak wavelength of 388 nm or less.

(2) a light source and a light guide plate having the light source disposed on a side surface, and at least one of a front surface or a back surface of the light guide plate is a light emitting surface that emits light from the light source, A surface emitting device characterized in that a surface other than a side surface on which a light source is disposed is formed as a light shielding surface, and the light guide plate is formed as a porous body.
(3) The surface emitting device according to (2), wherein the light guide plate formed as the porous body has a through-hole penetrating the front surface and the back surface.

(4) The surface light-emitting device according to any one of (1) to (3), wherein the light guide plate has a flat plate shape or a curved shape.
(5) The surface emitting device according to (3), wherein a plurality of light guide plates having a predetermined shape are disposed with a predetermined gap interval, and the gap is a through hole. Surface emitting device.

(6) The surface emitting device according to any one of (2) to (5), wherein the surface emitting device emits light having a peak wavelength of 540 nm or less.
(7) The surface emitting device according to (6), wherein the surface emitting device emits light having a peak wavelength of 420 nm or less.
(8) The surface emitting device according to (7), wherein the surface emitting device emits light having a peak wavelength of 388 nm or less.
(9) The surface emitting device according to any one of (1) to (8), wherein the surface emitting device emits light having a peak wavelength in a range of 355 to 375 nm.

(10) The surface emitting device according to any one of (1) to (9), wherein the light source is an LED.
(11) The surface light emitting device according to any one of (1) to (9), wherein the light source is an inorganic EL, wherein the light source is a cold cathode fluorescent lamp. The surface emitting device according to any one of (1) to (9)

(13) The surface-emitting device according to any one of (1) to (12), wherein a photocatalyst or a porous body carrying the photocatalyst is disposed on the light-emitting surface of the light guide plate.
(14) The surface-emitting device according to (13), wherein the distance between the light guide plate and the photocatalyst or the porous body carrying the photocatalyst is zero.
(15) The surface according to (13), wherein at least one of a diffusion sheet and a light collecting sheet is disposed between a light emitting surface of the light guide plate and a photocatalyst or a porous body supporting the photocatalyst. Light emitting device.
(16) The surface-emitting device according to any one of (13) to (15), wherein the photocatalyst is rutile titanium oxide.

(17) A light source and a light guide plate having the light source disposed on a side surface thereof are formed, and a plurality of through holes penetrating from the front surface to the back surface are formed so that fluid can pass through the light guide plate, and the through holes are formed. A surface-emitting device, wherein the surface is a light-emitting surface that emits light from a light source.
(18) The surface emitting device according to (17), wherein a surface other than the side surface on which the light emitting surface and the light source are arranged is formed as a light shielding surface.

(19) A filtration filter using the surface-emitting device according to any one of (2) to (18).
(20) An air cleaner or air conditioner filter using the filtration filter according to (19).
(21) A liquid purification filter using the filtration filter according to (19).

  The present invention is a device having a light source and a light guide plate on which the light source is disposed on the side surface, and capable of converting a line or point light source such as a mercury lamp or LED, particularly an LED that is a point light source, into a surface light source. By selecting the wavelength, a compact and thin surface emitting device having various functions can be obtained. Furthermore, by making the light guide plate have a porous structure, it also functions as a filter through which fluid can pass, and by combining it with a photocatalyst, it can be used as a filter for an air cleaner or the like.

The surface emitting device of the present invention will be described in detail.
The surface-emitting device of the present invention includes a light source and a light guide plate having the light source disposed on a side surface, and at least one of the front surface or the back surface of the light guide plate is a light-emitting surface that emits light from the light source. A surface emitting device characterized in that a surface other than the light emitting surface of the light plate and the side surface on which the light source is disposed is formed as a light shielding surface, and emits light having a peak wavelength of 388 nm or less;
Alternatively, the light source includes a light source and a light guide plate having the light source disposed on a side surface, and at least one of the front surface and the back surface of the light guide plate is a light emitting surface that emits light from the light source, and the light emitting surface of the light guide plate and the light source The surface light emitting device is characterized in that a surface other than the side surface on which is disposed is formed as a light shielding surface, and the light guide plate is formed as a porous body.

The light emitted from the light source installed on the side surface of the light guide plate passes through the inside of the light guide plate, but is partially reflected by the uneven pattern formed on at least one surface of the light guide plate or the back surface. And radiated to the outside in a substantially vertical direction.
When the emission wavelength of the light emitted from the light guide plate is 388 nm or less, the ability to sterilize and decompose organic substances is enhanced. Further, ultraviolet rays having a wavelength close to 365 nm can cure the ultraviolet curable resin. In addition, by disposing a photocatalyst on the light emitting surface, a surface light emitting device having a function of exciting the photocatalyst by radiant light and decomposing and sterilizing harmful substances can be obtained.

Further, if a plurality of through holes penetrating from the front surface to the back surface of the light guide plate and allowing the fluid to pass therethrough are formed, and the fluid is circulated so as to pass through the through holes, it can function as a kind of filter.
For example, if a porous layer (photocatalyst sheet) having a photocatalyst is placed on both surfaces of a double-sided (front and back) luminescent type surface emitting device, the contaminated fluid is transmitted in a direction perpendicular to the surface of the photocatalyst sheet. It can always contact the photocatalyst efficiently. The light emitted from the front and back surfaces of the light guide plate is not necessarily emitted only in the direction perpendicular to the front surface of the light guide plate, but spreads at a certain angle, so that it is only directly above the light emitting surface where no through hole is formed. In addition, the photocatalyst located immediately above the through hole can be excited. The fluid makes the most efficient contact with the photocatalyst directly above the through hole. Accordingly, it is preferable that the size of the through hole is small, and a diameter of about 5 mm is the upper limit with a high effect. If it is too small, the pressure loss during fluid permeation will increase. The lower limit with high effect is several tens of μm. The shape of the through hole is not limited.
When the fluid permeates, a heat dissipation effect that releases heat generated when the light guide plate generates heat can be exhibited.

On the other hand, in the present invention, visible light or ultraviolet light emitted from the light guide plate can be concentrated in the through hole.
In the light guide plate, a surface other than the side surface on which the light source is arranged and the surface serving as the surface of the through hole is used as a light shielding surface, and light from the light source is radiated from the surface serving as the surface of the through hole. be able to.
In a device in which photocatalysts are arranged on the front and back surfaces of the light guide plate, it is clear that the fluid passes mainly in the part of the photocatalyst directly above the flow path (through hole), and the light is condensed on this part. Thus, the most efficient photocatalytic performance can be exhibited. In the case of such a structure, the size of the lattice serving as the flow path does not need to be 5 mm or less. This is because light concentrates on the flow path.

  These surface light-emitting devices can be made extremely thin by arranging the light source on the side surface of the light guide plate, and by arranging the photocatalyst on the light emitting surface of the light guide plate, and can efficiently cause a catalytic reaction. it can. For example, when installed as a filter for an air cleaner or an air conditioner, the photocatalytic performance equivalent to or higher than that of a conventional mercury lamp directly irradiated to the photocatalyst is used. Can be realized with a marked decrease. In particular, even in the case of a polluted fluid that absorbs ultraviolet rays that cannot be processed by an external light source such as a mercury lamp, the light-emitting surface that is the light source of the photocatalyst is located in the immediate vicinity of the photocatalyst.

The photocatalyst sheet is a porous material with high porosity, such as resin, that bears photocatalyst powder such as titanium oxide. However, when the sheet thickness increases, it becomes difficult to transmit light. It is preferable to irradiate each photocatalyst with light by halving the thickness.
Accordingly, in the present invention, when irregularities are formed on both sides (front and back) of the light guide plate, light is emitted on both sides, so by installing a photocatalytic sheet on both sides of the light guide plate, it is higher than one side. Photocatalytic performance is developed.

  When the distance between the light guide plate and the photocatalyst or the porous body carrying the photocatalyst is zero, the photocatalyst can be excited most efficiently. When the photocatalyst sheet is excited with an external light source such as a mercury lamp, it is necessary to install an external antigen away from the photocatalyst sheet surface when irradiating light to a certain area. In this case, the light emitted from the light source A part of the light is reflected on the surface of the photocatalyst sheet and cannot excite the photocatalyst, resulting in energy loss. On the other hand, in this invention, by arrange | positioning a photocatalyst just above or directly under the light emission surface of a light-guide plate, all the light radiated | emitted from the light-guide plate can be confined in a photocatalyst sheet, and a photocatalyst can be excited.

In the light guide plate having a through hole according to the present invention, instead of forming the through hole in the light guide plate, a plurality of light guide plates having various shapes are arranged with a predetermined gap interval, and the gap is a flow path (through hole). The structure may be a hole).
A structure that is easy to manufacture is a structure in which strip-shaped light guide plates are arranged with gaps at regular intervals.

  In the present invention, at least one of a diffusion sheet and a light collecting sheet may be disposed on the surface of the light emitting surface of the light guide plate. The diffusion sheet has an effect of spreading light emitted from the light guide plate to the outside in a uniform manner, and can uniformly irradiate the photocatalyst with light. The condensing sheet is used to narrow the emission angle of the light emitted from the light guide plate. For example, it is effective when the distance between the light guide plate and the photocatalyst is long and the area is the same. Demonstrate. This is not necessary when the photocatalyst sheet is disposed immediately above the light emitting surface of the light guide plate.

  The diffusion sheet is formed from a transparent resin such as acrylic resin (PMMA), polycarbonate (PC), or cycloolefin polymer. The diffusion sheet has a minute uneven surface and serves to spread light like a wide light cone.

  When a visible light responsive photocatalyst is used as the photocatalyst, the surface emitting device preferably emits light having a peak wavelength of 540 nm or less. Beyond this, the photocatalytic performance cannot be fully exhibited. It is preferable to emit ultraviolet rays having a peak wavelength of 420 nm or less because rutile type titanium oxide having high photocatalytic activity can be excited. More preferably, the peak wavelength of the emission spectrum is preferably 388 nm or less. Below this wavelength, anatase titanium oxide, which has high photocatalytic activity and is inexpensive as in rutile titanium oxide, can be excited most efficiently. Further, when the wavelength of ultraviolet light is 365 nm, the application range of the present invention is further expanded. The 365 nm ultraviolet ray is most widely used as an ultraviolet ray for curing an ultraviolet curable resin, and is also a wavelength preferred by insects, and can be used in a insect collecting apparatus. These effects are high when the emission peak wavelength of the surface light emitter device is in the range of 355 to 375 nm. When the wavelength of ultraviolet rays is 300 nm or less, bacteria and viruses can be sterilized without using a photocatalyst. Most preferably, the wavelength is 240 to 280 nm.

The light source can be a CCFL (Cold Cathode Fluorescent Lamp) or the like, and has a linear line shape, an ellipse (L) shape, a U-shape, etc., and direct light enters the light guide plate from the incident portion of the light guide plate. To do. The light source is not limited to a linear CCFL, and may be an array having semiconductor light emitting elements arranged as a linear light source. Further, the light source may be constituted by a semiconductor light emitting element such as an LED or a laser. The light source may be a mercury lamp such as a cold cathode fluorescent tube, but it is preferable to use a green, blue, or ultraviolet LED in order to reduce the space occupied by the light source. When the above-described point light source or line light source is used as the light source, it can be converted into a surface light source. Moreover, you may use the direct current | flow type inorganic electroluminescent surface emitting body which expresses high light intensity. In the case where the surface light emitter is used as the light source, light can be applied to the entire area of the side surface of the light guide plate, so that there is an advantage that the light intensity uniformity on the light emitting surface is increased.
Although the light source may need to be slightly separated from the side surface depending on the shape of the light source, it is preferable to arrange the light source as close as possible to the side surface of the light guide plate because the space occupied by the light source is small.

FIG. 1 shows an example (first structure) of a specific structure of a surface emitting device in which a through hole of the present invention is formed. In FIG. 1, (a) is a side view and (b) is a perspective view.
The surface light emitting device of FIG. 1 has a plurality of strip-shaped light guide plates in which a front surface and a back surface are light emitting surfaces, and a surface other than the side surface on which the light emitting surface and the light source are disposed is formed as a light shielding surface. A porous layer (photocatalyst sheet) having a photocatalyst is arranged on the light emitting surface of the light guide plate. The fluid to be treated flows in from the surface of one porous body layer, passes through the gap between the light guide plates, and is discharged through the opposite porous body layer. Visible light or ultraviolet light emitted from the light guide plate can be incident on the photocatalyst sheet to excite the photocatalyst. The fluid that has passed through the porous layer on one side passes through the gap between the light guide plates, and is finally discharged as a clarified fluid through the porous layer on the other side. As the area occupied by the gap of the light guide plate with respect to the entire area of the upper surface (front surface) or the lower surface (back surface) of the light guide plate (herein referred to as the flow path area ratio) is higher, the fluid transmission characteristics are improved. As a result, the porous body having the photocatalyst is not uniformly irradiated with light, or the luminance is lowered. As a guideline, the channel area ratio is preferably 30% to 70% of the whole.

  Moreover, the surface emitting device from which the light radiated | emitted from the light source is discharge | released from the side surface used as the through-hole is, for example, the surface of the strip-shaped light-guide plate arranged at fixed intervals as described in FIG. It can be obtained by using the back surface and the side surface facing the light source as a light shielding surface. The front and back surfaces can be made light-shielding surfaces by a method such as forming irregularities on the front and back surfaces of the light guide plate or forming a metal reflector on the front and back surfaces. Moreover, the said surface can be made into a light-shielding surface by giving a metal coating etc. to the side surface facing a light source.

  The 2nd structure of the surface emitting device in which the through-hole of this invention was formed is a structure where the through-hole was arrange | positioned at the grid | lattice form, as shown in FIG. This structure is easier to manufacture than the first structure. Further, the through hole may be formed in an elongated slit shape. (The photocatalyst is omitted in FIG. 2)

It is preferable that the formation pattern of the through holes serving as the flow paths has a structure that does not hinder the progress of light emitted from the light source as much as possible. For example, as shown in FIGS. 3A and 3B, a flow path is formed radially around the light source, or a flow path is formed radially as shown in FIG. A pattern in which the light source is arranged so that the light from the light directly reaches can be considered, but this is only an example.
Instead of forming the through hole in the light guide plate, the light guide plate itself may be a porous body or a porous body having communication holes. It can be said that the light guide plate in which the through holes are formed is a kind of porous body.

In the present invention, at least one of the front surface and the back surface is a light emitting surface, the light source is disposed on the side surface, and the light emitting surface and the surface other than the side surface on which the light source is disposed are the light shielding surface, and guides light from the light source to the light emitting surface. Is provided with light deflecting elements on the surfaces facing each other in order to perform total reflection on the front surface portion and the back surface portion of the light guide plate to advance and emit in the surface directions of the front surface portion and the back surface portion facing each other. Further, it can be realized by providing a light deflecting element for performing total reflection on one of the surfaces of the rear surface and proceeding in the direction of the opposing surface. In this structure, there is a case where the emission angle from the light guide plate is large in the emitted light from the light guide plate (output along the surface of the light guide plate), but the photocatalytic sheet is disposed directly above the light emitting surface of the light guide plate. If there is no problem in particular.
When the distance between the light guide plate and the photocatalyst sheet is large, a diffusion sheet or a light collecting sheet may be disposed on the surface of the light guide plate.
In the present invention, the light guide plate is not limited to a flat plate shape, and may have a curved shape, for example, a cylindrical shape (see FIG. 3C).

In the present invention, the light shielding surface refers to a surface other than the light emitting surface except for the side surface on which the light source is disposed, and can be used as a light shielding surface by adding irregularities or coating a metal thin film. There is no particular limitation on the metal used for thin film coating, and any metal may be used. For example, gold, aluminum, copper, etc. are mentioned.
Further, the side surface on which the light source is arranged can be metal-coated except for the portion where light enters.

  An example using the light deflection element of the surface emitting device of the present invention is shown in FIG. The surface light-emitting device in FIG. 4 includes a light source that supplies light to the light guide plate, and a convex or concave prism that emits light existing inside the light guide plate to both the front surface portion and the back surface portion. It comprises a light guide plate in which light deflection elements made of dots or the like are provided on each of the front surface portion and the back surface portion. Although the light deflecting element has been described here as an arc-shaped convex shape or concave shape, other shapes such as an elliptical arc, a cone, a cylinder, a polygonal pyramid, and a polygonal column can be used as the surface portion of the light guide plate. Randomly provided on the back surface, or pillow-shaped convex portions or concave light deflecting elements having a circular or polygonal cross section may be provided continuously or discontinuously. In addition, even when the light deflecting element has a convex shape or concave shape such as an elliptical arc, a cone, a cylinder, a polygonal pyramid, a polygonal column, etc., the same operation and effect as the above-described configuration are obtained, and the description is duplicated. Omitting.

  Further, as shown in FIG. 5, the light guide plate is formed by continuously or concentrically placing pillow-shaped convex portions or concave light deflecting elements having an arc-shaped or polygonal cross section on both sides or one side of the front surface portion and the back surface portion. It is good also as a structure provided discontinuously. In the example of FIG. 5, in order to provide the light source at the corner with respect to the light guide plate, the light deflection element is provided at a concentric position centering on the light source so as to face the light source. In addition, a storage portion for storing the light source in the light guide plate is integrally formed at the corner (side surface) of the light guide plate. Then, a light source is inserted into the storage portion to achieve mechanical stability.

The light guide plate is formed of a transparent acrylic resin, methacrylic resin (PMMA), polycarbonate (PC), or the like. The light guide plate has at least one of the side surface portions as an incident portion, and has a light deflection element on the front surface portion and / or the back surface portion (the front surface portion and the back surface portion in the example of FIG. 4).
Transparent acrylic resin, methacrylic resin (PMMA), and polycarbonate resin have their transmittance drastically decreased when the wavelength of light is 400 nm or less and 350 nm or less, respectively. (PC) is preferred. When an amorphous cycloolefin-based polymer is used, an ultraviolet ray having a wavelength of 300 nm is transmitted through about 60%, so that it is most preferable for a light guide plate as an ultraviolet light emitting device.

  As the photocatalyst disposed on the light emitting surface of the light guide plate, a photocatalytic sheet can be used. The photocatalyst sheet is obtained by supporting a photocatalyst on a porous substrate, and a foamed metal, a foamed ceramic, a resin woven fabric, or the like can be used for the porous substrate. These materials have high porosity and excellent permeation performance. Moreover, the surface emitting device of this invention can also be set as the laminated structure where the light-guide plate and the photocatalyst sheet were laminated | stacked repeatedly.

  The surface emitting device in which the through-hole of this invention was formed can also be used as a filtration filter. For example, relatively large particles such as particles floating in the air are physically collected on the surface of the photocatalyst sheet having the photocatalyst, and small particles are decomposed by the photocatalyst in the process of passing through the photocatalyst sheet. Therefore, the more reliable the laminated structure of the light guide plate and the porous body, the more reliable the filter is. However, there is a disadvantage that the transmission performance is lowered.

  Of the products of the present invention, when ultraviolet light having a peak wavelength of 388 nm or less is emitted, it functions as an ultraviolet surface light source without drilling.

When the filtration filter of the present invention is used as a filter for an air cleaner, a filter for an air conditioner, or the like, the thinner the device, the better. As a guideline, the thickness of the surface emitting device is 1 mm or less.
Since the catalytic reaction container using the surface light emitting device of the present invention can decompose organic substances and sterilize bacteria, NOx, SOx, CO gas, diesel particulates, pollen, dust, mites that become pollutants in the atmosphere Decomposition and removal of organic compounds, decomposition and removal of organic compounds in sewage, sterilization light sources such as general bacteria and viruses, decomposition of harmful gases generated in chemical plants, decomposition of odorous components such as acetaldehyde and formaldehyde, ultrapure water It can be applied to various fields such as sterilization light source in manufacturing equipment. It can also be applied to honeycomb materials for automobile exhaust gas treatment, filters for air purifiers / air conditioners, sewage filtration filters, various water purifiers, hot spring disinfection, and insect repellents.

Example 1
(1) Constituent member Light guide plate: 100 × 100 × 1 mm size Methacrylic resin (PMMA), polycarbonate resin (PC), ring-opening metathesis polymer hydrogenated polymer (HROP: amorphous cycloolefin polymer) sheet, light deflected by press Elements were formed concentrically.
Through holes having a diameter of 1 mm were formed in the light guide plate at a pitch of 1 mm.
2. Light source: LEDs with various emission peak wavelengths
Peak wavelength 365nm, output 2.4mW
Peak wavelength 380nm, output 2.4mW
Peak wavelength 465nm, output 20mW
Peak wavelength 535nm, output 20mW

(2) Assembly Eleven LEDs were mounted on one side of the light guide plate at 10 mm intervals. The light source part was sealed with moisture resistant resin. On the side surface of the light guide plate, Al was deposited to a thickness of 0.2 μm except for the light source part.
As described above, a surface emitting device was obtained in which the light source was disposed on the side surface, the surface was the light emitting surface, and the side surface on which the light source was disposed and the surface other than the surface were the light shielding surface.

(3) Photocatalyst sheet Anatase TiO ₂ average particle size 0.03 μm (commercially available)
TiO ₂ : S Average particle size 0.03 μm
Thiourea (CH ₄ N ₂ S) powder and Ti (OC ₃ H ₇ ) ₄ were mixed in ethanol and concentrated under reduced pressure until a white slurry was formed. Thereafter, it was baked in the atmosphere at 588 ° C. for 2 hours to obtain a powder. The doping amount of S was 2 at% with respect to oxygen.
A liquid in which various photocatalyst particles were dispersed in alcohol was prepared, and after dipping the porous fluororesin, it was pulled up and heated in the atmosphere at 230 ° C. for 0.5 hr to support the photocatalyst particles. This was repeated 10 times.

(4) Photocatalyst performance evaluation 1500cm < ³ > of 100ppm aqueous solution of the methylene blue which is 1 type of pigment | dye was produced. A filter was obtained by laminating a photocatalytic sheet on the light guide plate after the above-described LEDs were attached.
Each LED was circulated while being filtered with a filter as shown in FIG. 6 while emitting light at 4V. The time until the concentration of the methylene blue solution reached 90 ppm was measured. The concentration was measured by chemical analysis. The emission intensity of the surface light emitting device was measured in advance using an illuminometer in the air.
An experiment was also conducted when the surface emitting device was not perforated. Further, as a comparative example, a lamp in which 11 LEDs of the same kind were arranged was manufactured, and an experiment was performed in which only the photocatalyst sheet was irradiated as an external light source from the outside of the quartz glass container. The distance between the light source and the photocatalyst sheet was 90 mm.
The results are shown in Table 1.

  The shorter the emission wavelength, the shorter the reaction time. The reaction time was long with an external light source. This is presumably because light is absorbed in the solution and hardly reaches the photocatalyst. The reaction time was shortened by circulating. This is thought to be because the photocatalyst and methylene blue come into efficient contact by circulation.

Example 2
(1) Constituent member Light guide plate: 100 × 100 × 5 mm size An optical deflection element was formed by pressing on one side of an Asahi Kasei Delpet (560MF, PMMA) sheet having the shape shown in FIG. The light deflection element was designed so that both sides of the light guide plate emit light. A slit-like through hole having the shape shown in FIG. 7 was formed in the light guide plate by machining.
2. light source:
(LEDs with various emission peak wavelengths)
Peak wavelength 365nm, output 2.4mW
Peak wavelength 410nm, output 7.4mW
(External light source)
Black light with a peak wavelength of 365 nm and an output of 7 W

(2) Assembly On the two side surfaces in the long axis direction of the slit-shaped through holes of the light guide plate, 10 LEDs were attached on the upper side of one side surface and 10 on the lower side of the other side surface, for a total of 20 LEDs. At this time, the LED was installed so as to face the light guide plate between the slit-shaped through holes. The light source part was sealed with moisture resistant resin. On the side surface of the light guide plate, Al was deposited to a thickness of 0.2 μm except for the light source part.
As described above, a surface emitting device was obtained in which the light source was disposed on the side surface, the front surface and the back surface were light emitting surfaces, and the surface other than the side surface, the front surface, and the back surface on which the light source was disposed was a light shielding surface.

(3) Photocatalyst sheet anatase TiO ₂ average particle size 0.03 μm (Taika MT-600)
Rutile TiO ₂ : Average particle size 0.03 μm (Ishihara Sangyo MPT-623)
A liquid in which various photocatalyst particles were dispersed in alcohol was prepared, and after dipping the porous fluororesin, it was pulled up and dried at room temperature to obtain a photocatalyst sheet.

(4) Photocatalytic performance evaluation One or two surface emitting devices were installed on a quartz glass desiccator. Using a microsyringe, acetaldehyde gas was injected into the desiccator until the concentration reached 20 ppm. The concentration was measured with a multi-gas monitor.
The photocatalyst sheet was adhered to the front surface (upper surface) of the light guide plate or the front surface and back surface (upper and lower surfaces).
Each LED was circulated while allowing gas to pass through the photocatalytic sheet as shown in FIG. The time until the concentration of acetaldehyde gas reached 10 ppm was measured, and from this result, the average decomposition rate was calculated. The light emission intensity of the light guide plate was measured in advance using an illuminometer without a photocatalytic sheet.

As a comparative example, as shown in FIG. 8 (a), black light was used as an external light source, and the decomposition rate was measured at various light illuminances.
The results are shown in Table 2.

It can be seen that the rutile photocatalyst used has an activity comparable to that of the anatase photocatalyst. When the surface emitting device of the present invention was used, high photocatalytic performance was exhibited as compared with an external light source. This is presumably because all of the light emitted from the light guide plate contributes to the photocatalytic reaction because the light guide plate and the photocatalytic sheet are in close contact. On the other hand, when an external light source is used, it is considered that only a part of the emitted light contributes to the photocatalytic reaction and is not efficient.
It can be seen that the photocatalytic performance increases when the photocatalytic sheets are installed on the upper and lower surfaces of the light guide plate. Further, it was found that when the light guide plate is laminated, the photocatalytic performance is further increased.
Thus, in the case of using a light guide plate, by alternately laminating a plurality of photocatalysts and light guide plates, there is a feature that a photocatalyst having a large surface area can be installed in an extremely thin space. It has been found to be optimal for air cleaning devices.

The surface light emitting device of the present invention includes NOx, SOx, CO gas, diesel particulates, pollen, dust, mites, and the like, which are pollutants in the atmosphere, decomposition and removal of organic compounds contained in sewage, general bacteria It can be applied to various fields such as sterilization of viruses, decomposition of harmful gases generated in chemical plants, decomposition of odorous components, etc. Moreover, as a product kind, it can expand | deploy to all the filters of the said field | area, and it can apply also to air purification, sewage filtration, various water purifiers, insect repellents, etc.
In addition, it can be used for a light source for fixing toner used in a digital photo printer for a digital camera, a light source for curing an ultraviolet curable resin, and the like. In addition, when utilizing the property that insects prefer to collect ultraviolet rays having a wavelength centered on 365 nm, it can be used as a sheet-like insect collecting panel, which is effective in preventing malaria.

It is a figure which shows an example of the structure of the surface emitting device which formed the through-hole of this invention. (A) is a side view, (b) is a perspective view. It is a figure which shows the other example of the structure of the surface emitting device which formed the through-hole of this invention. It is a figure which shows the other example of the structure of the surface emitting device which formed the through-hole of this invention. It is a figure which shows an example of the structure of the surface emitting device of this invention. It is a figure which shows the structure of the light-guide plate of this invention. 1 is a schematic diagram of an apparatus used in the photocatalytic evaluation of Example 1. FIG. It is a figure which shows the shape of the light-guide plate used in Example 2. FIG. 6 is a schematic diagram of an apparatus used in the photocatalyst evaluation of Example 2. FIG.

Claims (21)

A light source;
It has a light guide plate with this light source arranged on the side,
At least one of the front surface or the back surface of the light guide plate is a light emitting surface that emits light from a light source,
Surfaces other than the light emitting surface of the light guide plate and the side surface on which the light source is disposed are formed as light shielding surfaces,
A surface-emitting device that emits light having a peak wavelength of 388 nm or less. A light source;
It has a light guide plate with this light source arranged on the side,
At least one of the front surface or the back surface of the light guide plate is a light emitting surface that emits light from a light source,
Surfaces other than the light emitting surface of the light guide plate and the side surface on which the light source is disposed are formed as light shielding surfaces,
A surface light-emitting device, wherein the light guide plate is formed as a porous body.   The surface light-emitting device according to claim 2, wherein the light guide plate formed as the porous body has a through-hole penetrating the front surface and the back surface.   The surface light-emitting device according to claim 1, wherein the light guide plate has a flat shape or a curved shape.   The surface emitting device according to claim 3, wherein a plurality of light guide plates having a predetermined shape are arranged with a predetermined gap interval, and the gap is a through hole.   The surface emitting device according to any one of claims 2 to 5, wherein the surface emitting device emits light having a peak wavelength of 540 nm or less.   The surface emitting device according to claim 6, wherein the surface emitting device emits light having a peak wavelength of 420 nm or less.   The surface emitting device according to claim 7, wherein the surface emitting device emits light having a peak wavelength of 388 nm or less.   The surface emitting device according to any one of claims 1 to 8, wherein the surface emitting device emits light having a peak wavelength in a range of 355 to 375 nm.   The surface light-emitting device according to claim 1, wherein the light source is an LED.   The surface light-emitting device according to claim 1, wherein the light source is an inorganic EL.   The surface emitting device according to claim 1, wherein the light source is a cold cathode fluorescent lamp.   The surface-emitting device according to claim 1, wherein a photocatalyst or a porous body carrying the photocatalyst is disposed on the light-emitting surface of the light guide plate.   The surface emitting device according to claim 13, wherein a distance between the light guide plate and the photocatalyst or the porous body carrying the photocatalyst is zero.   The surface emitting device according to claim 13, wherein at least one of a diffusion sheet and a light collecting sheet is disposed between the light emitting surface of the light guide plate and a photocatalyst or a porous body supporting the photocatalyst.   The surface emitting device according to any one of claims 13 to 15, wherein the photocatalyst is rutile titanium oxide. A light source;
It has a light guide plate with this light source arranged on the side,
A plurality of through holes penetrating from the front surface to the back surface are formed so that fluid can pass through the light guide plate,
A surface-emitting device characterized in that the surface on which the through hole is formed is a light-emitting surface that emits light from a light source.   The surface emitting device according to claim 17, wherein a surface other than the side surface on which the light emitting surface and the light source are arranged is formed as a light shielding surface.   The filtration filter using the surface emitting device as described in any one of Claims 2-18.   An air cleaner or air conditioner filter using the filtration filter according to claim 19.   A liquid purification filter using the filtration filter according to claim 19.