JP4845390B2 - Light wavelength conversion film and illumination device including the same - Google Patents

Description

  The present invention relates to a light wavelength conversion film and a lighting device including the same, and particularly to a light wavelength conversion film that can be easily manufactured at low cost and can be used for various applications, and a lighting device including the light wavelength conversion film.

  Today, light emitting diodes (LEDs) and semiconductor lasers (LDs) that are excellent in energy conversion efficiency and small are being used as white light sources and illumination devices, and there are examples that have already been put into practical use.

  However, since the LED chip or the LD chip emits light corresponding to the energy band gap of the light emitting layer, white light including a wide wavelength range cannot be emitted, and light unevenly distributed within a specific wavelength range is emitted. It is common. Therefore, in order to use the LED or LD as a white light source, light within a specific wavelength range emitted from the light emitting chip must be whitened and used.

  For example, as an example of a white light source using LEDs, there is an RGB composite LED. In this case, a red (R) light-emitting chip, a green (G) light-emitting chip, and a blue (B) light-emitting chip are combined as a pair to form a white LED. An LED including such a three-primary-color light-emitting chip can emit high-purity white light and has excellent color rendering. However, each light emitting chip of RGB is manufactured using different compound semiconductor materials, and requires a complicated drive circuit in order to apply a driving voltage suitable for each.

  Therefore, Japanese Patent No. 3503139 of Patent Document 1 discloses a white LED in which a blue light emitting chip and a fluorescent material that emits yellow light upon receiving the light emitted from the blue light emitting chip are combined. That is, in this white LED, white light is obtained by a color mixture of blue light and yellow light having a complementary color relationship. Therefore, the light from this white LED has a low light intensity in the red wavelength region, and the color rendering property cannot be said to be sufficient. Moreover, the fluorescent material which can be utilized contains rare earth elements, such as Y, Lu, Sc, La, Gd, and Sm, and these are comparatively expensive rare elements.

  On the other hand, various light sources capable of emitting intense ultraviolet light have been developed today. As such an ultraviolet light source, for example, a GaN-based LED or LD, a mercury discharge tube, a gas laser device, a solid-state laser device, or the like can be used. These ultraviolet light sources are generally much more efficient at converting electrical energy into light energy than incandescent lamps.

  However, ultraviolet light cannot be recognized by the human eye and is harmful to the eyes. Therefore, in the case where ultraviolet light is converted into visible light and used, fluorescent materials are generally used conventionally. However, many conventional general and inexpensive fluorescent materials emit bluish light. The fluorescent material capable of emitting white light capable of full color display often includes rare and expensive rare earth elements.

  By the way, in recent years, organic-inorganic hybrid materials expected as materials that can be used in various technical fields have attracted attention (The 33rd JSAP School B of Non-Patent Document 1, “Organic devices and their development”). Forefront: Part 1 Materials ", published September 2, 2003, pp. 33-45, Yoshiki Nakajo" Possibility of organic-inorganic hybrid materials "(JSAP Catalog Number: AP031333)). Here, the organic / inorganic hybrid means a combination of an organic material and an inorganic material. However, it has been proposed that the mixture is nano-order or molecular order, especially organic / inorganic hybrid, in distinction from a simple mixture such as a composite material known conventionally.

  Such an organic / inorganic hybrid material can be expected to have various physical or chemical properties that cannot be obtained by either an organic polymer or an inorganic substance alone. For example, an organic / inorganic hybrid material that is flexible and excellent in mechanical strength, heat resistance, weather resistance, etc., such as plastic, can be expected. The present inventor expected that the organic / inorganic hybrid material may have special optical characteristics.

  Silica can be used as the most typical example of the inorganic component contained in the organic / inorganic hybrid material. In this case, no matter how finely the silica gel is pulverized, it is impossible to pulverize it to the molecular level. However, molecular dispersion is possible by using the sol-gel method. More specifically, the sol-gel method includes hydrolysis of silicate followed by condensation reaction of silanol groups. Therefore, an organic / inorganic hybrid material in which an organic polymer and silica gel are molecularly dispersed can be synthesized by allowing an organic polymer to coexist in such a sol-gel reaction.

FIG. 10 conceptually illustrates an example of an organic / inorganic hybrid material in which such an organic polymer and silica gel are molecularly dispersed. The organic polymer molecules are dispersed in the silica (SiO ₂ ) matrix. It shows the state.
Japanese Patent No. 3503139 The 33rd Japan Society of Applied Physics, School B, “Organic devices and the forefront of their development: Part 1 Materials”, published on September 2, 2003, pp. 33-45

  In the organic / inorganic hybrid material formed by using the sol-gel method as described above, the silica molecule and the polymer molecule are maintained by hydrogen bonds. FIG. 11 illustrates an example of the chemical structure of an organic / inorganic hybrid material in which the silica molecule and the polymer molecule are maintained by hydrogen bonds. In FIG. 11, the arrow represents a hydrogen bond.

  As is well known, hydrogen bonds are weak bonds compared to ordinary covalent bonds. Therefore, even if the organic / inorganic hybrid material by the sol-gel method has flexibility, it is considered difficult to have a sufficiently high strength, for example. Moreover, since the hydrogen bond in such an organic-inorganic hybrid material can react with water vapor | steam and oxygen in air | atmosphere, the hybrid material may deteriorate with time.

  Furthermore, since the sol-gel method is performed in a liquid, it is difficult to form an organic / inorganic hybrid film by directly applying the sol-gel method on the surface of a semiconductor electronic device or an organic electronic device. is there. When an organic / inorganic hybrid film by a sol-gel method is formed as a film, the film is generally formed by applying the obtained organic / inorganic hybrid material on a base. In that case, it is not easy to obtain sufficiently strong bondability at the interface between the substrate surface such as glass or polymer film and the organic / inorganic hybrid material. Moreover, when forming a film by the apply | coating method, it is difficult to control the film thickness by nano order.

  In view of the situation of fluorescent materials and organic / inorganic hybrid materials in the prior art as described above, the present invention provides a light wavelength conversion film that can be easily manufactured at low cost and can be used for various applications, and an illumination device including the same. It is intended to provide.

According to one aspect of the present invention, the light wavelength conversion film that converts the wavelength of received light into light of a different wavelength and radiates includes a Si-based organic / inorganic hybrid film, and the Si-based organic / inorganic hybrid film includes: It is obtained by heat synthesis that occurs by introducing a vapor of an organic compound containing Si toward a high-temperature filament, and its chemical skeleton structure contains at least carbon and silicon. The inorganic hybrid film is characterized in that it receives first light having a shorter wavelength than visible light, converts it into second light having a wavelength in the visible light range, and emits it. The chemical skeleton structure of the Si-based organic / inorganic hybrid film can further include at least one of oxygen and nitrogen.

  Such a light wavelength conversion film can emit light having a peak intensity in the green wavelength region as the second light. In addition, the second light having the peak intensity in the green wavelength region is recognized as white light as a whole by including the light intensity tail region in the short wavelength region and the long wavelength region compared to the wavelength of the peak intensity. Can be done. The second light may have a peak intensity in the blue wavelength region, and may have a peak intensity in the red wavelength region.

  The Si-based organic / inorganic hybrid film may further include a dopant for adjusting a wavelength distribution in visible light that is converted and emitted from incident light. For example, boron may be used as such a dopant, in which case the second light may have a peak intensity in the red wavelength region.

  According to another aspect of the present invention, an illumination device including the light wavelength conversion film as described above includes a light source that emits a first light having a shorter wavelength than visible light, and the first light. And the above-described Si-based organic / inorganic hybrid film disposed so as to emit second light including a wavelength within the visible light range.

  The light source can include any of a light emitting diode, a semiconductor laser element, a discharge tube, a solid state laser device, and a gas laser device. The Si-based organic / inorganic hybrid film can be formed in contact with the light emitting surface of the light source. On the other hand, the Si-based organic / inorganic hybrid film may have a plane or curved surface having a larger area than the light emitting surface of the light source. The Si-based organic / inorganic hybrid film may further include an optical component that guides light in at least one of the front part that receives the first light and the rear part that emits the second light. The lighting device as described above can also be preferably used as a backlight of a display device.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the light wavelength conversion film which can be used for various uses, and an illuminating device containing the same at low cost and simply.

  First, it is generally considered that when an organic compound is heated to a high temperature, the reaction proceeds in the direction in which the molecule decomposes. However, the present inventor introduces a vapor of an organic compound containing Si (hereinafter, also referred to as “organic Si compound”) toward a high-temperature filament, so that a synthetic reaction occurs along with a decomposition reaction. It has been found that inorganic hybrid membranes can be synthesized. Such a synthesis reaction caused by the action of the high-temperature filament is hereinafter also abbreviated as “heat synthesis” in the present specification. The present inventor has also found that the organic / inorganic hybrid film thus obtained has a light wavelength conversion function.

  The chemical mechanism of the heat synthesis of such a Si-based organic / inorganic hybrid film is not necessarily clear, but the following mechanism can be assumed. That is, the organic Si compound is considered to generate radicals by a decomposition reaction due to interaction with the high temperature filament. Then, it is presumed that a Si-based organic / inorganic hybrid film can be synthesized when these radicals react to form a stable C—Si bond.

In the usual case where a polymer is synthesized by polymerizing a monomer, a polymerization initiator is required. In the case of the synthesis of the Si-based organic / inorganic hybrid film in the present invention, hydrogen radicals generated by the interaction with the high-temperature filament, SiH _n (n = 1, 2, 3), CH _n (n = 1, 2, It can be presumed that the radical 3) has a similar effect to the polymerization initiator.

  As the organic Si compound, alkylsilane, alkoxysilane, aminosilane, or the like can be used. As examples of alkylsilanes, monomethylsilane, dimethylsilane, trimethylsilane, tetramethylsilane and the like can be preferably used. As examples of alkoxysilanes, tetraethoxysilane, dimethyldimethoxysilane and the like can be preferably used. As an example, trisdimethylaminosilane can be preferably used.

(Embodiment 1)
FIG. 1 is a schematic block diagram illustrating a film forming apparatus that can be used for forming a Si-based organic / inorganic hybrid film by heat synthesis in Embodiment 1 of the present invention. This film forming apparatus includes a reaction vessel 1 having a gas inlet 1a and an exhaust 1b. In the reaction vessel 1, a stage 4 is provided for supporting the heating filament 2 and the substrate or substrate 3 facing it. The filament 2 is connected to a power source 5 outside the reaction vessel 1. As can be seen from FIG. 1, in the heat synthesis of the first embodiment, the Si-based organic / inorganic hybrid film can be formed by a very simple and low-cost film forming apparatus.

  As a specific example of heating and synthesizing a Si-based organic / inorganic hybrid film using the film forming apparatus of FIG. 1, 10 sccm dimethylsilane gas and 364 Pa styrene vapor are placed in a reaction vessel 1 in which a substrate 3 of a silicon single crystal wafer is placed. And mixed gas was introduced. At this time, the pressure inside the reaction vessel 1 was set to 13300 Pa. When the W filament 2 was heated to 1800 ° C., a rapid synthesis reaction occurred in a short time of about 5 minutes, and a Si-based organic / inorganic hybrid film was formed on the silicon substrate 3. The crystallinity of the obtained Si-based organic / inorganic hybrid film was examined by X-ray diffraction, but no X-ray diffraction showing the crystallinity of the film was observed. That is, it is considered that an amorphous Si-based organic / inorganic hybrid film is formed in the present invention.

A curve PL-1 in the graph of FIG. 2 indicates infrared absorption in FTIR (Fourier transform infrared spectroscopy) of the Si-based organic / inorganic hybrid film obtained in the first embodiment. The horizontal axis of this graph represents the wave number (cm ⁻¹ ) of absorbed light, and the vertical axis represents light absorption (arbitrary unit). In addition, the absolute value of the vertical axis | shaft regarding the curve PL-1 does not have a special meaning, and only the relative change in the vertical axis | shaft direction of the curve has the meaning of an absorption rate change. And the peak part in the curve in a graph is a wave number part with a large infrared absorption, and has produced the absorption corresponding to a specific chemical bond. As can be seen from the representative chemical bonding examples illustrated in this graph, the obtained Si-based organic / inorganic hybrid film includes Si—C bonds, Si—CH _n (n = 1, 2, 3) bonds, and the like. Is included. Therefore, as a chemical structure of this hybrid film, in view of the composition of the raw material gas, C and Si are contained in the skeleton structure in an amorphous state, and these floating bonds (dangling bonds) are terminated by H (terminate). ) (Ie, including Si—H bonds and C—H bonds).

  A curve PL-1 in the graph of FIG. 3 indicates the PL (photoluminescence) characteristics of the Si-based organic / inorganic hybrid film obtained in the first embodiment. The horizontal axis of this graph represents the wavelength (nm) of PL light, and the vertical axis represents PL intensity (arbitrary unit). The PL characteristics were measured by irradiation with ultraviolet light having a wavelength of 325 nm from a He—Cd laser device. As can be seen from this graph, the PL light of the obtained Si-based organic / inorganic hybrid film has a peak intensity at a wavelength of 510 nm, but also includes a broad base wavelength region, so it is a little greenish. Has a characteristic of emitting substantially white PL light.

  That is, it was found that the Si-based organic / inorganic hybrid film of Embodiment 1 has a wavelength conversion function for converting ultraviolet light into visible light. And, emitting white PL light including such a wide wavelength region suggests that the hybrid film contains chemical bonds of various energy levels corresponding to its chemical structure. it is conceivable that.

  Further, the Si-based organic / inorganic hybrid film according to Embodiment 1 was left in the atmosphere for several months, but its PL emission characteristics hardly changed. This is because the Si-based organic / inorganic hybrid film according to the first embodiment is chemically very stable as compared with the conventional organic / inorganic hybrid material maintained by hydrogen bonds as shown in FIG. It is thought that it is a perfect film.

(Embodiment 2)
Similar to the first embodiment, also in the second embodiment, the Si-based organic / inorganic hybrid film was synthesized by heating using the film forming apparatus of FIG. However, in the second embodiment, a mixed gas of 10 sccm of N ₂ gas and 394 Pa of trisdimethylaminosilane vapor was introduced into the reaction vessel 1 in which the silicon single crystal wafer substrate 3 was disposed. At this time, the inside of the reaction vessel 1 was set to a pressure of 166 Pa. When the W filament 2 was heated to 2000 ° C., a rapid synthesis reaction occurred in a short time of about 5 minutes, and a Si-based organic / inorganic hybrid film was formed on the silicon substrate 3.

A curve PL-2 in the graph of FIG. 2 indicates the infrared absorptance in FTIR of the Si-based organic / inorganic hybrid film obtained in the second embodiment. As can be seen from the representative chemical bonding examples illustrated in this graph, the obtained Si-based organic / inorganic hybrid film has Si—C bonds, Si—N bonds, Si—O bonds, Si—CH _n ( n = 1, 2, 3) and the like. Note that the Si—O bond has an absorption peak at substantially the same position as Si—CH ₂ , which is considered to be caused by oxygen remaining in the reaction chamber 1. That is, as a chemical structure of the hybrid film, the skeleton structure in an amorphous state includes a C—Si bond, a Si—N bond, and a Si—O bond, and their floating bonds (dangling bonds) are H (Ie, including Si—H bonds, C—H bonds, N—H bonds, and O—H bonds).

  A curve PL-2 in the graph of FIG. 3 shows the PL characteristics of the Si-based organic / inorganic hybrid film obtained in the second embodiment, similar to the case of the first embodiment. That is, also in the measurement of the PL characteristics of the second embodiment, ultraviolet light with a wavelength of 325 nm from the He—Cd laser apparatus was irradiated. As can be seen from this graph, the PL light of the obtained Si-based organic / inorganic hybrid film has a peak intensity at a wavelength of 440 nm and also includes a relatively broad base wavelength region. That is, the Si-based organic / inorganic hybrid film of Embodiment 1 also has a wavelength conversion function for converting ultraviolet light into visible light. The emission of PL light including a relatively wide wavelength region in this way indicates that the hybrid film of Embodiment 2 also includes chemical bonds of various energy levels corresponding to the chemical structure. It seems to suggest. However, the PL light of the Si-based organic / inorganic hybrid film in Embodiment 2 is detected as bluish light based on the peak intensity at a short wavelength of 440 nm.

  Further, the Si-based organic / inorganic hybrid film according to Embodiment 2 was also left in the atmosphere for several months, but its PL emission characteristics hardly changed. This is because the Si-based organic / inorganic hybrid film according to Embodiment 2 is also chemically very stable compared to the conventional organic / inorganic hybrid material maintained by hydrogen bonding as shown in FIG. It is thought that it is a perfect film.

(Embodiment 3)
Similar to Embodiments 1 and 2, also in Embodiment 3, a Si-based organic / inorganic hybrid film was synthesized by heating using the film forming apparatus of FIG. However, in the third embodiment, in a reaction vessel 1 in which a substrate 3 of a silicon single crystal wafer is disposed, 6.7 Pa trimethoxy is added to 10 sccm monomethylsilane gas, 10 sccm N ₂ gas, and 10 sccm H ₂ gas. A mixed gas including boron vapor was introduced. At this time, the inside of the reaction vessel 1 was set to a pressure of 13.3 Pa. When the W filament 2 was heated to 2000 ° C., a Si-based organic / inorganic hybrid film was formed on the silicon substrate 3 by a synthesis reaction for about 10 minutes.

  A curve PL-3 in the graph of FIG. 2 indicates the infrared absorptance in FTIR of the Si-based organic / inorganic hybrid film obtained in the third embodiment. As can be seen from the representative chemical bonding examples illustrated in this graph, the obtained Si-based organic / inorganic hybrid film includes Si—C bonds, Si—O bonds, and the like. In other words, the chemical structure of this hybrid film also includes C—Si bonds and Si—O bonds in the skeleton structure in an amorphous state, and these floating bonds (dangling bonds) are terminated by H. (Ie, including Si—H bonds, C—H bonds, and O—H bonds).

  A curve PL-3 in the graph of FIG. 3 shows the PL characteristics of the Si-based organic / inorganic hybrid film obtained in the third embodiment, similar to the first and second embodiments. That is, also in the measurement of the PL characteristics of the third embodiment, ultraviolet light with a wavelength of 325 nm from the He—Cd laser apparatus was irradiated. As can be seen from this graph, the PL light of the obtained Si-based organic / inorganic hybrid film has a peak intensity at a wavelength of 600 nm and also includes a very wide wavelength range. That is, the Si-based organic / inorganic hybrid film of Embodiment 3 also has a wavelength conversion function for converting ultraviolet light into visible light. The emission of PL light including a very wide wavelength region in this way indicates that the hybrid film of Embodiment 3 also includes chemical bonds of various energy levels corresponding to the chemical structure. It seems to suggest. However, the PL light of the Si-based organic / inorganic hybrid film in the third embodiment is detected as reddish light based on the peak intensity at a long wavelength of 600 nm.

  Further, the Si-based organic / inorganic hybrid film according to Embodiment 3 was also left in the atmosphere for several months, but its PL emission characteristics hardly changed. This is because the Si-based organic / inorganic hybrid film according to Embodiment 3 is also chemically very stable compared to the conventional organic / inorganic hybrid material maintained by hydrogen bonding as shown in FIG. It is thought that it is a perfect film.

  Note that in the Si-based organic / inorganic hybrid films in the various embodiments as described above, even if the W filament is heated to a high temperature of 1800 ° C. or 2000 ° C., the PET (polyethylene terephthalate) film substrate It can also be formed on such an organic film substrate. That is, even when a PET film is used as the substrate 3 in the film forming apparatus of FIG. 1, the PET film substrate 3 was not thermally deformed during a short synthesis reaction. In this case, the substrate support 4 was made of stainless steel, and no cooling means was taken. The PET film has a low glass transition temperature of about 75 ° C. (in a film having an amorphous degree of about 95%), but a Si-based organic film that can be formed on an organic film having such a low glass transition temperature. The inorganic hybrid membrane is considered to be very useful industrially. Of course, since the Si-based organic / inorganic hybrid film by heat synthesis in the present invention can be formed on an organic film having a low glass transition temperature, it can be formed on a glass substrate such as quartz glass, Pyrex (registered trademark), or soda glass. Needless to say, film formation is possible.

  As exemplified in the various embodiments as described above, according to the present invention, an amorphous Si-based organic / inorganic hybrid film that contains at least C and Si and can also contain O and / or N can be easily used. And it can be formed at low cost. Such Si-based organic / inorganic hybrid films are considered to contain at least C and Si in the chemical skeleton structure and may also contain O and / or N from the results of FTIR and PL measurements.

  FIG. 4 shows, as an example, a schematic three-dimensional network of an atomic arrangement in a Si-based organic / inorganic hybrid film containing C, Si, and O in the skeleton structure. In this figure, the circles with left-sloped hatching represent Si atoms, the circles with right-sloped hatching represent O atoms, and the circles with cross-hatching represent C atoms. And white circles represent H atoms. That is, in the Si-based organic / inorganic hybrid film, the atoms of C, Si, and O form a network having a skeleton structure by covalent bonds, and the dangling bonds of these atoms are terminated by H atoms. It is done. Such a chemical structure is completely different from the structure of a conventional organic / inorganic hybrid material in which organic molecules and inorganic molecules are dispersed with each other through hydrogen bonds as shown in FIG. It will be understood.

(Embodiment 4)
In the fourth embodiment, the light wavelength conversion film obtained in the first to third embodiments is used for a white illumination device. That is, in the schematic side view of FIG. 5, an example of a white illumination device manufactured using the light wavelength conversion film according to the present invention is shown. This white illumination device includes an ultraviolet light emitting LED (or LD) 10 to which power is supplied from a lead wire 10a. Then, the light wavelength conversion film 11 obtained by the present invention is formed on the ultraviolet light emitting surface of the LED 10. Such an ultraviolet light emitting surface of the LED 10 may be, for example, a resin surface encapsulating the LED chip. As described above, since the light wavelength conversion film according to the present invention can be formed on an organic material having low heat resistance, it goes without saying that it can also be formed on the surface of such a sealing resin.

  That is, in the illuminating device of FIG. 5, the ultraviolet light radiated | emitted from LED10 is converted into the visible light 12 by the light wavelength conversion film 11, and is radiated | emitted. In that case, when only the light wavelength conversion film of Embodiment 1 is formed as the light wavelength conversion film 11, white light with a slight green color is obtained by the single layer film. On the other hand, when the light wavelength conversion films according to the first to third embodiments are stacked as the light wavelength conversion film 11, white light with high color rendering properties obtained by mixing three color lights having peak intensities in the blue, green, and red regions. can get. Needless to say, a light diffusion film may be superimposed on the light wavelength conversion film 11 if desired.

  The schematic cross-sectional view of FIG. 6 shows another example of a white illumination device manufactured using the light wavelength conversion film according to the present invention. This white illumination device includes an ultraviolet light emitting discharge tube 20 to which power is supplied from a terminal 20a to a coil filament 20b. As such an ultraviolet light emitting discharge tube, for example, a mercury discharge tube can be used. A light wavelength conversion film 21 obtained by the present invention is formed on the ultraviolet light emitting surface of the discharge tube 20 (usually the surface of a glass tube).

  That is, also in the illumination device of FIG. 6, ultraviolet light emitted from the discharge tube 20 is converted into visible light 22 by the light wavelength conversion film 21 and emitted. Even in this case, when only the light wavelength conversion film of Embodiment 1 is formed as the light wavelength conversion film 21, white light having a slightly greenish color can be obtained by the single layer film. On the other hand, when the light wavelength conversion films of Embodiments 1 to 3 are stacked as the light wavelength conversion film 21, white light with high color rendering properties is obtained by mixing three color lights having peak intensities in the blue, green, and red regions. can get. Needless to say, if desired, a light diffusion film may be superimposed on the light wavelength conversion film 21. Furthermore, instead of the light diffusion film, the surface of the glass discharge tube 20 may be polished and formed into a glass shape. The light wavelength conversion film according to the present invention can be formed on a surface of any shape with good bonding properties, and can be formed on a fine uneven surface of polished glass with good adhesion.

  In the above example, a white light emitting device in which the light wavelength conversion film of the present invention is applied to an ultraviolet light emitting semiconductor light emitting device and a discharge tube has been described. Needless to say, it is also possible to produce a white illumination device by applying the light wavelength conversion film of the present invention on the radiation surface.

(Embodiment 5)
Also in the fifth embodiment, the light wavelength conversion film obtained in the first to third embodiments is used for the white illumination device. That is, in the schematic side view of FIG. 7, still another example of the white illumination device manufactured using the light wavelength conversion film according to the present invention is shown. This white illumination device includes a plurality of ultraviolet light emitting LEDs (or LDs) 30 arranged in an array. Then, a light wavelength conversion film 32 obtained by the present invention is formed on one main surface of a glass substrate (or an acrylic substrate or the like) 31 so as to face the arrayed LEDs 30. Then, if desired, a light diffusion film 33 is formed on the other main surface of the glass substrate 31. It goes without saying that such a light diffusion film 33 may be laminated on the light wavelength conversion film 32.

  Also in the illumination device of FIG. 7, ultraviolet light 34 emitted from the arrayed ultraviolet light emitting LED (or LD) 30 is converted into visible light by the light wavelength conversion film 32, and visible light is transmitted through the light diffusion film 33. Radiated as 35. Even in this case, when only the light wavelength conversion film of the first embodiment is formed as the light wavelength conversion film 32, white light having a slight green color is obtained by the single layer film. On the other hand, when the light wavelength conversion films of Embodiments 1 to 3 are stacked as the light wavelength conversion film 32, white light with high color rendering properties obtained by mixing three color lights having peak intensities in the blue, green, and red regions. can get.

  Needless to say, a plurality of ultraviolet light discharge tubes may be arranged instead of the arrayed LED, and a plurality of solid state laser devices or gas laser devices emitting ultraviolet light may be arranged. Further, the glass substrate (or acrylic substrate or the like) 31 does not have to be a flat substrate, and may be an arbitrarily curved substrate if desired. That is, the light wavelength conversion film of the present invention can be formed on any curved surface with good bonding properties. Furthermore, instead of the light diffusion film 33, the surface of a glass substrate (or an acrylic substrate or the like) 31 may be polished into a glass shape. In the illuminating device as shown in FIG. 7, the light wavelength conversion film 32 itself acts as a planar light source of visible light, so that an observer recognizes a plurality of ultraviolet light sources 30 arranged behind the light source. Therefore, it can be perceived as a uniform planar light emitting lighting device.

(Embodiment 6)
Also in the sixth embodiment, the light wavelength conversion film obtained in the first to third embodiments is used for the white illumination device. That is, the schematic side view (or cross-sectional view) of FIG. 8 shows still another example of the white illumination device manufactured using the light wavelength conversion film according to the present invention. The white illumination device includes a light guide plate 42 having a substantially rectangular shape made of glass (or acrylic). A plurality of ultraviolet light emitting LEDs (or LDs) 40 are arranged in a line along one side surface of the outer periphery of the light guide plate 42, and the light wavelength conversion film 43 of the present invention is formed on the side surface. On the other side and bottom of the light guide plate 42, a reflective metal film 45 such as an Ag film or an Al film is formed. Further, if desired, a light diffusion film 46 is formed on the upper surface of the light guide plate 42. In such an illuminating device, the ultraviolet light 41 emitted from the LED 40 is converted into visible light 44 by the light wavelength conversion film 43, guided by the light guide plate 42, and then converted into visible light 47 through the light diffusion film 46. Radiated. Even in this case, when only the light wavelength conversion film of Embodiment 1 is formed as the light wavelength conversion film 43, white light having a slightly greenish color can be obtained by the single layer film. On the other hand, when the light wavelength conversion films according to the first to third embodiments are stacked as the light wavelength conversion film 43, white light having high color rendering properties obtained by mixing three color lights having peak intensities in blue, green, and red regions. can get.

  Instead of the plurality of LEDs arranged in a line, elongated ultraviolet light discharge tubes may be arranged along the side surface of the light guide plate 42, and a plurality of solid-state laser devices and gas laser devices that emit ultraviolet light are provided. Needless to say, they may be arranged along the side surface of the light guide plate 42. Further, instead of the light diffusion film 46, the upper surface of the light guide plate 42 may be polished glass. Furthermore, it goes without saying that the light wavelength conversion film 43 may be formed not on the side surface of the light guide plate 42 but on the upper surface thereof. In that case, the light wavelength conversion film 42 and the light diffusion film 46 can be laminated.

  Since the white illumination device as shown in FIG. 8 can be formed as a planar light source with a small thickness, it can be preferably used as a backlight of a liquid crystal display device, for example.

  The schematic side view (or cross-sectional view) of FIG. 9 shows a lighting device in which a part of the lighting device of FIG. 8 is changed. That is, in FIG. 9 and FIG. 8, the same reference numerals indicate the same or corresponding parts. In the illuminating device of FIG. 9, a columnar (or prismatic) light guide column 51 made of glass (or acrylic or the like) is disposed along one side surface of the light guide plate 42. Most of the outer periphery of the light guide column 51 is covered with a reflective metal film 52 such as an Ag film or an Al film, and the reflective metal film 52 includes a line-shaped opening 52a. An LD 50 that emits ultraviolet light, a solid-state laser device, a gas laser device, or the like is disposed on at least one end of the light guide column 51.

  The ultraviolet light injected from the LD into the light guide column 51 is introduced into the light guide plate 42 as visible light 44 through the line-shaped openings 52 a and the light wavelength conversion film 43. The illumination device as shown in FIG. 9 is preferable in the case of converting into a planar white light source by using a powerful single ultraviolet light source 50, and such a planar illumination device is also used as a liquid crystal backlight. It can be preferably used.

  As described above, according to the present invention, it is possible to provide a light wavelength conversion film that can be easily manufactured at low cost and can be used for various applications, and an illumination device including the same.

It is a typical block diagram which shows an example of the film-forming apparatus which can be utilized for the formation method of Si type organic / inorganic hybrid film | membrane by this invention. It is a graph which shows the infrared absorption factor in FTIR of the Si type organic and inorganic hybrid film | membrane obtained by this invention. It is a graph which shows the PL characteristic of the Si type organic and inorganic hybrid film | membrane obtained by this invention. It is a model figure which shows an example of the chemical structure of Si type | system | group organic / inorganic hybrid film | membrane obtained by this invention. It is a typical side view which shows an example of the white illuminating device using the light wavelength conversion film obtained by this invention. It is typical sectional drawing which shows the other example of the white illuminating device using the light wavelength conversion film obtained by this invention. It is a typical side view which shows the further another example of the white illuminating device using the light wavelength conversion film obtained by this invention. It is a typical side view which shows the further another example of the white illuminating device using the light wavelength conversion film obtained by this invention. It is a typical side view which shows the further another example of the white illuminating device using the light wavelength conversion film obtained by this invention. It is a schematic diagram which shows an example of the dispersion | distribution state of the organic molecule in the conventional Si type organic and inorganic hybrid material. It is a figure which shows an example of chemical formula containing the hydrogen bond between an organic molecule and silica in the conventional Si type organic and inorganic hybrid material.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Reaction container, 1a Gas introduction port, 1b Exhaust port, 2 Heating filament, 3 Substrate, 4 Support stand, 5 Power supply for heating filament, 10 Ultraviolet light emitting LED or LD, 10a terminal, 11 Light wavelength conversion film, 12 Visible light, 20 UV light discharge tube, 20a terminal, 20b coil filament, 21 light wavelength conversion film, 22 visible light, 30 UV light emitting LED or LD, 31 substrate such as glass or acrylic, 32 light wavelength conversion film, 33 light diffusion film, 34 UV light, 35 visible light, 40 UV light emitting LED or LD, 41 ultraviolet light, 42 light guide plate, 43 light wavelength conversion film, 44 visible light, 45 reflective metal film, 46 light diffusion film, 47 visible light, 50 ultraviolet light emission LD, 51 Columnar light guide, 52 Reflective metal film, 52a Line-shaped opening.

Claims (14)

An optical wavelength conversion film that converts the wavelength of received light into light of a different wavelength and emits it,
The optical wavelength conversion film includes a Si-based organic / inorganic hybrid film, and the hybrid film is obtained by heat synthesis generated by introducing a vapor of an organic compound containing Si toward a heating filament. The skeleton structure contains at least carbon and silicon,
The Si-based organic / inorganic hybrid film receives first light including a shorter wavelength than visible light, converts the first light into second light including a wavelength within the visible light range, and emits the first light. An optical wavelength conversion film characterized by:   The light wavelength conversion film according to claim 1, further comprising at least one of oxygen and nitrogen in the chemical skeleton structure.   3. The light wavelength conversion film according to claim 1, wherein the second light has a peak intensity in a green wavelength region. 4.   4. The second light according to claim 3, wherein the second light includes a tail region of light intensity in a short wavelength region and a long wavelength region as compared with the wavelength of the peak intensity, and can be recognized as white light as a whole. Light wavelength conversion film.   3. The light wavelength conversion film according to claim 1, wherein the second light has a peak intensity in a blue wavelength region. 4.   3. The light wavelength conversion film according to claim 1, wherein the second light has a peak intensity in a red wavelength region. 4.   The light according to claim 1, wherein the Si-based organic / inorganic hybrid film further includes a dopant for adjusting a wavelength distribution in the second light converted from the first light. Wavelength conversion film.   The optical wavelength conversion film according to claim 7, wherein the dopant is boron. An illumination device comprising the light wavelength conversion film according to claim 1 or 2,
A light source that emits the first light;
An illumination device comprising: the Si-based organic / inorganic hybrid film disposed to receive the first light and emit the second light.   The lighting device according to claim 9, wherein the light source includes any one of a light emitting diode, a semiconductor laser element, a discharge tube, a solid-state laser device, and a gas laser device.   The lighting device according to claim 9 or 10, wherein the Si-based organic / inorganic hybrid film is formed in contact with a light emitting surface of the light source.   The illumination device according to claim 9 or 10, wherein the Si-based organic / inorganic hybrid film has a plane or curved surface having a larger area than the light emitting surface of the light source.   The Si-based organic / inorganic hybrid film further includes an optical component that guides light in at least one of a front part that receives the first light and a rear part that emits the second light. Item 11. The lighting device according to Item 9 or 10.   The lighting device according to claim 9, wherein the lighting device is incorporated as a backlight of a display device.

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