JP7546342B2 - Lighting fixtures - Google Patents

Description

The present invention relates to a lighting fixture, particularly a lighting fixture equipped with a light-emitting element such as an LED. The lighting fixture here broadly means any lighting fixture that emits visible light. For example, in the case of an LED lighting fixture, it is not limited to an LED lighting fixture equipped with a power supply unit that converts AC from a commercial power source into DC for lighting the LED, but also includes an LED module that is only a light-emitting unit without a power supply unit, and its form is not limited to a hard case in which LED light-emitting elements are arranged in a hard case, but includes a flexible type in which LED light-emitting elements are arranged in a soft case or tube, and the arrangement of LED elements is not limited to a linear shape, but also includes a circular ring shape or a random arrangement. Furthermore, the form of the lighting fixture includes various shapes according to various mounting objects such as ceilings, walls, floors, trees, exterior walls of buildings, shelves of product display shelves, showcases, etc. Therefore, for example, it may be in the form of a ceiling-embedded downlight, and its shape may be various shapes such as a circle, a rectangle, an ellipse, etc.
Furthermore, the present invention is not necessarily limited to lighting fixtures equipped with LED light-emitting elements, but can also be applied to lighting fixtures equipped with other types of light-emitting elements as long as they contribute to solving the problems that are the objective of the invention described below.

In recent years, LED lighting fixtures equipped with LED modules that incorporate a large number of LED elements have become widespread, and are used, for example, by attaching them to the underside of shelves of product display shelves or inside showcases to illuminate products. Alternatively, interior lighting fixtures are also known in which an LED lighting fixture embedded in the floor illuminates the room from the floor surface. Such long LED lighting fixtures are widely known, and there are many patent applications related to this type of device. For example, Patent Document 1.
The light emitted from the LED light-emitting elements of the LED lighting fixtures used for these various purposes is basically visible light (400 to 800 nm), but it also contains near-ultraviolet and near-infrared rays, so long-term irradiation can cause discoloration or fading of the irradiated object due to the near-ultraviolet rays, and the near-infrared rays can cause the irradiated object to deteriorate due to heat or drying caused by the heat. This problem cannot be overlooked in display shelves and showcases for clothing and ornaments, or in art galleries and museums, as it reduces the value of the products and exhibits. The same is true for food showcases.

To solve this problem, it is conceivable to provide a filter that cuts near-ultraviolet and near-infrared rays, but according to the inventors' research, it has been found that when such a cut filter is used, the light emitted from the lighting fixture takes on a greenish tint depending on the angle of irradiation, and a greenish linear light is irradiated onto the target object. In particular, this greenish color is observed near the boundary between the irradiated and non-irradiated parts, which is in the shadow of the edge of the lighting fixture case, and is visually undesirable. This is thought to be due to the green light lines that are generated by color separation due to polarization.

JP 2013-179014 A JP 2017-27916 A

In order to solve the above problems, the present invention aims to provide a lighting fixture equipped with a light-emitting element that can cut the near-ultraviolet and near-infrared light emitted from the light-emitting element, suppressing discoloration and deterioration of the irradiated object, and prevent greenish light from being irradiated onto the irradiated object.

In the course of research to achieve the above object, the inventors discovered that when they placed a light diffusion plate outside the UV/IR cut filter to diffuse the light that had passed through the cut filter, the greenish light was diffused and became less noticeable. That is, the lighting fixture according to the present invention is characterized in that it has a light emitting element mounted inside, a UV/IR cut filter is provided to cover an opening of a housing that has an opening for emitting light emitted from the light emitting element to the outside, and a diffusion filter is provided outside the cut filter.
In other words, the lighting device according to the present invention is characterized by comprising a light-emitting element, a housing in which the light-emitting element is mounted and which has an opening for emitting light emitted from the light-emitting element to the outside, a UV/IR cut filter arranged to cover the opening, and a diffusion filter arranged on the outside of the cut filter.

In the lighting device according to the present invention, the UV/IR cut filter and the diffusion filter may be stacked adjacent to each other or may be spaced apart.

The UV/IR cut filter is preferably made of resin, and specifically, the UV/IR cut filter may be, for example, a transparent acrylic plate on which a UV/IR cut film is vapor-deposited.
This UV/IR cut filter can be a filter that cuts light having wavelengths in the near ultraviolet region of 410 nm or less and the near infrared region of 740 nm or more, for example.

Currently, LED light-emitting elements (light-emitting diodes) are the mainstream light-emitting elements in the present invention, but as long as they achieve the objectives of the present invention, they are not limited to LED light-emitting elements, and it goes without saying that elements that have the potential to become widely used as lighting fixtures as they are developed in the future, such as organic electroluminescence (OLED), can also be used.

The housing with an opening for emitting light emitted from the light-emitting element in this invention to the outside is not limited to a long shape, but also includes a cylindrical shape such as a downlight, and any shape can be used as long as it can be fitted with a UV/IR cut filter and a diffusion filter.

In the present invention, the UV/IR cut filter provided to close the opening of the housing may be one in which a UV/IR cut film is vapor-deposited on a resin plate such as acrylic, or may be one in which a film is attached, or one in which a dye is mixed into a resin plate. In any case, it is sufficient that the filter has a spectral transmittance capable of cutting near-ultraviolet and near-infrared rays, and it is not necessary that the filter cuts light with wavelengths in the near-ultraviolet region of 410 nm or less and the near-infrared region of 740 nm or more, and the wavelengths to be cut may deviate slightly from these wavelengths.
If the filter is made of resin, it can be easily processed when incorporated into a lighting fixture, and damage to the filter can be prevented.

In the present invention, the diffusion filter provided on the outside of the UV/IR cut filter may be any filter that diffuses the direction of travel of light that has passed through the cut filter, and may be a translucent plate-like member that contains elements that diffuse or scatter light on its surface or inside. For example, it may be a transparent resin or glass that has fine particles that reflect light mixed into it, or a transparent plate material that has fine irregularities on its surface that reflect or refract light in multiple directions. The transparent plate material and the irregularities may be integrated or separate. In the case of separate components, it may be a thin film with an irregular surface that is attached to a thicker support with a smooth surface.

In addition, in the present invention, the UV/IR cut filter and the diffusion filter may be in close contact with each other or may be separated. If they are in close contact with each other, it is advantageous for ease of construction to have both be flat, but they are not limited to being flat. If they are spaced apart, the cut filter and the diffusion filter may have different shapes; for example, the cut filter may be flat and the diffusion filter may be dome-shaped.

The claims of Patent Document 2 describe an illumination device equipped with a filter element containing a pigment that absorbs light of a specific wavelength between a light source and a diffusive optical member, which is similar in wording to the present invention, but the purpose and effect of the invention are completely different, and therefore the configuration is also different. In other words, the "specific wavelength" to be absorbed in Patent Document 2 does not mean near ultraviolet and near infrared rays, but a specific wavelength near the center of the visible light range (yellow 585 nm to 595 nm), and the purpose is to absorb it to make the color of the filter element less visible. There is no idea or configuration to prevent discoloration or deterioration of the irradiated object by near ultraviolet and near infrared rays as in the present invention, and the technical idea is completely different from that of the present invention. Therefore, Patent Document 2 does not disclose or suggest the present invention at all, and does not affect the patentability of the present invention.

The lighting fixture of the present invention cuts out the near-ultraviolet and near-infrared rays emitted from the light source, suppressing discoloration and deterioration of the irradiated object, preventing greenish light from being irradiated onto the irradiated object, and preventing the generation of green linear light observed due to polarized light.

FIG. 1 is a cross-sectional view showing an example of an LED module that is an embodiment of a lighting fixture according to the present invention. Graph showing the spectral energy distribution of an LED used in a luminaire according to the present invention. Graph showing the spectral transmittance of a UV/IR cut filter used in a lighting fixture according to the present invention

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Figure 1 shows a cross-sectional view of a lighting device according to one embodiment of the present invention.

As shown in FIG. 1, this embodiment is intended for an LED module as a lighting fixture, and a long (long in the direction perpendicular to the paper surface of the figure) board 2 equipped with an LED light-emitting element 1 is fixed to the bottom wall 3c of the housing 3 (casing) of a long-type LED module with a U-shaped cross section. The upper part of the side walls 3a and 3b of the housing 3 in the figure is open to form an opening 3d that is long in the longitudinal direction of the housing 3, and a long groove is formed in the inner surface of the side walls 3a and 3b in the longitudinal direction near the opening 3d, and a filter assembly consisting of a UV/IR cut filter 4 and a diffusion filter 5 stacked on top of each other is loaded into the groove. During installation, the two filters 4 and 5 are loaded by sliding them into the end of the groove that is opened at the end of the housing 3. The diffusion filter 5 is always loaded so that it is on the outside of the UV/IR cut filter.

According to this embodiment, the green light resulting from color separation due to polarization is not observed. When the diffusion filter 5 is removed from this state, green light is generated. On the other hand, when the UV/IR cut filter 4 is replaced with a simple transparent plate (clear cover) while the diffusion filter 5 is still attached, the green light resulting from color separation due to polarization is not observed, but near ultraviolet and near infrared light remain.

As is clear from the spectral energy distribution in Figure 2 and the graph of the spectral transmittance of the UV/IR cut filter in Figure 3, the cut filter 5 cuts out the near ultraviolet light of 410 nm or less and the near infrared light of 740 nm or more from the light emitted from the LED light-emitting element 1, and the diffusion filter 4 diffuses that light, making the green line less noticeable.

The lighting fixture according to the present invention is not limited to the above-described embodiment, as described above, and the contents thereof are sufficiently realizable by those skilled in the art based on the conventional technology and common technical knowledge.
The present invention includes embodiments that are various modifications thereof, the scope of which will be apparent to those skilled in the art from the above description of the embodiments and modifications described in this specification.

Reference Signs List 1 LED light emitting element 2 LED board 3 Housing 3a Side wall 3b Side wall 3c Bottom wall 4 UV/IR cut filter 5 Diffusion filter

Claims (9)

A light-emitting element;
a housing having the light emitting device mounted therein and an opening for emitting light emitted from the light emitting device to the outside;
A UV/IR cut filter provided to cover the opening;
and a diffusion filter which is a flat plate-like member provided on the outside of the cut filter. The lighting device according to claim 1, in which the UV/IR cut filter and the diffusion filter are stacked adjacent to each other. The lighting device according to claim 1, wherein the UV/IR cut filter and the diffusion filter are spaced apart. The lighting device according to any one of claims 1 to 3, wherein the UV/IR cut filter is made of resin. The lighting device according to claim 4, wherein the UV/IR cut filter is made by depositing a UV/IR cut film onto a transparent acrylic plate. The lighting device according to claim 1, wherein the UV/IR cut filter is a filter that cuts light with wavelengths in the near ultraviolet range of 410 nm or less and the near infrared range of 740 nm or more. The lighting fixture according to any one of claims 1 to 6, wherein the lighting fixture is an LED module. The lighting fixture according to any one of claims 1 to 6, wherein the lighting fixture is a lighting device equipped with an LED module and a power supply unit. The lighting fixture according to any one of claims 1 to 6, wherein the lighting fixture is a downlight.