JPH07322944A - Penetrable board - Google Patents

Abstract

PURPOSE:To improve the transmission factor of a penetrable board while reducing the operating cost. CONSTITUTION:This penetrable board is provided with a transparent board 2 stuck with a heat ray reflecting film 4 provided with a conducting selective transmission reflecting layer 9 made of a thin film of a metal and/or a metal oxide film and having the electric resistance inversely proportional to the transmission factor of the visible light all over the surface and an electric heater 7 connected in series to the selective transmission reflecting layer 9. The voltage applied to the selective transmission reflecting layer 9 is divided by the selective transmission reflecting layer 9 and the electric heater 7, the voltage applied to the selective transmission reflecting layer 9 is suppressed low, and the dew condensation preventing effect of a penetrable board 1 is improved without impairing the transmission factor. No transformer is required, the operating cost is reduced, the portion of the selective transmission reflecting layer 9 having the electric resistance inversely proportional to the transmission factor is used, and the penetrable board 1 having a high transmission factor is provided with no cost increase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a see-through plate, and more particularly, it relates to a see-through plate having a heat ray reflective film attached to one surface thereof.

[0002]

2. Description of the Related Art For example, Japanese Utility Model Laid-Open No. 54985 / F25D23 /
02) is provided with a see-through plate on the back surface of which a vapor deposition layer made of a conductive metal and having a selective transmission / reflection function is provided, and a plurality of slits are alternately provided at the vapor deposition layer. There is disclosed a refrigeration showcase in which the vapor-deposited layer is an electric heating element and a see-through plate in which the electric resistance in the vapor-deposited layer is increased by the slit is provided.

V of “Monthly Food Distribution” published monthly from Distribution System Research Center on April 1, 1985
OL14. Nos. 27 to 31 of NO4 show a transparent heat insulating film: a "heated.
Leftel "is introduced.

[0004]

In the above conventional technique, since the slit is formed by a cutter or the like, the opposing slit edges are extremely close to or in contact with each other. Occurs, and not only is there a problem in safety, but there is also a problem in that processing is required because the slit is formed.

Further, in the prior art, when the transparent heat insulating film is used as a surface heater, the commercial power supply cannot be used as it is because of its small electric resistance, and a transformer must be used. There was a problem of cost increase and operation cost increase.

[0006]

In order to solve the above-mentioned problems, the present invention comprises a metal or a thin film of a metal oxide film, and an electrically conductive selective transmission / reflection layer 9 whose electric resistance is inversely proportional to the transmittance of visible light. A transparent plate (1) comprising a transparent plate (2) having a heat ray reflective film (4) attached to one surface thereof and an electric heater (7) connected in series with a selective transmission / reflection layer of the heat ray reflective film.

[0007]

The heat ray-reflecting film 4 has a function of reflecting the heat ray transmitted through the transparent plate 2 to the outside by itself, and has a function of heating the transparent plate 2 as a surface heater by being energized. The electric heater 7 connected in series to the heat ray reflective film 4 functions as a voltage divider for the voltage applied to the heat ray reflective film.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 and 2 are, for example, a low-temperature showcase, that is, a see-through plate that is used for windows and doors that cover the opening of a freezer showcase or a refrigerated showcase and separates the inside and the outside of the showcase. The transparent plates 2 and 3 made of a plurality of transparent glasses or transparent plastic plates, the heat ray reflection film 4 attached to the transparent plate 2 on the outside of the inside of the transparent plate, and the space. An annular metal frame 6 for covering the outer periphery of the spacer interposed between the transparent plates 2 and 3 for maintaining, and a dew-proof electric heater 7 annularly arranged along the inner surface of the metal frame. Has been done.

The heat ray reflective film has a selective transmission / reflection layer 9 formed by laminating thin films of a metal and / or a metal oxide, and a glue layer 10 made of a transparent adhesive, as indicated by a circle P in FIG.
It has a function of transmitting visible light and reflecting heat rays such as infrared rays. The selective transmission / reflection layer 9 is made of a metal and / or a metal oxide, has a function as a dielectric, and generates heat when energized. Therefore, the pair of parallel electrodes 11 and 12 are formed at both ends of the heat ray reflective film. Provided and connected in series with the electric heater 7 to connect to 100V
Connected to the commercial power supply 13 of. The selective reflection / transmission layer 9 acts as a surface heater by being energized,
Its electric resistance is 1 when the visible light transmittance is 80%.
In the case of 0 Ω / cm 2 and 60%, it becomes 15 Ω / cm 2, which is inversely proportional to the transmittance of visible light, that is, the electrical resistance of the selective transmission / reflection layer 9 is small when the transmittance of visible light is high, and is large when it is low. The inventors of the present application found out by experimentation that there is a relationship.

Here, the transmittance is the transmittance of the selective transmission layer 9 itself. Since the selective transmission / transmission layer itself is thin and soft, for example, the selective transmission / reflection layer is attached to a transparent plate of glass to measure the transmittance. However, the transmittance of glass itself is 10
The measured transmittance, not 0%, is not the true transmittance of the selective transmission / transmissive layer itself because it was measured by attaching the selective transmission / transmissive layer to glass. Further, the transmittance of the glass itself is different depending on the wavelength (μm) of the light ray in the range visible to human eyes (range of visible light ray). Therefore, in order to obtain the transmittance of the selective transmission / transmissive layer itself, it is necessary to correct the value obtained by adhering the selective transmission / transmissive layer to glass and measuring it by taking the transmittance of glass into consideration. Therefore, in the present invention, a value obtained by sticking a selective transmission / transmissive layer to glass and measuring the transmittance is corrected by adding the transmittance of the glass, and as described above, the electrical resistance of the selective transmission / transmissive layer itself is: They have discovered that there is a portion that is inversely proportional to the visible light transmittance of the selective transmission / reflection layer.
Further, in the present invention, the use of the above-mentioned inversely proportional portion makes it possible to increase the transmittance without increasing the cost.

Therefore, the see-through plate 1 used for the freezing / refrigerating showcase needs to use the heat ray reflective film 4 having a high visible light transmittance, that is, a low electric resistance, in order to see through the inside of the refrigerator. . Therefore, in order to use the selective transmission / reflection layer 9 of the heat ray reflection film 4 as a surface heater, the voltage of the commercial power supply 13 is high, and therefore the electric heater 7 for heating the metal frame 6 is connected in series to the selective transmission / reflection layer 9. The commercial power supply is divided in proportion to both resistances, and the electric heater 7
Is also acting as a transformer. In addition, one transparent plate 1
In the selective transmission / reflection layer 9 and the electric heater 7, for example,
Voltage between each terminal 25V, resistance 25Ω, power consumption 25W
, The required voltage for series connection is 50V,
In this case, when using the commercial power supply 13, it is preferable to provide a diode D as shown by the chain line in FIG. 1 and perform half-wave rectification.

The metal and / or metal oxide (hereinafter abbreviated as a metal layer) is one or more metal thin films selected from the group consisting of gold, silver, copper, palladium and aluminum and / or In2O3, SuO2. , An oxide thin film of CdSnO4 or the like, and is formed on the surface of a transparent plastic film or on an anchor coat layer of about 2 μm or less made of, for example, a silicon-based or titanium-based organometallic compound provided on the surface. . Further, a high-refractive-index dielectric layer (to be referred to as a dielectric layer hereinafter) formed on plastic and having a thickness of 50 to 4000 angstrom is formed. The metal layer has a refractive index of 1.8 or more, for example, titanium dioxide, tin oxide, indium oxide or the like and has a film thickness of 50 to 6
It may be a structure sandwiched between 00 dielectric layers. In addition, the metal layer or the dielectric layer can be protected by an organic or inorganic layer such as an acrylic resin, a polyester resin, or a silicone resin in order to improve mechanical durability, and a transparent heat insulating layer. May be laminated.

Examples of the transparent plastic film serving as a base layer on which the thin film is formed include polyester resins such as polyethylene terephthalate, polyethylene-2.6-naphthalate and polybutylene terephthalate, polycarbonate resins, polyketones, polyethylene and polypropylene. Polyolefin resin, polyvinyl chloride, polystyrene polyphenylene oxide, polymethylmethacrylate, polystyrene, etc. or polyamide resin, polyimide resin, cellophane, cellulose triacetate or other cellulose resin film or sheet is used.

FIG. 3 shows a refrigerating showcase 20 having two see-through plates 1, and FIG. 4 shows electrical connection of the see-through plate 1. As shown in FIG. 4, with respect to the commercial power source 13, each electric heater 7,
7 and the selective transmission / reflection layers 9 and 9 are connected in series. In this case, the applied voltage of 100 V is divided into four in proportion to the resistance of each electric heater and the selective transmission / reflection layer. According to the above-mentioned structure, the heat ray reflective film 4 reflects the heat ray transmitted through the transparent plate 2 toward the outside of the low temperature showcase with the selective transmission / reflection layer 7 to raise the temperature of the transparent plate 2 to increase the temperature outside the refrigerator. On the other hand, when the selective transmission / reflection layer 9 is energized, it acts as a surface heater to heat the transparent plate 2, and by both of these actions, condensation on the surface of the transparent plate 2 can be prevented. By connecting the selective transmission / reflection layer 9 and the electric heater 7 or the selective transmission / reflection layers 9, 9 to each other, the applied voltage can be divided in proportion to its resistance and the other can act as a voltage divider. Therefore, the selective transmission / reflection layer 9 having a low electric resistance and a high transmittance can be used, and the heat ray reflection film having the selective transmission / reflection layer is used while ensuring the transmittance of the see-through plate 2. Prevents condensation

[0015]

According to the present invention described above, a heat ray reflective film comprising a thin film of a metal or a metal oxide film and having an electrically conductive selective transmission / reflection layer whose electric resistance is inversely proportional to the transmittance of visible light is attached to one surface. Since it is a see-through plate comprising a transparent plate and an electric heater connected in series with the selective transmission reflection layer of the heat ray reflective film, the selective transmission reflection layer and the other electric heater can be used as a selective transmission reflection layer. By dividing the applied voltage and suppressing the voltage applied to the selective transmission / reflection layer to a low level, the heat ray reflective film is covered with the heat ray reflective film without impairing the visible ray transmittance and heat ray reflectance of the heat ray reflective film itself. It can also be used as a heater to improve the dew condensation prevention effect of the see-through plate. Further, the other electric heater acts as a voltage divider, which eliminates the need for a transformer and the like, thus reducing operating costs.

The electrical resistance of the selective transmission / reflection layer itself is
There is a portion that is inversely proportional to the transmittance of visible light of the selective transmission / reflection layer. Therefore, the selective transmission / reflection layer of the present invention uses the above-mentioned inversely proportional portion to increase the transmittance without increasing the cost. it can.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a see-through plate showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a front view of a frozen showcase showing an embodiment of the present invention.

FIG. 4 is an electrical connection diagram of a see-through plate in the refrigerating showcase of FIG.

[Explanation of symbols]

 1 Transparent Plate 2 Transparent Plate 4 Heat Ray Reflective Film 7 Electric Heater 9 Selective Transmission Reflective Layer

Claims (1)

[Claims] 1. A transparent plate comprising a thin film of a metal or a metal oxide film and a heat ray reflective film having an electrically conductive selective transmission / reflection layer whose electrical resistance is inversely proportional to the transmittance of visible light and which is adhered on one surface thereof. A see-through plate comprising a selective transmission reflection layer of the heat ray reflection film and an electric heater connected in series.