JP5656147B2 - Light control transparent window material - Google Patents

Description

  The present invention relates to a dimming transparent window member that can be seen almost completely from the inside of a room, blocks sunlight from summer, and takes in sunlight from winter.

  In recent years, the reduction of carbon dioxide emissions has become an important issue. Among them, especially in the consumer sector, the amount of carbon dioxide emissions has greatly increased, and the reduction is urgently needed. The energy used to heat and cool buildings and vehicles reaches nearly one-third of the energy consumption of the consumer sector, and if this can be reduced, it will greatly contribute to the reduction of carbon dioxide emissions. The window glass of buildings and vehicles is a major factor that determines the heating and cooling load, and if a window glass that can control the entrance and exit of light and heat can be realized, the heating and cooling load can be greatly reduced.

  Blinds, curtains, and the like that are typically used to shield sunlight have no selectivity for the angle of incidence of light on the window glass, and adjust all light incident at all angles to the window uniformly.

  In addition, glass that has been coated with a thin film that reflects the heat ray component of sunlight that has recently been sold as “eco-glass”, and heat-reflective glass that has been coated with a metal thin film can be used to spectrally control sunlight. Although the air conditioning load is reduced, these also function in the same way for any incident light on the window, although it is essentially sufficient to act only on sunlight. However, for example, the altitude of the summer sun in Japan is high, and sunlight enters the window facing the south side at an angle of 70 degrees or more. This is the incident angle to a vertically installed window. Then, the angle is only 20 degrees when viewed from above. The remaining light incident at an angle in the range of 160 degrees does not need to be blocked, but if these lights are transmitted, the outside scenery will be almost completely visible.

  So far, there have been various proposals for dimming glass that has the function of blocking sunlight using total reflection and refraction. It was not considered. The fact that the outside scenery can be seen well is very important as a window function. If both the condition that sunlight does not enter and the condition that the scenery can be seen are compatible, it will be a new energy-saving glass that has never been seen before. Become.

  On the other hand, in Patent Document 1, a combination of total reflection and specular reflection is selected for the purpose of preventing strong direct sunlight in summer, directing weak winter light into the room, and adding a role to save energy to windows. A transflective material has been proposed. This selective transmission / reflection material is configured such that a plurality of inclined portions are provided stepwise on the indoor side and the step portion is a mirror surface. However, in such a configuration, there are thick and thin parts, so when looking out from the room, the outside scenery appears to rise due to refraction, and the mirror part becomes blocked by light, You can no longer play the original role of the window.

  Patent Document 2 (FIG. 14) proposes a glass panel that selectively transmits and blocks sunlight according to the incident angle. FIG. 7 schematically shows the glass panel in a sectional view. The glass panel 51 includes a pair of transparent bodies 52 and 53, and a plurality of prism portions 54 are formed at regular intervals on the side of the transparent body 52 to be combined with the transparent body 53. A plurality of prism portions 55 are formed at regular intervals on the side combined with the body 52 in the vertical width direction. The prism portion 54 and the prism portion 55 have a complementary shape, and when the transparent body 52 and the transparent body 53 are combined, a gap 56 with a constant interval is formed. The prism portions 54 and 55 have a right cross section. The gap 56 is an air layer, for example. In that case, the refractive index of the transparent bodies 52 and 53 is larger than the refractive index of the gap 56 formed of the air layer.

  In such a configuration, incident light 58 having a large angle from the direction perpendicular to the incident surface 57 of the glass panel 51 does not pass through the glass panel 51 and is blocked by total reflection at the interface between the transparent body 53 and the gap 56. . On the other hand, incident light 59 having a small angle from the direction perpendicular to the incident surface 57 of the glass panel 51 passes through the glass panel 51. In this way, light is captured and blocked selectively according to the incident angle of light.

However, the glass panel 51 described in Patent Document 2 has a problem in that the transparent bodies 52 and 53 have prism portions 54 and 55 each having a right-angled tip, so that the thickness is inevitably increased. It was.
In consideration of actual production, it is difficult to process the inner shape of the transparent bodies 52 and 53 into a prism shape, which has been a major factor hindering practical use.

Japanese Patent Laid-Open No. 2003-202159 European Patent Publication No. 0092322

  The present invention has been made in view of the actual situation of the prior art as described above. Even when looking outside from the room, the outside scenery does not appear to be lifted or partially blocked, Dimmable transparent window member that can be taken into the room effectively, effectively cuts off sunlight in the summer, greatly reduces the heating and cooling load, has a simple structure, is easy to process, and can be made thinner It is an issue to provide.

In order to solve the above-mentioned problems, first, the present invention provides a transparent window member made of a plate-like or sheet-like plastic material having a pair of parallel planes, and a planar slit having a certain thickness. A plurality of air layers extending in the vertical direction, extending in the width direction of the transparent window member at regular intervals, and inclined with respect to the plane, wherein the air layers adjacent to each other in the vertical direction are The light incident from the horizontal direction at an inclination angle different from the inclination angle of the air layer is communicated with another air layer composed of oppositely facing slits having an inclination angle to transmit the light, and the transparent window member on the outdoor side. Due to the interface with the air layer, sunlight incident at a predetermined angle or less with respect to the direction perpendicular to the plane from the outdoor in winter is taken into the room and predetermined in the direction perpendicular to the plane from the outdoor in summer. Provided is a dimming transparent window member that totally reflects sunlight incident at an angle greater than 50 degrees, blocks intrusion into the room, and can be seen from the inside to the outside like a normal window glass .

Second, the light control transparent window member according to the first invention, wherein the air layer has a thickness of 2 mm or less .

According to the present invention, since the above-described configuration is adopted, winter sunlight can be effectively taken into the room without being exposed to the outside scenery or partially missing even when viewed from outside the room. Sunlight can be effectively blocked and the heating / cooling load can be greatly reduced. Moreover, according to this invention, in addition to the said effect, the provision of the light control transparent window member which can be easily manufactured with a thin and simple structure is attained.
The dimming transparent window member of the present invention may be used by being attached to a window glass or suspended so as to be in contact with the window glass, or may constitute the window glass itself.

It is a figure which shows the basic structure of the member for light control transparent windows of this invention. It is explanatory drawing of a critical angle and total reflection. It is a figure which shows the result of having calculated the incident angle when sunlight injects into the air layer which consists of a slit in the window which faced the south in Tokyo. It is explanatory drawing of the incident angle with respect to the air layer which consists of a slit. It is sectional drawing which shows the structure of the member for light control transparent windows of embodiment by this invention. It is structure explanatory drawing of the member for light control transparent windows of another embodiment by this invention. It is sectional drawing which shows typically the structure of the conventional glass panel which selectively permeate | transmits and interrupts sunlight according to the incident angle.

  Next, the present invention will be described in more detail.

The basic structure of a light control transparent window member (hereinafter also referred to as a light control member) according to the present invention will be described with reference to FIGS. The light control member 11 is made of a transparent material such as plastic such as acrylic resin, and has a flat surface 12A on the indoor side and a flat surface 12B on the outdoor side. The flat surface 12A and the flat surface 12B are parallel to each other. Yes. The refractive index of plastic is generally in the range of 1.3 to 1.7, and its light transmittance is as high as about 90%, similar to ordinary glass. For example, an acrylic resin has a refractive index of about 1.5 and a light transmittance of 92 to 93%. Light adjusting member 11 has an air layer 13 consisting of a slit planar shape having a predetermined thickness which is inclined at an angle to the plane 12 A, 12 B. The air layer 13 is formed in a band shape on so that extends in the width direction of the light adjusting member 11. That is, the air layer 13 is formed so as to be inclined so that the upper part is close to the outdoor side and the lower part is close to the indoor side. The inclination angle α of the air layer 13 is set in consideration of the technical matters described below. In FIG. 1, the dimming member 11 is shown as being divided into two plastic structures 11 </ b> A and 11 </ b> B by the air layer 13. ing.

Here, a case where the transparent material of the light control member 11 is a plastic having a refractive index of 1.5 will be described as an example. In general, when light (air) travels from a medium (plastic) having a large refractive index to a medium having a small refractive index, refraction occurs at the interface between the two when the incident angle is small, as shown on the right side of FIG. In this example, since the refractive index of plastic is 1.5 and the refractive index of air is 1, the refractive angle is larger than the incident angle. As the incident angle gradually increases, the refraction angle also increases gradually. When the incident angle reaches a certain angle, as shown in the center of FIG. 2, the refraction angle becomes 90 °, and light does not travel from the plastic to the air side. This angle is called the critical angle and is denoted here as θ _m . When the incident angle is further increased, as shown on the left side of FIG. 2, all the light is reflected at the interface, resulting in a state called total reflection.

In the case of this example, there is the following relationship between the critical angle θ _m and air and plastic.
sin θ _m = (refractive index of air) / (refractive index of plastic) = 1 / 1.5
Therefore, the critical angle is θ _m = 41.8 °.

  In the case of FIG. 1, when light is incident on a plane (hereinafter also referred to as a plastic surface) 12B from the outdoor side with a small incident angle as shown by the light beam 2, the light is refracted by the plastic surface 12B and then enters the plastic structure portion 11B. After refracting at the interface between the plastic structure portion 11B and the air layer 13, the air layer 13 is advanced, and after being refracted at the interface between the air layer 13 and the plastic structure portion 11A, the plastic surface portion 11A is advanced through the plastic structure portion 11A. The light is refracted and enters the room.

  On the other hand, as shown by the light beam 1, when light is incident on the plastic surface 12B from the outdoor side with a large incident angle, the light is refracted by the plastic surface 12B and then travels through the plastic structure portion 11B. Is totally reflected at the interface, and does not transmit to the air layer 13 and the plastic structure 11A side, and is prevented from entering the indoor side. The angle at which the incident angle gradually increases and the light is not incident on the indoor side is referred to as a “specific angle” in this specification.

  The specific angle can be changed according to the inclination angle α of the air layer 13. Table 1 shows the relationship between the inclination angle α of the air layer 13 and the specific angle when a plastic having a refractive index of 1.5 is used for the transparent material of the light control member 11. However, it is considered that the horizontal azimuth angle is perpendicularly incident on the light control member.

For example, when the inclination of the air layer 13 is 7 degrees, the specific angle is about 60 degrees when the refractive index is 1.5. Angle greater than 60 degrees, for example, light entering from above at an angle 70 degrees from the direction perpendicular to the plastic surface 12B as shown by ray 1 in Fig. 1 is refracted when entering the plastic surface 12 B, the oblique air It enters the layer 13 at an angle of 45 degrees. Since this angle is larger than the critical angle at the interface between the plastic structure portion 11B and the air layer 13, total reflection occurs and light is reflected at this interface. The reflected light is reflected in the plastic structure portion 11B and does not pass through the air layer 13 and the plastic structure portion 11A. On the other hand, for light incident at an angle smaller than 60 degrees, which is the specific angle indicated by the light beam 2, the plastic is formed at an angle smaller than the critical angle at the interface between the plastic structure portion 11B and the air layer 13 with respect to the air layer 13. since the structural unit 11 B into the air layer 13, the total reflection is refracted not occur. Then, reverse refraction occurs when entering the plastic structure 11A from the air layer 13, and if the width of the air layer 13 is small, it is hardly affected by the air layer 13 and permeates in the same manner as normal glass. For this reason, the thickness of the air layer 13 is desirably 0.1 mm or less. The lower limit of the thickness of the air layer 13 is about 0.01 mm from the viewpoint that the role of the air layer 13 can be exhibited. When the thickness of the air layer 13 is within the above range, the outside scenery looks the same as that of ordinary glass when the outside is viewed from the inside.

  Further, as is clear from Table 1, it can be seen that the tilt angle can be further reduced by using a material having a large refractive index. In light shielding, it is very effective to consider the refractive index of the material.

  FIG. 3 shows a case in which sunlight is incident on a window facing south in Tokyo using a light control member as shown in FIG. The incident angle (refer FIG. 4) with respect to the air layer 13 is calculated. This incident angle is an angle when light reaches the interface between the plastic structure portion 12B and the space portion 13 formed of a slit, and the three-dimensional incident angle is calculated in consideration of the horizontal azimuth angle. When this angle exceeds 42.8 degrees (horizontal solid line in FIG. 3), total reflection occurs. Therefore, it can be seen that sunlight is blocked during the warm or hot season from April to September, and the sunlight is transmitted during the cool or cold season from October to March. In this specification, summer means, for example, from April to September in Tokyo, and winter means from October to March.

  By attaching such a light control member 11 to the inside of the window glass, the function of automatically blocking sunlight in summer and taking in sunlight in winter automatically appears, and the outside scenery is always almost completely visible. It is possible to realize an unprecedented new window. However, if you approach the window on the indoor side and look up at the sky at an angle of 60 degrees or more, you cannot see the outside, but this is limited to looking up at the sky at the window and has little effect.

  Therefore, when the light control member having such a structure is used, it is possible to prevent sunlight from entering the room when the altitude of the sun is higher than a specific angle. In addition, light incident from below is transmitted in the same manner as normal glass, so that the outside scenery can be seen in the same manner as a normal glass window.

For example, if the light control member 11 having the structure of FIG. 1 in which the inclination angle of the air layer 13 is 7 degrees is made of a large 1 m square transparent plastic plate, the thickness of the plastic plate is 12 cm, which is not realistic. The structure of FIG. 1 is characterized by having an equivalent dimming function regardless of the size as long as it has a similar shape when viewed from the side. This can solve this problem. FIG. 5 is an example showing a cross-sectional structure of a transparent structure having such a structure. For example, when a light control member in which an air layer formed of slits as shown in the figure is formed by laser processing or processing using a cutter blade using a transparent acrylic plate, a structure having the same function as in FIG. 1 is obtained. When the length of the period in the vertical direction is 10 cm, the thickness can be about 2 cm.

  With this structure, light incident on the light control member from above at an angle larger than a specific angle is refracted and reaches the interface between the transparent structure and the air layer. If it is larger than a specific angle between the two, it is totally reflected and does not penetrate into the room. On the other hand, light incident on the transparent structure at an angle smaller than a specific angle is refracted at the interface with the air layer, but reverse refraction occurs when entering the transparent structure from the air layer. If the air layer is offset and the width of the air layer is small, the air layer is transmitted without being affected by the air layer.

If the angle of inclination on the lower side is 40 degrees, total reflection does not occur in any part of the light incident from the horizontal direction, so the air layer formed inside is not visible at all, and it is outside like a transparent acrylic plate. You can see the scenery. When the thickness of the air layer is 2 mm or less, light distortion and dispersion are small.

  Next, two examples of another embodiment according to the present invention are shown in perspective views in FIGS. 6A is an example in which an air layer is formed by slitting a transparent plastic plate or sheet from the side (side) with a laser or a cutter blade. The light control member of the embodiment of FIG. 6B is an example in which an air layer is formed by slitting a transparent plate or sheet of plastic so as to pass from the front to the back. In this case, by attaching a transparent member having the same refractive index as that of the light control member and having a thickness of three times or more to the outdoor side of the light control member so that total reflection does not occur, the light control member of FIG. A light control member having an equivalent function can be realized.

11, 31 Light control transparent window member (light control member)
11A, 11B Plastic structure 12A, 12B Plane (plastic surface)
13, 33 Air layer (slit)

Claims (2)

A transparent window member made up of a plurality of planes of slits having a constant thickness in a transparent window member made of a plate-like or sheet-like plastic material having a pair of parallel planes in the vertical direction at regular intervals. The plurality of air layers adjacent to each other in the vertical direction are inclined at a different inclination angle from the inclination angle of the air layer from the horizontal direction. Incident light is communicated by another air layer composed of oppositely facing slits having an inclined angle to transmit light, and is perpendicular to the plane from the outdoor in winter by the interface between the transparent window member on the outdoor side and the air layer. Sunlight incident at a predetermined angle or less with respect to a certain direction is taken into the room, and sunlight incident at an angle larger than the predetermined angle with respect to the direction perpendicular to the plane from outside the room in summer is totally reflected. , Blocked from entering the room, the light transparent window member regulating, characterized in that the chamber outside can see like a normal window glass. The light control transparent window member according to claim 1, wherein the air layer has a thickness of 2 mm or less .