Windows and refrigerators

Abstract

To provide a window free from reflections from a half mirror and a refrigerator using the same by constructing an optical system that eliminates reflected light from a half mirror. [Solution] Incident light 4 transmitted through the polarizing plate 3 travels back and forth through the λ / 4 retardation plate 2 before and after being reflected by the half mirror 1 , and the reflected light 6 is blocked by the polarizing plate 3 .

Description

[Technical field]

[0001] This invention relates to a window glass using a half mirror (magic mirror) that eliminates reflected light, and to a refrigerator using the same. [Background technology]

[0002] Half mirrors are used as one-way mirrors. To explain how they work, the bright side of the one-way mirror functions as a pure mirror when the light coming from the dark side can be ignored, and the dark side functions as a semi-transparent window, allowing you to observe the outside if the light from the bright side is large enough.

[0003] For example, consider the case where a half mirror is used in the window of a building. The illuminance outside is about 100,000 lx on a sunny day, about 30,000 lx on a cloudy day, and about 0.2 lx at night with the light of a full moon. Meanwhile, indoors, the normal illuminance is about 100 to 1000 lx when lighting is used. Therefore, during the day, the half mirror functions as a mirror from the outside, and functions as a normal window indoors, letting in the outside light and allowing the outside to be observed. Meanwhile, at night, on the other hand, it functions as a mirror indoors, but functions as a normal window from the outside, allowing the inside of the building to be seen.

[0004] Refrigerators are one example of a product that uses a half mirror as a magic mirror, and several utility model and patent applications have been filed since the 1970s, with products beginning to be sold in recent years. Patent documents 1 to 5 are examples of such known products.

[0005] Patent Document 6 is a known example of irradiating vegetables with visible light and ultraviolet light emitted from an LED to increase antioxidants such as carbohydrates and vitamins. Patent Document 7 is a known example of preventing food from losing its freshness by activating a photocatalyst with light from a light source. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Publication No. 51-050354 [Patent Document 2] Publication No. 51-074270 [Patent Document 3] Publication No. 54-067854 [Patent Document 4] Publication No. 01-178581 [Patent Document 5] JP 2004-225968 A [Patent Document 6] Patent No. 4903485 [Patent Document 7] Patent No. 5750084 Summary of the Invention [Problem to be solved by the invention]

[0007] When a half mirror acts as a mirror surface, inconveniences may occur. For example, when used as window glass for a building, it functions as a mirror from the outside during the day, but the regular reflection of sunlight may cause glare and cause inconvenience to those around. In addition, in an embodiment in which the door of a refrigerator is a half mirror, when the internal light is not turned on, the half mirror acts as a mirror, and when the internal light is turned on, the contents of the refrigerator can be seen, but there is a problem that unless the intensity of the internal light is increased or the brightness of the external light is reduced, the reflection in the mirror cannot be ignored and the visibility of the contents of the refrigerator becomes poor.

[0008] Furthermore, the technology for improving the shelf life of food by using light emitted from a light source in a refrigerator entails an economic burden in the form of the cost of the light source device or the energy costs required for its operation. [Means for solving the problem]

[0009] A λ / 4 phase difference plate and a polarizing plate are placed in that order on the half mirror surface that should not function as a mirror.

[0010] Fig. 1 shows an embodiment of the present invention. A λ / 4 retardation plate 2 and a polarizing plate 3 are arranged in this order on the side of a half mirror 1 where it is desired to extinguish the reflected light from the mirror surface.

[0011] Incident light 4 is generally unpolarized, but after passing through polarizing plate 3, the polarized light becomes polarized in a direction like polarization 8, passes through λ / 4 phase difference plate 2, becomes circularly polarized at the position of half mirror 1, and is split into transmitted light 5 and reflected light 6. Reflected light 6 in a circularly polarized state passes through λ / 4 phase difference plate 2 again, achieving the effect of passing through a total λ / 2 phase difference plate, and has its polarization direction 9 rotated by 90°, and is blocked by polarizing plate 3. As a result, the reflection from half mirror 1 is eliminated.

[0012] At this time, the maximum reflected component of the incident light 4 is reflected light 7 at the interface between the air and the filter, and its intensity is about a few percent of the incident light. Although this is due to the reflectance of the half mirror 2, this can be reduced to about 1 / 10, and visibility is improved when looking through the other side by making the other side brighter.

[0013] When this invention is applied to a refrigerator, it is possible to increase antioxidants such as sugar and vitamin C by irradiating vegetables with external light 5, which is unexpectedly introduced into the refrigerator by this invention. In addition, by activating the photocatalyst 16 placed inside the refrigerator, it is possible to decompose ethylene, which promotes the ripening of vegetables, decompose and deodorize odorous components, and kill bacteria. Effect of the Invention

[0014] By arranging a λ / 4 phase difference plate and a polarizing plate in that order on the half mirror, it is possible to eliminate the reflected light from the half mirror, improving visibility when looking through the other side. In addition, when applied to a refrigerator, by making effective use of the outside light that is unexpectedly introduced into the refrigerator, it improves the nutritional value of vegetables and promotes the decomposition of troublesome organic matter including bacteria by activating the photocatalyst, realizing further high performance of the refrigerator. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a principle diagram and a basic embodiment of the present invention. [Diagram 2] FIG. 2 shows an embodiment of a refrigerator incorporating the present invention. [Diagram 3] FIG. 3 shows an embodiment in which a UV-LED is added to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Figure 1 shows a basic embodiment. A λ / 4 phase difference plate 2 and a polarizing plate 3 are arranged in that order on the surface of a half mirror 1 where it is desired to eliminate reflected light. With regard to the crystal axis of the phase plate 2, the polarization axis of the polarizing plate 3 is aligned in the middle direction between the fast axis (advance axis) and the slow axis (slow axis). In addition, since the three optical elements in Figure 1 may be on a film, the general configuration is that one side is supported by a transparent substrate such as glass. In addition, other optical components such as an ultraviolet ray cut filter or an infrared ray cut filter are additionally arranged as necessary.

[0017] When the embodiment of FIG. 1 is used as window glass for a building, the incident light 4 from outside passes through the polarizing plate 3 and becomes linearly polarized light with a polarization direction 8, which passes through the λ / 4 retardation plate 2 and is split into transmitted light 5 and reflected light 6 by the half mirror 1, but is converted into circularly polarized light by the effect of the λ / 4 retardation plate 2. The reflector 6 passes through the λ / 4 retardation plate 2 again and becomes linearly polarized light 9, but for the incident light 4, it becomes equivalent to passing through a λ / 2 retardation plate, the polarization direction is rotated by 90°, and the light cannot pass through the polarizing plate 3 and is blocked, and the reflection from the half mirror 1 is erased. Therefore, the maximum reflected component of the incident light 4 is the reflected light 7 from the polarizing plate 3, and its intensity is at most a few percent of the incident light 4. Although it depends on the reflectance of the half mirror 1, if the reflectance is set to 50% as the name suggests, the reflected light can be suppressed to about 1 / 10. In this way, it is possible to eliminate the glare caused by the regular reflection of direct sunlight and avoid causing inconvenience to those around.

[0018] The surface in contact with the half mirror 1 in Figure 1 is indoors. During the day, outdoor illuminance is around 30,000 to 100,000 lx, while indoor illuminance is at most around 1,000 lx, so the mirror reflection from indoor lighting can be ignored and it functions as a normal window from which the outdoors can be observed. At night, even with a full moon, it is only around 0.2 lx, so if the indoor illuminance is a normal illuminance of 100 to 1,000 lx, the light passing through from outdoors can be ignored and it functions as a normal mirror. However, users should be careful as the inside of the building can be seen from outside at night.

[0019] When the embodiment of FIG. 1 is applied to window glass, the reflected light 6 from the mirror surface is eliminated from the outside, and the window glass appears dark even during the day. If the reflectance of the half mirror 1 is R, the transmittance is (1-R), and the light intensity seen from the outside when the transmitted light 5 is totally reflected by a white object is

[0020]

number

[0021] TIFF0003251208000003.tif6166 has a reflectivity of about 4 to 5%, so it is inferior to a simple half mirror in terms of its ability to conceal the interior from the outside.

[0022] Methods for improving the hiding power include increasing the reflectance R of the half mirror 1, or intentionally shifting the axial alignment between the λ / 4 retardation film 2 and the polarizing plate 3 from the ideal state to allow some of the regular reflection component of the half mirror to pass through the polarizing plate 2. In actual products, both methods are combined to achieve a balance between eliminating external light reflections, hiding performance, and external light transmittance. Also, if the increase in cost is ignored, there is a method of additionally placing a low-reflection mirror on the polarizing plate 3.

[0023] Figure 2 shows an embodiment in which the basic embodiment shown in Figure 1 is applied to a refrigerator. The front door 13 of the refrigerator is designed to allow light to pass through, and from the outside, is composed of a polarizing plate 3, a λ / 4 retardation plate 2, a half mirror 1, a transparent substrate 10 such as glass, a heat insulating layer 11, and a transparent substrate 12. The heat insulating layer 11 is generally a vacuum. An object to be cooled 14 and a light source 15 such as an LED that is required to view the contents of the refrigerator are arranged therein.

[0024] Even when the light source 15 is not turned on, the incident light 4, which is external light, passes through the light-transmitting portion 13 of the front door. The transmitted light 5 illuminates the inside of the refrigerator and is barely visible from the outside. When one wishes to see the contents, the light source 15 is turned on to make the inside easily visible. In this case, a simple half mirror (magic mirror) would impair visibility due to reflections caused by external light, whereas in the embodiment of FIG. 2, the reflections caused by the half mirror 1 can be eliminated by the λ / 4 retardation plate 2 and the polarizing plate 3, improving visibility. Furthermore, if the external transmitted light 5 that is incidentally incident on the refrigerator is effectively utilized to activate the photocatalyst 16, it becomes possible to decompose malodorous components such as ethylene and ammonia that promote the ripening of vegetables, and to sterilize bacteria, thereby contributing to the high performance of the refrigerator. Therefore, in the case of the vegetable compartment, in order to secure the amount of light entering the interior, it is also possible to sacrifice visibility of the contents and remove the λ / 4 retardation plate 2 and the polarizing plate 3 to make a simple half mirror (magic mirror).

[0025] To maximize the performance of the photocatalyst 16, it is necessary to irradiate the photocatalyst 16 with light, especially ultraviolet light, even at the back of the object to be cooled 14, at the back of the refrigerator where external light does not reach. Figure 3 shows an embodiment in which ultraviolet light is irradiated onto the photocatalyst 16 by a UV-LED 17 separately installed in an area not hit by transmitted external light 5. This allows the function of the photocatalyst 16 to be exerted over a wider range.

[0026] However, the light emitted from inside the refrigerator is not a panacea and can actually deteriorate the object being cooled 14. For example, when refrigerating potatoes, light can cause the production of toxic solanine and the growth of sprouts. Generally, plants buried in soil should be stored in a cool, dark place, and since it is difficult to completely block out light even when wrapped in paper or black vinyl, it is desirable to provide a separate light-blocking vegetable compartment that does not let in light.

[0027] As described above, by providing a light-illuminated vegetable compartment and a light-shielded vegetable compartment, for example, leafy vegetables can be refrigerated in the light-illuminated vegetable compartment, where freshness is maintained by the decomposition of ethylene by the photocatalyst and the nutrients are improved by irradiating the vegetables with light (ultraviolet rays), while potatoes, root vegetables, and other vegetables dug up from the ground can be refrigerated in the light-shielded vegetable compartment, making it possible to refrigerate each type of vegetable in the optimal way. [Explanation of symbols]

[0028] 1 Half mirror (magic mirror) 2 λ / 4 retardation plate 3. Polarizing Plate 4 Incident light 5 Transmitted light 6. Reflected light from half mirror 1 7 Reflected light from polarizing plate 3 8 Polarization direction immediately after passing through polarizing plate 3 9 Polarization direction after going back and forth through the λ / 4 retardation plate 10 Transparent substrate (glass) 11 Insulation layer (vacuum) 12 Transparent substrate 13 Light-transmitting part on the front of the door 14 Cooling target 15 Lighting (LED) 16 Photocatalyst 17 UV-LED

Claims

1. A window glass comprising an optical filter in which a half mirror, a λ / 4 phase difference plate and a polarizing plate are arranged in this order.

2. A refrigerator having a light-transmitting housing portion with an optical filter, in which a half mirror, a λ / 4 phase difference plate, and a polarizing plate are arranged in this order.

3. 3. The refrigerator according to claim 2, further comprising a vegetable refrigerating compartment into which light can be introduced by the light-transmitting casing portion with the optical filter, and a light-shielding vegetable refrigerating compartment at the same time.

4. 4. The refrigerator according to claim 2 or 3, wherein a λ / 4 retardation plate and a polarizing plate are removed from the vegetable refrigerator compartment into which light can be introduced by the light-transmitting casing portion with the optical filter.

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