JPH08329719A - Heat ray cutting filter - Google Patents

Abstract

PURPOSE: To provide such a heat ray cutting filter over a broad band as being capable of sharply and almost completely cutting a heat ray over a broad band from a near infrared radiation area to a far infrared radiation area. CONSTITUTION: A heat ray cutting filter 1 for a lamp is formed by applying an optical multilayer film to a glass substrate. The filter 1 is provided with a heat ray reflecting film A to reflect most of the heat rays in a wavelength band where a large quantity of heat arises from the lamp and a heat ray absorbing film B to absorb the remaining heat rays in sequence as approaching the lamp 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat ray cut filter, and more particularly to a heat ray cut filter for a lamp using an optical multilayer film.

[0002]

2. Description of the Related Art The emission characteristics of light emitted from a lamp are as shown in FIG. 7 in the case of a halogen lamp. For example, when it is desired to prevent heat from being emitted to a product to be illuminated, a glass is used in front of the lamp. There is a case where a harmful heat ray (for example, an infrared ray having a wavelength of 800 nm or more) is removed by placing a filter or a filter and only effective visible light is extracted. At this time, conventionally, a heat ray absorbing glass, a heat ray reflecting filter, a heat ray absorbing filter, etc. have been used.

The heat ray absorbing glass is made by mixing heat ray absorbing component into glass, and the heat ray reflecting filter and the heat ray absorbing filter are formed by forming a heat ray reflecting film and a heat ray absorbing film composed of an optical multilayer film on a glass substrate. .

[0004]

However, in the heat ray absorbing glass and heat ray absorbing filter, when the heat amount of the light source is large, the glass or glass substrate may be damaged due to absorption or the filter film surface may be cracked. Further, the amount of transmitted visible light is low, and the cut characteristics in the near infrared region are poor.
Further, there are drawbacks such as impairing the color rendering property and color temperature.

In addition, the heat ray reflection filter has a narrow infrared ray reflection area, and even if the near infrared ray area is cut, the heat ray in the mid infrared ray area or the far infrared ray area is not cut but is transmitted as it is. Further, when a plurality of heat ray reflection filters are used to widen the cut area, the number of parts increases and the cost increases.

Further, it is possible to combine the heat-ray absorbing glass and the heat-ray reflecting filter, but even if the heat-ray absorbing glass and the heat-ray reflecting filter are combined, a wide band cannot be cut cleanly, and an uncut region remains. The number of points increases, leading to higher costs.

It is an object of the present invention to provide a broadband heat ray cut filter capable of cutting the heat ray in a wide band from the near infrared region to the far infrared region in a sharp manner and almost completely.

[0008]

To this end, in the present invention,
In a heat ray cut filter for a lamp, which is formed by applying an optical multilayer film to a glass substrate, a wavelength band in which the amount of heat generated from the lamp is large from one side or both sides of the glass substrate, closer to the lamp. Heat ray reflection film that reflects most of the heat rays of, and then the heat ray absorption film that absorbs the remaining heat rays in this order:
The heat ray reflection film and the heat ray absorption film are formed.

The radiation characteristics of the lamp differ depending on the type of the lamp. For example, in the case of a halogen lamp, as shown in FIG. 7, the peak is around 1000 nm, and the energy-intensity is in the shorter wavelength region (near 200 nm to 1000 nm). Rapidly decreases, and in the wavelength region longer than the peak wavelength (around 1000 nm to 4000 nm or more), a mountain-shaped curve is drawn. Visible light range is almost 400
It is in the vicinity of nm to 700 nm.

In the heat ray cut filter of the present invention, the heat ray reflective film reflects infrared rays having a wavelength of about 800 nm to about 2000 nm from a peak wavelength region where a large amount of heat is generated from the lamp to a longer wavelength region. As a result, about 80% or more of harmful heat rays emitted from the lamp are removed. The remaining 20% or less of heat rays, that is, the wavelength is 200
Infrared rays in the wavelength region near 0 nm or more are absorbed by the heat ray absorbing film.

The heat ray reflective film may be composed of a plurality of two or more films so as to share the reflected wavelength band.
For example, in two cases, the peak wavelength range of the lamp (for example, 8
A film mainly reflecting around 00 nm to around 1200 nm) and a long wavelength region (1200 n apart from the peak).
m-near 2000 nm) which is a film that reflects infrared rays. These two films mainly reflect the peak wavelength region, and the film that reflects the peak wavelength region is located on the near side of the lamp and in the wavelength region away from the peak region. Infrared-reflecting films are arranged in that order. Further, these two films do not necessarily have to be adjacent to each other, and may be arranged with the glass substrate sandwiched as long as the order is not disturbed.

The heat ray reflective film is preferably SiO ₂ and MgF.
One and one of _{2, TiO 2, ZrO 2,} Ta 2 O 5,
It consists of alternating layers with a substance selected from Nb ₂ O ₅ and Al ₂ O ₃ . For example, alternating layers of SiO ₂ and TiO ₂ or S
There are alternating layers of iO ₂ , ZrO _2, and TiO _2, and the like, and the material, the number of layers, the thickness of layers, etc. are selected according to the desired wavelength band to be reflected.

Further heat absorbing film and at least one substance selected from the constituents of the heat ray reflective film, or mixed with In ₂ O _3, for example, 4% to 7% of SnO ₂ (this is called ITO), SnO ₂ is mixed with, for example, 4 to 7% of Sb ₂ O ₃ to form an alternating layer with a layer-constituting substance. For example, MgF
₂ , alternating layers of ITO and ZrO ₂ . The substance, the number of layers, the thickness of layers, etc. are selected according to the desired wavelength band to be absorbed.

As long as the heat ray reflecting film and the heat ray absorbing film are arranged on one surface of the glass substrate, as long as the heat ray reflecting film and the heat ray absorbing film are arranged in this order from the side closer to the lamp, they may be arranged on both surfaces. It may be arranged separately. Similarly, when the heat ray reflecting film is also composed of a plurality of pieces, as described above, the film that mainly reflects the peak wavelength region of the lamp is on the lamp side of the heat ray absorbing film, and then separated from the peak. Moreover, the films that reflect infrared rays in the longer wavelength region are arranged in this order.

For example, if the glass substrate is G, the heat ray reflection film is A, and the heat ray absorption film is B, then from the lamp side, for example, A
・ G ・ B, A ・ B ・ G, G ・ A ・ B can be arranged in this order. When the heat ray reflective film is divided into a film A1 which mainly reflects in the peak wavelength region and a film A2 which reflects infrared rays in a longer wavelength region away from the peak,
For example, A1, A2, G, B, A1, G, A2, B, A1
-A2, B, G, G, A1, A2, B can be arranged in this order.

[0016]

By the heat ray reflecting film arranged on the side closer to the lamp, most of the heat quantity generated from the lamp, for example, about 80% or more is reflected, and the remaining heat quantity of 20% or less is absorbed by the heat ray absorbing film. . That is, among the harmful heat rays generated from the lamp, those having a high risk of damaging the filter are removed in order. Therefore, the temperature rise of the filter is extremely small. Moreover, the heat ray is cut over a wide band by the combination of the heat ray reflecting film and the heat ray absorbing film.

[0017]

【Example】

<Example 1>

FIG. 1 shows a first embodiment of the heat ray cut filter of the present invention, 1 is a heat ray cut filter, 2 is a lamp, and the heat ray cut filter 1 is a heat ray reflection film A, a glass substrate G, and a heat ray. The heat ray reflecting film A is formed on the surface of the glass substrate G close to the lamp, and the heat ray absorbing film B is formed on the surface of the glass substrate G far from the lamp. The heat ray reflective film A reflects infrared rays having a wavelength of around 800 nm to 2000 nm, and the heat ray absorbing film B absorbs infrared rays having a wavelength of around 2000 nm or more.

<Example 2>

FIG. 2 shows Example 2 of the heat ray cut filter of the present invention. Reference numeral 3 is a heat ray cut filter, 2 is a lamp, and the heat ray cut filter 3 is a heat ray reflective film A, a glass substrate G, and a heat ray. On the surface of the glass substrate G near the lamp, which is made of the absorption film B, the heat ray reflection film A,
Next, the heat ray absorbing film B is formed. Heat ray reflective film A is 8
The infrared ray having a wavelength of around 00 nm to 2000 nm is reflected, and the heat ray absorbing film B absorbs the infrared ray having a wavelength of around 2000 nm or more.

<Third Embodiment>

FIG. 3 shows Example 3 of the heat ray cut filter of the present invention. Reference numeral 4 is a heat ray cut filter, 2 is a lamp, and the heat ray cut filter 4 is a heat ray reflective film A, a glass substrate G, and a heat ray. The heat ray reflection film A1 is formed on the surface of the glass substrate G close to the lamp, and the heat ray reflection film A2 and the heat ray absorption film B are formed on the surface of the glass substrate G far from the lamp. The heat ray reflective film A1 is around 800 nm to 120
The infrared ray having a wavelength of around 0 nm is reflected, the heat ray reflective film A2 reflects an infrared ray having a wavelength of around 1200 nm to 2000 nm, and the heat ray absorbing film B absorbs an infrared ray having a wavelength of around 2000 nm or more.

<Test Example 1>

A heat ray cut filter having a layer structure as shown in FIG. 3 was prepared having the following layer structure, and its spectral transmittance comprehensive characteristics were measured. The measurement results are shown in FIG. The infrared reflective film A1 is composed of 36 layers, and the materials and thicknesses of the respective layers are as follows.

Layer number Material Thickness (nm) 1 TiO ₂ 21.74 2 SiO ₂ 27.75 3 TiO ₂ 117.78 4 SiO ₂ 181.18 5 TiO ₂ 111.29 6 SiO ₂ 177.91 7 TiO ₂ 111.50 8 SiO ₂ 176.77 9 TiO ₂ 109.95 10 SiO ₂ 178.72 11 TiO ₂ 111.57 12 SiO ₂ 179.17

13 TiO ₂ 111.70 14 SiO ₂ 180.11 15 TiO ₂ 112.40 16 SiO ₂ 178.70 17 TiO ₂ 108.51 18 SiO ₂ 169.92 19 TiO ₂ 101.68 20 SiO ₂ 162. 09 21 TiO ₂ 97.97 22 SiO ₂ 157.40 23 TiO ₂ 94.79 24 SiO ₂ 156.10

25 TiO ₂ 94.39 26 SiO ₂ 154.58 27 TiO ₂ 94.14 28 SiO ₂ 156.58 29 TiO ₂ 94.55 30 SiO ₂ 157.33 31 TiO ₂ 100.07 32 SiO ₂ 165. 03 33 TiO ₂ 21.74 34 SiO ₂ 23.45 35 TiO ₂ 30.61 36 SiO ₂ 91.01

The materials and thickness of each layer of the infrared reflective film A2 are as follows.

1 SiO ₂ 96.42 2 ZrO ₂ 76.67 3 TiO ₂ 121.74 4 ZrO ₂ 76.67 5 SiO ₂ 192.84 6 ZrO ₂ 76.67 7 TiO ₂ 121.74 8 ZrO ₂ 76. 67 9 SiO ₂ 192.84 10 ZrO ₂ 76.67 11 TiO ₂ 121.74 12 ZrO ₂ 76.67

13 SiO ₂ 192.84 14 ZrO ₂ 76.67 15 TiO ₂ 121.74 16 ZrO ₂ 76.67 17 SiO ₂ 192.84 18 ZrO ₂ 76.67 19 TiO ₂ 121.74 20 ZrO ₂ 76. 67 21 SiO ₂ 168.73 22 ZrO ₂ 57.50 23 TiO ₂ 91.30 24 ZrO ₂ 57.50

25 SiO ₂ 144.63 26 ZrO ₂ 57.50 27 TiO ₂ 91.30 28 ZrO ₂ 57.50 29 SiO ₂ 144.63 30 ZrO ₂ 57.50 31 TiO ₂ 91.30 32 ZrO ₂ 57. 50 33 SiO ₂ 144.63 34 ZrO ₂ 57.50 35 TiO ₂ 91.30 36 ZrO ₂ 57.50

37 SiO ₂ 144.63 38 ZrO ₂ 57.50 39 TiO ₂ 91.30 40 ZrO ₂ 57.50 41 SiO ₂ 144.63 42 ZrO ₂ 57.50 43 TiO ₂ 91.30 44 ZrO ₂ 57. 50 45 SiO ₂ 313.36

The materials and the thickness of each layer of the infrared absorbing film B are as follows.

46 MgF ₂ 186.52 47 ITO 132.84 48 MgF ₂ 192.98 49 ITO 134.38 50 MgF ₂ 178.61 51 ZrO ₂ 111.47 52 MgF ₂ 78.84

From the total spectral transmittance characteristics of FIG. 4, the wavelength is 8
It can be seen that heat rays in the vicinity of 00 nm or more are almost completely removed (cut) over a wide band.

<Test Example 2>

Using the heat ray cut filter of Test Example 1,
A comparative test was performed on the temperature characteristics. As a comparative example, a conventional heat ray absorbing glass and heat ray reflecting filter were used. In the comparative test, as shown in FIG. 5, the above sample was placed 100 mm away from a 100 V, 1 kW halogen lamp, the subject was placed 100 mm further away, and the halogen lamp was lit for 25 minutes. The temperature change of the subject was measured using a thermocouple. The measurement result is shown in FIG.

As is apparent from FIG. 6, the heat ray-cutting filter of the present invention cuts heat rays better than the conventional heat ray-absorbing glass and infrared ray reflecting filter, and shows that the temperature rise is small.

[0040]

According to the heat ray cut filter of the present invention, infrared rays in an extremely wide area can be reflected and absorbed by one filter and removed almost completely.

Further, due to the heat ray reflecting film disposed on the side close to the lamp, most of the heat generated from the lamp, for example, 8
About 0% or more is reflected, and the remaining amount of heat, for example, 20% or less, is absorbed by the heat ray absorbing film. Among the harmful heat rays generated from the lamps, those having a high risk of damaging the filter are in order. Since it is removed, the temperature of the heat ray cut filter does not rise so much, and heat does not damage the filter.

Further, the heat ray cut filter of the present invention is capable of sharply cutting infrared rays while leaving the visible region, the amount of visible light transmitted is not decreased, and the color rendering property and color temperature are further impaired. Nor.

Further, in the heat ray cut filter of the present invention,
Since the heat ray reflecting film and the heat ray absorbing film are arranged on one glass substrate, the number of parts does not increase and the cost is reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a heat ray cut filter of the present invention.

FIG. 2 is a diagram showing a second embodiment.

FIG. 3 is a diagram showing a third embodiment.

FIG. 4 is a diagram showing the overall spectral transmittance characteristics of Test Example 1.

FIG. 5 is a diagram illustrating a test method of Test Example 2;

FIG. 6 is a diagram showing test results of Test Example 2;

FIG. 7 is a diagram showing a radiation characteristic of a halogen lamp.

[Explanation of symbols]

 1 Heat ray cut filter 2 Lamp 3 Heat ray cut filter 4 Heat ray cut filter

Claims (3)

[Claims] 1. A heat ray-cutting filter for a lamp, which comprises an optical multilayer film on a glass substrate, and is generated from the lamp from one side or both sides of the glass substrate, which is closer to the lamp. A heat ray reflection film that reflects most of the heat rays in a wavelength band with a large amount of heat, then a heat ray absorption film that absorbs the remaining heat rays, in that order, a heat ray reflection film and a heat ray absorption film are formed. Heat ray cut filter. 2. A heat ray reflecting film is formed from a film which reflects heat rays in a peak wavelength band having the largest amount of heat generated from the lamp from a side closer to the lamp, and a film which reflects heat rays in a wavelength region having the next largest amount of heat. The heat ray cut filter according to claim 1, comprising a plurality of films arranged in order. 3. A heat ray reflective film comprising one of SiO ₂ and MgF ₂ , TiO ₂ , ZrO ₂ , Ta ₂ O ₅ and Nb ₂ O.
₅ , In the alternate layer with a substance selected from Al ₂ O ₃ , whether the heat ray absorbing film is a mixture of at least one substance selected from the constituent substances of the heat ray reflecting film and SnO ₂ in In ₂ O ₃ , S
The heat ray-cutting filter according to claim 1 or 2, which is an alternate layer with a layer-constituting substance formed by mixing Sb ₂ O ₃ with nO ₂ .