JP3300518B2 - Reflector and reflector for strobe using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver reflector and, more particularly, to a silver reflector which can be suitably used for a strobe reflector and its reflector.

[0002]

2. Description of the Related Art Conventionally, as a reflector for a strobe, an aluminum plate having a polished surface formed by sheet metal processing has been used. In recent years, however, a strobe is also used for a simple camera such as a film with a lens. As a result, the weight and size of the electronic flash system have become increasingly important as a whole. A capacitor for discharging a xenon lamp used for a strobe occupies a large proportion in a strobe circuit, and reducing the size of the capacitor not only leads to a reduction in the size of the entire strobe system but also a reduction in cost, which is extremely important in industry. It is. One method of reducing the size of this capacitor is to use silver having a higher reflectivity in place of the above-polished aluminum in order to allow the light emitted from the xenon lamp to efficiently reach the subject. Can be considered as one solution. The present inventors have disclosed a technique relating to a reflector having a higher reflectance in the visible light region than aluminum and capable of performing sheet metal working or punching as in the case of an aluminum plate (for example, Japanese Patent Application Laid-Open No. 5-162227).

The reflector proposed by the present inventors has a transparent polymer film (A), a silver thin film layer (B), an adhesive layer (C), and a plate-like molded body (D) formed in the order of ABCD. In this method, the surface of the silver thin film was not directly exposed to the atmosphere, the problem of corrosion of the surface of the silver thin film was solved, and the weather resistance of the reflector using silver was remarkably improved.

[0004]

SUMMARY OF THE INVENTION The present inventors have
The above-mentioned reflector using silver was punched out, processed into a sheet metal for a strobe, and actually used for a strobe to emit light 10 to 50 times, so that the surface of the polymer film layer of the silver reflector was expected to be blackened. I encountered an inconvenient problem. Therefore, it is desired that the reflector actually used does not blacken at least 50 times of light emission. The present inventors have conducted intensive studies on the cause of the blackening, and surprisingly discovered that the high voltage high-frequency trigger applied from outside the lamp to induce light emission causes the blackening. Accordingly, the present inventors have made intensive studies on a method for solving this problem. As a result, they have found that the above problem can be solved by using a transparent polymer film having a dielectric loss tangent of 0.0025 or less for the reflector, and arrived at the present invention. The present invention has been made based on such findings.

[0005]

That is, according to the present invention, at least the transparent polymer film (A), the silver thin film layer (B), the adhesive layer (C) and the plate-like molded product (D) are made of AB.
A surface of the transparent polymer film (A) is formed as a reflection plate having a surface A as a reflection surface.
A silver reflector having a dielectric loss tangent of not more than 0.0025 at a high frequency of 10 MHz, or a silver reflector having a normal heat resistance of the transparent polymer film (A) of 80 ° C. or more; The molecular film (A) is a silver reflector made of polyethylene, polypropylene, polycarbonate, or polystyrene, and the transparent polymer film (A) has a transmittance of 80% or more for light rays in the wavelength range of 400 nm to 750 nm. A silver reflecting plate, wherein the silver thin film layer (B) is a silver reflecting plate formed by a sputtering method or a vacuum evaporation method, and the plate-like formed body (D) is aluminum, an aluminum alloy, stainless steel, copper It is a silver reflector selected from a zinc alloy and steel, and has a reflectance for light rays in a wavelength range of 450 nm to 750 nm. A silver reflection plate is 3% or more, also, the film thickness of the silver thin film layer (B) is 70nm~300n
m, which is a reflective umbrella for a strobe formed by processing the above-mentioned silver reflective plate into an umbrella shape.

Hereinafter, the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing an example of the cross-sectional structure of the reflector of the present invention. In FIG. 1, 01 is a transparent polymer film, 02 is a silver thin film layer, 03 is an adhesive layer, 04 is a plate-like molded body, and 01 to 04 form a silver reflecting plate 20. Also,
FIG. 2 is a view showing a cross section of a strobe structure in which a silver reflector is brought into contact with a xenon tube, and FIG. 3 is a view seen from the back side of a light emitting surface of the strobe structure in which a silver reflector is brought into contact with a xenon tube. FIG. 4 is a diagram showing a strobe light emitting circuit. In addition, 1
0 indicates a xenon lamp, 20 indicates a silver reflector, and 30 indicates a trigger terminal.

[0007] The material of the polymer film in the present invention is:
Polyethylene, polypropylene, polycarbonate, polystyrene, or the like can be used, but is not necessarily limited thereto, or among them, it is transparent, has a relatively high normal heat resistance, and has a dielectric loss tangent of 0.0.
If it is 025 or less, it can be used. Polyethylene film, polypropylene film, polycarbonate film and polystyrene film are widely used as dielectrics of film capacitors, and are recognized as a material having a low dielectric loss tangent.
Some have a dielectric loss tangent greater than 0.0025,
It should be noted that these cannot be used for the purposes of the present invention. However, it is important in the present invention to use a polymer film having a dielectric loss tangent of 0.0025 or less. Even if a silver reflector is formed using a polymer film having a dielectric loss tangent of greater than 0.0025, the film is blackened by 10 to 50 strobe light emissions, and sufficient durability cannot be obtained. .

It is understood by those skilled in the art that the dielectric loss of the film is proportional to the product of the dielectric loss tangent and the relative dielectric constant, but the relative dielectric constant of the transparent polymer film is generally 100 kHz to 100 kHz. 2.0 to 3.5 in the range of 10 MHz
It is known that there is no great difference depending on the type of the film, and the value is small. Therefore, there is not much room for selection of the relative dielectric constant when producing the silver reflector according to the present invention, but for the purpose of the present invention, the relative dielectric constant is 2.0 to 3.0.
It is preferred to use a film in the range of 5.

The thickness of the polymer film used in the present invention is not limited, but a thickness of about 25 to 150 μm is preferably used. The optical characteristics of the polymer film used are such that the light transmittance of light having a wavelength of 550 nm is 8
It is preferably 0% or more. More preferably, the light transmittance is 80% for light having a wavelength of 500 to 700 nm.
And more preferably 85% or more. If the light transmittance is much lower than 80%, the total reflectance of the reflective film will not reach a desired value.

In the present invention, as shown in FIG. 1, a silver thin film layer is formed on one main surface of such a transparent polymer film. Such a silver thin film is formed by a wet method or a dry method. Can be applied. The wet method is a general term for a so-called plating method, and is a method of depositing silver from a solution to form a film. Specific examples include a silver mirror reaction. On the other hand, the dry method is a general term for a vacuum film forming method, and specific examples thereof include a resistance heating type vacuum deposition method, an electron beam heating type vacuum deposition method, an ion plating method, and an ion beam assisted vacuum deposition method. And a sputtering method. In particular, in the present invention, a vacuum film forming method capable of a roll-to-roll system for continuously forming a film is preferably used.

In the vacuum deposition method, a silver raw material is an electron beam,
Melt by resistance heating, induction heating, etc., raise the vapor pressure,
Preferably, 0.1 mTorr (about 0.1 Pa) or more is introduced to cause high-frequency or direct-current glow discharge.

In the sputtering method, a DC magnetron sputtering method, an rf magnetron sputtering method, an ion beam sputtering method, an ECR sputtering method, a conventional rf sputtering method, a conventional DC sputtering method, or the like can be used. In the sputtering method, a silver plate-shaped target may be used as a raw material. Helium, neon, argon, krypton, xenon, or the like can be used as the sputtering gas, but argon is preferably used. The purity of the gas is preferably 99.0% or more, more preferably 99.0%.
9.5% or more.

The thickness of the silver thin film layer is not particularly critical, but is preferably about 70 nm to 300 nm, more preferably 70 nm to 200 nm. If the thickness of the silver thin film layer is too small, for example, less than 70 nm, the thickness of the silver film is not sufficient, so that transmitted light is present and the reflectance is not sufficient. On the other hand, if the film thickness is too large, for example, more than 300 nm, the reflectance does not increase, showing a tendency to saturate, and the adhesion of the silver layer to the polymer film is undesirably reduced.

The film thickness can be measured by a stylus roughness meter, a repetitive reflection interferometer, a microbalance, a quartz oscillator method, etc.
The quartz oscillator method is suitable for obtaining a desired film thickness because the film thickness can be measured during film formation. There is also a method in which film formation conditions are determined in advance, a film is formed on a sample substrate, the relationship between the film formation time and the film thickness is examined, and the film thickness is controlled by the film formation time. The silver thin film layer may contain metal impurities such as gold, copper, nickel, iron, cobalt, tungsten, molybdenum, tantalum, chromium, indium, manganese, and titanium, which do not impair the performance. Of course.

After the silver layer is formed, a single metal layer or an alloy layer of Inconel, chromium, nickel, titanium, aluminum, molybdenum, tungsten, or the like is formed to a thickness of 10 nm in order to protect the silver layer and improve the slipperiness of the film. ~ 3
It will be understood by those skilled in the art that lamination of about 0 nm is effective. When providing the silver thin film layer on the transparent polymer film,
It is within the technical common sense of those skilled in the art that performing corona discharge treatment, glow discharge treatment, surface chemical treatment, surface roughening treatment, etc. is effective in improving the adhesion between the silver thin film layer and the polymer film. There will be.

However, when the above process is performed, the transparent polymer film as the substrate is heated, and the lamp generates heat when a strobe light is emitted. In order to reduce the temperature, the normal heat resistance temperature of the film is somewhat high, for example, 8
The temperature is preferably 0 ° C. or higher. More preferably, the normal heat resistance temperature is 100 ° C. or higher. Since the normal heat-resistant temperature of polystyrene is 80 ° C., it can be suitably used for a silver reflector for strobe light. The normal heat-resistant temperature of polyethylene is 120
° C, the common heat-resistant temperature of polypropylene is 130 ° C, and the common heat-resistant temperature of polycarbonate is 120 ° C. Therefore, these films can be suitably used for a silver reflector for a strobe light.

In the present invention, the silver thin film layer (B) and the plate-like molded body (D) are bonded and integrated by an adhesive layer (C). The adhesive used here is heat or with the aid of a catalyst. Any adhesive can be used as long as it can be adhered. Specifically, a general adhesive such as a silicone adhesive, a polyester adhesive, an epoxy adhesive, and a cyanoacrylate adhesive can be used. Silicone-based adhesives and polyester-based adhesives have excellent heat resistance and electrical properties, and thus can be suitably used for a strobe reflector for applying a trigger. Epoxy-based adhesives are excellent in strength and heat resistance, and therefore can also be suitably used. The cyanoacrylate-based adhesive has excellent quickness and strength, and can be used for efficient reflector production. These adhesives are roughly classified into a thermosetting type, a hot-melt type, and a two-component mixing type depending on the bonding method, and a thermosetting type or a hot-melt type which can be continuously produced is preferably used. Although the thickness of the thermal adhesive is not particularly limited, it is generally about 0.5 μm to 50 μm, preferably about 1 μm to 20 μm.

The adhesion between the polymer film having the silver thin film layer formed thereon and the plate-shaped molded product is usually performed by the steps of coating the silver thin film layer with an adhesive, drying, and laminating the plate-shaped molded product with a roller. . There are many methods for coating the adhesive, depending on the type of substrate and adhesive.
The gravure coater method and the reverse coater method are widely used. In the gravure coater method,
The gravure roll partially immersed in the adhesive is rotated, and the film fed by the backup roll is coated by contacting the gravure roll with the adhesive. The coating amount can be adjusted by controlling the number of rotations of the roll and the viscosity of the adhesive. The reverse coater method is similar to the gravure roll method, but the amount of the adhesive adhering to the coating roll is adjusted by a metering roll installed in contact with the coating roll.
The drying temperature and the laminating temperature of the coated adhesive vary depending on the type of the adhesive, but are around 100 ° C. when the above-mentioned general adhesive is used.

The adhesive strength between the transparent polymer film having the silver thin film layer formed thereon and the plate-like molded body obtained as described above, measured with a 180 degree peel strength, was 100 g.
/ Cm or more. If the adhesion strength is not reached, when the sheet metal is processed as a strobe reflector, the transparent polymer film having the silver thin film layer may be peeled off from the plate-like molded body, which may cause deformation or the like.

As a material for forming the plate-like molded body used in the present invention, usually, a metal is preferable. For example, aluminum, aluminum alloy, stainless steel, steel zinc alloy, steel and the like are used. Each has advantages, and can be selected and used depending on the application as follows.
Aluminum is lightweight and excellent in workability, and has high thermal conductivity and can effectively release the heat applied to the atmosphere, so that it can be suitably used as a reflector for a strobe in which a reflector is heated by lamp emission. . Since aluminum alloy is lightweight and has high mechanical strength, it can be suitably used as a reflector for strobe light. Stainless steel has high mechanical strength,
Further, since it has excellent corrosion resistance, it can be suitably used as a reflector for strobe light. A steel zinc alloy, that is, brass or brass, has a high mechanical strength and is easy to solder, so that it is easy to take a trigger terminal, and this can also be suitably used for a reflector for strobe light. Since steel is inexpensive, it is preferably used when it is necessary to reduce costs.

Thus, the reflectance of the produced reflector is
Typically, it is 93% or more for light having a wavelength of 550 nm, and more specifically, 9% in the range of 450 nm to 750 nm.
3% or more.

In order to process and form a silver reflector for a strobe using such a silver reflector, a conventional method of processing an aluminum plate into a reflector for a strobe can be applied as it is. For example, a reflector is cut into a shape obtained by expanding a reflector umbrella in a plane, and the cut flat plate is bent and formed (JP-A-55-118002). Since this method has a low production cost, it is suitably used for films with lenses.

The structure of the silver reflector according to the present invention and a typical method for evaluating the electrical characteristics will be described below. The thickness of each part of the transparent polymer film, the silver thin film layer, the adhesive layer, and the plate-like molded body can be directly measured by observing the cross section with a transmission electron microscope (TEM). Material analysis of polymer film
This can be done by infrared spectroscopy (IR). The material analysis of the adhesive is performed by peeling off the silver thin film layer and the plate-like molded body, exposing the adhesive, preparing a sample in which the adhesive is dissolved in an appropriate solvent, and taking an infrared spectrum (IR) thereof. Done. Material analysis of the silver thin film layer and the plate-like formed body can be performed by X-ray fluorescence spectroscopy (XRF). Furthermore, an X-ray microanalyzer (EPM
In A), elemental analysis of a finer part than X-ray fluorescence spectroscopy can be performed. In addition, if the polymer film on which the silver thin film layer is formed is peeled from the adhesive layer to expose the silver thin film layer, the composition can be analyzed by Auger electron spectroscopy (AES) and the thickness can be determined by taking a depth profile. Can be. The dielectric constant and the dielectric loss tangent of the transparent polymer film are determined according to JIS-K-6911.
It can be measured by a method according to. If more accuracy is required, a mutual induction bridge method (transformer bridge method), or more simply, a voltage rise ratio method (Q meter method) is used. Less than,
An example of an embodiment of the present invention will be described with reference to an example.

[0024]

EXAMPLES Examples of the embodiments of the present invention will be described below with reference to examples. In addition, the total light transmittance, the reflectance, and the dielectric loss tangent described in the examples were measured by the following devices and methods. Total light transmittance, reflectance: spectrophotometer (Hitachi U-340
0). Dielectric tangent: Measured by a voltage rise ratio method (Q-meter method) according to JIS-K-6911. The measurement was performed at room temperature, and the measurement frequency was 1 MHz, and the average of five measurements was taken.

Hereinafter, the strobe for photographing in Examples 1 to 5 and Comparative Examples 1 to 3 is as schematically shown in FIGS. 2 and 3. Here, FIG. 2 shows a cross section of a strobe structure in which a silver reflector is brought into contact with a xenon tube, and FIG.
Shows a view from the back side of the light emitting surface of the strobe structure in which a silver reflector is brought into contact with a xenon tube. As a precautionary measure, 10 is a xenon lamp, 20 is a silver reflector, and 30 is a trigger terminal. FIG. 4 shows a light emitting circuit for emitting a flash. The voltage charged by the electric field capacitor is applied to the xenon lamp, and a high-voltage, high-frequency trigger is applied to the trigger terminal to induce light emission. Here, the voltage applied to the xenon lamp, the voltage applied to the trigger terminal, and the frequency may be set to appropriate values that allow the xenon lamp to emit light.

Example 1 Polypropylene film (50 μm thick, total light transmittance = 87%, dielectric loss tangent at 1 MHz = 0.0003)
Was deposited with a purity of 99.9% by electron beam vacuum evaporation. When the thickness of the silver layer was measured with a quartz crystal film thickness monitor, it was 100 nm. The silver side of the film and the aluminum plate were bonded with a polyester hot melt adhesive to form a silver reflector. Its reflectance was 94.6%. It is used as a strobe reflector umbrella by sheet metal processing, the xenon lamp and the polypropylene film side are fixed in contact, and the trigger terminal of the strobe light emission circuit is connected to the aluminum plate of the silver reflector to form a strobe for photography. did.

Example 2 Polyethylene film (25 μm thick, total light transmittance =
88%, dielectric loss tangent at 1 MHz = 0.0005), formed by DC magnetron sputtering using a 99.9% pure silver as a target and a 99.5% pure argon as a sputter gas to a thickness of 150 nm on the film. did. The silver side of the film and the stainless steel plate were bonded with a polyester hot melt type adhesive to form a silver reflection plate. Its reflectivity was 95.3%. It is used as a strobe reflector umbrella by sheet metal processing, the xenon lamp and the polyethylene film side of the silver reflector are brought into contact and fixed, and the trigger terminal of the strobe light emitting circuit is connected to the stainless steel plate of the silver reflector, for photographing A strobe was formed.

Example 3 Polycarbonate film (50 μm thickness, total light transmittance = 88%, dielectric loss tangent at 1 MHz = 0.001)
Was deposited with a purity of 99.9% by electron beam vacuum evaporation. The thickness of the silver layer was measured with a quartz film thickness monitor and found to be 120 nm. The silver side of the film and the hard zinc alloy plate were bonded with an epoxy adhesive to form a silver reflector. Its reflectance was 95.0%. It is made into an umbrella for a strobe reflector by sheet metal processing, the xenon lamp and the polycarbonate film side of the silver reflector are fixed in contact, and the trigger terminal of the strobe light emitting circuit is connected to the steel zinc alloy plate of the silver reflector, A flash for photography was formed.

Example 4 Polystyrene film (50 μm thick, total light transmittance =
88%, dielectric loss tangent at 1 MHz = 0.0003) by DC sputtering, using 99.9% pure silver as a target, and using 99.5% pure argon as a sputtering gas, so that the thickness becomes 120 nm on the film. Formed. The silver side of the film and the aluminum plate were adhered with an epoxy adhesive to form a silver reflector. Its reflectance was 94.2%. It is made into an umbrella for a strobe reflector by sheet metal processing, and the xenon lamp and the polystyrene film side of the silver reflector are contacted and fixed, and the trigger terminal of the strobe light emitting circuit is connected to the aluminum plate of the silver reflector for photography. A strobe was formed.

Example 5 A polycarbonate film (thickness: 50 μm, total light transmittance: 88%, dielectric loss tangent: 0.0025) was subjected to a DC magnetron sputtering method using silver having a purity of 99.9% as a target, and a purity of 99.5. % Argon was used as a sputtering gas to form a film on the film to a thickness of 120 nm. The silver side of the film and the steel zinc alloy plate were bonded with a polyester hot melt type adhesive to form a silver reflector. Its reflectivity was 95.3%. It is made into an umbrella for a strobe reflector by sheet metal processing, the xenon lamp and the polycarbonate film side of the silver reflector are fixed in contact, and the trigger terminal of the strobe light emitting circuit is connected to the steel zinc alloy plate of the silver reflector, A flash for photography was formed.

Comparative Example 1 A polyethylene terephthalate film (50 μm thick,
Total light transmittance = 88%, dielectric tangent at 1 MHz =
0.005) by DC sputtering method, with a purity of 99.9.
% Of silver as a target, and a sputtering gas of 99.5% purity of argon was formed on the film to have a thickness of 120 nm. The silver side of the film and the aluminum plate were bonded with a polyester hot melt adhesive to form a silver reflector. Its reflectivity was 95.5%. It is made into an umbrella for a strobe reflector by sheet metal processing, the xenon lamp and the polyethylene terephthalate film side of the silver reflector are fixed by contact, and the trigger terminal of the strobe light emitting circuit is connected to the aluminum plate of the silver reflector, taking a picture Strobe was formed.

Comparative Example 2 Polyethylene naphthalate film (thickness: 50 μm, total light transmittance = 84%, dielectric loss tangent at 1 MHz = 0.
In 003), silver having a purity of 99.9% was deposited by an electron beam vacuum deposition method. The thickness of the silver layer was measured with a quartz crystal film thickness monitor to be 100 nm. The silver side of the film and the stainless steel plate were adhered with an epoxy adhesive to form a silver reflector. Its reflectance was 94.9%. This is made into a strobe reflector umbrella by sheet metal processing, and the xenon lamp and the polyethylene naphthalate film side of the silver reflector are contacted and fixed.The trigger terminal of the strobe light emitting circuit is connected to the stainless steel plate of the silver reflector. A flash for photography was formed.

Comparative Example 3 Silver having a purity of 99.9% was vapor-deposited on a polyethersulfone film (thickness 25 μm, total light transmittance = 88%, dielectric loss tangent = 0.005) by an electron beam vacuum vapor deposition method. When the film thickness of the silver layer was measured with a quartz crystal film thickness monitor, it was 90 nm.
Met. The silver side of the film and the aluminum plate were bonded with a polyester hot melt adhesive to form a silver reflector. Its reflectance was 95.1%. By making it into a strobe reflector umbrella by sheet metal processing, fixing the xenon lamp and the silver reflector with the polyether sulfone film side in contact, connecting the trigger terminal of the strobe light emitting circuit to the aluminum plate of the silver reflector, A strobe for photography was formed.

The strobe for photographing formed in Examples 1 to 5 and Comparative Examples 1 to 3 is incorporated in the strobe circuit described with reference to FIG. 4, the voltage applied to the xenon lamp is 320 V, and the voltage applied to the trigger terminal is 320 V. Was set at a peak-to-peak value of 15 kV and a frequency of 1 MHz, a xenon lamp was repeatedly emitted at intervals of 30 seconds, and a durability test was performed. The results shown in Table 1 were obtained.

[0035]

[Table 1] Symbols in the table are ○: No abnormality ×: Blackened

[0036]

The fact that Examples 1 to 5 according to the present invention are far superior in durability against strobe light emission as compared with Comparative Examples 1 to 3 which have been conventionally used as a silver reflection plate is that the former is 50%. It is clear from the experimental results that no abnormalities are shown for the one light emission, whereas the latter is already darkened by 10 to 50 light emission. In addition, Examples 1 to
It is to be noted that the sample No. 3 did not blacken even after 300 light emission. That is, according to the present invention, it is possible to provide an excellent silver reflector that can be suitably used for a silver reflector of a strobe.

[Brief description of the drawings]

FIG. 1 is a diagram showing a sectional structure of a reflector.

FIG. 2 is a cross-sectional view of a strobe structure in which a silver reflector is brought into contact with a xenon tube.

FIG. 3 is a view from the back side of a light emitting surface of a strobe structure in which a silver reflector is brought into contact with a xenon tube.

FIG. 4 is a diagram showing a strobe light emitting circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 01 Transparent polymer film 02 Silver thin film layer 03 Adhesive layer 04 Plate-shaped molded object 10 Xenon lamp 20 Silver reflector 30 Trigger terminal

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-7-191205 (JP, A) JP-A-7-32537 (JP, A) JP-A-7-32536 (JP, A) JP-A-4- 177758 (JP, A) JP-A-2-169244 (JP, A) JP-A-1-279202 (JP, A) JP-A-1-279201 (JP, A) JP-A-54-62843 (JP, A) 58-125 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 15/08 G02B 5/08 G03B 15/02

Claims (9)

(57) [Claims] At least the transparent polymer film (A), the silver thin film layer (B), the adhesive layer (C) and the plate-like molded body (D) are formed in the order of ABCD, and the surface of A is reflected. A transparent polymer film (A)
A silver reflector having a dielectric loss tangent to a high frequency of 100 kHz to 10 MHz of 0.0025 or less. 2. The silver reflector according to claim 1, wherein the transparent polymer film (A) has a normal heat resistance of 80 ° C. or higher. 3. The silver reflector according to claim 1, wherein the transparent polymer film (A) is polyethylene, polypropylene, polycarbonate, or polystyrene. 4. The wavelength 400 of the transparent polymer film (A).
80 for light in the range of
% Or more. 5. The silver reflector according to claim 1, wherein the silver thin film layer (B) is formed by a sputtering method or a vacuum evaporation method. 6. The silver reflection plate according to claim 1, wherein the plate-shaped formed body (D) is selected from aluminum, aluminum alloy, stainless steel, copper zinc alloy and steel. 7. The silver reflector according to claim 1, which has a reflectivity of 93% or more for light rays having a wavelength in the range of 450 nm to 750 nm. 8. The silver thin film layer (B) has a thickness of 70 nm to 30 nm.
The silver reflector according to any one of claims 1 to 7, which has a thickness of 0 nm. 9. A strobe reflecting umbrella obtained by processing the silver reflecting plate according to claim 1 into an umbrella shape.