JP2607838Y2 - Electronic device and liquid crystal display device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION The present invention is directed to an electronic device using an organic material such as a plastic film, which is a flexible or flexible material having a light-transmitting property, in an electronic device using a DLC film (diamond) on the surface of the plastic film. Like carbon), that is, a device coated with an amorphous diamond-like carbon film.

The present invention relates to a technique applied to a film-like solar cell having a light-transmitting property and having a high flexibility, a liquid crystal display device, and an electronic device such as a thin calculator composed of a plastic plate.

[0003]

2. Description of the Related Art Film-type solar cells, liquid crystal display devices, card-type calculators, and the like are used as electronic devices using a light-transmitting and flexible plastic film or a thin plastic film having a thickness of several millimeters.

For example, as a flexible solar cell,
Polyacrylate (PAR), polyether sulfone (PE) instead of the glass substrate used in conventional thin film solar cells (eg, amorphous silicon solar cells)
It is known to use a so-called engineering plastic having flexibility such as S), that is, flexibility.

The solar cell using these plastic films as a substrate has a wide range of applications because of its flexibility, and has advantages such as light weight and no breakage.

[0006] Further, a card type calculator using a plastic film having a thickness of several millimeters, which is not flexible but has a light transmitting property, has been widely spread.

[0007]

2. Description of the Related Art The following problems have been pointed out in the conventional electric equipment using a transparent plastic film as a substrate, for example, a film-shaped solar cell. (1) The plastic surface is easily scratched. (2) The plastic film absorbs ultraviolet rays and deteriorates.
As a result, the transparent one becomes gray, and when a plastic film is used on the light incident side, the photoelectric conversion efficiency decreases.

In general, liquid crystal display devices and thin film type electronic devices (for example, integrated circuits) have a short wavelength of ultraviolet rays (380 nm).
Below) is known to be weak. This can be seen from the fact that the display function deteriorates when the liquid crystal device is exposed to sunlight.

Furthermore, it is well known that electronic devices are generally sensitive to static electricity. This becomes a serious problem in an electronic device using a plastic film which is easily charged.

[0010]

SUMMARY OF THE INVENTION The present invention provides a plastic film exposed on the surface of an electronic device using a transparent plastic film, which is an organic material having a light-transmitting property and a wide range of applications, which is transparent and has a wide range of applications. Protecting the surface, preventing the deterioration of the plastic film due to the absorption of ultraviolet rays, preventing the electronic device parts from being directly exposed to ultraviolet rays, and preventing the plastic film from being charged with static electricity. The above is the purpose of the invention.

[0011]

The present invention is an electronic device using a translucent substrate material having a DLC film formed on at least one surface thereof.

The light-transmitting substrate material having a DLC film formed on at least one surface means the strength of the device in an electronic device using a transparent plastic film, which is generally a light-transmitting substrate material, as a substrate. Is a transparent plastic film, and the transparent plastic film is used as a substrate to provide, for example, a photoelectric conversion layer and a liquid crystal display layer, and the other surface is exposed to the outside. The translucent material (for example, the surface of a transparent plastic film) exposed to the inside is coated with a DLC film (diamond-like carbon), that is, an amorphous diamond-like carbon film.

The following effects can be obtained by coating the exposed surface of the transparent plastic film with the DLC film. (1) The surface of the plastic film is less likely to get scratched. (2) The DLC film absorbs light of 400 nm or less, so it can block UV rays, preventing deterioration of the plastic film and deterioration or failure of the electronic device body due to UV rays. I was able to. (3) Since the DLC film has a specific resistance of 10 ⁵ to 10 ¹⁴ Ωcm, electrostatic charging can be prevented. Knoop hardness of 50 for DLC film
The thing of 0-600 kg / mm < ² > was used.

As the electronic device, a photoelectric conversion device (for example, a solar cell), a liquid crystal display device, or other thin film type electronic device can be used.

Further, the transparent substrate material does not necessarily have to be flexible. This is because, even if only a transparent plastic substrate is used, it has characteristics such as light weight, easy handling, and high safety as compared with a conventional electronic device using a glass substrate.

[0016]

EXAMPLES Example 1 In this example, a transparent plastic film having a DLC film coated on one surface and a DL film of the plastic film were used.
It is a film-like solar cell having a photoelectric conversion layer provided on the other surface which is not coated with a C film.

FIG. 1 shows the structure of this embodiment. In this example, a polyarylate (12) of a transparent plastic film, which is an organic material having flexibility and translucency, provided with a DLC film (11) on the side where light (10) enters, and this polyarylate.
(12) a transparent conductive film which is a photoelectric conversion device provided on the (13)
And a photoelectric conversion layer (14) made of amorphous silicon,
It consists of the back electrode (15).

The thickness of the DLC film (11) is 1500 in this embodiment.
It is Å. The photoelectric conversion device has the same structure as the photoelectric conversion part of the film-shaped amorphous silicon solar cell, which is a known structure.

As shown in FIG. 1, in the case of a photoelectric conversion device in which light is incident from the side of the transparent plastic film that is the substrate, the transparent plastic film is exposed to the ultraviolet rays (wavelength of 380 nm or less) described in the problems of the prior art. It is possible to prevent the problem of deterioration and deterioration of light transmittance.

FIG. 2 shows the wavelength dependence of the light transmittance of polymarilate (100 μm thick) which is a general transparent plastic film. From this figure, it can be seen that a general transparent plastic film absorbs light having a wavelength of 400 nm or less, that is, ultraviolet rays.

The solar cell having the structure shown in FIG. 1 is generally used because the photoelectric conversion layer can be protected by the transparent electrode.

The important point of the present invention is that the DLC film can be used as a filter for cutting light of 400 nm or less.

The experimental fact that this DLC film absorbs light of 400 nm or less will be described below. Figure 3 shows a thickness of 1500Å
The dependence of the light transmittance of the DLC film on the incident light wavelength is shown. It can be seen from Fig. 3 that the light having a wavelength of 400 nm or more has a transmittance of 90% or more, but the light having a wavelength of 400 nm or less sharply decreases the transmittance.

Moreover, since the DLC film has a composition mainly composed of carbon bonds, the DLC film is not likely to be deteriorated and has a characteristic that the light transmittance hardly changes even when absorbing ultraviolet rays.

Therefore, it is effective to make the DLC film, which is hard to deteriorate in front of the transparent plastic film, absorb light of 400 nm or less, that is, ultraviolet light.

FIG. 4 is a graph showing the relationship between the standard value and the incident light wavelength, where the maximum efficiency of the amorphous silicon solar cell is 1, and the efficiency of the amorphous silicon solar cell is 400 nm or less. It can be seen that even if the light having the wavelength is cut, the efficiency is not significantly reduced.

The structure of the present invention has the effect of cutting off the ultraviolet rays of the DLC film in a photoelectric conversion device in which light is incident from the transparent plastic film substrate side as shown in FIG. The DLC film is also used in the solar cell where light does not enter (Fig. 5).
(11) can be used as a surface protective film and an antistatic film of a plastic film substrate which is easily charged.

It is needless to say that the structure of the present invention is not only applied to a solar cell but also to a substrate having a light-transmitting property and flexibility, such as a photosensor using a transparent plastic film substrate. Absent.

As the photoelectric conversion layer, not only a PIN structure but also a generally known photoelectric conversion structure such as PIP and NIN can be used.

Further, the type of semiconductor is not limited to amorphous silicon, and polycrystalline silicon, single crystal silicon, and other compound semiconductors can be used.

Needless to say, any known film forming method may be used in the manufacturing method of this embodiment. This is also apparent from the fact that the feature of the present invention is that the DLC film is used as the physical, electrical and optical protective film of the transparent plastic film.

In this example, polyarylate (PAR) was used as the transparent plastic film, but polyether sulfone (PES), polyethylene terephthalate (PE) was used.
T) etc. can be used, and other transparent substrate (eg glass substrate) if the purpose is to block ultraviolet rays.
May be used instead of the transparent plastic film.

By adopting the constitution of the present invention, the reliability of a film-shaped solar cell using a transparent plastic film as a substrate could be improved.

If attention is paid to the property of the DLC film that it is not charged, a plastic film can be used as a surface protective film for electronic devices and the like, a deterioration preventing film by ultraviolet rays, and an antistatic film for static electricity. In this case, a DLC film may be provided on both sides of the transparent plastic film if necessary.

Example 2 In this example, a transparent plastic film having a DLC film coated on one surface and a DL film of the plastic film were used.
In an electronic device characterized by having a layer having an electric action provided on the other surface not coated with the C film, a layer having a liquid crystal display function, that is, a liquid crystal layer as a layer having an electric action, This is an example of using a layered liquid crystal display device having electrodes, a drive circuit, and the like.

The liquid crystal display device may be driven by a simple matrix type or an active matrix type.
The liquid crystal type may be TN type, STN type or FLC type.

The transparent plastic film may or may not have flexibility.

The structure of this embodiment is shown in FIG. In this example, polyarylate (P
AR) (3 mm thickness) (61), and a DLC film (63) with a thickness of 1500 Å is provided on the display side of a liquid crystal display device comprising a liquid crystal display layer (62). The liquid crystal display layer has a simple matrix type structure using FLC (ferroelectric liquid crystal).

In the figure, (64) is a lower electrode and (67) is an upper electrode. A matrix was constructed with these two electrodes. Further, (65) and (66) are alignment films, and (68) is a ferroelectric liquid crystal (FLC).

It goes without saying that as the liquid crystal layer (62), another liquid crystal display device structure, for example, a TFT active matrix liquid crystal display device may be used.

In this embodiment, only the part exposed to sunlight or the like is used.
A DLC film was provided, but if it is used as an antistatic film,
A DLC film may be provided on the surface of (61) opposite to the liquid crystal layer.

By adopting the constitution of this embodiment, surface protection in a card type calculator or a card type liquid crystal display device using a plastic film, deterioration of the liquid crystal layer due to ultraviolet rays (wavelength of 380 nm or less) which is a problem during outdoor use ( It was possible to prevent blurring of the display and lowering of contrast when the liquid crystal layer was deteriorated by ultraviolet rays.

Further, since the static electricity is not charged, the internal IC and the like are not destroyed by the static electricity.

In order to prevent electrostatic charge, the entire electronic device (71), for example, the entire surface of the electronic device (71) may be covered with the DLC film (72) as shown in FIG.

In this case, the liquid crystal display of the card type calculator has a feature that it can block ultraviolet rays.

It is also effective to coat the DLC film on the surface of a substance which should not be exposed to ultraviolet rays, that is, a substance which is altered by the irradiation of ultraviolet rays.

On the surface of a substance having general light transmittance,
By coating the DLC film, a filter that blocks ultraviolet rays can be formed.

Similarly, DLC is applied to substances that must not be charged.
A film may be coated to form an antistatic film.

[0049]

The electronic device using the substrate material having a light-transmitting property, which is the structure of the present invention, has DL on the surface of the substrate material.
By providing the C film, it is possible to block the deterioration of the substrate material (generally a transparent plastic film) and the ultraviolet rays that cause failure or deterioration of electronic devices provided on this transparent substrate or through this substrate. Can
Moreover, it is possible to obtain an electronic device having surface protection and antistatic functions.

[Brief description of drawings]

FIG. 1 shows an example of a photoelectric conversion device to which the configuration of the present invention is applied.

FIG. 2 shows the relationship between the light transmittance and the wavelength of transmitted light of polymarilate, which is a transparent plastic film.

FIG. 3 shows the relationship between the light transmittance of a DLC film and the wavelength of transmitted light.

FIG. 4 shows the relationship between the standard value of the efficiency of an amorphous silicon solar cell and the wavelength of incident light.

FIG. 5 shows another example of the first embodiment.

FIG. 6 shows the structure of the second embodiment.

FIG. 7 shows an example of applying the present invention.

[Explanation of symbols]

10 ... Incoming light 11 ・ ・ ・ DLC membrane 12 ... Transparent plastic film 13 ... Transparent conductive film 14 ... Photoelectric conversion layer 15 ... Back electrode 61 ... Transparent plastic film 62 ... Liquid crystal display layer 63 ... Transparent plastic film 71 ・ ・ ・ Electronic devices 72 ・ ・ ・ DLC membrane

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-2-177373 (JP, A) JP-A-62-149175 (JP, A) JP-A-2-87117 (JP, A) JP-A-63- 169769 (JP, A) JP 58-159520 (JP, A) JP 63-39365 (JP, A) JP 62-144104 (JP, A) JP 55-157274 (JP, A) JP 62-273780 (JP, A) Actual development Sho 62-196362 (JP, U) Actual development Sho 59-191747 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L G09F G02F

Claims (2)

(57) [Scope of utility model registration request] 1. A thin film type electronic device is provided on one surface of a transparent substrate , and light is incident on the other surface of the substrate.
An electronic device characterized in that a DLC film is provided on the exposed surface . 2. A pair of substrates sandwiching a liquid crystal layer, at least one substrate surface of the pair of substrates has a DL
The C film is provided, and the DLC film is on the side opposite to the side on which the liquid crystal layer is provided.
The liquid crystal display device is provided on the surface of the substrate .