Patent Application
20050280358
The present invention relates to a light-polarizing film with high permeability for improving an interference light of a color OLED, and more particularly to a light-polarizing film with high permeability absorbing and reflecting the interference light, whereby the necessary light-polarizing effect is acquired, the color OLED doesn't need to increase power, and the color OLED can keep original economical lifetime.
From conventional TV screen with cathode-ray tubes to current TFT panel display with high colorful density, not only the quality and quantity is increased in the high-tech filed, but also the next generation of display is further expected and requested in the market. Lately, many national well-known companies have changed their target and developed an Organic Light Emitting Diode (OLED) and Ploymer Light Emitting Diode (PLED) to apply in the next generation of panel display with high quality.
The structure and light emitting principle of the OLED are similar to those of a light emitting diode, the OLED has many advantages, such as self emitting light, little weight and size, simple structure, low driving voltage, wide visual angle, etc. The advantage of the self-emitting light is that the OLED can emit light by itself instead of a backlight module. The advantage of the little weight and size is that the weight of the OLED is not only light but also the thickness of the OLED is less than 1.5 mm. The advantage of the simple structure is that the cost of the OLED is low but also the lasting of the OLED is increased. The advantage of the low driving voltage is that the low operating voltage is less 10V, generally the low operating voltage is merely less 5V for driving the OLED so as to save power. The advantage of the wide visual angle is that the wide visual angle is more than 160 degrees upward, downward, leftward and rightward so as to be viewed. The OLED has an advantage of good illumination, high brightness, and high contrast so as to acquire good display quality. The OLED has an advantage that the fast response is less 10 μs or merely less than 1 μs so as to be conveniently used. The OLED utilizes a RGB fluorescent material or a color filter to achieve the object of full color so as to be widely applied. The OLED utilizes a plastic substrate to acquire the advantage of flexibility so as to realize a flexible display device. The temperature of the OLED can be within the wide range from −40 degrees centigrade to 60 degrees. centigrade.
The color OLED is a self-emitting light source. There is apparent reflective image on a panel after external light source emits light to a bottom aluminum plate, and therefore it is necessary to have a light-polarizing film (or plate) for filtering an incident light and separating the incident light into a part of one which pass through light-polarizing film and the other one which is masked by means of absorbing, reflecting and scattering. However, the permeability and polarization degree of conventional light-polarizing film is lower than those of current light-polarizing film such that the illumination and contrast of the OLED with conventional light-polarizing film is low. For example, Taiwan Patent No. 500931 discloses that a light-polarizing film has the permeability being more than 35% and the polarization degree being more than 90%. For example, Japanese Patent No. 59-159109 also discloses that a light-polarizing film has the permeability being more than 30%. The above-mentioned permeability is low and cause the illumination of the OLED is not enough. In order to increase the illumination and brightness, the power of the OLED must be increased. Oppositely, the lifetime of the OLED is decreased because the power of the OLED is increased. As shown in
Accordingly, there exists a need for a light-polarizing film with high permeability to solve the above-mentioned problems and disadvantages.
It is an object of the present invention to provide a light-polarizing film with high permeability and a phase retardation plate to cause a color OLED to acquire high contrast and brightness.
In order to achieve the foregoing objects, the present invention provides a light-polarizing film with high permeability for improving an interference light of a color organic light emitting diode (OLED), wherein a phase retardation plate is disposed on the color OLED for transforming light phase, and the light-polarizing film is disposed on the phase retardation plate for absorbing the projective light, characterized in that:
the polarization degree of the light-polarizing film is between 15% and 93%, the corresponding permeability is between 46% and 80%, whereby the light-polarizing film with high permeability is utilizes to acquire necessary light-polarizing effect of emitting light of the color OLED itself, the color OLED doesn't need to increase power, and the color OLED can keep original economical lifetime. Furthermore, the incident external interference light is partly absorbed by the light-polarizing film; and the phase the incident external interference light is transformed by the phase retardation plate, the external interference light is reflected by the color OLED to be reflected light, the reflected light is transformed by the phase retardation plate again, and the reflected light is mostly absorbed by the light-polarizing film so as to improve the interference light.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
Referring to
The present invention is a method for improving interference light of a color OLED. The phase retardation plate 20 is disposed on the color OLED 10 for transforming light phase, and then the light-polarizing film 30 is disposed on the phase retardation plate 20 for absorbing the projective light. The method for improving interference light of a color OLED includes the following steps of:
(A). absorbing a part of an external light by using the polarization degree of the light-polarizing film 30 being between 15% and 93%, and the corresponding being between 46% and 80% when the external light first passes through the light-polarizing film 30 and is processed in light vector distribution, and transforming incident angle of the other part of the external light by light-polarizing effect;
(B). transforming phase of the other part of the external light the first time by the phase retardation plate 20, then the other part of the external light into the color OLED 10 to generate reflection so as to form the interference light;
(C). transforming phase of the other part of the external light the second time by the phase retardation plate 20 after the interference light is reflected, then the interference light into the light-polarizing film 30; and
(D). absorbing a part of the interference light by using the light-polarizing film 30 after the interference light is processed in light vector distribution, and transforming incident angle of the other part of the interference light by light-polarizing effect, thereby decreasing the interference light reflected by the external light, decreasing the interference phenomenon of interlacing or overlapping between the emitting light of the OLED itself and the interference light, and then achieving the object of improving display quality.
Referring to
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In order to describe the difference between the present invention and the prior art, Applicant provide the comparison between the present invention and the prior art, which is shown in FIGS. 5 to 9. Referring to
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As described above, the present invention utilizes the light-polarizing film 30 to acquire necessary light-polarizing effect of emitting light of the color OLED itself, the present invention doesn't need to increase power, and the present invention can keep original economical lifetime. Furthermore, the incident external interference light is partly absorbed by the light-polarizing film 30, and the phase the incident external interference light is transformed by the phase retardation plate 20. Then, the external interference light is reflected by the OLED to be reflected light, the reflected light is transformed by the phase retardation plate 20 again, and the reflected light is mostly absorbed by the light-polarizing film 30 so as to improve the interference light. Moreover, the light-polarizing film of the present invention is provided with the additional functional film for acquiring functions of avoiding glisten and reflective light. According to the technical field of the invention, if the invention can solve the problem that technology and knowledge of one of ordinary skill in the art doesn't solve long time yet, then the invention should acquire non-obviousness. The permeability 46% to 80% chosen by the present invention is apparently different from the permeability 30% chosen by the prior art, therefore the invention should be a patentable invention.
Although the invention has been explained in relation to its preferred embodiment, it is not used to limit the invention. It is to be understood that many other possible modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention as hereinafter claimed.
