The present invention relates to a device and a method for automatically calibrating an LCD panel, and more particularly, to an fast LCD auto-calibrating device and method thereof capable of adjusting and detecting the phase of the LCD panel automatically to meet with specific requirements by comparing the same to a standard specification.
A Liquid crystal display is a thin, lightweight display device with no moving parts. It consists of an electrically-controlled light-polarising liquid trapped in cells between two transparent polarising sheets. The polarising axes of the two sheets are aligned perpendicular to each other. Each cell is supplied with electrical contacts that allow an electric field to be applied to the liquid inside.
Liquid crystals exist in a state that is transitional between that of a solid or liquid. In this intermediate state, liquid crystal molecules tend to point the same way, like the molecules in a solid, but can also move around to different positions, like the molecules in a liquid. This tendency of the liquid crystal molecules to point along a certain direction results in the liquid crystal displaying certain properties that are specific to the direction to which these properties are measured. This fundamental property of liquid crystals, called anisotropy, is what is exploited in the engineering of LCDs. Liquid crystals can also be further categorized by their specific structure and properties, such as the twisted nematic (TN) LCD, the super-TN (STN) LCD, and the thin film transistor (TFT) LCD panels.
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Conventionally, the calibration is done by manually rotating the first 11 and the second retardation plates 13 for adjusting the relative phase thereof to a specific value, or by changing to the retardation plates of different wavelength and calibrating the same manually to match the specific value.
In view of the description above, the conventional method for calibration an LCD panel possesses at least the following disadvantages:
In view of the disadvantages in the prior art, the primary object of the present invention is to provide a device and a method for automatically calibrating an LCD panel, capable of improving the calibration precision and assuring the quality of the LCD panels produced.
The secondary object of the present invention is to provide a device and a method for automatically calibrating an LCD panel, capable of increasing the market competitiveness by simplifying the calibrating procedure and reducing the production cost.
Another object of the present invention is to provide a device and a method for automatically calibrating an LCD panel, capable of maintaining the same objective criteria in each calibration and therefore assuring the quality of the calibration and the reproducibility of the product.
Yet, another object of the present invention is to provide a device and a method for automatically calibrating an LCD panel, capable of increasing the productivity and reducing the production cost by automating the production.
To achieve the above objects, the present invention provides a device for automatically calibrating an LCD panel. The LCD panel comprises successively: a first polarizer, a first retardation plate, a liquid crystal monomer, a second retardation plate, and a second polarizer. The LCD calibration device includes: a light generation device, capable of providing a light source; a rotatory base, capable of carrying and orientating the LCD panel to form a proper angle between the same and an incident light from the light source, and adjusting the relative phase between the first and the second retardation plates by rotating the same, and optionally changing the first retardation plate and/or the second retardation plate if necessary; a light detection unit, arranged at a position corresponding to the light generation device for receiving/detecting the light emitted from the LCD panel, and an optical signal examination device, connected to the light detection unit, capable of examining the data of the light detection unit.
The LCD calibration device further comprises a comparison device that is arranged between the optical signal examination device and the rotatory base and provides a standard value to be compared with the data of the optical signal examination device. The standard value is acting as a base for calibrating the rotatory base.
In a method for automatically calibrating an LCD panel according to a preferred embodiment of the present invention, the LCD panel is arranged on a rotatory base, and the LCD panel comprises successively: a first polarizer, a first retardation plate, a liquid crystal monomer, a second retardation plate, and a second polarizer. The method comprises the steps of:
To make the esteemed review committee can further understand and recognize the present invention, a detailed description in accordance with several accompanying diagrams are presented as following.
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The light source 203 is then passing through a comparison device 204, which includes: a beam splitter 2040, an sample LCD panel 2041, and a sample light detection device 2042, wherein the beam splitter 2040 is capable of splitting the light source 203 into light sources 203a and 203b with same intensities and same lengths of optical path (D1=D2). The light source 203a and the light source 203b are arranged to perpendicularly enter the sample LCD panel 2041 and the LCD panel 201 respectively, so that the objective criteria for the sample LCD panel 2041 and the LCD panel 201 will be under the same condition. The sample light detection unit 2042 arranged at the position corresponding to the beam splitter 2040 is then being used to detect the light from the light source 203a.
The light source 203b passes through the LCD panel 201 supported by the rotatory base 205 perpendicularly and is detected by a light detection unit 206. The optical path from the LCD panel 201 to the light detection unit 206 (D4) is equal to the optical path from the sample LCD panel 2041 to the sample light detection unit 2042 (D3). The data from the light detection unit 206 and the sample light detection unit 2042 are examined by connecting both the light detection unit 206 and the sample light detection unit 2042 to the optical signal examination device 207. Since the sample LCD panel 2041 has the specs that meet the required standard, the comparison device 204 is capable of providing a standard value Ch2 to compare with the data Ch1 of the testing LCD panel 201 from the optical signal examination device 207. Meanwhile, the rotatory base 205 is capable of adjusting the relative phases of the first 2011 and the second retardation plates 2013 by rotating them from 0 to 360 degrees, or optionally changing the first retardation plate 2011 and/or the second retardation plate 2013 if necessary, so that the data Ch1 can approach the standard value Ch2 hence the phase of the LCD panel 201 can achieve the required standard value.
The optical signal examination device 207 is connected with a recording device 208 for data recording. It is also connected to a digital retardation device by external trigger signals, and then to the light generation device 202 so as to synchronize the light generation device 202 with the optical signal examination device 207 for smoothing the calibration process. Typically, an oscilloscope is used as the examination device for the optical signal examination device 207, a computer or an integrator is used as the recording device 208, while a CCD, a CMOS, or a PMT is used as the light detection unit 206 and the sample light detection unit 2042. Since most of the elements are identical or similar to the preferred embodiment described hereinafter, the same name and numbering will be used for the identical elements, while the same name with an additional English alphabet attached will be used for the similar elements in the following preferred embodiments of the present invention.
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In summary, the LCD-panel calibrating device and method thereof of the present invention is capable of improving the calibration precision that assures the quality of the LCD panel, and simplifying the calibrating procedure to lower the production cost, and fixing the objective criteria in each calibration so as to automate the production and boost the productivity. While the preferred embodiment of the invention has been set forth for the purpose of disclosure, modifications of the disclosed embodiment of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraces therein.