Liquid crystal coating apparatus and liquid crystal coating method

The present invention provides a liquid crystal (LC) coating apparatus and an LC coating method. The LC coating apparatus comprises a plurality of liquid crystal coating devices, at least one real-time detector and a controller. The LC coating method comprises the following steps: utilizing the LC coating devices to coat a LC on a substrate; utilizing the real-time detector to real-time detect the LC coated on the substrate and outputting a detection signal; and utilizing the controller to control the LC coating devices according to the detection signal. The present invention can real-time monitor the coating status of the LC for coating and forming a uniform LC film.

FIELD OF THE INVENTION

The present invention relates to a liquid crystal (LC) coating apparatus and an LC coating method, and more particularly to an LC coating apparatus and an LC coating method capable of real-time monitoring the LC coating status and forming a uniform LC film.

BACKGROUND OF THE INVENTION

Liquid crystal displays (LCDs) have been widely applied in electrical products. Currently, most of LCDs are backlight type LCDs which comprise an LC panel and a backlight module.

The LC panel is composed of two transparent substrates and an LC sealed there-between. In an assembly process of the LC panel, the LC is filled and sealed between the transparent substrates. Currently, the methods for filling the LC between the transparent substrates may be a vacuum siphon method and a one-drop filling (ODF) method.

However, the filling time of the conventional vacuum siphon method is too long, and thus the vacuum siphon method can be not applicable to large-scale panels. Furthermore, the machine used for the ODF method is too expensive, and the process thereof is more complicated. Besides, when the dispensed amount (about 0.5 mg-1.5 mg) of the LC is not precise, the problems of bubbles or non-uniform coating are susceptible to arise.

As a result, it is necessary to provide an LC coating apparatus and an LC coating method to solve the problems existing in the conventional technologies, as described above.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a liquid crystal coating apparatus, and the liquid crystal coating apparatus comprises: a plurality of liquid crystal coating devices configured to coat a liquid crystal on a substrate, wherein the liquid crystal coating devices are inkjet printing heads or slit coating heads; at least one real-time detector disposed at one side of the liquid crystal coating devices configured to real-time detect the liquid crystal coated on the substrate and output a detection signal; and a controller configured to control the liquid crystal coating devices according to the detection signal.

Another object of the present invention is to provide a liquid crystal coating method, and the method comprises the following steps: utilizing a plurality of liquid crystal coating devices to coat a liquid crystal on a substrate, wherein the liquid crystal coating devices are inkjet printing heads or slit coating heads; utilizing at least one real-time detector to real-time detect the liquid crystal coated on the substrate and outputting a detection signal; and utilizing a controller to control the liquid crystal coating devices according to the detection signal.

In one embodiment of the present invention, the liquid crystal coating devices are piezoelectric droplet ejectors, and the controller adjusts a voltage of the liquid crystal coating devices according to a relation between a droplet amount and the voltage.

In one embodiment of the present invention, the real-time detector is at least one charge coupled device configured to real-time detect the liquid crystal coated on the substrate and output the detection signal to the controller, and the detection signal is a real-time image signal, and the controller implements an image gray-scale comparison processing for the real-time image signal outputted from the real-time detector, so as to calculate the actual weight, number, size or position of the liquid crystal coated on the substrate.

In one embodiment of the present invention, the liquid crystal coating devices are the slit coating heads, and the liquid crystal coating apparatus further comprises a plurality of measuring cylinders, a pumping device and a liquid crystal tank, and the measuring cylinders are connected to the liquid crystal coating devices respectively configured to provide the liquid crystal to the liquid crystal coating devices, and the pumping device is connected between the measuring cylinders and the liquid crystal tank for pumping the liquid crystal from the liquid crystal tank to the measuring cylinders.

In one embodiment of the present invention, the liquid crystal amount of each of the measuring cylinders is a liquid crystal coated amount for one or more liquid crystal units.

In one embodiment of the present invention, the controller adjusts a moving speed of the liquid crystal coating devices, a pressure of the measuring cylinders, a slit width of the slit coating heads or a pitch between each two of liquid crystal units by calculating a liquid crystal amount for the liquid crystal units and a moving distance in coating.

In one embodiment of the present invention, the liquid crystal coating devices are the inkjet printing heads, and the liquid crystal coating method further comprises the following step: before coating the liquid crystal on the substrate, ensuring whether a number and a weight of liquid crystal droplets ejected by the liquid crystal coating devices satisfy a predetermined requirement.

In one embodiment of the present invention, the liquid crystal coating devices are the inkjet printing heads, and the controller calculates the number of the droplets of the liquid crystal ejected by the liquid crystal coating devices according to the real-time image signal, and implements a comparison between the number and a predetermined droplet number, and then adjusts the ejection of the liquid crystal coating devices according to a comparison result.

The LC coating apparatus and the LC coating method of the present invention can rapidly coat and form the LC film on the transparent substrate, thereby considerably raising the production efficiency and simplifying the manufacturing process to reduce the labor and time. Furthermore, the problems of bubbles or non-uniform LC film can be improved by the LC coating apparatus of the present invention, and in this way, the LC coated amount, thickness and uniformity can be precisely controlled.

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following embodiments are referring to the accompanying drawings for exemplifying specific implementable embodiments of the present invention. Furthermore, directional terms described by the present invention, such as upper, lower, front, back, left, right, inner, outer, side and etc., are only directions by referring to the accompanying drawings, and thus the used directional terms are used to describe and understand the present invention, but the present invention is not limited thereto.

In the drawings, structure-like elements are labeled with like reference numerals.

Referring toFIG. 1, a schematic diagram showing an LC coating apparatus according to a first embodiment of the present invention is illustrated. The LC coating apparatus100of the present embodiment may be configured to coat and form an LC101between two transparent substrates102, thereby forming an LC display panel. The LC coating apparatus100comprises a plurality of LC coating devices110, a plurality of real-time detectors120and a controller130. The LC coating devices110are configured to coat the LC101on one of the transparent substrates102, wherein the LC coating devices110may be inkjet printing heads or slit coating heads. The real-time detectors120are disposed at one side of the LC coating devices110configured to real-time detect the status of the LC coated on the transparent substrate102and output a detection signal to the controller130. The controller130is electrically connected to the LC coating devices110and the real-time detectors120and can control the coating of the LC coating devices110according to the detection signal outputted from the real-time detectors120.

Referring toFIG. 1again, in this embodiment, the LC coating devices110may be, for example, the inkjet printing heads configured to eject droplets of the LC101with a high density on a transparent substrate102, wherein the weight of each droplet of the LC101ejected by the LC coating devices110may be less than 1 mg, preferably less than 0.1 mg. A pitch between each two adjacent droplets of the LC101ejected by the LC coating devices110may be less than 1 mm, preferably less than 200 μm. The droplets of the LC101ejected by the LC coating devices110are arranged on the transparent substrate102densely, thus naturally spreading as a uniform LC film under the action of the surface tension for significantly improving the non-uniform droplet problem of the conventional ODF method.

Referring toFIG. 1again, the LC coating devices110of the present embodiment may be, for example, piezoelectric droplet ejectors which can control the amount or size of the droplets ejected by the LC coating devices110using a voltage. In this embodiment, the droplet amount ejected by each droplet ejector can be measured in advance, so as to obtain a relation between the droplet amount of each ejector and the voltage. Normally, the droplet amount of each ejector is proportional to the voltage. Subsequently, the voltage of each of the ejectors can be adjusted according to the relation between the droplet amount and the voltage, thereby allowing the droplet amount ejected by each of the ejectors (the LC coating devices110) being identical.

Referring toFIG. 1again, the real-time detectors120of the present embodiment are configured to real-time monitor the coating status of the LC coating devices110, such as the weight, number, size or position of the LC coated on the transparent substrate102, and the real-time detectors120can output the detection signal to the controller130. In this embodiment, the real-time detectors120may be, for example, charge coupled devices (CCD) disposed at one side of each of the LC coating devices110for real-time detecting the LC coated on the transparent substrate102, and the real-time detectors can transmit a real-time image signal (the detection signal) to the controller130.

Referring toFIG. 1again, the controller130of the present embodiment can control the coating of the LC coating devices110according to the detection signal outputted from the real-time detectors120. In this embodiment, the controller130can implement an image gray-scale comparison processing for the real-time image signal (the detection signal) outputted from the real-time detectors120, so as to calculate the actual weight, number, size or position of the LC coated on the transparent substrate102. Subsequently, according to the actual coating status of the LC coated on the transparent substrate102, the controller130may, for example, adjust the voltage of the LC coating devices110, so as to adjust the LC amount ejected by the LC coating devices110.

Referring toFIG. 2, a flow diagram showing an LC coating method according to the first embodiment of the present invention is illustrated. When utilizing the LC coating apparatus100of the present embodiment to coat and form the LC101on the transparent substrate102, the LC coating method of the present embodiment may comprise the following steps: utilizing the LC coating devices110to coat the LC101on the transparent substrate102(step S201); utilizing the real-time detectors120to real-time detect the LC coated on the transparent substrate102and outputting the detection signal (step S202); and utilizing the controller130to control the LC coating devices110according to the detection signal (step S203). Before the step S201, for example, the real-time detectors120can be utilized to detect the number of the LC droplets ejected by the LC coating devices110in advance, and the weight of the LC droplets can be measured, so as to ensure whether the number and weight of the LC droplets ejected by the LC coating devices110satisfy a predetermined requirement. In the step S201, the LC coating devices110can move toward a predetermined direction, and thus the LC coating devices110can coat the LC101on the transparent substrate102toward the predetermined direction. In the step S202, for example, the real-time detectors120may real-time record an image of the droplets of the LC101on the transparent substrate102and output the real-time image signal (the detection signal) to the controller130. In the step S203, for example, the controller130may calculate the number of the droplets of the LC101ejected by the LC coating devices110according to real-time image signal, and implement a comparison between the number and a predetermined droplet number, and then adjust the ejection (coating) of the LC coating devices110according to the comparison result.

Therefore, the LC coating apparatus100of the present embodiment can utilize the inkjet printing heads to coat and form a uniform LC film on one transparent substrate102, and another transparent substrate102can be assembled on the transparent substrate102with the LC film using a sealant, thereby forming the LC display panel.

Referring toFIG. 3AandFIG. 3B, schematic diagrams showing an LC coating apparatus according to a second embodiment of the present invention are illustrated. The LC coating apparatus200of the second embodiment comprises a plurality of LC coating devices210, a plurality of real-time detectors220and a controller230, a plurality of measuring cylinders240, a pumping device250and an LC tank260. The LC coating devices210are configured to coat the LC101on the transparent substrate102, wherein the LC coating devices210may be, for example, slit coating heads. The real-time detectors220are disposed at one side of the LC coating devices210configured to real-time detect the status of the LC coated on the transparent substrate102and output a detection signal to the controller230, wherein the real-time detectors220may be image sensors disposed at one side of each LC coating device210and capable of laterally moving when coating the LC (referring toFIG. 3B), so as to real-time detect whether the flow rate of the LC ejected by the LC coating devices210is uniform, thereby real-time detecting the LC film coated by the slit coating heads210and outputting a real-time image signal (the detection signal) to the controller230. The controller230can implement an image processing for the detection signal outputted from the real-time detectors220, so as to obtain a real-time LC coating amount and control the ejection amount or coating of the LC coating devices210.

Referring toFIG. 3Aagain, the measuring cylinders240are connected to the LC coating devices210respectively configured to provide the LC101to the LC coating devices210, and thus the LC coating devices210can coat the LC101on the transparent substrate102. In this embodiment, the measuring cylinders240may include sensors (not shown) for detecting the LC amount within the measuring cylinders240. Therefore, the LC amount provide by the measuring cylinders240to the LC coating devices210can be obtained for monitoring the LC amount within the measuring cylinders240and the coating amount of the LC coating devices210. In this case, the measuring cylinders240can provide the LC101to the LC coating devices210by a pressure of a gas (such as N2). The pumping device250may be, for example, a pump connected between the measuring cylinders240and the LC tank260for pumping the LC from the LC tank260to the measuring cylinders240. The LC tank260is connected to the pumping device250for storing the LC.

Referring toFIG. 3Aagain, when utilizing the LC coating apparatus100of the present embodiment to coat and form the LC101on the transparent substrate102, firstly, the pumping device250can pump the LC from the LC tank260to the measuring cylinders240, wherein the LC amount of each of the measuring cylinders240may be the LC coated amount for one or more LC units (LC display panels). Subsequently, the measuring cylinders240can provide the LC101to the LC coating devices210by the pressure of the gas (such as N2). Subsequently, the LC coating devices210can coat the LC101on the transparent substrate102, wherein the LC coating devices210can coat the LC101on the transparent substrate102toward the predetermined direction. Subsequently, the real-time detectors220can detect the LC101coated on the transparent substrate102and output the detection signal. Subsequently, the controller230can control the coating of the LC coating devices210according to the detection signal. Furthermore, the controller230can control the pressure or a slit width of the slit coating heads.

Referring toFIG. 3Aagain, in the second embodiment, the LC coating devices210can coat the LC101on a plurality of regions of the transparent substrate102at the same time for forming a plurality of LC units103which are cut and assembled as LC display panels. At this time, each of the LC coating devices210may be configured to coat a LC unit103, and the controller230can adjust the moving speed of the LC coating devices210, the pressure of the measuring cylinders240, the slit width of the slit coating heads or a pitch between each two of the LC units103by calculating the LC amount for the LC units103and a moving distance in coating, so as to enhancing the uniformity of the LC film of each of the LC units103. Moreover, when the LC coating devices210move between each two of the LC units103, the pumping device250can pump the LC from the LC tank260to the measuring cylinders240for renewing the LC amount thereof the measuring cylinders240.

As described above, in comparison with the conventional LC coating method, the LC coating apparatus and the LC coating method of the present invention can rapidly coat and form the LC film on the transparent substrate, thereby considerably raising the production efficiency. Furthermore, the steps of the LC coating method are very simple, thereby reducing the labor and time. Besides, the LC coating apparatus of the present invention can coat the LC film with high uniformity for improving the problems of bubbles or non-uniform LC film. Moreover, the LC coating apparatus includes the real-time detector to real-time detect the coating status of the LC for precisely controlling the LC coated amount, thickness and uniformity to improve the LC coating quality and reduce the waste of the LC.