Touch panel and liquid crystal display panel

A touch panel having a color-filtering function is provided. The touch panel includes a first electrode layer, a second electrode layer, a first dielectric layer and a second dielectric layer. The second electrode layer is disposed above the first electrode layer. The first dielectric layer is disposed between the first electrode layer and the second electrode layer, while the second dielectric layer is disposed on the second electrode layer. Further, the second electrode layer is located between the first dielectric layer and the second dielectric layer. Here, either the first dielectric layer or the second dielectric layer is a color filter layer. A liquid crystal display panel using the above touch panel as a color filter is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan and China patent applications serial no. 96138670 and 200710186694.2, filed on Oct. 16, 2007 and Nov. 20, 2007. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a touch panel and a liquid crystal display (LCD) panel, and more particularly to a touch panel having a color-filtering function and a color LCD panel having a touch-control function.

2. Description of Related Art

In the current information era, the reliance on electronic products is increasing. The electronic products including mobile phones, handheld personal computers (PCs), personal digital assistants (PDAs) and smart phones have pervaded everywhere in our daily life. Some of the electronic products may integrate touch panels into display panels, so as to result in a formation of a color touch display panel and enable users to see relatively large display frames and operate the device in a simple operation mode when considering restricted volumes of the miniature electronic products.

FIG. 1illustrates a conventional color touch display panel. Referring toFIG. 1, a color touch display panel100includes a display panel110and a touch panel120bonding to the display panel110through a double-sided tape130. The display panel110is, for example, a flat display panel, such as an LCD panel which can achieve a color display effect, an organic light emitting display (OLED) panel, and so on. The touch panel120is a digital capacitance touch panel including a plurality of stripe upper electrodes122, a plurality of stripe lower electrodes124, and a dielectric layer126disposed between the upper electrodes122and the lower electrodes124. As the touch panel120is adhered to the display panel110through the double-sided tape130, the color touch display panel100is characterized by the touch-control function and the color display function. Nevertheless, the double-sided tape130is merely attached to edges of the display panel110and the touch panel120, such that a gap G exists between the touch panel120and the display panel110. Due to the difference in refraction index of media, as the light passes through the gap G, the display quality is worsened because of light leakage of the display panel110or a reduction of light transmittance. Besides, the touch panel120and the display panel110adhered to each other results in an unlikelihood of reducing the thickness of the color touch display panel100, such that the market demand on miniature electronic products cannot be satisfied.

On the other hand,FIG. 2illustrates another conventional color touch display panel. Referring toFIG. 2, a color touch display panel200is similar to the color touch display panel100, while the difference therebetween lies in that the touch panel120is adhered to the display panel110through an optical glue230in the color touch display panel200. An area between the display panel110and the touch panel120is completely coated by the optical glue230. Thus, it is rather unlikely for the color touch display panel200to have light leakage, and thus the color touch display panel200is characterized by a favorable display quality. Unfortunately, the optical glue230requires higher costs, and the thickness of the color touch display panel200stays unchanged. Furthermore, the reliability of the optical glue230is reduced after the optical glue230is used for a long period of time. Based on the above, the conventional color touch display panel is neither capable of catering to the trend of compactness and lightness required by the miniature electronic products nor able to achieve a desirable display quality of the touch-control display panel.

SUMMARY OF THE INVENTION

The present invention is directed to a touch panel having a color-filtering function, such that it is not necessary for the touch panel in a color touch display panel to be additionally adhered to a color display panel.

The present invention is further directed to an LCD panel equipped with a color display function and a touch-control function.

The present invention provides a touch panel having a color-filtering function. The touch panel includes a first electrode layer, a second electrode layer, a first dielectric layer and a second dielectric layer. The second electrode layer is disposed above the first electrode layer. The first dielectric layer is disposed between the first electrode layer and the second electrode layer, and the second dielectric layer is disposed on the second electrode layer. Further, the second electrode layer is located between the first dielectric layer and the second dielectric layer. Here, either the first dielectric layer or the second dielectric layer is a color filter layer.

The present invention further provides an LCD panel including a first substrate, a second substrate, and a liquid crystal layer. The first substrate includes, a first electrode layer, a second electrode layer, a first dielectric layer, a second dielectric layer, and a third electrode layer. The second electrode layer is disposed above the first electrode layer. The first dielectric layer is disposed between the first electrode layer and the second electrode layer, and the second dielectric layer is disposed on the second electrode layer. Further, the second electrode layer is located between the first dielectric layer and the second dielectric layer. Here, either the first dielectric layer or the second dielectric layer is a color filter layer. The third electrode layer completely covers the second dielectric layer. The second substrate is parallel to the first substrate, and the liquid crystal layer is disposed between the second substrate and the third electrode layer of the first substrate.

According to an embodiment of the present invention, the first electrode layer includes a plurality of first stripe electrode patterns arranged in parallel. In addition, the second electrode layer includes a plurality of second stripe electrode patterns. The second stripe electrode patterns are arranged in parallel, for example, and a direction in which the second stripe electrode patterns are arranged is substantially perpendicular to a direction in which the first stripe electrode patterns are arranged.

According to an embodiment of the present invention, the touch panel and the liquid crystal display panel further comprise a substrate, wherein the first electrode layer is disposed on the substrate. The color filter layer includes a plurality of color filter films and a black matrix defining a plurality of sub-pixel areas on the substrate. Each of the color filter films is located within one of the sub-pixel areas. In addition, an overlapping area between the first electrode layer and the second electrode layer covers two or more sub-pixel areas. Specifically, the color filter films include red filter films, green filter films or blue filter films.

According to an embodiment of the present invention, the touch panel and the liquid crystal display panel further include a passivation layer disposed between the second electrode layer and the second dielectric layer. Besides, the touch panel further includes a grounding conductive layer disposed between the passivation layer and the second dielectric layer, for example.

According to an embodiment of the present invention, the touch panel and the liquid crystal display panel further include a planar layer disposed on a surface of the color filter layer. Said surface is away from the first electrode layer.

According to an embodiment of the present invention, a material of the first electrode layer, the second electrode layer, and the third electrode layer includes a transparent conductive material comprising indium tin oxide (ITO) or indium zinc oxide (IZO).

According to an embodiment of the present invention, a thickness of the color filter layer ranges from 0.2 μm to 4 μm.

According to an embodiment of the present invention, the second substrate of the liquid crystal display panel includes an active device array structure.

According to an embodiment of the present invention, the first dielectric layer comprises a glass substrate or a plastic substrate.

According to an embodiment of the present invention, the touch panel and the liquid crystal display panel further comprise an optical lens disposed on a surface of the first electrode layer, wherein the surface is away from the first dielectric layer.

In the present invention, the color filter layer and the touch panel are integrated onto the same substrate, such that the touch panel of the present invention is equipped with the color-filtering function. Additionally, the LCD panel of the present invention is not only able to achieve the color display effect, but also capable of performing the touch-control function. Moreover, the LCD panel of the present invention is in a thickness less than that of the color display panel having the touch-control function according to the related art.

In order to the make the aforementioned and other objects, features and advantages of the present invention comprehensible, several embodiments accompanied with figures are described in detail below.

DESCRIPTION OF EMBODIMENTS

First Embodiment

FIG. 3is a schematic view of a touch panel according to a first embodiment of the present invention. Referring toFIG. 3, a touch panel300A includes a substrate310, a first electrode layer320, a second electrode layer330, a first dielectric layer (350) and a second dielectric layer360. Here, the first dielectric layer (350) is a color filter layer350, for example. The first electrode layer320is disposed on the substrate310, while the second electrode layer330is disposed above the first electrode layer320. The color filter layer350is disposed between the first electrode layer320and the second electrode layer330, whereas the second dielectric layer360is disposed on the second electrode layer330. The second electrode layer330is disposed between the color filter layer350and the second dielectric layer360.

In the present embodiment, a thickness of the first dielectric layer, i.e., the color filter layer350, poses an impact on a filtering effect of the touch panel300A and on capacitance between the first electrode layer320and the second electrode layer330. Hence, the thickness of the color filter layer350ranges from 0.2 μm to 4 μm, for example. In general, the thickness of the color filter layer350employed by the display panel is approximately in a range of 0.8 μm˜1.2 μm, so as to achieve favorable filtering performance. On the other hand, the second dielectric layer360is made of dielectric materials including polyimide, silicon oxide, silicon nitride, silicon oxynitride, or acrylic resin, for example.

The touch panel300A is, for example, a capacitive touch panel. In particular, the first electrode layer320includes a plurality of first stripe electrode patterns322arranged in parallel. In addition, the second electrode layer330includes a plurality of second stripe electrode patterns332. The second stripe electrode patterns332are arranged in parallel, for example, and a direction in which the second stripe electrode patterns332are arranged is substantially perpendicular to a direction in which the first stripe electrode patterns322are arranged. That is to say, the first stripe electrode patterns322are parallel to the direction of the drawing, while the second stripe electrode patterns332are perpendicular to the direction of the drawing, for example. When a user touches an overlapping area between the first stripe electrode patterns322in an ithrow in the first electrode layer320and the second stripe electrode patterns322in a jthline in the second electrode layer330, the action of touching triggers a production of a signal, e.g., (Xi, Yj), so as to control an electronic product.

On the other hand, the color filter layer350includes a plurality of color filter film352and a black matrix354defining a plurality of sub-pixel areas P on the substrate310, and each of the color filter films352is located within one of the sub-pixel areas P. In addition, the overlapping area between the first electrode layer320and the second electrode layer330covers two or more sub-pixel areas P. As a matter of fact, the overlapping area between the first electrode layer320and the second electrode layer330varies upon actual design demands on the resolution of the touch panel300A. Moreover, in the present embodiment, the first electrode layer320and the second electrode layer330are not necessarily composed of the plurality of the stripe electrode patterns. A material the first electrode layer320and the second electrode layer330includes a transparent conductive material comprising ITO or IZO.

Specifically, the color filter films352include red filter films, green filter films or blue filter films. However, in other embodiments, the color filter films352may have different combinations of colors. In the present embodiment, the color filter layer350serves as the first dielectric layer and is integrated into the touch panel300A, such that the touch panel300A is equipped with a color filtering function. Thus, when the touch panel300A is assembled to another substrate, and liquid crystal molecules are filled therebetween, an LCD panel having a touch-control function as illustrated inFIG. 4is then formed.

Referring toFIG. 4, an LCD panel400includes the touch panel300A depicted inFIG. 3, a second substrate420, and a liquid crystal layer430. The touch panel300A of the present embodiment has the color filtering function, and accordingly the touch panel300A can serve as a color filter after being assembled to the second substrate420, such that the LCD panel400is able to achieve a color display effect. In other words, the LCD panel400is able to perform the touch-control function in no need of adhering the touch panel300A to the display panel with use of an adhesive (a double-sided tape or optical glue). Accordingly, the touch-control LCD panel400is in a thinner thickness, and light leakage due to a gap existing between the touch panel300A and the LCD panel400is not likely to occur in the touch-control LCD panel400. Besides, an issue regarding a reduction of reliability of the optical glue because of using the optical glue for a long period of time does not take place in the present invention.

A third electrode layer440is disposed on the touch panel300A and serves as a common electrode in the LCD panel400, for example. A material of the third electrode layer440includes a transparent conductive material comprising ITO or IZO. An active device array structure422is disposed on the second substrate420, for example. According to other embodiments, however, the LCD panel400may also be designed as a passive LCD panel, such as a super twisted nematic LCD (STN-LCD) panel, a twisted nematic LCD (TN-LCD) panel, and so on.

It is of certainty that the touch panel300A of the present invention is not limited to be merely applied to the LCD panel. In other embodiments, the touch panel300A can also be employed in a flat display including an OLED. Thus, the OLED is not only able to achieve the color display effect, but also capable of performing the touch-control function. In other embodiments, the touch panel300A can be applied to various displays as the color filter.

On the other hand, the touch panel of the present invention may denote a touch panel300B as depicted inFIG. 5. Referring toFIG. 5, in the touch panel300B, a planar layer370is further disposed on the color filter layer350of the touch panel300A. The planar layer370ensures desirable planarity of the color filter layer350, improving the process yield of subsequently fabricating film layers.

Specifically, referring toFIG. 6, the touch panel of the present invention may be referred to as a touch panel300C as depicted inFIG. 6. The touch panel300C further includes a passivation layer380disposed between the second electrode layer330and the second dielectric layer360. Besides, the touch panel300C further includes a grounding conductive layer390disposed between the passivation layer380and the second dielectric layer360. When the touch panel300C is assembled to the second substrate for forming the LCD panel, the disposition of the grounding conductive layer390prohibits signals of the second electrode layer330and those of the common electrode layer of the LCD panel from interfering with one another, so as to maintain the favorable display quality of the LCD panel.

Second Embodiment

FIG. 7is a schematic view of a touch panel according to a second embodiment of the present invention. Referring toFIG. 7, a touch panel700is similar to the touch panel300A, while the difference therebetween lies in that the second dielectric layer of the touch panel700is a color filter layer760, but a first dielectric layer750is not a color filter layer. Like the structure of the touch panel300A, the structure of the touch panel700varies in a wide range. For example, a planar layer (not shown) can be further disposed on the color filter layer760of the touch panel700. In an alternative, a grounding conductive layer (not shown) can be formed on the color filter layer360of the second dielectric layer, and a third dielectric layer (not shown) can be formed on the grounding conductive layer (not shown). Moreover, the touch panel700can further include a passivation layer (not shown) disposed between the second electrode layer330and the color filter layer760.

In another embodiment, the first dielectric layer750of the touch panel700may be a glass substrate or a plastic substrate. In this case, the touch panel700is not necessarily disposed on the substrate310, and takes the first dielectric layer750as a supporting base. In addition, when the first dielectric layer750is a glass substrate or a plastic substrate, an optical lens (not shown) is supposed to be disposed on a surface of the first electrode layer320, wherein the surface is away from the first dielectric layer750. In another word, the substrate310can be replaced by an optical lens (not shown) while the first dielectric layer750is a glass substrate or a plastic substrate. As a whole, the integration of the touch panel700and the color filter layer760gives rise to a significant reduction of the thickness of the touch-control display panel. Besides, in other embodiments, the first dielectric layer of the touch panel and the second dielectric layer thereof can be made up of the color filter layer, so as to enhance color saturation after the light passes through the touch panel and to simultaneously reduce the thickness of the touch panel.

In light of the foregoing, the touch panel of the present invention and the LCD panel thereof at least have the following advantages. The touch panel of the present invention is equipped with the color-filtering function, such that the touch panel of the present invention can be utilized as the color filter. After the touch panel of the present invention is assembled to one active device array substrate, and liquid crystal molecules are filled therebetween, the LCD panel having the touch-control function can be formed. Here, it is not required to bond two panels with different functions together, such that the thickness of the touch-control LCD panel is reduced. Additionally, the display quality of the touch-control LCD panel according to the present invention is not worsened on account of the adhesive or the gap existing between the two panels. In other words, the touch-control LCD panel integrates two panels having different functions together, such that the fabrication of components of the touch-control LCD panel is simplified, and the manufacturing costs are thus reduced. Particularly, the touch panel of the present invention is applicable not only to the LCD panel, but also to other flat display panels requiring the color filters. Thereby, the flat display panels are equipped with the touch-control function and are able to achieve the color display effect at the same time.