Patent Application
20080024414
a) and 3(b) are diagrams illustrating the pixel structure of still a further conventional touch display according to the prior art, wherein
a) to 5(c) are diagrams schematically showing the different waveforms of the gate pulse applicable for the pixel of the first preferred embodiment according to the present invention;
a) to 8(c) are diagrams schematically showing the different waveforms of the gate pulse applicable for the pixel of the second preferred embodiment according to the present invention; and
The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only; it is not intended to be exhaustive or to be limited to the precise form disclosed.
In the present invention, the exclusive readout line for signal readout is not necessary anymore, and through the well-designed configuration for the novel pixel, the data line carrying on a data signal would transmit a signal to be read as well. In this respect, the present invention provides a method for driving the novel pixel for the touch display, which is illustrated with an equivalent circuit therefor.
Please refer to
As shown in
The pixel according to the present invention is distinguishable from the conventional pixel structure in that there is no additional readout line configured in the pixel area 40. Accordingly, the second transistor Switch TFT is electrically connected to the second data line D2 rather than to a conventional readout line. The second data line D2 is further electrically connected to a data driver through a switch, D-Switch, on one end thereof, and to a readout circuit including an amplifier through a further switch, AMP-switch, on the other end thereof. Preferably, the data driver is constructed of a data driving integrated circuit, Data driver IC, and the amplifier is a current amplifier, Current AMP, which is further coupled to a processor.
In the pixel writing duration, the pixel is on a writing voltage level with a pixel voltage applied. The second data line D2 is applied with a control signal of low state, and thereby the switch, i.e. D-Switch, would be switched on so that the second data line D2 would carry a data signal from the external data driver electrically coupled therewith, i.e. Data driver IC. At this time, the AMP-Switch is at the off state, whereby the current amplifier is electrically decoupled with the second data line D2, so that the data writing procedure would not be affected thereby.
In the signal readout duration, on the other hand, a control signal of high state is applied to the D-switch and the D-Switch is thus turned off, so that the DATA driver IC would be electrically disconnected with the second data line D2. Meanwhile, the AMP-Switch is at the on state, i.e. the current AMP is electrically connected with the second data line D2, so that the photo signal generated by the Photo TFT would be transmitted therethrough to the current AMP for being further processed.
Furthermore, the Switch TFT is controlled by a gate pulse applied thereto through the second gate line SELECT2, i.e. the so-called readout gate pulse. The Switch TFT is switched on while the gate pulse is at a high state, e.g. a high voltage level, so that the photo signal generated by the Photo TFT would be transmitted to the current amplifier through the second data line D2. In other words, when the control signal is at the high state, the gate pulse is also at the high state as well, and in this case, the pixel voltage is no longer applied to the pixel and the generated photo signal could be readout as well.
Since the D-switch is electrically disconnected with the second data line D2 while the control signal is at the high state, the Data driver IC would hold the data signal which is not sent out until a further control signal of low state is applied thereto, so as to keep the pixel being input with a correct voltage correspondingly thereto. In a preferred embodiment, accordingly, the Data driver IC serves for holding the signal level when the control signal is at the high state.
After the photo signal is transmitted through the second data line D2 and read out, the Switch TFT would be switched on again due to a subsequent pixel writing gate pulse applied thereto. For avoiding the voltage level of the second data line D2 from being influenced by the biased voltage input thereto through the Photo TFT and the Switch TFT, the biased voltage is preferably a negative one. In this case, the current would not be transmitted to the second data line D2 that is applied with a positive voltage through the Photo TFT, so that the voltage level thereof is never influenced thereby. Moreover, the reference voltage of the current AMP is preferably a suitable negative voltage as well, so as to improve the operation therefor. In a preferred embodiment, the biased voltage is −10V and the reference voltage is −5V.
In the present invention, the waveform of the gate pulse applied to the second gate line SELECT2 needs to be well selected for the Switch TFT, so as to allow the data signal transmission as well as the photo signal readout through the same data line D2. With reference to
In more specifics, while the Switch TFT is switched on for a bit longer duration t1, a relatively wide pulse P1 would be applied to the gate line G3, whose pulse width is larger than those applied to the remaining gate lines G1, G2 and G4. Accordingly, the relatively wide pulse P1 may be divided into two portions, wherein the first portion P11 is preferably corresponding to the signal readout duration and the second portion P12 is corresponding to the pixel writing duration, as shown in
Please refer to
Please refer to
As shown in
Similarly, there is no additional readout line configured in the present pixel. Accordingly, the second transistor Switch TFT is electrically connected to the second data line D2 rather than to a conventional readout line. The second data line D2 is further electrically connected to a data driver through a switch, D-Switch, on one end thereof, and to an amplifier through a further switch, AMP-switch, on the other end thereof. Preferably, the data driver is constructed of a data driving integrated circuit, Data driver IC, and the amplifier is a current amplifier, Current AMP, which is further coupled to a processor.
The working principle of such pixel structure is similar to that of the first and second embodiments as shown in
With reference to
Please refer to
As above, through the provided method of the present invention, the pixel is advantageous in that no further readout line needs to be configured therein for the data signal transmission and/or the photo signal readout. Accordingly, the mentioned issues of the conventional touch sensitive display are well overcome and the uniformity of lightness therefor is significantly improved. In comparison with the conventional touch display, the present invention is also advantageous in an improvement in yield, which reduces the production cost of the touch display and enhances the display property thereof. Hence, the present invention not only has novelty and progressiveness, but also has an industry utility.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
