This application claims priority to Taiwan Patent Application Serial Number 100142378, filed Nov. 18, 2011, which is herein incorporated by reference.
1. Technical Field
The present disclosure relates to a display device. More particularly, the present disclosure relates to a multiplexer circuit in a display device.
2. Description of Related Art
In recent years, a liquid crystal display (LCD) is commonly used as a display device because of its capability of displaying images with good quality while using lower power. However, since the quality of the displayed image is required to be better and better, the display device must display the image with a higher resolution, and therefore, the circuit design for the display device becomes more complex, resulting in that the resistive and capacitive (RC) loadings and the effects thereof on signal transmission lines in the display device become more significant, thereby further causing distortions of transmission signals and affecting the quality of the image displayed by the display device.
Moreover, a transistor made of InGaZn Oxide (IGZO) has advantages such as high electron mobility, so it has higher current driving capability and thus IGZO can be used as the material for fabricating the display device. However, when it is applied in the display device displaying the image with a higher resolution, the RC loadings and the effects thereof on the control lines are more significant as well.
For example,
In operation, the control signals are transmitted to the processing circuit 120 through the control lines CTRL1, CTL2, . . . , CTRLK, such that the processing circuit 120 operates according to the control signals, and furthermore video signals SL1, SL2, . . . , SLP can be transmitted to the data lines DL1, DL2, . . . , DLN through the processing circuit 120, so as to drive the data lines DL1, DL2, . . . , DLN.
However, since each of the control lines CTRL1, CTL2, . . . , CTRLK is connected to several data lines of the data lines DL1, DL2, . . . , DLN through the processing circuit 120 (e.g., the control line CTRL1 is connected to the data lines DL1, DL3, DL5, etc., through the processing circuit 120), the resistive and capacitive (RC) loading and its effect on each control line are significant, such that the control signals on the control lines have distortions, and the related circuits or data lines may not operate normally, thereby further affect the quality of the image.
An aspect of the present invention is to provide a multiplexer circuit comprising a plurality of switches, a first group of control lines and a second group of control lines. The switches comprise a first group of switches and a second group of switches. Each of the first group of control lines is coupled to a control end of at least one of the first group of switches, and the first group of control lines is configured to transmit a first group of control signals. Each of the second group of control lines is coupled to a control end of at least one of the second group of switches, and the second group of control lines is configured to synchronously transmit a second group of control signals which are the same as the first group of control signals.
Another aspect of the present invention is to provide a display panel comprising a plurality of scan lines, a plurality of data lines, and a multiplexer circuit. The data lines interlace with the scan lines. The multiplexer circuit comprises a plurality of switches and a plurality of groups of control lines. First ends of the switches are coupled to one ends of the data lines. Two of the groups of control lines are coupled to control ends of different ones of the switches, respectively, and the groups of control lines are configured to synchronously transmit a plurality of identical groups of control signals.
Still another aspect of the present invention is to provide a method for transmitting signals, applicable for the display panel as described in the immediately previous paragraph. The method comprises synchronously transmitting a plurality of identical groups of control signals through the groups of control lines to a plurality of groups of corresponding switches, the groups of switches being activated in accordance with the groups of control signals, and transmitting a plurality of video signals through a plurality of corresponding video signal lines and the activated switches to the data lines.
It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed.
The invention can be more fully understood by reading the following detailed description of the embodiments, with reference to the accompanying drawings as follows:
In the following description, specific details are presented to provide a thorough understanding of the embodiments of the present invention. Persons of ordinary skill in the relevant art will recognize, however, that the present invention can be practiced without one or more of the specific details, or in combination with other components. Well-known implementations or operations are not shown or described in detail to avoid obscuring aspects of various embodiments of the present invention.
The terms used in this specification generally have their ordinary meanings in the art and in the specific context where each term is used. The use of examples anywhere in this specification, including examples of any terms discussed herein, is illustrative only, and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the present invention is not limited to various embodiments given in this specification.
As used herein, the terms “comprising,” “including,” “having,” “containing,” “involving,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to.
Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, implementation, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, uses of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, implementation, or characteristics may be combined in any suitable manner in one or more embodiments.
In the following description and claims, the terms “coupled” and “connected”, along with their derivatives, may be used. In particular embodiments, “connected” and “coupled” may be used to indicate that two or more elements are in direct physical or electrical contact with each other, or may also mean that two or more elements may not be in direct contact with each other. “Coupled” may still be used to indicate that two or more elements cooperate or interact with each other.
The display array 210 includes a plurality of data lines (e.g., N data lines DL1-DLN, where N is a positive integer) and a plurality of scan lines (e.g., M scan lines GL1-GLM, where M is a positive integer), and the data lines interlace with the scan lines to form a pixel array. In the present embodiment, the data lines DL1-DLN are coupled to the multiplexer circuit 220 and configured to receive video signals according to the operation of the multiplexer circuit 220.
On the other hand, the multiplexer circuit 220 includes a plurality of switches and a plurality of control lines, in which the switches may further be separated into several groups of switches, the control lines may further be separated into several groups of control lines, each control line in each group of control lines is coupled to a control end of at least one switch in the corresponding one group of switches, and two of the groups of control lines are configured to synchronously transmit two identical groups of control signals.
Specifically, as illustrated in
In practice, each of the aforementioned switches may be an analog switch, a digital switch, a thin-film transistor switch or the other type of switch, the appropriate type of switch can be selected and used by persons of ordinary skill in the art according to practical needs for the design of the multiplexer circuit 220, and thus the types of the aforementioned switches are not limited. In one embodiment, each of the aforementioned switches may further include a transistor made of InGaZn Oxide (IGZO).
In addition, in one embodiment, any two group of control lines are coupled to the control ends of the different switches, respectively; in other words, the switches coupled to one group of control lines are different from the switches coupled to the other group of control lines. For example, the 1st group of control lines CTRL1-1-CTRL1-K is coupled to the switches M11-M1K, the switches M31-M3K, etc., the 2nd group of control lines CTRL2-1-CTRL2-K is coupled to the switches M21-M2K, the switches M41-M4K, etc., and the switches coupled to the 1st group of control lines are different from the switches coupled to the 2nd group of control lines.
It is noted that, in practice, each of the aforementioned control lines may be coupled to the control ends of two or more than two switches according to practical needs. Therefore, the connections of the control lines and the switches shown in
Moreover, as illustrated in
For example, the first ends of the 1st group of switches M11-M1K are coupled to the data lines DL1-DLK, respectively, and the video signal line SL1 is coupled to the second ends of the 1st group of switches M11-M1K. Furthermore, the first ends of the dth group of switches Md1-MdK are coupled to the data lines DLM-DLN, respectively, and the video signal line SLP is coupled to the second ends of the dth group of switches Md1-MdK.
Therefore, when the switches M11-M1K are sequentially activated (or turned on) according to the control signals transmitted by the control lines CTRL1-1-CTRL1-K, the video signal transmitted by the video signal line SL1 can be transmitted to the data lines DL1-DLK sequentially through the switches M11-M1K correspondingly. In addition, when the switches Md1-MdK are sequentially activated (or turned on) according to the control signals transmitted by the control lines CTRLd-1-CTRLd-K, the video signal transmitted by the video signal line SLP can be transmitted to the data lines DLM-DLN sequentially through the switches Md1-MdK correspondingly.
Specifically, the 1st group of control lines CTRL1-1-CTRL1-K sequentially transmit the control signals, the 2nd group of control lines CTRL2-1-CTRL2-K is synchronized with the 1st group of control lines and sequentially transmit the control signals, the dth group of control lines CTRLd-1-CTRLd-K is synchronized with the 1st group of control lines and sequentially transmit the control signals, and so on. In other words, the control lines CTRL1-1, CTRL2-1, CTRLd-1 synchronously transmit the control signals, the control lines CTRL1-2, CTRL2-2, CTRLd-2 synchronously transmit the control signals, and the control lines CTRL1-K, CTRL2-K, CTRLd-K synchronously transmit the control signals, and so on.
In one embodiment, the control signals transmitted by each group of control lines includes a plurality of clock signals, and phases of the clock signals are different from one another; that is, any two of the clock signals have a phase difference therebetween. For example, the 1st group of control lines CTRL1-1-CTRL1-K sequentially transmit the clock signals in the time period t1, t2, . . . , tk, respectively, such that the phases of the clock signals transmitted by the control lines CTRL1-1-CTRL1-K are different from one another, and any two of the clock signals transmitted by the control lines CTRL1-1-CTRL1-K have a phase difference therebetween, such that the switches corresponding to the control lines CTRL1-1-CTRL1-K are sequentially activated to transmit the signals.
The operation of the display panel 200 shown in
Thereafter, the Kth control lines CTRL1-K, CTRL2-K, . . . , CTRLd-K separately in the 1st group, the 2nd group, . . . , and the dth group of control lines synchronously transmit the identical groups of control signals in another time period tk to the corresponding switches M1K, M2K, . . . , MdK, respectively, such that the Kth switches M1K, M2K, . . . , MdK separately in the groups of switches are activated according to the control signals, and the video signals transmitted by the video signal lines SL1-SLP are transmitted through the corresponding switches M1K, M2K, . . . , MdK, respectively, to the data lines DLK, . . . , DLN.
In the condition that the number of the data lines is N, if only K control lines CTRL1-1, . . . , CTRL1-K are coupled to the data lines through the switches, each of the control lines is ideally coupled to N/K switches (where N and K are positive integers, and N is greater than K); in other words, the resistive and capacitive (RC) loading on each control line is basically represented by N×C×R/K, in which C and R are a capacitive loading and a resistive loading, respectively, on a single control line.
Compared to the condition described above, in the embodiment of the present invention, the multiplexer circuit 220 includes d groups of control lines (where d is a positive integer), and each group of control lines includes K control lines, then each of the control lines is ideally coupled to N/(K×d) switches; in other words, the resistive and capacitive (RC) loading on each control line is basically represented by N×C×R/(K×d). Therefore, the RC loading on each control line and its effect can be reduced significantly, the distortions of the control signals on the control lines also can be decreased, and the quality of the display image can be improved accordingly.
The multiplexer circuit 520 in the present embodiment is similar to the multiplexer circuit 220 shown in
Likewise, each of the switches 525 may be an analog switch, a digital switch, a thin-film transistor switch or the other type of switch, and the appropriate type of switch can be selected and used by persons of ordinary skill in the art according to practical needs for the design of the multiplexer circuit 520.
Moreover in practice, each of the control lines may be coupled to the control end of at least one switch 525 or coupled to the control ends of two or more than two switches 525 according to practical needs. Therefore, the connections of the control lines and the switches shown in
On the other hand, the application circuit 540 is coupled to the video signal lines SL1-SLP and the d groups of control lines. The application circuit 540 is configured for generating the video signals transmitted through the video signal lines SL1-SLP and configured for generating the multiple groups of control signals transmitted synchronously through the multiple groups of control lines. In practice, the application circuit 540 in the present embodiment or the application circuit described in the following embodiments can be an application specific integrated circuit (ASIC) or other circuits with the same function and operation.
The operation of the display panel 500 in the present embodiment is similar to that of the display panel 200 shown in
Similarly, the multiplexer circuit 520 includes d groups of control lines, and each group of control lines includes K control lines, so the resistive and capacitive (RC) loading on each control line is basically represented by N×C×R/(K×d). Therefore, the RC loading on each control line and its effect can be reduced significantly, the distortions of the control signals on the control lines also can be decreased, and the quality of the display image can be improved accordingly.
The multiplexer circuit 620 in the present embodiment includes more groups of control lines, e.g., 2d groups. Specifically, the upper part of
In the present embodiment, the multiplexer circuit 620 includes 2d groups of control lines, and each group of control lines includes K control lines, so the resistive and capacitive (RC) loading on each control line is basically represented by N×C×R/(2×K×d). Therefore, compared to the embodiment shown in
In practice, each of the aforementioned control lines may be coupled to the control end of one or more than one switch or coupled to the control ends of two or more than two switches according to practical needs. Therefore, the connections of the control lines and the switches shown in
In the present embodiment, the application circuit 740 is coupled to the video signal lines SL1-SLP, the d groups of control lines (e.g., CTRL1-1-CTRL1-K, . . . , CTRLd-1-CTRLd-K) and the scan lines GL1-GLM, in which the application circuit 740 is configured for generating the video signals transmitted through the video signal lines SL1-SLP, configured for generating the multiple groups of control signals transmitted synchronously through the multiple groups of control lines, and further configured for generating the scan signals transmitted through the scan lines GL1-GLM. In other words, compared to the display panel 500 shown in
In practice, each of the aforementioned control lines may be coupled to the control end of one or more than one switch or coupled to the control ends of two or more than two switches according to practical needs. Therefore, the connections shown in
Compared to the embodiment in
Compared to the embodiment in
Compared to the embodiment in
Another aspect of the present disclosure is related to a method for transmitting signals, which is applicable for the display panel shown in
In one embodiment, the multiple groups of control signals are transmitted synchronously in a period of one scan signal transmitted by a scan line, each of the groups of control signals includes a plurality of clock signals, and two of the clock signals have a phase difference therebetween.
The multiplexer circuit in the present disclosure can be applied in a transistor display panel made of InGaZn Oxide (IGZO), so as to significantly reduce the RC loading caused by high electron mobility.
The steps are not necessarily recited in the sequence in which the steps are performed. That is, unless the sequence of the steps is expressly indicated, the sequence of the steps is interchangeable, and all or part of the steps may be simultaneously, partially simultaneously, or sequentially performed.
As described above, the display panel, the multiplexer circuit therein, and the method for transmitting signals in the foregoing embodiments of the present invention can be applied to reduce the RC loading and it effect on each control line by the multiple groups of control lines synchronously transmitting the control signals, and to decrease distortions of the control signals on the control lines, thereby improving the quality of the display image accordingly.
As is understood by a person skilled in the art, the foregoing embodiments of the present invention are illustrative of the present invention rather than limiting of the present invention. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
Number | Date | Country | Kind |
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100142378 | Nov 2011 | TW | national |