Patent Application
20140085171
This application claims priority to and the benefit of Korean Patent Application No. 10-2012-0107162, filed on Sep. 26, 2012, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.
1. Field
The disclosed technology relates to a flat panel display device, and more particularly, to a layout of a driving circuit used in a flat panel display device.
2. Description of the Related Technology
Generally, a flat panel display device such as a liquid crystal display (LCD), an organic light emitting diode (OLED), and the like, includes a display panel in which a plurality of pixels are arranged, and a driving circuit for displaying an image on the display panel by driving the plurality of pixels. Since the driving circuit generally includes an integrated circuit, it is called a display driver IC (DDI).
The display panel includes pixels connected to each other in, for example, a matrix. Each pixel is at least partially between two scan lines and two date lines, and the driving circuit (DDI) includes a scan driving circuit for driving the scan lines and a data driving circuit for driving the data lines. Scan signals are sequentially supplied from the scan driving circuit to the plurality of scanning lines, such that the pixel is selected, and data signals are supplied from the data driving circuit to the data line connected with the selected pixel, such that an image is displayed.
The driving circuit is configured to receive grayscales voltages corresponding to 64 grayscale, 128 grayscale, 256 grayscale, and the like, from a grayscales voltage generator and select one of the grayscale voltages according to image data input from the outside to supply the selected grayscale voltage to a corresponding data line.
In order to perform an operation as described above, the driving circuit includes a digital to analog converter converting digital image data into an analog signal and a channel amplifier for transmitting the selected grayscale voltage to the data line.
Generally, several hundred to several thousand channel amplifiers are required. In addition, since the digital to analog converter and the channel amplifier include a large number of thin film transistors (TFTs) and complicated wiring, they occupy a large layout area.
Recently, in accordance with a continuous increase in resolution of the flat panel display device, the number of scan lines and data lines has increased. Therefore, the area occupied by the driving circuit has rapidly increased. However, since the area occupied by the driving circuit in the flat panel display device is limited, it is difficult to efficiently layout (design) the driving circuit in the limited area.
One inventive aspect is a driving circuit for a flat panel display device. The driving circuit includes a first region having a first width and a first length, a second region on one side of the first region and having the first width and the first length, and a third region on one side of the second region and having a second width and a second length, wherein the second width and the second length are different from the first width and the first length. The driving circuit also includes a fourth region on one side of the third region and having the second width and the second length, wherein each region has one or more transistors of only one type.
Another inventive aspect is a driving circuit for a flat panel display device. The driving circuit includes first and second amplifier circuits, each amplifier including a first region having a first width and a first length, a second region on one side of the first region and having the first width and the first length, and a third region on one side of the second region and having a second width and a second length, where the second width and the second length are different from the first width and the first length. Each amplifier also includes a fourth region on one side of the third region and having the second width and the second length, where each region has one or more transistors of only one type.
The accompanying drawings, together with the specification, illustrate exemplary embodiments, and, together with the description, serve to explain certain aspects and principles of the present invention.
Hereinafter, certain exemplary embodiments are described with reference to the accompanying drawings. When a first element is described as being coupled to a second element, the first element may be directly coupled to the second element or may be indirectly coupled to the second element via a third element. Further, some of the elements that are not essential to the complete understanding of the invention are omitted for clarity. Also, like reference numerals generally refer to like elements throughout.
Hereinafter, certain embodiments are described with reference to the accompanying drawings. The following exemplary embodiments may be modified in many different forms so that those skilled in the art may implement the various features and aspects, and the scope of the present invention should not be limited to the embodiments to be described below.
In the case in which the driving circuit 100 is operated as a data driving circuit, it may be configured to receive grayscale voltages corresponding to 64 grayscale, 128 grayscale, 256 grayscale, and the like, from a grayscale voltage generator (not shown) and select a grayscale voltage according to image data input from the outside to supply the grayscale voltage to a corresponding data line.
The circuit unit 120 supplies power for operating the driving circuit 100 and processes the image data input from the outside to generate the data signal, and the channel amplifier 140 amplifies the data signal and transfers the amplified signal to a corresponding data line.
In this embodiment, the first width W1 and first length L1 are larger than the second width W2 and the second length L2, respectively, and the first width W1 is equal to or greater than the sum of the first length L1 and the second length L2.
Different types of transistors (TFTs) are disposed in the first region 10, the second region 20, the third region 30, and fourth region 40, respectively. N-type transistors or P-type transistors are divided into a group and disposed as the different types of transistors (TFTs) at the first to fourth regions 10 to 40, thereby making it possible to facilitate a layout (design) and effectively reduce the area.
For example, N-type transistors may be disposed in the first and third regions 10 and 30 and P-type transistors may be disposed in the second and fourth regions 20 and 40, or the N-type transistors may be disposed in the first and fourth regions 10 and 40 and the P-type transistors may be disposed in the second and third regions 20 and 30.
Alternatively, the P-type transistors may be disposed in the first and third regions 10 and 30 and the N-type transistors may be disposed at the second and fourth regions 20 and 40, or the P-type transistors may be disposed in the first and fourth regions 10 and 40 and the N-type transistors may be disposed in the second and third regions 20 and 30.
Accordingly, in these embodiments, each region has only one type of transistor.
A plurality of transistors at least partly forming circuits for amplifying the data signals and transferring the amplified signals to the plurality of data lines are each either N-type or P-type and are located in the first and second regions 10 and 20, and a plurality of transistors at least partly forming an input circuit and an output circuit are each either N-type or P-type and are located in the third and fourth regions 30 and 40.
It may be advantageous that the channel amplifiers 140 may be arranged at upper and lower portions, as shown in
Referring to
Referring to
It may be advantageous that the driving circuit in the flat panel display device has a rectangular shape in which one side (width) is larger than another side (length). In accordance with an increase in a resolution of the flat panel display device, a larger number of channel amplifiers are required, such that a size of the driving circuit is inevitably increased. However, when the size is increased only at one side, several problems are generated.
For example, as shown in
On the other hand, since the channel amplifier (See
In addition, in the case in which the channel amplifier (See
Since the width and the length of the channel amplifier according to the exemplary embodiment are substantially the same as each other, both of the connection path between the transistor of one region and the transistor of another region and the connection path between the transistors within of the respective regions may be short. In addition, since the widths of the respective regions are sufficient, the channel width or length of the channel of the each transistor may be sufficient and the space may also be efficiently used. Further, since the input circuit and output circuit are between each channel amplifier, an offset of the transistor is minimized, and the distances from the each channel amplifier to the pad unit are substantially the same as each other, such that all channel amplifiers may maintain uniform input/output characteristics.
While various aspects and features have been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2012-0107162 | Sep 2012 | KR | national |
