(a) Field
Embodiments of the present invention relate generally to flat panel displays. More specifically, embodiments of the invention relate to a data driver circuit and a display device using the same.
(b) DESCRIPTION OF SYMBOLS
A display device such as a liquid crystal display (LCD), an organic light emitting diode display (OLED display), and an electrophoretic display includes a field generating electrode and an electro-optical active layer. For example, the organic light emitting diode device includes an organic emission layer as the electro-optical active layer. The field generating electrode may be connected to a switching element such as a thin film transistor that receives a data signal, and the electro-optical active layer converts the data signal into an optical signal to display an image.
Such a display device may include a touch sensing function which enables touch interaction with a user, in addition to the function of displaying an image. By the touch sensing function, when a user writes a letter or draws a picture on a screen by approaching or contacting the screen with a touch point or using a touch pen, the display device detects a change on the screen, such as a pressure, a charge, or light to detect contact information such as whether an object approaches or is in contact with the screen or a contact position. The display device may receive the image signal and display an image based on the contact information.
Such a touch sensing function may be implemented using touch sensors. Touch sensors may be classified in various was including as a resistive type, a capacitive type, an electro-magnetic type (EM), and an optical sensing type (optical type) touch sensor.
Touches which are detected by touch-sensitive display modules are processed by high level application software which typically operates on a mobile application processor (AP). Due to what is typically a large number of processing steps taken by the display module and the AP, as well as a non-deterministic processing time (including delays due to other computing jobs performed by the AP) for the AP, a high level latency which reduces responsiveness of a computing device with respect to the touch input of the user is introduced. Therefore, a low latency visual accelerator (LLVA) technique has been suggested, which has an advantage in which a part of the touching function is reflected on the display module without passing through a touch processor, so that a response time of the touch is shortened. Particularly, mobile devices such as smart phones or tablets often feature the ability to rotate their displayed image according to the device's orientation.
However, when the LLVA is used, such rotation information is not accounted for in touch detection, which is implemented in a different driver IC. Thus, rotation of the image is not accounted for when determining a touch coordinate. Therefore, an incorrect image is displayed and thus a touch error of the user may be incurred.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.