1. Field of the Disclosure
The present disclosure relates to a circuit and a display system, and in particular relates to a photosensitive circuit and a photosensitive display system.
2. Description of the Related Art
Touch panel technology has been widely used in commercial electronic devices such as PDAs, mobile phones and laptop computers etc. Touch panels provide an intuitive user interface and have the multi-touch ability that is not achievable by using conventional mouse input interface. Touch panel technology uses various materials and has various structures and designs. For example, add-on type touch panels with resistive type, capacitive type and other type designs have been developed for many years and are used in commercial applications. Recently, in-cell integrated touch panels have gained much attention due to their simpler structures, and low-cost manufacturing. Of all the in-cell-type touch panels, photo-sensing is an attractive scheme because photo-sensor arrays can be integrated into display panels by leveraging the mature TFT-LCD industrial technology without additional large capital investments. Also, the photosensitive display may be used to sense the photo images of the objects that come into contact with the display and may operate as a scanner with real-time display.
U.S. Pat. No. 4,345,248 discloses a liquid crystal display device with write-in capability, wherein display data lines and readout lines of the photosensitive elements share the column lines, and the photosensitive element is a two-terminal rectifier. The display signal and the photosensitive signal are transmitted with a time sharing manner. However, a photocurrent may be leaked into a display data input due to shared column lines.
U.S. Pat. No. 7,053,967 discloses a light sensitive display, wherein photosensitive elements and a readout circuit are disposed between LCD pixels. That is, photo-sensors are disposed between column lines and row lines. For example, there may be 30 lines sharing a sensor. The current is generated by the sensor according to ambient light charges or discharges the capacitor Cst. However, the column lines connected with the sensors may appear as dim lines, causing a non-uniform display of the image.
Thus, a display circuit and a display device for low signal leakage and high display uniformity is provided.