According to the latest report, TJ Lin, chairman of Photoelectricity, a touch panel manufacturer in Taiwan Province Province, recently said that with the promotion of capacitive touch screen technology by major manufacturers, it is estimated that 20 1 1, 40% to 50% of touch screen phones will adopt capacitive touch screen technology, but the share of resistive touch screen technology will also remain at about 50%.
TJ Lin pointed out that the panel of capacitive touch screen uses glass or film as the substrate, so it has certain advantages in cost. At present, most small-sized capacitive touch screens use thin film panels, and glass capacitive panels account for about 20% of the touch screen mobile phone market.
From the perspective of market positioning, touch-screen phones with display sizes below 2.8 inches basically use resistive touch-screen panels, while touch-screen phones with display sizes above 2.8 inches mostly use capacitive touch-screen technology.
At present, 0/9% of Huayang Optoelectronics/KLOC-comes from capacitive touch screen panels. TJ Lin revealed that in the fourth quarter of this year, capacitive touch screen panels will account for about 30% of the company's market share, and will increase to 40% to 50% next year. The transparency and clarity of capacitive touch screen are better than those of four-wire resistance screen, but not as good as those of surface acoustic wave screen and five-wire resistance screen. The capacitive screen is seriously reflective. Moreover, the four-layer composite touch screen with capacitive technology has the problems of uneven light transmittance at various wavelengths and color distortion. Because of the reflection of light between layers, image characters are blurred. In principle, the capacitive screen uses the human body as the electrode of the capacitive element. When the conductor is close to the capacitor coupled to the ITO working surface of the interlayer, the current flowing away is enough to cause misoperation of the capacitive screen. We know that although the capacitance is inversely proportional to the electrode spacing, it is directly proportional to the relative area, and it is also related to the dielectric insulation coefficient. Therefore, when the palm or hand-held conductor is close to the capacitive screen in a large area instead of touching it, it will cause misoperation of the capacitive screen, especially in wet weather. Holding the display screen by hand, with the palm close to the display screen within 7 cm or the body close to the display screen 15 cm, may lead to misoperation of the capacitive screen. Another disadvantage of capacitive screen is that there is no response when a gloved hand or a non-conductive object touches it, because a more insulating medium is added. The main disadvantage of capacitive screen is drift: when the environmental temperature and humidity change and the environmental electric field changes, it will cause the capacitive screen to drift and cause inaccuracy. For example, the temperature rise of the display will cause drift: when the user touches the screen, his other hand or one side of his body will drift near the display; Large objects near the capacitive touch screen will drift backwards after moving, and if someone comes around to watch when you touch it, it will also drift; The reason of capacitive screen drift belongs to technical congenital deficiency. Although the environmental potential surface (including the user's body) is far away from the capacitive touch screen, it is much larger than the finger area, which directly affects the determination of the touch position. In addition, in theory, many relationships should be linear, but in fact they are nonlinear. For example, people with different weights or different finger wetting degrees inhale different amounts of total current, but the changes of total current and four partial currents are nonlinear. The four-corner custom polar coordinate system used in capacitive touch screen has no coordinate origin, so the controller cannot detect and recover after drift. Moreover, after the four A/D are completed, the values of the four partial currents are at right angles to the touch point. Because there is no origin, the drift of capacitive screen is cumulative, and calibration is often needed in the workplace. The silicon dioxide protective glass on the outermost layer of capacitive touch screen has good scratch resistance, but for fear of nails or hard objects, knocking out a small hole will hurt the interlayer ITO. No matter whether the interlayer ITO or the ITO layer on the inner surface is damaged during installation and transportation, the capacitive screen will not work normally.