This might be old news: On January 12, 2006, Apple submitted patent application No.20060007222. The application involves a LCD that does dual duty: it is both a sensor and a display. An array of display elements and image sensor elements are co-located within the display area. Interesting, but the manufacturability of this type of LCD is, let’s say, very low. Currently a standard 17″ TFT LCD module or a 32″ LCD TV module has yields of around 90%. But modules like the 30″ 2560*1600 that go into Apple’s 30″ monitor experienced less than 50% yields for many many months in the beginning. Now it is probably up to roughly 60% or so. There were a couple of reasons for the low yields, but the main point is that with increased complexity in the manufacturing process that includes materials that are not easy to manipulate, the lower the yields are. Lower yields automatically lead to higher prices.
The only problem with this type of sensor is that the more megapixels you want in the sensor, the display itself has to have that many more pixels too. For instance, right now a fairly high pixel format display would be a 23″ Apple Cinema HD display with about 2.3 megapixels (1920*1200). 2.3 megapixels might be high for a display but is old news when it comes to an image sensor. I think there will be uses for such a low pixel count image sensor such as video conferencing and low-quality scanner (fingerprint?) but I can’t think of anything else.
Source: the Mac Observer