Toshiba has showcased prototypes of its LTPS (Low Temperature Poly-Silicon) LCD screens at the Society for Information Display International Symposium. The screens will be available in 3.3" to 4" sizes. The 4" version boasts a pixel density of 367 ppi. The panels sport pixel dimensions of 1280x720 and feature a contrast ratio of 1500:1. For comparison, iPhone 4 is currently equipped with a 327 ppi "Retina" screen with a contrast ratio of 800:1.