The most common method of presenting tactile stimuli to touch screens has been to directly attach a tactile display to the screens. This requires a transparent tactile display so that the view is not obstructed. In contrast, transparency is not required if the tactile stimuli are presented on the back of the device. However, stimulating the entire palm is not appropriate because touch screens are typically used by only one finger. To overcome these limitations, we propose a new method in which tactile feedback is delivered to a single finger on the back of a touch screen. We used an electro-tactile display because it is small and dense. The tactile display presents touch stimuli as mirror images of the shapes on the touch screen. By comparing cases in which the device was operated by one or two hands, we found that shape discrimination is possible using this method.