The tactile sense is one of the fundamental senses, and some tactile sensations which are obtained through the active touch have an important role in our life. For instance, palpation that can quickly examine patient's skin condition is one of the important diagnosis procedures. However, haptic sensations are subjective, so it is difficult to quantify them and share them with others. Therefore, development of measurement sensor system for objectively evaluation of haptic sensations is demanded by dermatologists, cosmetic industries, and so on. For developing the haptic sensor system, it is necessary to find out the mechanism and characteristic of haptic sensation. In this paper, a simple tactile display that we can feel various degree of smoothness is developed. Three bimorph cells are used as actuator to generate vibratory stimulus. Through the two experiments, effectiveness of amplitude and frequency distribution of vibratory stimulus for smoothness are investigated for haptic sensor.