In the session of Automotive Display Systems & Applications (PC1^*), there were only five papers presented, one of them related to Vacuum Fluorescent Displays (VFDs) by Futaba Corporation. Another paper related to VFD was presented in the session of Audio Systems (PC4 A^*), also by Futaba Corp., and we were the only presenter in the field of VFDs.
This paper describes a display unit for automotive navigation systems. The distinguishing feature of this display unit is the fact that it employs a 5.6 inch TFT-LCD (Thin Film Transistor Liquid Crystal Display) for on-vehicle use. Compared with a 6-inch CRT, the unit has an expanded effective display area (screen) for improved readability. as well as greater compactness (for savingspace), lighter weight, and lower power consumption. In terms of reliability, the display unit outperforms conventional LCDS due to its wider working temperature range and outstanding resistance to thermal shock. In terms of operation, the system employs a combination of infrared touch switches, hard-key switches and a joy stick to ensure safety and ease of operation. The 1994 Model MAZDA "SENTIA" is equipped with this newly developed display unit for an automobile navigation system.
We have developed the Automatic Set-Up System for front type projection display. This system can adjust geometric distortion, convergence and white balance automatically and correctly by newly developed error detection system and stable multi-scan display.
The repair of pixel defects on TFT-LCD, which is executed with laser processing or redundancy structure. is very effective for the high productivity. This paper describes the survey of the pixel defect repair. The pixel defect repair may bring the asymmetry of the pixel voltage, which is caused by the pixel voltage shift when the TFTS are turned off. The asymmetry causes the difference of the display characteristics. The pixel defect visibility was evaluated considering the dependence of the contrast threshold on the background luminance. Consequently, the relation between the asymmetry and the pixel defect visibility has been acquired. This can be applied to the use of degraded redundancy structure.