Drive circuit for an electroluminescence display device

• Main Authors: IKARASHI; MASAMI, MITSUMORI; KENICHI
• Format: Patent
• Language: English
• Published: 25.06.1991
• Subjects: ADVERTISING; ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICESUSING STATIC MEANS TO PRESENT VARIABLE INFORMATION; CRYPTOGRAPHY; DISPLAY; EDUCATION; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; PHYSICS; SEALS

There is provided a drive circuit for an electro-luminescence (EL) display device comprising a variable frequency oscillator circuit whose output signal frequency is externally modifiable, a voltage booster circuit for boosting the output signal of said variable frequency oscillator circuit to a predetermined level and supplying it to an EL display device as drive voltage, an impedance matching circuit whose impedance is externally modifiable and which is connected to said display device, a timing means for timing the duration of application of drive voltage to said display device and a control means for switching the output signal frequency of said variable frequency oscillator circuit and the impedance of said impedance matching circuit in accordance with said duration of voltage application. It is apparent that a drive circuit having such an arrangement as described above can effectively correct any shift of color of the light emitted from the connected EL display device and maintain the origninal color of the EL display device. Moreover, such a drive circuit for an EL display device can effectively compensate the loss of brightness of the screen of the EL display device connected therewith and hence prolong the apparent life of the display device.