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LCD C/D – LCD Driver and Controller

The twisted nematic field effect in liquid crystals was patented on December 4, 1970 by Hoffmann-LaRoche in Switzerland and led to the development of TN-LCD’s and numerous other products in the early 70s. Twisted nematic displays contain liquid crystal elements which twist and untwist at varying degrees to allow light to pass through. When no voltage is applied to a TN liquid crystal cell, the light is polarized to pass through the cell. In proportion to the voltage applied, the LC cells twist up to 90 degrees changing the polarization and blocking the light's path. By properly adjusting the level of the voltage almost any grey level or transmission can be achieved. It is easy to understand that large TN-LCD’s use in Graphing Calculators, Pocket Dictionaries and Personal Digital Assistants (PDAs) with thousands and even ten-thousands of pixel need complex drivers to control every single pixels. Semiconductor manufacturers like Epson, Hitachi , Sharp and Toshiba pioneered the development of drivers in CMOS technology for modern displays and today we know different approaches:

External Drivers:

Include no Display RAM, connected to LCD Controller. Available as Column, Row, or selectable Column / Row driver.  

LCD Drivers with built-in RAM:

 

Row drivers provide the timing for the display and and control the column drivers. Column drivers integrate bit-mapping Display RAM, some drivers, for instance the Toshiba T6A04 / T6K04 used in most TI-83 Plus / TI-84 Plus graphing calculators, combine Row and Column drivers.

 

LCD Controller:

 

Provide timing, internal or external Display RAM and use external drivers.

 

LCD Controller/Driver:

 

Provide timing, Display RAM and integrated drivers in a single-chip package.

Display Driver

Manufacturer Type Year Number of Columns Number of Rows Comments Related Products
Toshiba T6361        ?   
Toshiba T6879        ?   
Toshiba T7778A 1990  80 -    TI-81 (1990), TI-81 ViewScreen
Toshiba T7900 1990 - 68    TI-81 (1990), TI-81 ViewScreen
Toshiba T7932   50 -      
Toshiba T7933    - 32      
Toshiba T9841B   120 -    TI-78
Toshiba T9842B    - 64    TI-78
Toshiba T6A04 1991 120 64 = T9841B
+ T9842B
TI-73, TI-81 (1993), TI-83 Plus
Toshiba T6A04A 1999 120 64 = T6A04 TI-82 Parcus, TI-83 Plus (1999)
Toshiba T6A21 1990 66 - segments PS-6200
Toshiba T6A23 1990 tbd -    TI-86
Toshiba T6A39 1991 80 - = T7778A TI-81, TI-89, TI-92, ViewScreen 82
Toshiba T6A40 1991 - 68 = T7900 TI-81, TI-85, TI-89, TI-92, ViewScreen 82
Toshiba T6A41   64 -     
Toshiba T6A46 1991 - 80 segments   
Toshiba T6A92   80 -     
Toshiba T6B07   80 -    TI-92 Plus, Voyage 200
Toshiba T6B08    - 68    TI-92 Plus, Voyage 200
Toshiba T6B23   80 -      
Toshiba T6B36    - 80      
Toshiba T6B65A   80 -      
Toshiba T6B66B    - 65      
Toshiba T6B79   64 48 = T9841B
+ T9842B
  
Toshiba T6C03   160-0 0-160 Col. + Rows   
Toshiba T6C13B   240-0 0-240 Col. + Rows   
Toshiba T6C23   160 -    Avigo 10
Toshiba T6C24    - 240    Avigo 10
Toshiba T6C25   160-0 0-160 Col. + Rows   
Toshiba T6C61   160 -      
Toshiba T6C63   240 -      
Toshiba T6C72A    - 120      
Toshiba T6C84   136 34 = T9841B
+ T9842B
  
Toshiba T6J05    - 128      
Toshiba T6J06    - 120      
Toshiba T6J14    120 -      
Toshiba T6J15A    - 80      
Toshiba T6K01   240 -      
Toshiba T6K04 2003 128 64 = T9841B
+ T9842B
TI-83 Plus (2004), TI-83 Plus S.E., TI-84 Plus
Toshiba T6K11   160 64 = T9841B
+ T9842B
  
Toshiba T6K14   128 64 = T9841B
+ T9842B
  
Toshiba T6K17   80 18 = T9841B
+ T9842B
  
Toshiba T6K18   80 26 = T9841B
+ T9842B
  
Toshiba T6K19   132 33 = T9841B
+ T9842B
  
Toshiba T6K34   - 168      
Toshiba T6K41   128 128 = T9841B
+ T9842B
  
Toshiba T6K44   - 168      
Novatek NT7564H 2007 128 64 = T6K04
Novatek NT7702H 2007 - 240   TI-Nspire
SMOS SED1520   61 16
SMOS SED1521   80

Display Controller

Manufacturer Type Year Number of Pixels (x) Number of Pixels (y) Comments Related Products
Toshiba T6963C    140 128       
Toshiba T7934    40 16    
Toshiba T6A34    50 16 incl. Drivers  
Toshiba T6B20    50 16 incl. Drivers  

Novatek Microelectronics Corp., headquartered in Hsinchu Science Park, Taiwan, is a leading fabless chip design company specializing in the design, development and sales of a wide range of display driver ICs & SoC solutions.
July 2007: Novatek is recognized as the largest supplier of Display Driver IC for large-size LCD panels, as well as the world's second largest supplier of Display driver IC by world's leading reserach company - iSuppli.

SMOS Systems Inc., headquartered in San Jose, CA, started already in 1983 the marketing and sales of low power, advanced CMOS integrated circuits developed and manufactured by Seiko Epson Corporation of Japan.

 

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© Joerg Woerner, February 28, 2009. No reprints without written permission.