Shift register method: A method whereby data is written into an internal shift register for lighting a single horizontal row of LEDs. Data display within the shift register is performed via designation from an external device. Display and control are synchronized, making this method compatible with simple gradation displays. However, LED timing is performed externally, increasing the processing load vs. the memory method.
Memory method: A method of writing two screen's worth of display data to an internal memory (RAM) circuit. The data written to the memory circuit is automatically displayed via a lighting circuit. Since lighting operations are processed automatically, there is no need for external processing. This reduces the processing load. If fixed characters are used, many units or multiple-step units can be controlled by a simple control device.
With the shift register method data is written to the shift register in groups of a single horizontal row (16 dots), "1" indicates lighting and "0" non-lighting en into the shift register. Each row is written consecutively up to the 16th row, resulting in an entire screen. This method is repeated continuously. In the memory method, in contrast to the shift register method, data is written into internal memory. When all 16 rows have been completed the content is automatically displayed.
ROHM's lineup includes products for both indoor and outdoor use. However, please note that the packages are not waterproof. Therefore, when using in places where contact with water/moisture will occur relevant countermeasures, such as utilizing waterproof housing, is recommended.
ROHM displays are ideal for applications of all types, from commercial (i.e. arrival/departure displays in train stations and airports, ticket gate entry, escalator entrance) to industrial displays in factories to artistic and interior lighting.
Generally, LEDs have a range of brightness. Our dot matrices are classified by individual LED brightness as well as for each module. Each module is adjusted and optimized, resulting in uniform panels with little difference in brightness. We also offer an IC designed to correct for luminance and chromaticity at the dot level in full-color applications, minimizing variations and ensuring that all of our products can be used interchangeably and in any combination.