Binary Conversion (Mono); Scaling Of Input Image; Intelligent Scan Motor Controller; Auto-Run - Ricoh B174 Service Documentation

SCANNER

Binary conversion (mono)

1. 256 grey scales for photo documents: 3x5 EDF (Error Diffusion) method
proposed by Stucki.
2. LAT (Local Adaptive Thresholding) for Text documents:
• Use of 5x5 Local Window (Tip Algorithm)
• ABC (Automatic Background Control): Tmin Automatic change
3. Mixed mode processing for text/photo mixed documents
4. EDF data memory: 2x4Kx16 bits = 128K bits (internal)
5. LAT data memory: 4x4Kx16 bits = 256K bits (external)

Scaling of input image

1. Scaling factor
• Horizontal direction: 25 ~ 800% by 1% unit
• Vertical direction: 25 ~ 100% by 1% unit
2. Scaling data memory: 2x8Kx8 bits = 128K bits (internal)

Intelligent scan motor controller

1. Automatic acceleration/deceleration/uniform velocity
2. Data memory: 256x16 bits = 4K bits (internal)

Auto-Run

Automatic CLK_LINE (line processing start control) and øTG (line scan start
control) signal generation.
1. Available resynchronization of øTG signal
2. Programmable øTG's period & CLK_LINE's occurrence number

Processed data output format in DTM (Data Transfer Module)

1. DMA mode: Burst/On-demand mode
2. CDIP I/F: LINE_SYNC, PIXEL_SYSNC, PIXEL_DATA[7:0]

Others

36 General Purpose Input/Output ports: 8 (GPO), 28 (GPIO)
Black/White inversion, and Image Mirroring support
B174 6-4 SM