Overview

The LC821031 converts analog video signals from CCD

and contact sensors to high-quality binary image data. It

includes both an 8-bit A/D converter and a 6-bit D/A

converter for setting the reference potential and creates

high-quality multi-valued data using a gamma conversion

technique that supports arbitrary gamma curves. It also

provides both black and white all-pixel distortion

correction and multi-valued resolution conversion. It then

applies two-dimensional filtering to this multi-valued data

to separate the document image into text, photograph, and

halftone areas. After converting the image to a binary

image using an error diffusion technique that acquires

high-quality images, it applies reduction in both the

primary and secondary scan directions. Since the

LC821031 limits the number of pixels processed per line

to 3072 pixels, it needs no external memory to implement

this processing. Thus the LC821031 implements the image

processing used by facsimile, copier, and OCR products.

Features

• Number of pixels processed: 3072 pixels/line

• Processing speed: 250 ns/pixel, maximum (When

CLKIN = 32 MHz)

• 8-bit A/D converter (Includes a sensor signal timing

adjustment function.)

• 6-bit D/A converter for setting the A/D converter

reference potential

• Sensor drive circuit (Supports most CCD and CIS

devices.)

• Digital clamp (single-point clamping and even/odd

clamping)

• Distortion correction (white correction: all-pixel

correction, black correction: all-pixel correction)

• Gamma correction (Supports user-defined curves: 8-bit

data)

• Image area separation

• Simple binary coding (fixed threshold and density

adaptive threshold)

• Halftone processing: error diffusion method (64 levels)

• Multi-value resolution conversion (Conversion ratios of

1:2, 2:3, 3:2, and 2:1)

• Binary image reduction (Main scan line direction:

decimation, fine black line retention, fine white line

retention; secondary scan line direction: decimation, fine

line retention)

• Fabricated in a CMOS process for single 5-V power-

supply and low power.

Package Dimensions

unit: mm

3159-QFP64E

CMOS LSI

22898HA (OT) No. 5735-1/5

Preliminaly

SANYO: QIP64E

[LC821031]

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-0005 JAPAN

Image-Processing IC for Facsimile, Copier,

and OCR Products

LC821031

Ordering number : EN*5735

Parameter

Symbol

Conditions

Ratings

Unit

Maximum supply voltage

–0.3 to +7.0

V

Input and output voltage

V

Allowable power dissipation

Pd max

Ta

≤ 70°C

350

mW

Operating temperature

Topr

–30 to +70

°C

Storage temperature

Tstg

–55 to +125

°C

Soldering conditions

Hand soldering: 3 seconds

350

°C

Reflow soldering: 10 seconds

235

°C

Specifications

Absolute Maximum Ratings at Ta = 25°C, GND = 0 V