Canon Canoscan N650U Canoscan N650U

SERVICE MANUAL

REVISION 0

JUNE 2000

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

JY8-1317-00Z

Printed in Japan

Imprimè au Japon

Use of this manual should be strictly supervised to avoid disclosure of confidential information.

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

LIST OF SERIAL NUMBER

CanoScan N650U F91-4611-200 AZJ000001-

F91-4631-200 CZJ000001F91-4641-200 DZJ000001F91-4661-200 FZJ000001F91-4671-200 LZJ000001F91-4681-200 JZJ000001F91-4691-200 KZJ000001-

CanoScan N656U F91-4612-200 AZK000001-

F91-4622-200 MZK000001F91-4632-200 CZK000001F91-4642-200 DZK000001F91-4662-200 FZK000001F91-4672-200 LZK000001F91-4682-200 JZK000001F91-4692-200 KZK000001-

CanoScan N1220U F91-4712-200 AZL000001-

F91-4722-200 MZL000001F91-4732-200 CZL000001F91-4742-200 DZL000001F91-4762-200 FZL000001F91-4772-200 LZL000001F91-4782-200 JZL000001F91-4792-200 KZL000001-

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

PREFACE

This service manual contains the basic information necessary for servicing the N650U/N656U/ N1220U image scanners.

The service manual consists of the following chapters.

Chapter 1: General Descriptions

Features, specifications, exterior features, installation, customer’s daily maintenance

Chapter 2: Operation and Timing

Basic operation, optical system, image processing system, control system, power supply

Chapter 3: Mechanical System

Externals, drive system, optical system, electrical system

Chapter 4: Maintenance and Servicing

Periodical replacement parts, consumable parts durability, periodical servicing, special tools, solvents and lubricants

Chapter 5: Troubleshooting

Introduction, troubleshooting, location of electrical parts, canon scanner test

Chapter 6: Parts Catalog

Appendix: General Circuit Diagram, Main PCB Circuit Diagram, USB Connector PCB

Circuit Diagram

The information in this service manual is subject to change as the product is improved. All relevant information in such cases will be provided by the service information bulletins.

A thorough understanding of the N650U/N656U/N1220U, based on the service manual and service information bulletins, is vital to the serviceman in maintaining the product quality and performance, and in locating and repairing the cause of malfunctions.

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

CHAPTER 1

GENERAL DESCRIPTIONS

I. FEATURES ..................................... 1-1

II. SPECIFICATIONS ........................... 1-2

III. EXTERIOR FEATURES .................. 1-4

A. Front View ............................... 1-4

B. Rear View................................. 1-4

IV. INSTALLATION .............................. 1-5

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

A. Preface ..................................... 1-5

B. Installation .............................. 1-6

C. Connecting to the Host Computer

................................................. 1-7

D. Scanning a Document ............. 1-8

V. CUSTOMER’S DAILY MAINTENANCE

................................................. 1-9

CHAPTER 1

I. FEATURES

CanoScan N650U/N656U with 600 x 1200 dpi resolution, CanoScan N1220U with 1200 x

2400 dpi resolution are flatbed image scanners incorporating the following features.

1. High gradation and high image quality are achieved by employing a highly sensitive contact image sensor with LIDE (LED Indirect Exposure) technology for the scanning unit, and by reading each RGB color by 14 bits and outputting by 8 bits.

2. The scanner is a small size of 256.0(W) x 372.5(D) x 34.0(H) mm, and a light weight of 1.5 kg by using a downsized scanning unit.

3. The scanner can easily be connected to the host computer through a USB interface.

4. Double hinge structure (Z-lid) enables the document cover to hold a thick document.

5. The scanner can be placed vertically to scan by using an optional stand.

6. The scanner draws its power from USB port on the host computer requiring no AC adapter.

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

1 - 1

CHAPTER 1

II. SPECIFICATIONS

CanoScan N650U/N656U

MAIN UNIT

· Type : Flat bed image scanner

READING UNIT

· Image sensor : 5104 pixels contact image sensor

· Light source : LED indirect exposure (RGB each)

· Max. document size : A4 or Letter (216 x 297 mm)

· Image output : RGB 8 bits per channel (input 14 bits)

· Resolution : 600 x 1200 dpi

· Scan time : 112 sec. (color, A4, 600 dpi) 37 sec. (grayscale, A4, 600 dpi) 16 sec. (preview)

INTERFACE

· Interface : USB 1.1 (B plug) x 1

OTHERS

· Operating environment : Temperature range, 5 to 35°C Humidity range, 10 to 90% Air pressure range, 613 to 1013 hPa

· Power consumption : 2.5W (during operation)

· Dimensions : 256.0(W) x 372.5(D) x 34.0(H) mm

· Weight : 1.4 kg

1 - 2

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

CHAPTER 1

CanoScan N1220U

MAIN UNIT

· Type : Flat bed image scanner

READING UNIT

· Image sensor : 10208 pixels contact image sensor

· Light source : LED indirect exposure (RGB each)

· Max. document size : A4 or Letter (216 x 297 mm)

· Image output : RGB 8 bits per channel (input 14 bits)

· Resolution : 1200 x 2400 dpi

· Scan time : 449 sec. (color, A4, 1200 dpi) 149 sec. (grayscale, A4, 1200 dpi) 16 sec. (preview)

INTERFACE

· Interface : USB 1.1 (B plug) x 1

OTHERS

· Operating environment : Temperature range, 5 to 35°C Humidity range, 10 to 90% Air pressure range, 613 to 1013 hPa

· Power consumption : 2.5W (during operation)

· Dimensions : 256.0(W) x 372.5(D) x 34.0(H) mm

· Weight : 1.4 kg

Specifications are subject to change with product improvement.

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

1 - 3

CHAPTER 1

III. EXTERIOR FEATURES

A. Front View

2

1

A4

LTR

B5

q Document Cover w Document Glass e Alignment Mark r Start Button t Carriage Lock

B. Rear View

3

B5

A4

LTR

4

5

Figure 1-1

q USB Port

1 - 4

1

Figure 1-2

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

CHAPTER 1

IV. INSTALLATION

A. Preface

The following installation conditions are required.

1. Ambient temperature should be between 5°C and 35°C, and humidity between 10% and

90%. Avoid locations near water faucets, boilers, humidifiers, or refrigerators.

2. Avoid locations subject to open flame, dust, or direct sunlight. If it is installed near a

window, hang a curtain to block direct sunlight.

3. The room should be well ventilated.

4. Install on a sturdy and level desk, etc.

5. Moving a scanner from a cold place to a warm place can cause condensation on the metal

parts, resulting in a faulty operation. Give the scanner at least one hour to adjust to the room temperature before unpacking.

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

1 - 5

CHAPTER 1

B. Installation

1. Unlocking the carriage lock

The scanner is shipped with the scanning unit locked by the carriage lock to prevent

damage during transport. Unlock the scanning unit to use the scanner.

1) Turn the scanner over.

Figure 1-3

2) Push the carriage lock to the unlock mark position.

1

q Carriage Lock

Figure 1-4

3) Return the scanner to its standard position.

Note: Always lock the scanning unit during transport.

1 - 6

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

CHAPTER 1

C. Connecting to the Host Computer

The scanner is connected to the USB port on the host computer using a supplied USB cable. Refer to "Getting Started" for details. For connecting/disconnecting the host computer's cables, refer to the manual supplied with the host computer.

1) Connect the flat connector (A plug) of the USB cable to the USB port on the host computer.

2) Connect the square connector (B plug) of the USB cable to the USB port on the scanner.

q USB Port

w USB Cable

Figure 1-5

1

2

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

1 - 7

CHAPTER 1

D. Scanning a Document

1) Open the document cover.

2) Place a document on the document glass, orienting the image face down and aligning its top edge with the alignment mark.

A4

LTR

B5

1

1234

B5

A4

LTR

q Alignment Mark

Figure 1-6

3) Close the document cover, caring not to dislodge the document.

4) Send the "SCAN" command from the host computer to scan.

1 - 8

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

CHAPTER 1

V. CUSTOMER'S DAILY MAINTENANCE

Dirt on a document glass or a document cover may cause an unclear image or lines on an

image. Clean the document glass and the document cover using the following procedures.

1) Disconnect the USB cable from the scanner.

2) Wipe the dirt or dust off the document cover with a soft clean cloth dampened with water and well wrung, then thoroughly wipe water off with a dry cloth.

3) Wipe the document glass with a dry cloth caring not to leave wiper marks.

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

1 - 9

CHAPTER 2

OPERATION AND TIMING

I. BASIC OPERATION ........................ 2-1

A. Functions ................................ 2-1

B. Outline of Electrical System ... 2-2

C. Main PCB Input and Output ... 2-3

D. Basic Sequences .................... 2-4

II. OPTICAL SYSTEM ....................... 2-11

A. Outline .................................. 2-11

B. Document Scanning Sequence....

............................................... 2-12

C. Contact Image Sensor ........... 2-13

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

D. Drive Motor Control Circuit

............................................... 2-16

III. IMAGE PROCESSING SYSTEM.... 2-17

A. Outline .................................. 2-17

B. Image Processing Functions .......

............................................... 2-18

IV. CONTROL SYSTEM ..................... 2-20

A. Outline .................................. 2-20

B. Outline of USB ...................... 2-21

V. POWER SUPPLY........................... 2-23

CHAPTER 2

I. BASIC OPERATION

A. Functions

The scanner functions are divided into the three main blocks of optical system, image

processing system, and control system.

Contact image

sensor

Host computer

Drive motor

Control system

Figure 2-1

Optical system

Image processing system

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

2 - 1

CHAPTER 2

B. Outline of Electrical System

Figure 2-2 shows the outline of electrical system. CPU is not equipped in the main PCB. The device driver installed in the host computer includes a control program, which functions as CPU.

Image signals read by the contact image sensor are converted into digital data by the A/D converter in the gate array. The converted image data are image-processed by the gate array, then output to the host computer via USB port.

Host computer

J1

USB Connector

PCB

J2

Control

program

Contact

image

sensor

CS1

Drive motor

M1

J2

J3

Main PCB

Buffer

RAM

Gate array

Figure 2-2

J1

Start button

S1

Home position

sensor

Q4

2 - 2

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

C. Main PCB Input and Output

USB connector PCB

Vbus

J1-1

D-

To host computer

-2 D+

-3 GND

-4

Drive motor

M1

J2-1

-2

-3

-4

-5

-6

-7

-8

J1-1

J2-1

CHAPTER 2

Main PCB

GND

-2 +5V

-3 GND

-4 D-

-5 D+

-6 GND

-7 +5V

-8 +5V

PA+

-2 PB-

-3 PB+

-4 PA-

Drive motor drive signal

CS1

Contact image sensor

Home

position

sensor

Start button

Q4

S1

J3-1

-10

-11

-12

-2

-3

-4

-5

-6

-7

-8

-9

Vob Misc6 GND Vcis Vref TR PHI1 Vled BEN GEN REN GND

HPSEN

"H" when scanning unit is in home position

GND

SCANSW GND

"L" when start button was pressed

Figure 2-3

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

2 - 3

CHAPTER 2

D. Basic Sequences

The basic sequences of the scanner are divided into power ON sequence, calibration

sequence, and document scanning sequence.

1. Power ON sequence

Power ON

Sets gate array

Sets analog power

Checks PCB ID Checks CIS

Tests gate array

read/write

Gate array read/write was tested normally?

YES

Scanning unit is in home

position?

YES

NO

Sets error flag

NO

Returns scanning unit

Scanning unit returned

to the home position?

YES

NO

Returned more

than 300 mm?

Sets error flag

NO

YES

2 - 4

Stops scanning unit

1

Figure 2-4-1

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1

Moves scanning unit forward by x pulses

CHAPTER 2

Scanning unit is off the home position?

YES

Returns scanning unit by x pulses

LED ON

Adjusts LED ON period for white mark area detection

LED ON period

was adjusted normally?

YES

NO

Sets error flag

NO

Sets error flag

Detects white mark area

White mark area

was detected normally?

YES

LED OFF

Standby

NO

Sets error flag

Figure 2-4-2

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2 - 5

CHAPTER 2

When the scanner is powered ON, it performs hardware setting, home position detection, and

border detection between black and white according to the flowchart shown in Figure 2-4.

1) Hardware setting Gate array and buffer RAM in the main PCB are checked if they function normally.

2) Home position detection/Border detection between black and white The scanner detects the home position by the home position sensor by using a black mark

area and white mark area in the rear of the document glass.

Firstly the home position sensor defines the home position, where the scanning unit reads a

black mark area.

Secondly, the border between a white mark area and black mark area is detected. The

scanning unit moves forward reading image signals with the LED of the contact image sensor turned ON. When the scanning unit has reached the white mark area, and the peak value of the light intensity to the scanning unit has reached a white level, the scanning unit stops to define there as the border between a black mark area and white mark area. The number of steps of the drive motor is calculated to define the distance from the home position to the white mark area.

Black mark area

Document glass (rear side) White mark area

Figure 2-5

When the hardware setting, home position detection and border detection between black

and white have completed, the scanner is on standby to wait for a command from the host computer.

2 - 6

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2. Calibration sequence

CHAPTER 2

Standby

Corrects black level

Black level was

corrected nor mally?

YES

Obtains 32 lines of data

Data was

obtained normally?

YES

Composes black

calibration data

Sets black calibration

data to gate array

NO

Sets error flag

NO

Sets error flag

Black calibration data was

set to gate array normally?

YES

2

NO

Sets error flag

Figure 2-6-1

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2 - 7

CHAPTER 2

2

Moves scanning unit

to white mark area

Scanning unit moved to

white mark area normally?

YES

Adjusts LED ON per iod

LED ON

period was adjusted

normally?

YES

LED ON

Obtains 16 lines of data

NO

Sets error flag

NO

Sets error flag

Data was

obtained normally?

YES

Composes white

calibration data

LED OFF

Moves scanning unit to the home position

Stores white calibration

data as a file

Standby

Figure 2-6-2

NO

Sets error flag

2 - 8

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CHAPTER 2

When the host computer sends a calibration command, the scanner performs the calibration. Calibration is to compose black calibration data and white calibration data by reading the black mark and white mark in the rear of the document glass as color references for the proper color reading.

1) Black calibration data composition

Black calibration data is composed by reading and averaging 32 lines of output from the scanning unit with the LED turned OFF.

2) White calibration data composition

White calibration data is composed by reading 16 lines of each red, green and blue of the white mark, and averaging the highest 8 lines of output.

Above procedure is performed at high image quality color 600 dpi, color 600/300 dpi, and grayscale 600/300 dpi and the data is stored as a file in the host computer. For grayscale 600/300 dpi, only green data is processed.

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

2 - 9

CHAPTER 2

3. Document scanning sequence

Standby

LED ON

Moves scanning unit to the

vertical scan start position

Starts document scan

Scan cancellation

is required?

NO

All document lines

were scanned?

LED OFF

Returns scanning unit

Scanning unit returned

to the home position?

YES

NO

YES

NO

2 - 10

YES

Stops drive motor

Image data

was transmitted?

YES

Standby

NO

Figure 2-7

COPYRIGHT  2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)

Canon Canoscan N650U Canoscan N650U

Specifications and Main Features

Frequently Asked Questions

User Manual

SERVICE MANUAL

LIST OF SERIAL NUMBER

PREFACE

CONTENTS

CHAPTER 1

I. FEATURES

II. SPECIFICATIONS

III. EXTERIOR FEATURES

IV. INSTALLATION

V. CUSTOMER'S DAILY MAINTENANCE

CHAPTER 2

I. BASIC OPERATION