Platen Cover Angle Control for Original Size Detection

Solution Overview

Problem

Existing image reading apparatuses face difficulties in distinguishing the presence or absence of an original due to the small difference in reflected light between the original and the platen cover, leading to user dazzle and inaccurate size detection, especially when using reflection type sensors.

Innovation Solution

The apparatus incorporates an angle detector to control the platen cover's angle, allowing a sub-scanning size detector using invisible rays to determine the original's presence without dazzling the user, and a reader with illumination and light receiving portions to accurately read the original's size in both main and sub-scanning directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the platen cover is opened to detect original size using reflection type sensor, then original size detection is enabled, but user dazzle occurs due to direct light reaching eyes

Engineering Contradiction:

Improveoriginal size detection accuracyVSAvoiduser dazzle

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The platen cover is made dynamically adjustable with multiple angle positions (first angle for detection, second angle for reading). The controller dynamically switches between these angles based on the operational phase, allowing the system to detect original size at the first angle while preventing user dazzle by moving to the second angle during reading operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the angular parameter of the platen cover between detection mode (first angle) and reading mode (second angle). This parameter change allows the reflection type sensor to accurately detect original size when the platen cover is at the first angle, while preventing direct light from reaching the user's eyes when the platen cover is at the second angle during reading.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If the platen cover is closed to prevent user dazzle, then user safety is improved, but original size detection becomes inaccurate due to difficulty in distinguishing original from platen cover

Engineering Contradiction:

Improveuser dazzle preventionVSAvoidoriginal size detection accuracy

Core Design Contradiction:

Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The platen cover is made dynamically adjustable with multiple angle positions (first angle for detection, second angle for reading). The controller dynamically switches between these angles based on the operational phase, allowing the system to detect original size at the first angle while preventing user dazzle by moving to the second angle during reading operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The platen cover's angular position is segmented into distinct operational states: first angle for detection, second angle for reading. This segmentation allows the system to perform different functions at different angles, resolving the contradiction between detection accuracy and user safety.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If reflection type sensor is used for original size detection, then detection capability is provided, but distinction between original and platen cover becomes difficult due to small reflected light difference

Engineering Contradiction:

Improvedetection capabilityVSAvoidoriginal distinction accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system changes the angular parameter of the platen cover between detection mode (first angle) and reading mode (second angle). This parameter change allows the reflection type sensor to accurately detect original size when the platen cover is at the first angle, while preventing direct light from reaching the user's eyes when the platen cover is at the second angle during reading.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enables precise original size detection in both directions while preventing user dazzle by controlling light emission based on the platen cover's angle, ensuring accurate and safe operation.

Implementation Method 1

a sub-scanning size detector configured to detect presence or absence of an original placed on the original table by radiating invisible rays

Methodology Applied

Scientific EffectInvisible radiation detection:

Implementation Method 2

an illumination portion for irradiating the original placed on the original table with light and a light receiving portion for receiving reflected light of irradiated light reflected from the original

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS10897552B2Image reading apparatus and original size detection method

Publication Date: 2021.01.19 CANON KK

AI summary

An image reading apparatus includes: a reading unit, which is configured to read an original placed on an original table in a main scanning direction by irradiating the original with light; and a sub-scanning size detector, which is configured to detect presence or absence of the original on the original table by radiating invisible rays. When the platen cover forms an angle of equal to or smaller than a first angle with respect to the original table, the image reading apparatus determines a size of the original in a sub-scanning direction in accordance with a detection result acquired from the sub-scanning size detector. When the platen cover forms an angle equal to or smaller than a second angle, which is smaller than the first angle, with respect to the original table, the image reading apparatus determines a size of the original in the main scanning direction.