Sheet Detecting Apparatus Sensor Flag Pivot Mechanism
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Solution Overview
Problem
Existing sheet detecting apparatuses in image forming devices, such as copiers, face issues with erroneous detection due to the pivot movement of sheet width detecting levers, leading to incorrect sensor activation when the side guide is not properly positioned.
Innovation Solution
A sheet detecting apparatus with sensor flags and contact portions that pivot around specific axes, allowing for accurate detection of sheet presence and size by outputting distinct signals based on the position of the flags, eliminating the need for precise side guide alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If sheet width detecting levers pivot in response to side guide positions, then sheet size detection is enabled, but erroneous detection occurs when side guide is not properly positioned
Solution Approach 1:
A sensor flag is introduced as an intermediary element between the sheet and the photo-interrupter. The sensor flag pivots on a pivot shaft and includes contact portions that contact the sheet at different positions. When the sheet is inserted, the sensor flag pivots to a specific angle based on the sheet width, and this angular position is detected by the photo-interrupter. This intermediary mechanism converts direct mechanical contact into an optical detection signal, eliminating erroneous detection caused by improper side guide positioning.
Solution Approach 2:
The patent replaces the direct mechanical linkage system (side guide directly actuating detecting levers) with a combined mechanical-optical system. The sensor flag uses mechanical pivoting to convert sheet width variations into angular displacements, which are then detected optically by the photo-interrupter. This substitution eliminates the need for precise mechanical alignment of the side guide while maintaining accurate sheet size detection capability.
2Measurement precision
If multiple photo-interrupters are used to detect different sheet sizes, then detection accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes a single photo-interrupter multi-functional by using it to detect the angular position of the sensor flag, which can indicate different sheet sizes. The sensor flag is designed with contact portions at different positions that pivot the flag to different angles depending on the sheet width. One photo-interrupter can thus detect multiple sheet sizes (A3, A4, A5) by measuring the angular position of the sensor flag, eliminating the need for multiple photo-interrupters and reducing device complexity.
Solution Approach 2:
The patent transitions from a one-dimensional detection approach (multiple sensors along the sheet width) to a two-dimensional approach (single sensor detecting angular position). Instead of placing multiple photo-interrupters at different linear positions, the system uses a single photo-interrupter that detects the angular displacement of the sensor flag. This dimensional change allows one sensor to perform the work of multiple sensors, simplifying the device structure.
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
The apparatus provides reliable and accurate detection of sheet presence and size, reducing erroneous readings and allowing for cost reduction by using fewer photo-interrupters, while ensuring proper operation even if the user forgets to adjust the side guides.
Implementation Method 1
a first detection sensor configured to transit to a first state of outputting a first detection signal and to a second state of outputting a second detection signal different from the first detection signal, the first detection sensor transiting to either one of the first state and the second state in response to a position of the first flag portion, and a second detection sensor configured to transit to a third state of outputting a third detection signal and to a fourth state of outputting a fourth detection signal different from the third detection signal, the second detection sensor transiting to either one of the third state and the fourth state in response to a position of the second flag portion
Data Source
AI summary
A sheet detecting apparatus includes a sheet supporting surface, a first sensor flag including a first flag portion, a first contact portion, and a third contact portion, a second sensor flag including a second flag portion, and a second contact portion, a first detection sensor configured to transit to a first state of outputting a first detection signal and to a second state of outputting a second detection signal, the first detection sensor transiting to one of the first state and the second state in response to a position of the first flag portion, and a second detection sensor configured to transit to a third state of outputting a third detection signal and to a fourth state of outputting a fourth detection signal, the second detection sensor transiting to one of the third state and the fourth state in response to a position of the second flag portion.