Laundry Inspection Using Backlighting to Detect Both-Side Impurities
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for testing laundry fail to comprehensively inspect the finish side of cleaned items for impurities and stains, particularly hair and fibers, which are difficult to detect due to their location underneath or within multi-layered items, leading to unacceptable returns in the laundry industry.
Innovation Solution
A method involving backlighting or transillumination of the finish side of laundry items using an imaging device, such as a camera or sensors, allows for the detection of impurities and adhesions on both sides by illuminating the finish side opposite the camera, enabling complete examination without physically turning the items over.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laundry items are inspected from only one side using a camera, then the inspection process is simple and fast, but impurities on the finish side (underside) cannot be detected
Solution Approach 1:
The patent introduces a second dimension of inspection by placing a light source behind the laundry item (on the conveyor side) to illuminate the finish side from underneath. This backlighting technique allows the camera on the front side to capture impurities on both the top and bottom surfaces simultaneously, effectively adding depth perception to the 2D image capture process without requiring physical manipulation of the laundry item.
Solution Approach 2:
The patent uses light as an intermediary medium to make impurities on the finish side visible. By introducing backlighting, the light passes through the laundry item and causes impurities on the underside to appear as dark silhouettes or shadows in the captured image, enabling the camera to detect bottom-surface contaminants without direct line-of-sight access.
2Reliability
If laundry items are turned over to inspect both sides, then complete inspection is achieved, but the inspection process becomes time-consuming and reduces productivity
Solution Approach 1:
The patent performs preliminary action by pre-positioning the light source on the conveyor side before the inspection process begins. This allows the system to capture images of both sides of the laundry item in a single pass without requiring subsequent flipping or repositioning operations, thereby maintaining high inspection speed while achieving complete coverage.
Solution Approach 2:
The patent ensures continuous inspection by maintaining the laundry item in its original position on the conveyor throughout the imaging process. The backlighting and front-side camera work simultaneously and continuously to capture impurities on both surfaces, eliminating interruptions caused by turning or repositioning the items, thus preserving production flow and productivity.
3Measurement precision
If multiple cameras are used to inspect both sides of laundry, then detection accuracy improves, but device complexity and cost increase significantly
Solution Approach 1:
The patent uses light as an intermediary to enable a single camera to perform the function of what would otherwise require two cameras. The backlighting creates optical contrast that allows the front-side camera to visualize impurities on both surfaces, effectively using light as a mediator to extend the camera's detection capability without adding hardware complexity.
Solution Approach 2:
The patent creates an optical copy or silhouette of the finish side impurities by using backlighting. The light passing through the laundry item creates a negative image or shadow effect that replicates the appearance of bottom-surface contaminants, allowing the camera to detect them without directly viewing the underside, thus achieving dual-side detection with single-camera hardware.
4Reliability
If backlighting is used to illuminate the finish side, then impurities become visible on the opposite side, but additional lighting equipment is required
Solution Approach 1:
The patent achieves multi-functionality by positioning the light source on the conveyor side to serve dual purposes: it illuminates the finish side for detection purposes and simultaneously provides the backlighting needed to make impurities visible on the opposite side. This single lighting arrangement performs multiple functions (illumination and backlighting) without requiring separate lighting systems.
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 approach ensures reliable detection and evaluation of contamination and adhesions on both sides of laundry items, improving the inspection process by making impurities visible on the finish side from one accessible side, enhancing the ability to identify stains, hair, and patterns with higher contrast, thus preventing unacceptable returns.
Implementation Method 1
the lighting device (20) is arranged in such a way that it illuminates or transilluminates items of laundry (12) from below, in particular their underlying finish sides (19), in such a way that impurities, in particular stains, on the underside shine through to the upper side
Data Source
Figure 1
Figure 2
AI summary
Impurities, in particular stains, on cleaned or washed laundry items (12) can be on both sides. It is therefore necessary to check washed or cleaned laundry items (12) on each side for contamination. That is very complex. The invention provides for the laundry items (12) to be illuminated or transilluminated on one side by a lighting device (20), as a result of which impurities on this illuminated or transilluminated side of the laundry items (12) shine through on the opposite side. As a result, impurities on both sides of the laundry items (12) can be detected by a camera (24) or the like from a side that is directed away from the lighting device (20). Due to the invention, therefore, both sides of the laundry items (12) do not have to be checked simultaneously or one after the other for the presence of impurities.