PTP Tablet Inspection With Ambient-Light Spectral Correction
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Solution Overview
Problem
Existing inspection methods for PTP sheets using spectral analysis face accuracy issues due to ambient light reflections from cover films and pocket portion variations, leading to inconsistent spectral data and reduced inspection accuracy.
Innovation Solution
An inspection device that corrects spectral data by identifying and subtracting ambient light influences using pre-stage data from non-defective samples, employing a correction module to minimize ambient light effects and enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If spectral analysis is performed on contents in PTP sheets using ambient light, then inspection can be conducted without additional light sources, but inspection accuracy deteriorates due to light quantity and wavelength variations from cover film reflections and pocket portion differences
Solution Approach 1:
The invention extracts and separates the ambient light component from the total reflected light by acquiring a reference spectrum without the content present. This reference spectrum contains only the ambient light and structural reflections, which is then subtracted from the measurement spectrum to isolate the content's spectral characteristics, thereby eliminating the accuracy-deteriorating ambient light variations
Solution Approach 2:
The invention performs preliminary acquisition of reference spectral data before actual content inspection. By pre-acquiring the ambient light spectrum from empty PTP sheets and storing it as reference data, the system prepares correction information in advance that can be applied during content inspection to remove ambient light influences and improve measurement precision
2Measurement precision
If irradiation light is used to directly illuminate contents, then spectral data consistency improves, but ambient light reflections from cover films create harmful interference that reduces inspection accuracy
Solution Approach 1:
The invention converts the harmful ambient light reflections into a useful reference signal. By deliberately measuring the ambient light spectrum when no content is present, the system creates a reference dataset that characterizes the interference pattern. This reference is then subtracted from content measurements, transforming the previously harmful variable ambient light into a correctable known quantity that improves spectral data consistency
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
Stabilizes spectral analysis by eliminating ambient light interference, thereby improving inspection accuracy and reducing errors in determining content type within PTP sheets.
Implementation Method 1
irradiates the content with near-infrared light across the pocket portion (container film)
Implementation Method 2
disperses reflected light from the irradiation by a spectrometer
Implementation Method 3
performs an analysis process (principal component analysis) based on image data obtained by imaging the dispersed reflected light
Data Source
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AI summary
There are provided an inspection device configured to suppress reduction in inspection accuracy in an inspection that takes advantage of spectral analysis, as well as a PTP packaging machine and an inspection method. An inspection device 45 comprises an illumination device 52 configured to irradiate a tablet placed in a pocket portion 2 of a container film 3 with near-infrared light; and an imaging device 53 configured to disperse reflected light that is reflected from the tablet and take an image of the reflected light. The inspection device 45 is configured to perform different type inclusion inspection by taking advantage of spectral analysis with regard to the tablet, based on spectroscopic image data obtained by the imaging device 53. The inspection device 45 grasps spectral data with regard to a non-defective tablet attributed to ambient light, which is generated by irradiation of a predetermined disturbance factor by the illumination device 52, or approximate spectral data that is approximate to the spectral data attributed to the ambient light, as disturbance data, in a pre-stage before the inspection is performed. The inspection device 45 then corrects spectral data obtained by imaging an inspection object tablet, based on the disturbance data, in a process of performing the inspection.