Display glass: use line-light direction to make scratches visible
Three real application sheets show line-light approaches on dark screens and display glass. They belong to one practical problem: finding a direction and lighting field that preserves a visible scratch against reflections.
Choose a lighting direction on your screen before comparing light output.
Real camera capture
- Proposed light housing (spec)220 × 53 × 121.5 mm
- EvidenceReal application-lab captures
- Camera (proposed)2448 × 2048 monochrome
- Field (derived proposal)84.46 × 70.66 mm derived from printed 0.1x magnification
Lighting application-lab image sheet
What the camera saw
Cropped from the source test sheet; original test annotations are retained. Captures are not generated or enhanced. Drag a comparison slider, or open any image full size.
Water-cooled line light: Source water-cooled-line capture from the same comparison; surface features are brighter.
The challenge
Dark display surfaces reflect the room, fixtures, dust and fingerprints. Small scratches may return useful light only at a limited view and light angle.
How it was solved
The primary source uses white LS-2LIND220. Two related trials compare LS-3LINH300 with water-cooled LS-3LINP300 and show a separate LCD example under LS-3LINM500.
The proposed kit uses one LS-2LIND220 and a stationary area-camera trial. The other lights are source-tested alternatives, not simultaneous lights added to the kit. The proposed field covers a local glass inspection region, not the whole sheet shown in3D.
Why it works
- 1
Oblique illumination can brighten a vertical scratch against a dark field; a multi-angle field offers other directions to test.
- 2
The sheets are different specimens and trials. Only the two images from the water-cooling sheet are a paired comparison; the three sheets must not be treated as a controlled ranking or a measured speed comparison.
Lighting application-lab image sheet
Evidence you can inspect
The source captures show bright scratch/surface features on dark display regions.
The sheets report visible contrast and, in one pair, greater brightness with water cooling. They do not give a common exposure, defect size or camera system for all three trials.
An application-lab lighting demonstration, not a customer deployment or a qualified production inspection. Proposed camera, lens, fixture and scene spacing require a fresh trial. Source observations do not establish a defect-size limit, accuracy guarantee or production false-call rate.
From image contrast to a production decision
What to validate on your part
- 01
Keep specimen comparisons fair
Compare lighting on the same known good and scratched screens with fixed camera settings.
- 02
Check direction and background
Vary scratch orientation, screen coating and acceptable dust/fingerprint conditions.
- 03
Design cooling and motion
For another selected light, confirm its drive and cooling first, then validate exposure, blur and full-part coverage.
From the demo to your test bench
Parts in this setup
LightTested
LS-2LIND220
Double angle oblique light, 220 x 53 x 121.5 mm (LS-2LIND220)
Primary source white double-angle oblique light; 220 × 53 × 121.5 mm housing, 204 × 24 mm emitting area.
$499.00
In proposed setup
LightTested
LS-3LINH300
284 mm Ultra bright line scan light, fan cooled (LS-3LINH300)
Fan-cooled white light used in the paired source comparison.
$629.00
Separate test / alternative
LightTested
LS-3LINP300
Water cooling line scan light, 300 x 40 x 111.7 mm (LS-3LINP300)
Water-cooled white light used in the paired source comparison. Cooling circuit and connections require separate engineering.
$659.00
Separate test / alternative
LightTested
LS-3LINM500
Multi-angle line scan light, 516 x 313 x 82 mm (LS-3LINM500)
White multi-angle light in the separate LCD scratch source. The exact model is500, not400; 48 V catalog drive.
$1,059.00
Separate test / alternative
CameraOur pick
MV-CS050-10GM(NPOE)
Hikrobot MV-CS050-10GM(NPOE) 5 MP GigE area scan camera, IMX264, Gen 2 basic version, Mono, Without PoE
Proposed 5 MP monochrome global-shutter camera, 2448 × 2048 pixels at 3.45 µm, C-mount. The source camera is unidentified. This NPOE model requires separate power and does not support PoE.
$819.00
In proposed setup
LensOur pick
LS-KF1628M-ML
16mm, F2.8, 1.1", C-mount, Macro lens (52 mm (-0.25X) to 546 mm (-0.03X)) (LS-KF1628M-ML)
16 mm C-mount macro lens. Its printed 0.1x / 152 mm working-distance pair gives a derived 84.46 × 70.66 mm field on the proposed camera. Confirm focus, coverage and fixture clearance.
$319.00
In proposed setup
Camera test stationOur pick
LS-BT-XZ-G-6-6045
Camera stand with XZ adjustment and glass tray, height 600 mm (LS-BT-XZ-G-6-6045)
600 mm column, 600 × 450 mm breadboard, glass tray and two lighting holders. Proposed bench fixture; actual load, travel, clamps, mounting fasteners and light clearance must be confirmed.
$359.00
In proposed setup
"Tested" identifies the part named in the source. "Our pick" is a proposed alternative or supporting part. Confirm colour, optics, controllers, power supplies, cables and mounting before ordering.
The set-up
| Source camera | Not identified in the source sheet |
|---|---|
| Camera and lens | Proposed catalog components |
| Proposed field | 84.46 × 70.66 mm derived from printed 0.1x magnification |
| Lens-to-part in proposed scene | 152 mm; printed working-distance pair |
| Mounting (proposed) | LS-BT-XZ-G-6-6045 · catalog test station with two lighting holders |
Mount the optics with intent
The station is an optical test bench, with its two lighting holders included in the catalog listing. The 3D column and base follow the published height and footprint. Carriages, clamps and part supports are schematic: confirm camera screw pattern, lens support, light fasteners, permissible load and actual travel before ordering.
Complete the electrical system
Select a controller against the exact light voltage, drive mode and power, then confirm camera data/power/I/O cables and a suitable PC. These are not silently added to the proposed optical kit.
Build this system
Start from this setup, adapt it to your part.
The configurator opens with this study's camera, lens, light and station picked. Swap any part, check fit and price, then buy or ask for a quote.
Camera and available lens CAD are published models. Light envelopes and the station base/height use printed dimensions. Part shapes, brackets, holders, shielding and spacing are illustrative; they are not reconstructions of a source part or a complete mechanically validated assembly. Light paths explain the proposed arrangement and do not simulate optical performance. The proposed field is derived from the printed camera pixel dimensions and the stated lens magnification/working-distance pair, not measured from the source capture.
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Make the next trial specific.
Tell us the part size, smallest defect or tolerance, available working distance, material and line speed. Include what a good part and a reject look like.
About this case study: the photos and camera images come from the application laboratory of the maker of the lighting and optics we sell, imaged on the parts shown; your results depend on your part, camera and set-up. This is an application-lab study, not a LumaSpec customer deployment. Source figures are reported results; proposed components require a fresh trial. The 3D scene illustrates the arrangement and does not simulate imaging performance.