Self luminous calibration board-Self-luminous Calibration Board-Ningbo Zhixing Optical Technology Co., Ltd.

Self luminous calibration board

Product Series：Self-luminous Calibration Board

Material Overview
customization capability
Usage

Material Overview	K9 Glass	B270 Glass	Fused Silica	Soda-Lime Glass
Advantages	• High surface flatness and excellent surface figure accuracy • >90% light transmittance; suitable for transmission calibration • Sharp and smooth pattern edges; easily achieves micron and sub-micron precision • Clear imaging	• High surface flatness and excellent surface figure accuracy • >90% light transmittance; suitable for transmission calibration • Sharp and smooth pattern edges; easily achieves micron and sub-micron precision • Clear imaging	• High surface flatness and excellent surface figure accuracy • >90% light transmittance; suitable for transmission calibration • Sharp and smooth pattern edges; easily achieves micron and sub-micron precision • Clear imaging • Extremely low sensitivity to temperature and humidity variations	• High surface flatness and excellent surface figure accuracy • >90% light transmittance; suitable for transmission calibration • Sharp and smooth pattern edges; easily achieves micron and sub-micron precision • Clear imaging
Disadvantages	• Standard optical glass is brittle; prone to edge chipping and fracture upon impact • Front illumination causes glare/reflections	• Standard optical glass is brittle; prone to edge chipping and fracture upon impact • Front illumination causes glare/reflections	• Standard optical glass is brittle; prone to edge chipping and fracture upon impact • Front illumination causes glare/reflections	• Standard optical glass is brittle; prone to edge chipping and fracture upon impact • Front illumination causes glare/reflections
Surface Process	Chrome Plating	Chrome Plating	Chrome Plating	Chrome Plating
Substrate Thickness	2.3 mm (Tolerance: ±0.1 mm) 3 mm / 4.8 mm (Tolerance: ±0.2 mm) 7.8mm	2.3 mm (Tolerance: ±0.1 mm) 3 mm / 4.8 mm (Tolerance: ±0.2 mm) 7.8mm	2.3 mm (Tolerance: ±0.1 mm) 3 mm / 4.8 mm (Tolerance: ±0.2 mm) 7.8mm	2.3 mm (Tolerance: ±0.1 mm) 3 mm / 4.8 mm (Tolerance: ±0.2 mm) 7.8mm
Surface Roughness (Ra)	≤0.05 μm (Mirror Grade)	≤0.05 μm (Mirror Grade)	≤0.05 μm (Mirror Grade)	≤0.05 μm (Mirror Grade)
Visible Light Transmittance	85%–95% (Transparent)	85%–95% (Transparent)	85%–95% (Transparent)	85%–95% (Transparent)
Coefficient of Thermal Expansion (CTE)	K9:7.1 × 10⁻⁶/℃	B270：9.4 × 10⁻⁶/℃	Fused Silica: 5.0–5.5 × 10⁻⁷/℃	Soda-Lime: 8.5–9.5 × 10⁻⁶/℃
Applicable Wavelength Range	UV Region: Only transmits near-UV (>350 nm); virtually opaque to deep UV (<300 nm). IR Region: IR cutoff at 2100–2200 nm; transmittance drops rapidly beyond this range. Visible Region (400–760 nm): Good transmittance.	UV Region Only transmits long-wave near-UV (>330 nm); virtually opaque below 300 nm. UV cutoff shifts toward longer wavelengths as thickness increases. Not suitable for UVB or deep-UV detection. IR Region: IR cutoff ~3050 nm. High and stable transmittance in the 780–2500 nm NIR band; gradual attenuation above 2500 nm. Visible Region (400–760 nm) Low-iron composition eliminates greenish tint; average visible transmittance 91%–92%.	UV Region: Transmits deep UV (down to 185 nm); ideal for UV light sources, lithography, and UV inspection. IR Region: Furthest IR cutoff (~3500 nm); higher and more stable NIR transmittance. Visible Region (400–760 nm): Slightly higher transmittance and lower dispersion.	UV Region: Earliest UV cutoff (~360 nm); essentially unsuitable for UV applications. IR Region: IR cutoff at 2100–2200 nm; transmittance drops rapidly beyond this range. Visible Region (400–760 nm): Good transmittance.
Hardness & Scratch Resistance	Mohs 5.5–6; Prone to scratching	Mohs 5.5–6; Prone to scratching	Mohs 5.5–6; Prone to scratching	Mohs 5.5–6; Prone to scratching
Optical Path Compatibility	Transmission + Reflection	Transmission + Reflection	Transmission + Reflection	Transmission + Reflection
Typical Applications	High-precision lab calibration, microscopic vision, transmission calibration	High-precision lab calibration, microscopic vision, transmission calibration	High-precision lab calibration, microscopic vision, transmission calibration	High-precision lab calibration, microscopic vision, transmission calibration

I. Pre-Use Preparation

1. Confirm Calibration Target Parameters

Record Physical Dimensions: Document feature spacing (mm) for chessboard/circle patterns, number of rows and columns, and diameter of luminous dots.

Verify Illumination Mode: Confirm continuous/strobe operation, monochrome/color output, and adjustable brightness range.

Check Power Supply: Verify voltage, current, and connector type (DC/USB/battery).

2. Cleaning & Mounting

Gently wipe the active luminous surface with a lint-free cloth; strictly avoid fingerprints, dust, and scratches.

Secure the target using a stand or fixture to ensure absolute flatness, with no vibration or tilt.

3. Camera / Equipment Setup

Mount the camera securely; disable autofocus, auto-exposure, and auto white balance, and switch to full manual mode.

Lock focal length, aperture, ISO, and shutter speed; keep all settings unchanged throughout the entire process.

Ensure the lens is clean, free of oil smudges and dust.

4. Ambient Light Control

Turn off strong ambient lighting to prevent reflections, shadows, or stray light from falling on the calibration target.

Self-Illuminated Target Advantage: No external lighting is required; the built-in illumination alone produces high-contrast images.

II. Standard Operating Procedure

1. Power-On & Brightness Calibration

Connect power and allow a 1–3 minute warm-up period until brightness stabilizes.

Adjust brightness based on the camera preview: luminous features must be sharp-edged, clearly visible, and neither overexposed nor underexposed.

For strobe mode: synchronize with the camera frame rate to eliminate motion blur.

2. Image Acquisition

With the camera fixed in place, move or rotate the calibration target to capture 15–25 sharp images across diverse poses:

Full FOV Coverage: Position the target at center, top, bottom, left, and right regions of the frame.

Multi-Angle Tilts: Apply small rotations around X/Y/Z axes (±15°–±30°) to provide robust 3D constraints.

Variable Distances: Capture near-field (filling the frame), mid-range, and far-field (occupying 1/3–1/2 of the frame) shots.

Per-Image Quality Requirements:

All luminous features are complete, sharp, blur-free, and unbroken.

No reflections, shadows, or overexposure.

The entire calibration target remains fully within the frame without cropping.

3. Software Calibration Computation

In calibration software (e.g., OpenCV, MATLAB Calibration Toolbox, Halcon, or industrial vision platforms):

Select the self-illuminated target type (chessboard / circle grid / dot array).

Input physical parameters: feature spacing, row/column count, and unit (mm).

Import all captured images; the software automatically detects centers of luminous dots or corner points.

Run calibration to output:

Intrinsics: Focal length, principal point, distortion coefficients (radial/tangential).

Extrinsics: Rotation and translation vectors for each image.

Reprojection Error: Lower values indicate higher calibration accuracy.

4. Result Validation & Application

Apply undistortion to new test images using the calibrated parameters; verify that straight lines appear perfectly straight with no curvature.

Validate measurement accuracy using an object of known dimensions.

Save the calibration parameter file for subsequent measurement or 3D reconstruction tasks.

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