---
title: "Dark field light"
slug: "top-light"
updated: 2025-03-17T14:55:55Z
published: 2025-03-17T14:55:55Z
canonical: "docs-linescan.alliedvision.com/top-light"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs-linescan.alliedvision.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Dark field light

## Mechanical dimensions

[PDF document](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/DRW_CM061-B200-V1XX-X-C_R04_Darkfield.pdf)

## Setup

### ID2 = A

![reflector types-top light A_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/reflector%20types-top%20light%20A_v01.svg)

Focal length 60 mmWorking distance 50 mm – 70 mm

### ID2 = B

![reflector types-top light B_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/reflector%20types-top%20light%20B_v01.svg)

Focal length 95 mmWorking distance 70 mm – 120 mm

### ID2 = C

![reflector types-top light C_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/reflector%20types-top%20light%20C_v01.svg)

Focal length 190 mmWorking distance 120 mm – 300 mm

### ID2 = D

![reflector types-top light D_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/reflector%20types-top%20light%20D_v01.svg)

Parallel beamWorking distance > 300 mm

### Special options, coaxial module

In addition to the configuration in [Corona II Overview](/v1/docs/overview-corona-ii) there are special options available.

The additional option will be set to the identification number as ID0:

CP000200-CXT-340C-04-2.5-B1B

The coaxial module is an extension to the Top light module and the Bright field module. Protection screens are provided with an anti-reflective (AR) coating with to avoid dust on the beam splitter.

NOTE - unwanted optical effectsBe aware that protection screens might cause optical effects. 

| ID0 | Special option |
| --- | --- |
| CXN | - Coaxial module - No protection screen |  |
| 170 | 340 | 510 | 680 | 850 | 1020 | 1190 | 1360 |
| CXT | - Coaxial module - Protection screen top side |  |
| 170 | 340 | 510 | 680 | 850 | 1020 | 1190 | 1360 |
| CXB | - Coaxial module - Protection screen bottom side |  |
| 170 | 340 | 510 | 680 | 850 | 1020 | 1190 | 1360 |
| CXS | - Coaxial module - Two protection screens |  |
| 170 | 340 | 510 | 680 | 850 | 1020 | 1190 | 1360 |
| CH2 | - Cable with Hummel connector - Length: 0.5 m or 1.0 m |  |
| 170 | 340 | 510 | 680 | 850 | 1020 | 1190 | 1360 |
| DW1 | - Drag chain cable with standard Würth connectors - All standard lengths available |  |
| 170 | 340 | 510 | 680 | 850 | 1020 | 1190 | 1360 |

#### Mechanical dimensions and setup

[PDF document](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/drw_cp000200-cxx-xxxx-x_r01_Koaxial.pdf)

## Illumination characteristics

The following graphic defines the coordinate system with focal length, working distance and working range of the illumination.

![Lichtstrahl_xy-Achsen_1-3_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/Lichtstrahl_xy-Achsen_1-3_v01.svg)

Definition of coordinate system focal length, working distance, working range

The following graphic defines the coordinate system for the light distribution along the x-direction.

![illuminance-definition coordinate system02_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/illuminance-definition%20coordinate%20system02_v01.svg)

Definition coordinate system of light distribution along x-direction, colored dots as an example for different working distances

### Conditions

The following conditions apply to the charts:

- the curves represent cool white LED.
- maximum current is 1.8 A.
- simulations and measurements are performed with screen option 1 “glass low diffusion”.

Use the following correction factors for other screen options.

|  | screen 1, 3 | screen 2 | screen 4, 7 | screen B |
| --- | --- | --- | --- | --- |
|  | glass or plexiglas low diffusion | polarization | glass or plexiglas medium diffusion | anisotropic foil |
| relative illuminance @ 100 mm | 100 % | approx. 40 % | approx. 50 % | approx. 80 % |

The detector planes are orientated parallel to the x-axis.

| reflector type | focal length | recommended working distance |
| --- | --- | --- |
|  |  | from | to |
| A | 60 mm | 50 mm | 70 mm |
| B | 95 mm | 70 mm | 120 mm |
| C | 190 mm | 120 mm | 300 mm |
| D | parallel | 300 mm | ∞ |

### Reflector type A

![corona_Lichtverteilung_Typ-A_Z-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-A_Z-Achse_v01.svg)

Maximum light intensities over working distance with focal length 60 mm

![corona_Lichtverteilung_Typ-A_X-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-A_X-Achse_v01.svg)

Illumination profile with focal length 60 mm – measured in the center of a 680 mm module

### Reflector type B

![corona_Lichtverteilung_Typ-B_Z-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-B_Z-Achse_v01.svg)

Maximum light intensities over working distance with focal length 95 mm

![corona_Lichtverteilung_Typ-B_X-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-B_X-Achse_v01.svg)

Illumination profile with focal length 95 mm – measured in the center of a 680 mm module

![corona_Lichtverteilung_Typ-B_Y-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-B_Y-Achse_v01.svg)

Relative illuminance parallel to illumination unit – focal length 95 mm, module length 680 mm

### Reflector type C

![corona_Lichtverteilung_Typ-C_Z-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-C_Z-Achse_v01.svg)

Maximum light intensities over working distance with focal length 180 mm

![corona_Lichtverteilung_Typ-C_X-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-C_X-Achse_v01.svg)

Illumination profile with focal length 180 mm – measured in the center of a 680 mm module

![corona_Lichtverteilung_Typ-C_Y-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-C_Y-Achse_v01.svg)

Relative illuminance parallel to illumination unit – focal length 180 mm, module length 680 mm

### Reflector type D (parallel beam)

![corona_Lichtverteilung_Typ-D_Z-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-D_Z-Achse_v01.svg)

Maximum light intensities over working distance parallel beam

![corona_Lichtverteilung_Typ-D_X-Achse_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-D_X-Achse_v01.svg)

Illumination profile parallel beam

![corona_Lichtverteilung_Typ-D_Y-Achse_v02](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_Typ-D_Y-Achse_v02.svg)

Relative illuminance parallel to illumination unit – parallel beam, module length 680 mm

## Comparison of reflector types

![corona_Lichtverteilung_A-B_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_A-B_v01.svg)

Comparison light intensities reflector A – reflector B

![corona_Lichtverteilung_B-C_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_B-C_v01.svg)

Comparison light intensities reflector B – reflector C

![corona_Lichtverteilung_C-D_v01](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/corona_Lichtverteilung_C-D_v01.svg)

Comparison light intensities reflector C – reflector D

### Illuminance and irradiance

The illuminance and the irradiance on the target plane depends on the following parameters:

- Reflector type
- Operating current
- LED temperature
- LED type used in module
- LED specimen

For all illuminance values the LED chip temperature TS is 90 °C. Depending on the cooling system installed, the illuminance values can be higher or lower than in the tables.

The LEDs are selected by brightness and color. There may be a differences in brightness between different modules, even if temperature and operating current are identical.

#### LED type 01 red

| Reflector type | Illuminance [lux] min. @1.5 A | Irradiance [W/m2] min. @ 1.5 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- | --- |
| A | 2.200.000 | 12.500 | 60 |
| B | 670.000 | 3.800 | 90 |
| C | 330.000 | 1.900 | 120 |
| D | 230.000 | 1.300 | 50 |

#### LED type 02 green

| Reflector type | Illuminance [lux] min. @1.5 A | Irradiance [W/m2] min. @ 1.5 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- | --- |
| A | 2.300.000 | 4.600 | 60 |
| B | 780.000 | 1.600 | 90 |
| C | 360.000 | 730 | 120 |
| D | 250.000 | 500 | 50 |

#### LED type 03 blue

| Reflector type | Illuminance [lux] min. @1.5 A | Irradiance [W/m2] min. @ 1.5 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- | --- |
| A | 500.000 | 14.800 | 60 |
| B | 165.000 | 4850 | 90 |
| C | 77.000 | 2250 | 120 |
| D | 55.000 | 1600 | 50 |

#### LED type 04 standard white

| Reflector type | Illuminance [lux] min. @1.8 A | Irradiance [W/m2] min. @ 1.8 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- | --- |
| A | 3.500.000 | 11.000 | 60 |
| B | 1.200.000 | 3.800 | 90 |
| C | 550.000 | 1.750 | 120 |
| D | 390.000 | 1.200 | 50 |

#### LED type 08 infrared 850 nm

| Reflector type | Irradiance [W/m2] min. @ 1.8 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- |
| A | 16.900 | 60 |
| B | 5.500 | 90 |
| C | 2.500 | 120 |
| D | 1.800 | 50 |

#### LED type 09 infrared 940 nm

| Reflector type | Irradiance [W/m2] min. @ 1.8 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- |
| A | 15.500 | 60 |
| B | 5.100 | 90 |
| C | 2.400 | 120 |
| D | 1.600 | 50 |

#### LED type 30 UV 365 nm

| Reflector type | Irradiance [W/m2] min. @ 1.0 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- |
| A | 11.600 | 60 |
| B | 4.000 | 90 |
| C | 1.800 | 120 |
| D | 850 | 50 |

#### LED type 33 UV 395 nm

| Reflector type | Irradiance [W/m2] min. @ 1.0 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- |
| A | 13.900 | 60 |
| B | 4.800 | 90 |
| C | 2.100 | 120 |
| D | 1.000 | 50 |

#### LED type 60 SWIR 1100 nm

| Reflector type | Irradiance [W/m2] min. @ 1.0 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- |
| A |  | 60 |
| B |  | 90 |
| C |  | 120 |
| D |  | 50 |

#### LED type 61 SWIR 1300 nm

| Reflector type | Irradiance [W/m2] min. @ 1.0 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- |
| A |  | 60 |
| B |  | 90 |
| C |  | 120 |
| D |  | 50 |

#### LED type 62 SWIR 1450 nm

| Reflector type | Irradiance [W/m2] min. @ 1.0 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- |
| A |  | 60 |
| B |  | 90 |
| C |  | 120 |
| D |  | 50 |

#### LED type 63 SWIR 1550 nm

| Reflector type | Irradiance [W/m2] min. @ 1.0 A | Y-distance to module-top-plane [mm] |
| --- | --- | --- |
| A |  | 60 |
| B |  | 90 |
| C |  | 120 |
| D |  | 50 |