Lighting Methods with Bar Lights
Bar lights are most commonly used in one of these lighting methods. However, there are additional techniques that are specified in the respective product section.
Brightfield
By using a bar light as incident light, direct illumination causes reflections on the surface of the object being examined.
Low Angle
Using bar lights at a flat angle enables a contrast to be created at the edges, which allows slight illumination of the surface.
Darkfield
Positioned as a flat aligned illumination, the bar light highlights edges strongly while hardly any light falls on the surface.
LBA, LBL and LBO Bar Lights with Angle Changers for Machine Vision
wenglor LBA, LBL and LBO bar lights can be configured to suit almost any application. Pair the bar lights with the optional ZBAG angle changers to widen the beam angle and have flexibility and control of illumination across the field of view. The direct illuminators have a perfect balance between brightness and homogeneity, allowing the product to be used at both small and large working distances. The bar lights can be operated with high intensity in continuous mode or synchronized to the machine vision camera in strobe mode with increased luminosity (overdrive). They are available with white, red and infrared light.
Machine Vision Bar Lights – Effects and Features
What Is an Angle Changer?
Angle changers are a special type of diffuser that can be attached directly onto the LBA, LBL and LBO bar lights. By increasing the beam angle, angle changers also diffuse the light and help to achieve a better homogeneity across the field of view.
Angle changers are a special type of diffuser that can be attached directly onto the LBA, LBL and LBO bar lights. By increasing the beam angle, angle changers also diffuse the light and help to achieve a better homogeneity across the field of view.
Rapid feasibility testing for new projects: Quickly and easily identify the best illumination solution with our angle changer
Protected IP65 design integrity: No need to dismantle the product to change the beam angle
Huge flexibility: Attach angle changers to suit many working distances and machine vision applications
Impact on Beam Angle
Impact on Brightness
| 43,500 lux | 34,500 lux | 17,400 lux | 43,000 lux | ||||
|---|---|---|---|---|---|---|---|
| Measurements made at working distance WD = 500 mm with LBAW201, measured in the middle of the field of view (FoV) – strobe overdrive mode. | |||||||
Impact on Brightness
Impact on Exposure Time
| ×2 | ×2.5 | ×5 | ×2 | |||
|---|---|---|---|---|---|---|
| 200 μs | 250 μs | 500 μs | 200 μs | |||
|
×2
|
||||
|---|---|---|---|---|
|
×2.5
|
×5
|
×2
|
||
|
200 μs
|
||||
|
250 μs
|
500 μs
|
200 μs
|
||
Creating Excellent Uniformity and Homogeneity in Light
The Curve Effect is a powerful tool for creating excellent uniformity and homogeneity over a large field of view (FoV) such as those in Pick and Place applications. The patented curve effect is created using a bar light with variable intensity along its length and specifically dimming the light in the center of the projected illumination with the use of angle changers.
Bar Lights 125 mm
Bar Lights 250 mm
Bar Lights 375 mm
Bar Lights 500 mm
Estimating the illuminated field of view (FoV) covered from a distance according to the chosen bar light + angle changer configurations
- WD is the working distance – i.e. the distance between the bar light and the field of view
- H is the FoV size in a direction perpendicular to the bar length
- L is the FoV size in a direction parallel to the bar length
- U is the useful length of the bar (125 mm/250 mm/375 mm/500 mm)
| Bar Light | + ZBAG001 | + ZBAG002 | + ZBAG003 | |||||
|---|---|---|---|---|---|---|---|---|
| H = | WD × 24/100 | WD × 35/100 | WD × 60/100 | WD × 90/100 | ||||
| L = | (WD × 24/100) + U | (WD × 35/100) + U | (WD × 60/100) + U | (WD × 90/100) + U | ||||
Without angle changers, the bar light’s beam angle is ±7°. This turns it into a spot light at bigger working distances.
| Products / Working Distance in m | 1 | 1.5 | 2 | 3 |
|---|---|---|---|---|
| Bar Lights 125 mm | 20,000 lux | - | - | - |
| Bar Lights 250 mm | 41,000 lux | 24,000 lux | - | - |
| Bar Lights 375 mm | - | 28,000 lux | 18,000 lux | - |
| Bar Lights 500 mm | - | - | 23,000 lux | 11,000 lux |
| Bar Lights 125 mm | ||||
|---|---|---|---|---|
|
20,000 lux
|
-
|
-
|
-
|
|
| Bar Lights 250 mm | ||||
|
41,000 lux
|
24,000 lux
|
-
|
-
|
|
| Bar Lights 375 mm | ||||
|
-
|
28,000 lux
|
18,000 lux
|
-
|
|
| Bar Lights 500 mm | ||||
|
-
|
-
|
23,000 lux
|
11,000 lux
|
|
A dome effect can also be created using bar lights inside a box. Fitted with medium angle changers (ZBAG002), the bar light illuminates the ceiling of the box which should be made of a white, matte surface. This will create a homogeneous field of view which is perfect for illuminating complex surfaces.
Barlights can be used for line scan applications when fitted with the line angle changer (ZBAG004). The line angle changer creates an elliptical beam angle from each LED. This means that the combined array of all LEDs results in a homogeneous and highly intense line at a minimum working distance of 100 mm.
All angle changer options are available in polarized versions. By combining the angle changers with polarizers, you can also create excellent homogeneity on specular or shiny surfaces.
The LBL and LBO bar lights have three M12 connection options and can therefore be connected directly to the camera or in series with other bar lights. Precise signal synchronization between the camera and the connected bar lights is achieved through a single connection cable, with no additional power supply required. If the camera does not provide sufficient power for the bar light, this can also be supplied via the second M12 connector. The LBL series is particularly suitable for high-speed production lines.
Legend to the figures:
1: Bar light 1
2: Bar light 2
A: Input M12 × 5-pin
B: Output M12 × 5-pin
EC: Control cabinet
: 24 V power connection
: Signal cable
: 24 V power connection + signal
1: Bar light 1
2: Bar light 2
A: Input M12 × 5-pin
B: Output M12 × 5-pin
EC: Control cabinet
: 24 V power connection: Signal cable: 24 V power connection + signalConnection via Control Cabinet
Connection without Control Cabinet
LBT Mini Bar Light with Angle Changers for Industrial Image Processing
wenglor’s mini bar lights from the LBT series offer extremely flexible configuration for applications with limited space. They are characterized by a compact housing, high luminosity and uniform light distribution, making them suitable for both small and large working distances. The LBT mini bar lights can be used either continuously with high intensity or synchronously with the machine vision camera in strobe mode with increased brightness (overdrive). The optional ZBAG angle changers extend the illumination angle, allowing the illumination of the field of vision to be individually adjusted and controlled. The LBT series is also available in various light spectra, including white, red and infrared light.
LBT Mini Bar Lights – Wide Range of Product Highlights
The LBT mini bar light impresses with its anodized aluminum housing and integrated vent membrane, which prevents condensation from forming in the device. The illumination is fully compatible with modern machine vision cameras and smart cameras due to the robust housing and IP67 degree of protection.
Definition of angle changer
An angle changer is a special scattered light diffuser that can be mounted directly on the LBT mini bar light. It extends the beam angle and thus improves the light distribution over the entire visual field, resulting in homogeneous illumination.
An angle changer is a special scattered light diffuser that can be mounted directly on the LBT mini bar light. It extends the beam angle and thus improves the light distribution over the entire visual field, resulting in homogeneous illumination.
Quickly check the feasibility of new projects: Angle changers make it easy to find the ideal lighting solution
Protected design integrity according to IP67 standard: No need to disassemble the product to adjust the beam angle
High versatility: The use of angle changers enables different working distances and applications in the field of industrial image processing
Changes to the Aperture Angle
The simple and flexible magnetic attachment is suitable for testing purposes, while the angle changer can also be fixed with screws for continuous mode.
The angle changers for the LBT mini bar light are also available in a polarized version.
The angle changers for the LBT mini bar light are also available in a polarized version.
The LBT mini bar light is characterized by a highly flexible cable that connects the light to the power supply unit. Due to its compact form factor and flexible cable, the small bar light can be easily mounted in applications where space is limited.
Further mounting options for the mini bar light are provided by the M4 T-slot and four M2 threaded holes on the rear of the light. The power supply unit also has two M4 threaded holes for mounting.
Further mounting options for the mini bar light are provided by the M4 T-slot and four M2 threaded holes on the rear of the light. The power supply unit also has two M4 threaded holes for mounting.
The LBT mini bar light combines compact design with power and integrated electronics, which are connected to the light via a highly flexible cable. It offers various operating modes, including continuous mode and flash and flash overdrive mode. The standard M12 connector also enables infinitely variable dimming of the light intensity.
The innovative design of the LBT mini bar light allows two or more devices to be mounted side by side while maintaining the standard LED spacing. This enables seamless integration of several mini bar lights without creating interruptions in the light spot. Even for illumination of larger areas, the LBT series remains the optimal choice for industrial image processing applications due to its outstanding performance and flexibility.
LBD Diffuse Bar Light without Angle Changers
wenglor LBD bar lights are highly diffuse illuminators, perfect for diffuse low angle illumination, direct illumination at a close working distance and backlighting of specific features on the field of view. Thanks to integrated current control and flexible mounting options, the lighting is very easy to install and perfect for a myriad of Machine Vision and identification applications. They are available with white, red and infrared light.
The illumination surface is so diffused it can be used as a back light to create homogeneous transmitted light. This can be applied where the silhouette of an object needs to be inspected. The following sample pictures were captured using one LBDW101 with a working distance of 220 mm.
The stated working distance in this example is the distance from the camera to the sample part.
The stated working distance in this example is the distance from the camera to the sample part.
See samples on the right →
Screw Head
Milk Cap
Circuit Board
Back Light with Aperture f/4
Back Light with Aperture f/4
Back Light with Aperture f/4
Back Light with Aperture f/4
Back Light with Aperture f/8
Back Light with Aperture f/8
Back Light with Aperture f/8
Back Light with Aperture f/8
The shown samples were captured in each illumination method being common for bar lights. The following sample pictures were captured using two LBDW101 with a working distance of 220 mm and an exposure time of 1 ms.
The stated working distance in this example is the distance from the camera to the sample part.
The stated working distance in this example is the distance from the camera to the sample part.
Screw Head
Milk Cap
Circuit Board
Brightfield with Aperture f/2.8
Brightfield with Aperture f/2.8
Brightfield with Aperture f/2.8
Brightfield with Aperture f/2.8
Low Angle with Aperture f/4
Low Angle with Aperture f/4
Low Angle with Aperture f/4
Low Angle with Aperture f/4
Darkfield with Aperture f/4
Darkfield with Aperture f/4
Darkfield with Aperture f/4
Darkfield with Aperture f/4
LB9 IP69K Machine Vision Bar Light without Angle Changers
Waterproof IP69K Washdown Bar Lights
wenglor LB9 bar lights are industrial IP69K illuminators. The food grade enclosure is perfectly suited for environments subject to high pressure, high temperature washdowns containing steam and cleaning chemicals. The barlights are provided with L-brackets that allow 360° mounting, making them easy to install. They are available with red, infrared and white light.
- Easy installation
- Perfect for food, beverage and pharmaceutical Machine Vision applications
- Designed to withstand the harsh chemical cleaning and decontamination
- Wide ambient operating temperature range
IP69K Cable Gland
- IP69K protection
- For harsh environments
Internal Fans
- For homogenizing temperatures
- For moisture reduction
Ventilation
- For pressure equalization
- For moisture reduction
Smooth Body
- For reducing bacteria
- For easy cleaning
Function Principles and Illumination Techniques
| Brightfield | Low Angle | Darkfield | Dome | Back Light | Angle Changer Compatible | |
|---|---|---|---|---|---|---|
| LBA Bar Light |  |
|
|
|
 |
|
| LBD Bar Light | |
|
|
|
|
|
| LB9 Bar Light | |
|
|
|
|
|
| LBT Bar Light | |
|
|
|
|
|
| All bar lights are available with red, infrared and white light. | ||||||
Function Principles and Illumination Techniques
| LBA Bar Light | ||||||
|---|---|---|---|---|---|---|
|
Brightfield
|
Low Angle
|
Darkfield
|
Dome
|
Back Light
|
Angle Changer Compatible
|
|
| LBD Bar Light | ||||||
|
Brightfield
|
Low Angle
|
Darkfield
|
Dome
|
Back Light
|
Angle Changer Compatible
|
|
| LB9 Bar Light | ||||||
|
Brightfield
|
Low Angle
|
Darkfield
|
Dome
|
Back Light
|
Angle Changer Compatible
|
|
| LBT Bar Light | ||||||
|
Brightfield
|
Low Angle
|
Darkfield
|
Dome
|
Back Light
|
Angle Changer Compatible
|
|
|
All bar lights are available with red, infrared and white light.
|
||||||
