Line lights for line scan cameras

Illuminated length

The illuminated length is the length of the line of light that the luminaire actually illuminates. In the range it runs from 50 to 3600 mm; the “Illuminated length” filter groups it into steps from 50, 100, 200, 400, 800, 1200 and 1600 mm. It should cover the web width, respectively the field of view of the line scan camera, including the expected positional variation.

The number in the model name does not mean the same thing at the two manufacturers. At OPT it states the housing length: OPT-LSS104 has a 104 mm housing and an illuminated length of 86 mm, OPT-LSNS608 illuminates 590 mm. In the LTLNM, LTLNE and LTLNC series from Opto Engineering the number stands for the illuminated length; LTLNE-300 illuminates 300 mm and measures 340 mm. If you are looking at installation space, use the “Housing length” filter (80 to 3630 mm).

For some lights, mostly from the OPT-LSA and OPT-LSF series, the manufacturer does not state an illuminated length. They are listed in the filter under “no manufacturer data” and remain findable that way; we do not fill in a value from the model name.

Working distance and illuminance

A working distance is stated by the manufacturer only for the three Opto Engineering series, as a range of 10 to 100 mm, 100 to 200 mm, 10 to 200 mm or 20 to 100 mm, depending on the focusing (near field, far field or collimated). For the OPT series the manufacturer does not state a working distance per model. A filter for it would hide most of the range; for the Opto models the value is listed in the technical data.

Illuminance is not stored as a measured value for any model. OPT states it for the series: up to 2000 klx at 50 mm working distance for the OPT-LSS series (measured on four models) and up to 5000 klx at 50 mm for OPT-LSA (measured on two models), in each case as a guide value. Opto Engineering lists illuminance in the datasheet without a figure. A series figure cannot be transferred to every model; illuminance is therefore not a filter but appears as a series statement in the text of the products concerned.

Light color and wavelength

The light colours in the range are white, red, green, blue and infrared. White light suits colour cameras and tasks where contrast does not depend on a single wavelength. Red, green and blue are used with monochrome cameras to strengthen the contrast between material and feature; infrared helps when visible colour structures should recede. Which colour gives the best contrast depends on material, surface and camera sensitivity and is most reliably settled in an image test.

The manufacturer does not state a wavelength in nanometers for the line lights in the range, nor a color temperature for the white models. Filtering therefore works by light color; there is no second level for wavelength here. If you need a figure for a bandpass filter or for camera sensitivity, we request it from the manufacturer before the order.

Optical layout

The optical layout says how the light reaches the web: directly, coaxially through a beam splitter in the camera axis, or via a 45° mirror. Coaxial light makes flaws on reflective webs visible as dark spots, because smooth areas reflect the light back into the camera while scratches or inclusions scatter it away.

As a manufacturer specification the layout is stored for three series only: coaxial for OPT-LSSC and OPT-LSNLC as well as the CX versions of the LTLNE series, direct and with 45° mirror for the other LTLNE versions. For OPT-LSS, OPT-LSNS, OPT-LSNL, OPT-LSE, OPT-LSA, OPT-LSF, LTLNC and LTLNM the manufacturer states no optical layout; it is not derived from the model name. According to the manufacturer, the OPT-LSSX series illuminates the part from both sides through a special optical arrangement; that is a lighting arrangement, not an optical layout in the sense of this attribute. Because the field is filled for only about a quarter of the products, it is not a filter.

Cooling

Line lights convert a lot of power on a small area; cooling decides installation and environment. The range has four types: fan (OPT-LSS, OPT-LSSC, OPT-LSSX, OPT-LSA, LTLNM and part of LTLNE and OPT-LSE), passive cooling through the housing (OPT-LSNS, OPT-LSNL, OPT-LSNLC and the other part of LTLNE and OPT-LSE), compressed air or passive for LTLNC, and water cooling for most OPT-LSF.

Passively cooled series work without moving parts; OPT describes the fanless design as quiet and stable and recommends it for environments with requirements on noise, vibration and air flow. A fan needs free air paths in the installation space, and water cooling requires connections and a cooling circuit in the machine. The “Cooling” filter separates the types; where the manufacturer states nothing, the light is listed under “no manufacturer data”.

Control and controllers

Whether a model needs a controller is not stated consistently by the manufacturer. For the OPT-LSS, OPT-LSSC, OPT-LSSX, OPT-LSNS and OPT-LSNL series, OPT names a recommended controller per model: OPT-DPA2024E(B), OPT-DPA6024E, OPT-DPA6024E(C), OPT-DPA6024EB, OPT-DPA10024EB or OPT-DPA20024EB. The recommendation is listed in the product's technical data, and the controllers are linked as accessories.

The Opto Engineering series are designed for 24 V; at OPT the supply voltage is stored only for part of the models, likewise 24 V. The LTLNC series additionally states limits for pulsed operation: a pulse current per model, at most 100 ms pulse duration at 5 % duty cycle. An operating mode (continuous or strobe) is not stored as a field for any model and is therefore not a filter.

For most lights the connection is given as a connector type, for example JST SMR-02V-B, ZQ GX16M-6A and ZQ GX16M-6B, WS20K6Z, WS20J6TQ, WEIPU SP1710/P9 or M8; the “Connector” filter sits under “More filters”. Cables and controllers have to match the connector type and the power of the model; the matching controllers and cables are described under lighting accessories.