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EP-4195173-B1 - UV LIGHTING DEVICE

EP4195173B1EP 4195173 B1EP4195173 B1EP 4195173B1EP-4195173-B1

Inventors

  • MCKINLEY, Jack
  • MAZEAUD, GUILLAUME

Dates

Publication Date
20260506
Application Date
20211209

Claims (14)

  1. Lighting device (10) for illuminating an object (O) to be controlled, comprising: - at least one light source (20) for illuminating the object (O), said light source (20) being configured to emit at least one ultraviolet wavelength, - a housing (30) containing the at least one light source (20) and comprising a housing opening (32) for receiving the object to be illuminated, and a control window (34) for enabling the visualization of the object (O) illuminated by the at least one light source (20), said housing (30) comprising an inner wall (36) configured for reflecting the light emitted by said at least one light source (20) toward the object (O) to be illuminated, said housing (30) being in the shape of a dome, with the housing opening (32) at the base of the dome and the control window (34) at the upper part of the dome, characterised in that the housing (30) further comprising an outer wall (38), the lighting device comprising a space between the inner wall (36) and the outer wall (38) of the housing (30).
  2. Lighting device according to any preceding claim, said inner wall (36) of the housing comprising metal, in particular aluminium, and defining the same housing opening (32) at the base of the dome and control window (34) at the upper part of the dome.
  3. Lighting device according to any preceding claim, said inner wall (36) comprising an upper part (36a) around the control window (34) configured for improving the contrast of the illuminated object (O), said inner wall (36) of the housing comprising an inner coating at the upper part (36a) of the inner wall, the inner coating comprising anodised aluminium.
  4. Lighting device according to the preceding claim, said inner coating at the upper part (36a) of the inner wall comprising black anodised aluminium.
  5. Lighting device according to any preceding claim, comprising light sources (20) which are distributed along the periphery of the housing opening (32).
  6. Lighting device according to any preceding claim, the at least one light source (20) being configured to emit one, two and/or three different ultraviolet wavelengths, in particular wavelengths comprised between 355 and 405 nm, for example chosen from the following list: 365 nm, 395 nm, 405 nm.
  7. Lighting device according to any preceding claim, the at least one light source (20) comprising a plurality of light emitting diodes, in particular emitting each at a wavelength comprised between 355 and 405 nm, for example chosen from the following list: 365 nm, 395 nm, 405 nm.
  8. Lighting device according to any preceding claim, the device (10) being configured for enabling to choose between a plurality of modes differing by the wavelengths of the at least one light source.
  9. Lighting device according to any preceding claim, the at least one light source (20) being configured to emit visible light, in particular white light.
  10. Lighting device according to any preceding claim, comprising a control button (52) for choosing an appropriate mode among a plurality of modes.
  11. Lighting device according to the preceding claim, the control button (52) being covered by a removable cap (56).
  12. Lighting device according to any preceding claim, comprising a filter (42) for filtering the light issued from the illuminated object, in particular a longpass or bandpass filter.
  13. Lighting device according to the preceding claim, said filter (42) being configured for blocking the ultraviolet light, in particular under 400 nm, preferably under 415 nm, more preferably under 420 nm.
  14. Control device (1) comprising a lighting device (10) according to any preceding claim, and a camera (5) to capture the light emitted by the illuminated object (O) through the lighting device (10).

Description

The invention concerns an ultraviolet (UV) lighting device. The lighting devices are used in the Machine Vision and Identification market. New requirements from the emerging markets are required by law to put UV tax stamps (Excise Stamps) on their products. These stamps must be inspected for print quality and tracked to ensure quality in the luxury goods market. This new incentive is being pushed by governing agencies and is creating standards for the producers of luxury goods, such as tobacco, in the emerging markets. The standards require producers from these new markets to apply unique identifiers for Product Track and Trace systems to secure the supplier source and location. The tax stamp shows the necessary taxes have been paid and also provides proof that the product is genuine. It is typical that these tax stamps make up three quarters of the cost to produce tobacco products, so it is critical that the suppliers ensure the presence and quality of such a stamp. The tax stamp also provides a couple of secondary uses such as showing the product has not been tampered with. It is often referred to as a security seal. Tax stamps have existed for many years, however, the use of UV inks and fibres on the tax stamp is a new measure against counterfeiting of these luxury goods. US 2021/0299879 A1 shows a dome shaped illumination device which comprises UV light sources provided at the bottom and a viewing window at the top of the dome. There is therefore a need for benefiting from lighting devices enabling to facilitate the identification of stamps containing UV features such as UV inks and fibres. An aim of the invention is to at least partially meet this need. Summary of the Invention The invention proposes a lighting device for illuminating an object to be controlled, comprising: at least one light source for illuminating the object, said light source being configured to emit at least one ultraviolet wavelength,a housing containing the at least one light source and comprising a housing opening for receiving the object to be illuminated, and a control window for enabling the visualization of the object illuminated by the at least one light source, said housing comprising an inner wall configured for reflecting the light emitted by said at least one light source toward the object to be illuminated. In the invention, the object is advantageously illuminated with a homogeneous and diffuse light. The control window may be opposite the housing opening. The lighting device of the invention is easy to use for the user, it integrates a full vision solution, with multiple possible wavelengths, which may help the user to install the lighting device. The lighting device of the invention uses UV illumination to fluoresce a feature of the object and to create contrast, so that it can be properly inspected, for example by a camera, which may in particular comprise a Machine Vision or Automatic Identification software. The lighting device of the invention creates uniform lighting that can illuminate complex features on objects perfectly, such as shiny objects, comprising for example glass, metals or shiny plastics, with objects that are highly reflective, or with objects that are subject to shadowing with direct or low angle light sources, or with objects that have some very uneven surfaces. The lighting device is appropriate for illuminating every type of surface, from matte to highly reflective. The object may be a packaging of a luxury good, such as for example tobacco, perfume, spirits, water, milk, the list being not limited. The feature to be controlled on the object may be a feature which can be fluoresced under UV illumination. It can be glue, with presence or absence inspection, or inks or fibers, for UV codes for example. Housing The housing may be in the shape of a dome, with the housing opening at the base of the dome and the control window at the upper part of the dome. Such housing in the shape of a dome may enable to help providing contrast. The inner wall of the housing also defines the same housing opening at the base of the dome and control window at the upper part of the dome. A base of the housing may have a substantially square shape. A base of the inner wall may have a substantially circular shape, which may be inscribed in the square of the housing. The inner wall may have the shape of a hemisphere, with the control window at its top, and the housing opening at its base. There may be a space between the inner wall of the housing and the outer wall of the housing, in particular in the angles of the squared outer wall. There may also be a space between the two inner and outer walls all around the housing, particularly due to tolerances. The housing may comprise an outer wall, which may be made of plastic material. The plastic material may be crossed by the ultraviolet light, while the metal, in particular aluminium, may reflect ultraviolet light. Said inner wall of the housing may comprise metal, in par