Device and process for marking an ophthalmic lens with a pulsed laser of wavelength and energy selected per pulse

Patent metadata

Field	Value
Publication number	US-2019022921-A1
Application number	US-201816145266-A
Country	US
Kind code	A1
Filing date	Sep 28, 2018
Priority date	Sep 20, 2013
Publication date	Jan 24, 2019
Grant date	—

Abstract

A device for marking an ophthalmic lens (3), the lens (3) being made of at least one preset material, includes a laser (1) configured to produce permanent engravings on the lens (3) and configured to emit a focused beam of pulsed ultraviolet laser radiation that includes at least one radiation wavelength ranging between 200 nm and 300 nm, has a pulse length ranging between about 0.1 ns and about 5 ns, and has an energy per pulse ranging between about 5 μJ and about 100 μJ. A laser marking process configured to produce permanent engravings on an ophthalmic lens (3) via this device is also described.

First claim

1 . A device for marking an ophthalmic lens, said ophthalmic lens being produced from at least one predetermined material, including a laser configured to produce permanent engravings on the ophthalmic lens, wherein the laser is configured to emit a focused pulsed beam of ultraviolet laser radiation, the focused beam having at least the following parameters:
a radiation wavelength comprised between 200 nm and 300 nm; a pulse duration comprised between about 0.1 ns and about 5 ns; and an energy per pulse at the focal point comprised between about 10 μJ and about 80 μJ.

2 . The device as claimed in claim 1 , wherein the energy per pulse at the focal point is comprised between about 10 μJ and about 65 μJ.

3 . The device as claimed in claim 1 , wherein the energy per pulse at the focal point is comprised between about 10 μJ and about 60 μJ.

4 . The device as claimed in claim 1 , wherein the focused beam of ultraviolet laser radiation has a peak power comprised between about 2.5 kW and about 1 MW.

5 . The device as claimed in claim 4 , wherein the peak power is comprised between about 10 kW and about 100 kW.

6 . The device as claimed in claim 1 , wherein the focused beam of ultraviolet laser radiation has a pulse frequency comprised between about 100 Hz and about 10 kHz.

7 . The device as claimed in claim 6 , wherein the pulse frequency is comprised between about 100 Hz and about 1 kHz.

8 . The device as claimed in claim 1 , wherein the pulse duration is comprised between about 0.1 ns and about 2 ns.

9 . The device as claimed in claim 1 , wherein the radiation wavelength of the focused ultraviolet laser beam is comprised between about 230 nm and about 290 nm and preferably about 266 nm.

10 . The device as claimed in claim 1 , wherein the laser source is configured to emit a pulsed beam of laser radiation having an energy per pulse comprised between about 30 μJ and about 80 μJ.

11 . The device as claimed in claim 10 , wherein the energy per pulse emitted by the laser source is comprised between about 35 μJ and about 80 μJ.

12 . The device as claimed in claim 10 , wherein the energy per pulse emitted by the laser source is comprised between about 40 μJ and about 60 μJ.

13 . The device as claimed in claim 1 , further including an optical assembly provided with an F-theta lens, which lens is configured to focus a beam of ultraviolet laser radiation onto a focal plane of the F-theta lens with a focused beam diameter in the focal plane of the order of about 20 μm to about 50 μm.

14 . The device as claimed in claim 13 , wherein the optical assembly includes an energy attenuator configured to regulate a fluence of the beam of ultraviolet radiation focused on a surface of the ophthalmic lens to be marked according to a plurality of operating modes of the attenuator, which modes each define a determined fluence value.

15 . A process for marking an ophthalmic lens produced from at least one predetermined material, the process being implemented by a device as claimed in claim 1 , and the process including a step of laser marking permanent engravings on the lens, which marking step includes a step of emitting a focused pulsed beam of ultraviolet laser radiation having at least the following parameters:
a radiation wavelength comprised between 200 nm and 300 nm; a pulse duration comprised between about 0.1 ns and about 5 ns; and an energy per pulse at the focal point comprised between about 10 μJ and about 80 μJ.

Assignees

• Essilor Int

Inventors

• Maurice Sebastien
• Dubois Frederic

Classifications

• B23K26/0622

  by shaping pulses · CPC title

• B23K26/355

  Texturing · CPC title

• B23K26/0006 Primary

  taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence) · CPC title

• B23K26/361

  for deburring or mechanical trimming (B23K26/351 takes precedence) · CPC title

• B23K2103/50

  Inorganic materials other than metals or composite materials · CPC title