Electronic fail-safe laser shutter

• US 9,640,946 B2
• Filed: 06/06/2013
• Issued: 05/02/2017
• Est. Priority Date: 06/06/2013
• Status: Active Grant

• Current Assignee: Prima Electro North America LLC (Prima Industrie S.p.A.)
• Original Assignee: Prima Electro North America LLC (Prima Industrie S.p.A.)
• Inventors: Sgandurra, Francesco, DiStefano, Luca
• Primary Examiner(s): Niu, Xinning
• Assistant Examiner(s): Vu, Vu A
• Application Number:
  US13/911,225
• Publication Number:
  US 20140362882A1
• Time in Patent Office: 1,426 Days
• Field of Search: 372 29012
• CPC Class Codes: H01S 5/042 Electrical excitation ; Circuits therefor monolithically integrated laser drive components H01S5/0261
• CPC Class Codes: H01S 5/06825 Protecting the laser, e.g. during switch-on/off, detection of malfunctioning or degradation
• CPC Class Codes: H02M 1/10 Arrangements incorporating converting means for enabling loads to be operated at will from different kinds of power supplies, e.g. from ac or dc
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop
• CPC Class Codes: H02M 3/3376 with automatic control of output voltage or current

Abstract

An improved laser safety shutter is provided for the main supply power to the laser diode to be routed through an electronic shutter that prevents the passing of the supply power to the laser diodes to achieve laser shutdown or in the event of a control power failure. The main power is routed through a rectifier to convert the incoming alternating current (AC) feed to direct current (DC) power. A switching array operates in an alternating cycle so as to provide AC power to be transformed and passed along to the laser diode pump on the load side of the transformer. When shut down of the laser is desired or when power to the controller fails, the switches stop operating and the resultant DC power cannot be passed by the transformer effectively cutting the supply power to the laser diodes.

Claims

1. A fail-safe safety circuit for disabling a laser system including a main power supply and a laser output device, comprising:

a means for converting the main alternating current power to direct current power;

an array of switches, said switches converting said direct current power to alternating current power when operated in an alternating pulsed fashion, said switches leaving said direct current power unchanged when not operated in an alternating pulsed fashion;

an isolation transformer, said isolation transformer passing only said alternating current power to said laser output device, said isolation transformer stopping the transmission of direct current power; and

a control circuit for controlling said switches, said control circuit further including a control isolation transformer preventing transfer of power to said switches should there be a failure in any portion of the control circuit.

2. The fail-safe safety circuit of claim 1, wherein said means for converting the main power to direct current power is a rectifier.

3. The fail-safe safety circuit of claim 1, further comprising:

a switch mode controller for controlling operation of said switches.

4. The fail-safe safety circuit of claim 1, further comprising:

a gate driver to operate said array of switches.

5. The fail-safe safety circuit of claim 4, further comprising:

a switch mode controller for controlling operation of said gate driver and of said switches.

6. The fail-safe safety circuit of claim 1, wherein said switches are solid state switches.

7. A fail-safe safety circuit for disabling a laser system including a main power supply and a laser output device, comprising:

a rectifier for converting the main alternating current power to direct current power;

an array of switches, said switches converting said direct current power to alternating current power when operated in an alternating pulsed fashion , said switches leaving said direct current power unchanged when not operated in an alternating pulsed fashion;

a controller for controlling the operation of said array of switches said controller further including an isolation transformer preventing transfer of power to said switches should there be a failure in any portion of the control circuit; and

a control isolation transformer, said isolation transformer passing only said alternating current power to said laser output device, said isolation transformer stopping the transmission of direct current power.

8. A method for disabling a laser system including a main power supply and a laser output device, comprising:

converting the main alternating current power to direct current power;

routing said direct current power to an array of switches;

operating said switches in an alternating pulsed fashion to convert said direct current power to alternating current power output or, said switches leaving said direct current power unchanged when not operated in an alternating pulsed fashion;

routing said alternating or direct current output from said switches to an isolation transformer, said isolation transformer passing only said alternating current power to said laser output device, said isolation transformer stopping the transmission of direct current power; and

controlling said switches via a control circuit, said control circuit further including a control isolation transformer preventing transfer of power to said switches should there be a failure in any portion of the control circuit.

9. The method of claim 8, wherein said means for converting the main power to direct current power is a rectifier.

10. The method of claim 8, further comprising:

a switch mode controller for controlling operation of said switches.

11. The method of claim 8, further comprising:

a gate driver to operate said array of switches.

12. The method of claim 11, further comprising:

a switch mode controller for controlling operation of said gate driver and of said switches.

13. The method of claim 8, wherein said switches are solid state switches.