Method and device for viewing and/or illuminating a target surface in an evacuated chamber having condensable vapor therein

Patent metadata

Field	Value
Publication number	US-2021394271-A1
Application number	US-201917287760-A
Country	US
Kind code	A1
Filing date	Apr 2, 2019
Priority date	Oct 22, 2018
Publication date	Dec 23, 2021
Grant date	—

Abstract

A device for viewing and/or illuminating a target surface in an evacuated chamber having condensable vapor therein, the device comprising: a first section with a through hole having a first end with a first opening and a second end with a second opening; and a second section having a chamber comprising a first portion with a first opening, a second portion with a second opening and a gas inlet, where the second opening is covered with a first window, said first section is attached with the first end to the first portion of the chamber allowing free passage between the chamber and the first section, said gas inlet is connectable to a gas reservoir for feeding a gas into the chamber for prohibiting the first window in the chamber for being contaminated of the condensable vapor.

First claim

1 . A device for viewing and/or illuminating a target surface in an evacuated chamber having condensable vapor therein, the device comprising:
a first section with a through hole having a first end with a first opening and a second end with a second opening; and a second section having a chamber comprising a first opening, a second opening and a gas inlet, where the second opening of the second section is covered with a first window, wherein the first section is attached to the second section, allowing free passage between the chamber and the first section, wherein the first window is in line of sight with the second opening of the first section and said gas inlet is connectable to a gas reservoir for feeding a gas into the chamber for prohibiting the first window in the chamber from being contaminated of the condensable vapor, wherein the first opening of the first section is smaller than the second opening of the first section.

2 . The device according to claim 1 , wherein the first section has a frustoconical shape and comprises an inner wall extending at an angle α with respect to a symmetry line, wherein α is less than 50°.

3 .- 4 . (canceled)

5 . The device according to claim 1 , further comprising a third section having a through hole provided in between the first section and the chamber, wherein an inner wall of the third section extends at an angle β with respect to a symmetry line, wherein β≤50.

6 .- 10 . (canceled)

11 . The device according to claim 1 , wherein the first window is an optical lens.

12 . The device according to claim 1 , wherein the chamber further comprises a semitransparent mirror adapted to reflect electromagnetic radiation through the a window.

13 . The device according to claim 1 , further comprising at least one of:
a first electromagnetic radiation sensitive sensor for receiving electromagnetic radiation through said window; and a lens system in between the first electromagnetic radiation sensitive sensor and said window or said first window, wherein the first electromagnetic radiation sensitive sensor is an imaging camera, wherein the imaging camera is a CCD-camera, an infrared camera, a near infra-red camera, a C-MOS camera or a heat camera.

14 .- 18 . (canceled)

19 . The device according to claim 1 , wherein an area of the first opening of the first section is less than 30 mm 2 .

20 . The device according to claim 1 , wherein an area of the second opening of the first section is less than 1000 mm 2 .

21 . The device according to claim 1 , wherein the length of the first section is less than 300 mm.

22 . The device according to claim 1 , wherein the length of the second section is less than 100 mm.

23 . (canceled)

24 . The device according to claim 1 , wherein the gas is an inert gas and a gas pressure in the chamber is higher than the gas pressure in the first section.

25 .- 27 . (canceled)

28 . (canceled)

29 . The device according to claim 1 , further comprising:
the second section comprises a second window; and a semitransparent mirror disposed in the chamber, the semitransparent mirror reflecting portions of electromagnetic radiation emanating from said target surface through the first and second windows.

30 . The device according to claim 29 , further comprising a first electromagnetic radiation sensor disposed in front of the first window and a second electromagnetic radiation sensor disposed in front of the second window, wherein said first electromagnetic radiation sensitive sensor has a first spectral sensitivity band which is different to a second spectral sensitivity band of said second electromagnetic radiation sensitive sensor.

31 . The device according to claim 30 , wherein said first and second band are partially overlapping each other.

32 .- 34 . (canceled)

35 . The device according to claim 1 , further comprising a semitransparent mirror arranged outside said chamber and arranged so as to reflect at least a portion of said electromagnetic radiation emanating from the target surface in said evacuated chamber passing through said first window onto an electromagnetic radiation sensitive sensor.

36 .- 39 . (canceled)

40 . The device according to claim 1 , further comprising an electromagnetic radiation source for illuminating said target surface through the first window.

41 . The device according to claim 40 , wherein a wavelength of at least one of said electromagnetic radiation source is adapted to a sensitivity of an electromagnetic radiation sensitive sensor for receiving reflected radiation from the target surface.

42 . A device for viewing and/or illuminating a target surface in an evacuated chamber having condensable vapor therein, the device comprising:
a chamber comprising a first portion with a first opening, a second portion with a second opening and a gas inlet, where the second opening is covered with a first window, said first window is in line of sight with said first opening of the chamber and said gas inlet is connectable to a gas reservoir for feeding a gas into the chamber for prohibiting the first window in the chamber for being contaminated of the condensable vapor, wherein the first section comprises an inner wall extending at an angle α with respect to a symmetry line, wherein α is less than 50°.

43 .- 57 . (canceled)

58 . A method for forming three-dimensional articles by successive fusing together of selected areas of a powder bed in an evacuated chamber of an additive manufacturing apparatus, which areas correspond to successive cross sections of the three-dimensional article, said method comprising,
a. applying a powder layer to a work table in said evacuated chamber, b. fusing said powder layer by supplying energy from a high energy radiation source according to an operating scheme determined for the powder layer to said selected area within the powder layer such that the powder in said selected area is fused into cross sections of said three-dimensional article, c. providing a second chamber, said second chamber is provided with a gas inlet for providing a gas into said second chamber, a first opening covered with a window, said second chamber and said evacuated chamber having at least one common opening, d. viewing and/or illuminating a target surface in said evacuated chamber via said window and said common opening, and e. providing gas into said evacuated chamber through said common opening.

59 . The method according to claim 58 , wherein the pressure in said second chamber is higher than in said evacuated chamber.

60 .- 62 . (canceled)

Assignees

• Arcam Ab

Inventors

• Lock Tomas
• Löfving Björn
• Ramsperger Markus

Classifications

• F27D21/02 Primary

  Observation or illuminating devices · CPC title

• B22F10/85 Primary

  for controlling or regulating additive manufacturing processes · CPC title

• B22F12/38

  Housings, e.g. machine housings · CPC title

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F12/55

  Two or more means for feeding material · CPC title