# US 10,310,468 B2 · Method for controlling the activity of at least two light radiation sources belonging to a stereolithography machine

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- Number: US 10,310,468 B2
- Document ID: US10310468B2
- Status: Granted
- Kind: B2
- Application number: 15/329,033
- Filed: 2015-07-13
- Published: 2017-07-27
- Granted: 2019-06-04
- Earliest claimed: 2014-07-30
- Assignees: Dws S.R.L.
- Applicants: Dws S.R.L.
- Inventors: Roberto Fortunato
- Web page: https://patentgrep.com/patent/US10310468B2

## CPC

- B29C 64/135: the energy source being concentrated, e.g. scanning lasers or focused light sources
- B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting
- B29C 64/393: for controlling or regulating additive manufacturing processes
- B33Y 50/02: for controlling or regulating additive manufacturing processes
- G05B 19/042: using digital processors (G05B19/05 takes precedence)
- G05B 2219/49023: 3-D printing, layer of powder, add drops of binder in layer, new powder
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G)

## Abstract

The invention is a method for controlling the activity of two light radiation sources (2, 3) belonging to a stereolithography machine (1) and suited to act at the level of a portion (104) of a superimposition area (101) defined on the work surface (100) of the stereolithography machine (1) for the production of a three-dimensional object (200) through stereolithography. For each one of the lines (210) with generic length L that define each layer (201) of the three-dimensional object (200) within the portion (104), the method provides for activating: a first light radiation source (2) for a first section (211) of the line (210) having length X; a second light radiation source (3) for the remaining second section (212) of the line (210) having length Y, wherein the value X of the first section (211) is selected within the interval 0<=X<=L and wherein Y is calculated as equal to L−X.

## Claims

### Claim 1

A method for controlling the activity of at least two light radiation sources (2, 3) of a stereolithography machine (1) and suited to act at the level of a portion (104) of a superimposition area (101) defined on a work surface (100) of said stereolithography machine (1) for making a three-dimensional object (200) through stereolithography, said method providing to activate the following elements for each one of a plurality of lines (210) with generic length L that define each layer (201) of said three-dimensional object (200) within said portion (104):
a first one of said two light radiation sources (2) for a first section (211) of said line (210) with length X;
the second one of said two light radiation sources (3) for the remaining second section (212) of said line (210) with length Y,
the value of said length X of said first section (211) being selected within an interval 0<=X<=L and Y being calculated as equal to L−X;
characterized in that said value of said length X of said first section (211) for each one of said lines (210) is selected at random within the interval 0<=X<=L in such a way to create a connection line (220) of the broken type between two portions (202) and (203) of each layer (201) defined respectively by said first sections (211) of said lines (210) and by said second sections (212) of said lines (210).

### Claim 2 (depends on 1)

The method according to claim 1, of the type comprising the following steps:
acquiring a first set of data representative of the geometry of said three-dimensional object (200);
subdividing said three-dimensional object (200) into a plurality of layers (201);
defining the position of each one of said layers (201) on said work surface (100);
identifying, within said portion (104) of said superimposition area (101), each one of said lines (210) with generic length L that define each one of said layers (201);
characterized in that the method further comprises the steps of:
defining, for each one of said lines (210) with generic length L, said value of said length X of said first section (211) within the interval 0<=X<=L;
calculating, for each one of said lines (210) with generic length L, the length of said second section (212) equal to Y=L−X; and
generating the data relating to said activation of said two light radiation sources (2, 3) so that a first one of said two light radiation sources (2) is activated along said first section (211) of each one of said lines (210) and the second one of said two light radiation sources (3) is activated along said remaining second section (212).

### Claim 3 (depends on 1)

The method according to claim 1, characterized in that the method includes the following steps before said activation of said two light radiation sources (2, 3):
defining an intermediate line (300) of said portion (104) of said superimposition area (101) substantially in an orthogonal direction with respect to said lines (210); and
selecting, among all said lines (210) with generic length L, exclusively a subset (213) containing those of said lines (210) that are incident on said intermediate line (300).

### Claim 4 (depends on 3)

The method according to claim 3, characterized in that the method activates exclusively one of said two light radiation sources (2, 3) at the level of the lines (210) not belonging to said subset (213) of incident lines.

### Claim 5 (depends on 3)

The method according to claim 3, characterized in that the method includes the following steps before said activation of said two light radiation sources (2, 3):
selecting, in said subset (213) of incident lines, exclusively the subset (214) of lines (210) that extend over the entire width of said portion (104) of said superimposition area (101).

### Claim 6 (depends on 5)

The method according to claim 5, characterized in that the method activates exclusively one of said two light radiation sources (2, 3) at the level of the lines (210) not belonging to said subset (214) of lines extending over the entire width of said portion (104) of said superimposition area (101).

### Claim 7

An apparatus for controlling the activity of two light radiation sources (2, 3) of a stereolithography machine (1) and suited to act at the level of a portion (104) of a superimposition area (101) defined on the work surface (100) of said stereolithography machine (1) for making a three-dimensional object (200) through stereolithography, of the type comprising:
a calculator comprising a processing unit and a memory support suited to be accessed by said processing unit;
means suited to acquire a first set of data representative of the geometry of said three-dimensional object (200) and to upload the first set of data into said memory support;
means suited to subdivide said three-dimensional object (200) into a plurality of layers (201);
means suited to define the position of each one of said layers (201) on said work surface (100);
means suited to identify, within said portion (104) of said superimposition area (101), each one of a plurality of lines (210) with generic length L defining each one of said layers (201);
means suited to define, for each one of said lines (210) with generic length L, said value of said length X of said first section (211) within the interval 0<=X<=L;
means suited to calculate, for each one of said lines (210) with generic length L, the length of said second section (212);
means suited to generate the data relating to said activation of said two light radiation sources (2, 3) in such a way that a first one of said two light radiation sources (2) is activated along said first section (211) of each one of said lines (210), and the second one of said two light radiation sources (3) is activated along said remaining second section (212);
characterized in that said means suited to define said value of said length X of said first section (211) are means for the generation of random numbers within an interval 0<=X<=L.

### Claim 8

A computer program product comprising a data support provided with program portions configured in such a way that, when executed on a calculator comprising a processing unit and a memory support accessible by said processing unit, said program portions define:
a calculator comprising a processing unit and a memory support accessible by said processing unit;
means suited to acquire a first set of data representative of the geometry of said three-dimensional object (200) and to upload it into said memory support;
means suited to subdivide said three-dimensional object (200) into a plurality of layers (201);
means suited to define a position of each one of said layers (201) on said work surface (100);
means suited to identify, within a portion (104) of a superimposition area (101), each one of a plurality of lines (210) with generic length L defining each one of said layers (201);
means suited to define, for each one of said lines (210) with generic length L, a value of length X of a first section (211) within an interval 0<=X<=L;
means suited to calculate, for each one of said lines (210) with generic length L, a length of a second section (212);
means suited to generate data relating to activation of two light radiation sources (2, 3) in such a way that a first one of said two light radiation sources (2) is activated along said first section (211) of each one of said lines (210), and the second one of said two light radiation sources (3) is activated along said remaining second section (212);
characterized in that said means suited to define said value of said length X of said first section (211) are means suited to generate random numbers within the interval 0<=X<=L.