US 4,915,757 A · Creation of three dimensional objects

Abstract

Three dimensional objects or models, such as three dimensional images or shapes stored in a computer, are generated as real models by addition of material to a base, such as with photo-hardenable liquid, or by removal of material from an initially oversized mass. Optical feedback is employed to monotor the actual condition of the model being formed, at each work site. The condition of the model at the work site, e.g. the presence or absence of material, is fed back to the machine or building tool, or to a computer controlling the tool. On the basis of such monitoring and feedback, decisions are made whether or not to perform more work at any particular work site. In this way, the actual three dimensional model being constructed is made to conform substantially to stored information relative to the desired dimensions of the model. In a preferred embodiment, models are produced by ablating a mass of small spheres held together by a relatively weak wax or cement. The spheres are cemented together preferably only at their small areas of contact. The ablating may be accomplished by a laser beam whose energy is focused in succession on balls which are to be removed, heating them and breaking the wax or cement bonds. Feedback of the model condition may be optical, e.g. by laser distance measuring non-contact sensors. Alternatively, the spherical balls may be removed by blasts of hot air or gas delivered through a narrow tube. In this case monitoring and feedback may be via measuring of capacitance between the air-delivering tube and the model, representing distance, or by monitoring of the pressure in the tube, indicating distance from the model.

Claims17

Dependent claims

A method of constructing a three dimensional solid model, said method comprising,

(a) scanning a first area having a plurality of predetermined, known work location sites with a work element which can be selectively activated either to perform work or not to perform work at each one of the work location sites,
(b) supplying model information to the work element during said scanning of said first area,
(c) activating the work element to perform work at each of the work location sites only when the model information signals that work is to be done at that site,
(d) examining the actual condition of material at each site as affected by the action of the work element on the site,
(e) feeding back information on said actual condition of material at each site,
(f) comparing the feedback information on the actual condition of material at each site with the desired condition of material at that site as called for by the model information supplied pursuant to paragraph (b),
(g) making an appropriate correction for increasing or decreasing the amount of work done by the work element when the difference between the actual condition and the desired condition of the material at the work sites is greater than a selected difference,
(h) moving the work element to a second area having a plurality of predetermined and known work location sites,
(i) repeating steps (a) through (g) for the second area, and
(j) repeating step (i) for additional areas until the solid model has been physically constructed by the action of the work element.

7 more elements

A method for automated production of a three dimensional model, comprising,

providing a block or mass of ablatable material which has dimensions larger than those of the three dimensional shape to be created,
moving an end effector tool around the surface of the mass or block of material to remove portions of the block of material as required by the shape to be produced, the end effector tool being effective to direct a stream of energy at specific work sites on the block of material at which the end effector tool is aimed,
monitoring the dimensions of material at work sites to determine the condition of the work site, i.e. the amount of material which remains at the work site,
feeding back information from such monitoring of the dimensions at the work sites to a controller for the end effector tool, and making decisions in the controller as to whether further energy is to be directed at particular work sites based on the information fed back to the controller, and effecting such decisions by either directing further energy to a work site using the end effector tool or not directing further energy to the work site,
and repeating the steps of directing energy at work sites to remove material, monitoring the condition or dimension of the mass of material at work sites, and feeding back such monitored information and controlling the tool based on such fedback information, while minipulating the end effector tool to all facets of the block of material at which it is necessary to remove material, until the finished three dimensional model in the desired shape has been produced.

2 more elements

Dependencies are inferred from the claim text.

Creation of three dimensional objects

Life of this patent

Creation of three dimensional objects

Life of this patent

Abstract

Claims17