BOULDER - Orbotix Inc., the company that makes the Sphero robotic ball, has raised $4 million of a $10 million investment round, according to a filing made Thursday with the Securities and Exchange Commission.

Three investors bought equity in the Boulder-based company. The Sphero toy is a ball controlled by a smartphone that is used to play a variety of games. Its retail price is $129.99.

Orbotix has raised more than $11 million so far in venture capital. The Sphero ball started selling to customers in January 2012.

Orbotix also has created the "Sphero Rangers" program - a way for students to learn programming tools with the ball using a mobile device application called MacroLab, Brad Feld, a company director, said in a recent blog post. Feld also is a principal of Boulder-based venture capital firm Foundry Group, which has invested in Orbotix.

"In about an hour, kids will be commanding their robot to drive geometric patterns while also learning a bit about angles, degrees, time and distance calculations, loops and conditional branching," Feld said in the blog post.

Other investors include Boise-based Highway 12 Ventures. Orbotix raised $5 million last year to pay for additional development costs for Sphero.

Other directors on the Orbotix board include Paul Berberian and Ian Bernstein, founders of the company, and Mark Solon, a principal at Highway 12 Ventures, according to the filing.