Methods of positioning component in desired position on a board, pick and place machines, and sensors for such pick and place machines

Abstract

A method of positioning a component in a desired position on a board is provided. The method includes the steps of: (a) picking up the component with a nozzle of a movable placement unit of a pick and place machine; (b) transporting the component towards the board as a function of the desired position; (c) obtaining sensor data about an orientation of the component with respect to the nozzle with a sensor of the placement unit; (d) obtaining in the sensor rotational data about the orientation of the nozzle with respect to the placement unit; (e) combining in the sensor the sensor data and the rotational data into a data set; (f) sending the data set from the sensor to a stationary computer and computing a correction instruction in the stationary computer; and (g) placing the component on the board as a function of the correction instruction from the stationary computer.

What is claimed: 
     
         1 . A pick and place machine comprising:
 a component conveyor system;   a board conveyor system;   a stationary computer; and   at least one movable placement unit including a nozzle and a sensor, the placement unit being configured to move relative to the component conveyor system and the board conveyor system,   wherein the sensor includes (i) a receive circuit in the sensor configured to receive rotational data about a rotational position of the nozzle, (ii) optics and detection electronics in the sensor configured to obtain sensor data about the orientation of a component removably attached to the nozzle, and (iii) a signal processing circuit in the sensor configured to combine the rotational data and the sensor data into a data set and to send the data set to the stationary computer,   wherein the stationary computer includes (i) a receive circuit in the stationary computer to receive the data set from the sensor, and (ii) a signal processing circuit in the stationary computer to compute a correction instruction from the data set and to output the correction instruction as an correction signal to the at least one movable placement unit.   
     
     
         2 . The pick and place machine of  claim 1 , wherein the sensor includes a light source. 
     
     
         3 . The pick and place machine of  claim 1 , wherein the sensor data is representative of a side image of the component, wherein the signal processing circuit in the stationary computer is adapted to compute the shape of the visual hull of the component at a plurality of rotational positions. 
     
     
         4 . The pick and place machine of  claim 1 , wherein the at least one movable placement unit a plurality of movable placement units, each of the plurality of moveable placement units including a corresponding one of the nozzle and the sensor. 
     
     
         5 . The pick and place machine of  claim 4 , wherein the receive circuit in the stationary computer receive the data set from the sensor of each of the plurality of moveable placement units. 
     
     
         6 . The pick and place machine of  claim 5 , wherein the a signal processing circuit in the stationary computer computes the correction instruction from the data set for each of the plurality of placement units, and outputs the correction instruction as the correction signal to each of the plurality of placement units. 
     
     
         7 . A sensor for a pick and place machine, the pick and place machine including at least one nozzle and a stationary computer, the sensor comprising:
 (a) a receive circuit in the sensor configured to receive rotational data about a rotational position of the nozzle;   (b) optics and detection electronics in the sensor configured to obtain sensor data about the orientation of a component removably attached to the nozzle; and   (c) a signal processing circuit in the sensor configured to combine the rotational data and the sensor data into a data set and to send the data set to the stationary computer.   
     
     
         8 . A sensor according to  claim 7 , wherein the sensor comprises a light source. 
     
     
         9 . A sensor according to  claim 7 , wherein the sensor comprises a pre-processing circuit to compress to the sensor data into compressed sensor data, and combining the compressed sensor data and the rotational data into the data set.