System and method for determining a distance to an object

A system for determining a distance to an object comprising:

• a semiconductor light source arranged for projecting a pattern of discrete spots of laser light towards said object in a periodically repeated sequence of pulses;
• a detector comprising a plurality of CMOS picture elements, said detector being configured for detecting light representing said pattern of discrete spots as reflected by said object in synchronization with said sequence of pulses, said detector being provided with a narrowband filter;
• and
• processing means configured to calculate said distance to said object as a function of exposure values generated by said picture elements in response to said detected light;
• wherein said picture elements are configured to generate said exposure values by accumulating, for all of the pulses of said sequence, a first amount of electrical charge representative of a first amount of light reflected by said object during a first predetermined time window and a second electrical charge representative of a second amount of light reflected by said object during a second predetermined time window, said second predetermined time window occurring after said first predetermined time window;
• wherein each of said plurality of picture elements comprises at least two charge storage wells, and wherein said detecting of said first amount of light and said detecting of said second amount of light occurs at respective ones of said at least two charge storage wells;
• wherein said first charge storage well used for said detecting of said first amount of light has a charge storage capacity that is greater than said second charge storage well used for said detecting of said second amount of light;
• and
• wherein each of said plurality of picture elements comprises at least one further charge storage well configured to perform the function of acquiring background light values, said at least one further charge storage well having a charge storage capacity that is smaller than a charge storage capacity of said at least two charge storage wells.