Sunshine sensor and air conditioner for vehicle

A sunshine sensor for use with a car comprising:

• a first light receiving element facing upward and producing an output ic;
• a second light receiving element generating an output ia and a third light receiving element creating an output ib, each of said second and third light receiving elements having a light receiving surface inclined toward a front side by an identical angle along an advancing direction of the car, said light receiving surfaces being symmetrically inclined with respect the car advancing direction along a horizontal direction vertical to the car advancing direction;
• and
• computating means for computing based on the outputs respectively from said first, second, and third light receiving elements a relative sunshine intensity I, a sunshine elevation angle .theta., and a sunshine azimuth angle .phi.,
• said computing means computing the sunshine intensity I, the sunshine elevation angle .theta., and the sunshine azimuth angle .phi. based on the following equations. ##EQU5##

An air conditioner for use with a car comprising:

• a sunshine sensor including
• a first light receiving element facing upward, and
• a second light receiving element and a third light receiving element which each are inclined toward a front side by an identical angle along an advancing direction of the car and which are symmetrically inclined with respect the car advancing direction along a horizontal direction vertical to the car advancing direction,
• each of said second and third light receiving elements having a light receiving surface possessing an inclination angle such that a vector obtained by adding to each other normal vectors respectively of said light receiving surfaces of said respective light receiving elements has a direction substantially identical to a direction of sunshine which maximizes a quantity of heat supplied from the sunshine to the car;
• air conditioning means for regulating a temperature and an amount of air to be supplied to an interior room of the car;
• and
• a control means for computing sunshine components from outputs respectively created from said first, second, and third light receiving elements and controlling said air conditioning means based on a result of the computation.

A method of controlling an air conditioner for use with a car comprising the following steps of:

• obtaining an output ic generated from a first light receiving element facing upward, an output ia produced from a second light receiving element, and an output ib generated from a third light receiving element, each of said second and third light receiving elements being inclined toward a front side by an identical angle along an advancing direction of the car, said second and third light receiving elements being symmetrically inclined with respect the car advancing direction along a horizontal direction vertical to the car advancing direction;
• computing based on the outputs respectively from said first, second, and third light receiving elements a sunshine intensity I, a sunshine elevation angle .theta., and a sunshine azimuth angle .phi. based on the following equations;
• ##EQU6## computing a control target value of the air conditioner depending on the computed values respectively of the relative sunshine intensity I, the sunshine elevation angle .theta., and the sunshine azimuth angle .phi.;
• and
• controlling the air conditioner depending on the control target value.