Optical recording medium

An optical recording medium comprising:

• a transparent substrate made of resin having guide grooves;
• a thermochromic layer provided over said transparent substrate, said thermochromic layer having a masking effect for providing a larger light transmittance to allow said laser beam spot to pass therethrough when the thermochromic layer has a higher temperature than a threshold value by absorbing heat of said laser beam spot and for providing a smaller light transmittance to prevent said laser beam spot to pass therethrough when the thermochromic layer has a lower temperature than the threshold value by being cooled down, so that a substantial diameter of said laser beam spot is reduced;
• an information recording layer on which optically readable information signals are to be recorded, said information recording layer being provided on said thermochromic layer;
• a reflecting layer provided on said thermochromic layer, and
• a heat radiating layer composed of a transparent inorganic material having a thickness of between 5 to 100 nm and being arranged between said transparent substrate and said thermochromic layer in direct contact with said thermochromic layer for enhancing said masking effect of said thermochromic layer so as to quickly cool down the temperature of said thermochromic layer by causing said heat radiating layer to absorb heat generated in said thermochromic layer by being irradiated with said laser beam spot.