Optical detector having three light receiving areas

An optical pickup comprising:

• a semiconductor laser;
• an diffraction grating that divides an optical beam from the semiconductor laser into at least three optical beams, the at least three optical beams including 0 order light and ±1st order diffraction light;
• an optical lens that irradiates optical spots of the three optical beams on an optical disk;
• and
• an optical detector that detects the three optical beams reflected by an optical disk;
• and
• wherein the optical detector has a first receiving area which receives reflected 0 order light, a second receiving area which receives reflected +1st order diffraction light and a third receiving area which receives reflected −1st order diffraction light, the second and the third receiving areas being divided into four light receiving surfaces delimited by a first direction corresponding to a radius direction of the disk and the second direction which is substantially perpendicular to the first direction;
• and
• an output line which connects an output signal line from a light receiving surface of the second receiving area with an output signal line from a light receiving surface of the third receiving area, the light receiving surface of the third receiving area being located at a corresponding position in both of the first and the second directions to the position at which the light receiving surface of the second receiving area is located.

An optical pickup comprising:

• an optical system which irradiates optical spots of at least three optical beams on an information recording medium, the three optical beams including 0 order light and ±1st order diffraction light;
• an optical detector which has a first receiving area which receives reflected 0 order light, a second receiving area which receives reflected +1st order diffraction light and a third receiving area which receives the reflected −1st order diffraction light, the second and the third receiving areas being divided into four light receiving surfaces delimited by a first direction corresponding to a radius direction of the information recording medium and a second direction corresponding to a track direction of the information recording medium;
• and
• an output line which connects output signal lines from the light receiving surfaces of the second and the third receiving areas which are located at corresponding positions in both of the first and the second directions;
• wherein the output line is used for detecting both of a focus error signal and a tracking error signal.

An optical pickup comprising:

• an optical system which irradiates optical spots of at least three optical beams on an information recording medium, the three optical beams including 0 order light and ±1st order diffraction light;
• an optical detector which has a first receiving area which receives reflected 0 order light, a second receiving area which receives reflected +1st order diffraction light and a third receiving area which receives the reflected −1st order diffraction light, the second and the third receiving areas being divided into four light receiving surfaces delimited by dividing lines extending in a first direction corresponding to a radius direction of the recording medium and in a second direction corresponding to a track direction of the recording medium;
• and
• an output line for outputting a sum signal of an output from a light receiving surface of the second receiving area with an output from a light receiving surface of the third receiving area, the light receiving surface of the third receiving area being arranged in the same direction from an intersection of the dividing lines of the third receiving area as a direction in which the light receiving surface of the second receiving area is arranged from an intersection of the dividing lines of the second receiving area.

An optical pickup comprising;

• an optical system which irradiates optical spots of at least three optical beams on an information recording medium, the three optical beams including 0 order light and ±1st order diffraction light;
• and
• an optical detector which has a first receiving area which receives reflected 0 order light, and a second receiving area which receives reflected +1st order diffraction light and a third receiving area which receives reflected −1st order diffraction light, the second and the third receiving areas being divided into four light receiving surfaces delimited by a first direction corresponding to a radius direction of the recording medium and a second direction which is substantially perpendicular to the first direction;
• wherein each light receiving surface of the second and the third receiving areas located in the same direction from a center of a respective receiving area is connected to one another, and the connected light receiving surfaces are connected so as to output a sum signal.

An optical detector for detecting at least three optical beams reflected by an optical disk, the three optical beams are 0 order light and ±1st order diffraction light, comprising:

• a first receiving area which receives reflected 0 order light;
• a second receiving area which receives reflected +1st order diffraction light and a third receiving area which receives the reflected −1st order diffraction light, the second and the third receiving areas being divided into four light receiving surfaces delimited by a first direction corresponding to a radius direction of the disk and a second direction corresponding to a track direction of the disk;
• and
• wherein the optical detector outputs outside of the optical detector a sum signal of an output from the light receiving surfaces of the second and the third receiving areas which are located at corresponding positions in both of the first and the second directions.

An optical detector which detects at least three optical beams reflected by an optical disk, the three optical beams including 0 order light and ±1st order diffraction light, comprising:

• a first receiving area which receives reflected 0 order light, a second receiving area which receives reflected +1st order diffraction light and a third receiving area which receives reflected −1st order diffraction light, the second and the third receiving areas being divided into four light receiving surfaces delimited by dividing lines extending in a first direction corresponding to a radius direction of the disk and in a second direction corresponding to a track direction of the disk;
• and
• an output line for outputting a sum signal obtained by connecting an output from a light receiving surface of the second receiving area with an output from a light receiving surface of the third receiving area;
• wherein the light receiving surface of the third receiving area is arranged in the same direction from an intersection of the dividing lines of the third receiving area as the direction in which the light receiving surface of the second receiving area is arranged from an intersection of the dividing lines of the second receiving area.

An optical detector which detects at least three optical beams reflected by an optical disk, the three optical beams including 0 order light and ±1st order diffraction light, comprising:

• a first receiving area which receives reflected 0 order light;
• and
• a second receiving area which receives reflected +1st order diffraction light and a third receiving area which receives reflected −1st order diffraction light, the second and the third receiving areas being divided into four light receiving surfaces delimited by a first direction corresponding to a radius direction of the disk and a second direction which is substantially perpendicular to The first direction;
• wherein each light receiving surface of the second and the third receiving areas which is located in the same direction from a center of a respective receiving area thereof is connected to one another, and the connected light receiving surfaces are connected so as to output a sum signal.