Light detector, optical position detection apparatus, and display apparatus with position detection capability
View Patent ↗A light detector includes: a light receiving device having a central optical axis and first and second directions perpendicular thereto, the light receiving device detecting incident light; a first light shield provided on a light incident side of the light receiving device and disposed on one side in the first direction with respect to the light receiving device; and a second light shield provided on the light incident side of the light receiving device and disposed on the other side in the first direction with respect to the light receiving device, wherein the first and second light shields form a light incident slit over an angular range including the direction in which the central optical axis of the light receiving device extends, and the width of the slit increases as the angle with respect to the central optical axis of the light receiving device increases.
1. A light detector comprising:
a light receiving device that has a central optical axis and first and second directions perpendicular thereto, the light receiving device detecting incident light; and
a holder that includes first and second folder members that sandwich the light receiving device in the first direction, the first and second holder members include first and second bases and first and second light shields, respectively, wherein
the light receiving device has a directional characteristic of light sensitivity in which a first position located along the optical axis has a highest sensitivity and a second position angled from the first position in the second direction has a low sensitivity, and the sensitivity lowers and the angle becomes larger,
each of the first and second bases has a rectangular shape in which longitudinal sides extend in the second direction, a first thickness of the first base is larger than a second thickness of the second base, the light receiving device is provided on the second base next to the longitudinal side of the second base, and a portion of the longitudinal side of the first base that corresponds to the light receiving device has a recess that opens the central optical axis of the light receiving device toward a light incident side,
the first and second light shields continuously and respectively project from the longitudinal sides of the first and second bases toward the light incident side, each of the first and second light shields has a semi-circular shape, a third thickness of the first light shield is smaller than the first thickness so that the light receiving device detects the incident light, and a fourth thickness of the second light shield is the same as the second thickness, and
top surfaces of the first base and the first light shield are co-planar, the third thickness gradually decreases from a first tip closest to the light incident side of the first light shield toward ends of the first light shield connected to the first base, and the light receiving device receives the incident light that passes through a gap between the first and second light shields.
2. The light detector according to claim 1 , wherein
the holder is made of a light shielding material.
3. The light detector according to claim 1 , wherein
the first light shield, when viewed in the first direction, protrudes from the first base and has the semi-circular shape whose center is located on the side where the light receiving device is present, and
the second light shield, when viewed in the first direction, protrudes from the second base and has the semi-circular shape whose center is located on the side where the light receiving device is present.
4. The light detector according to claim 1 , further comprising:
a lens on the light incident side of the light receiving device, the lens having a convex curved surface facing forward when viewed in the first direction.
5. The light detector according to claim 1 , further comprising:
a light-transmissive member on the light incident side of the light receiving device, wherein
each of the first and second light shields is a light shielding layer formed on the light-transmissive member.
6. The light detector according to claim 5 , wherein
the light-transmissive member is a lens having a convex curved surface facing forward when viewed in the first direction.
7. The light detector according to claim 1 , wherein
the light receiving device detects at least infrared light.
8. An optical position detection apparatus that optically detects a position of an object in a detection region, the optical position detection apparatus comprising:
the light detector according to claim 7 ;
a light source apparatus for position detection that emits infrared position detection light toward the detection region to form an intensity distribution of the position detection light in the detection region; and
a position detector that detects the position of the object, wherein
the light detector has a light receiving portion facing the detection region,
the light receiving portion receives the position detection light reflected off the object in the detection region, and
the position detector detects the position of the object based on the light received by the light detector.
9. A display apparatus with a position detection capability comprising:
the optical position detection apparatus according to claim 8 ; and
an image generation apparatus that forms an image in a region corresponding to the detection region.