1. An obstacle detecting device comprising:
a distance measuring sensor arranged adjacent to a rotation axis of a door of a vehicle, the sensor measuring a distance to an object in a direction corresponding to a scanning angle by scanning a scanning plane;
a memory to store
a standard angle defined when the sensor is mounted at a normal position, and
a comparison distance defined between a mounting position of the sensor and an end of the door in the direction corresponding to the scanning angle when the sensor is mounted at the normal position;
an initializing portion to obtain a distance-shortest scanning angle defined by a shortest value of measured distance distances which are measured by the distance measuring sensor;
a correcting portion to correct the scanning angle, when the distance-shortest scanning angle is different from the standard angle; and
an object determining portion to determine the object to be an obstacle having a possibility to contact with the door, when a distance measured by the sensor measuring sensor is equal to or shorter than a corrected comparison distance which is defined by correcting the comparison distance to correspond to the corrected scanning angle.
2. The obstacle detecting device according to claim 1, wherein
the scanning plane has a predetermined angle relative to a surface of the door in an opening direction of the door, and
the standard angle is defined in a direction extending vertically downward from the sensor.
3. The obstacle detecting device according to claim 1, wherein
the scanning plane is approximately parallel to a driving plane of the vehicle,
the standard angle is defined in a directly lateral direction of the sensor, and
the object determining portion determines the obstacle to have the possibility to contact with the door, when the door has an opening degree corresponding to the corrected scanning angle.
4. The obstacle detecting device according to claim 3, wherein
the object is a surface of the door located in the directly lateral direction of the sensor,
the comparison distance is defined between the mounting position of the sensor and the surface of the door in the directly lateral direction, and
the distance-shortest scanning angle is defined by a shortest value of the measured distance between the mounting position of the sensor and the surface of the door.
5. The obstacle detecting device according to claim 1, further comprising:
a linear part determining portion to determine the object to have a linear part having a predetermined length or not based on the distance to the object, wherein
the initializing portion obtains the distance-shortest scanning angle, when the object is determined to have the linear part having the predetermined length.
6. The obstacle detecting device according to claim 1, wherein
the distance to the object is one of a plurality of distances measured by the sensor, and
the distance-shortest scanning angle is obtained by using an average value of the plurality of distances.
7. The obstacle detecting device according to claim 1, wherein
the vehicle has a plurality of doors, and
the initializing portion obtains the distance-shortest scanning angle, when all of the plurality of doors are determined to be closed.
8. The obstacle detecting device according to claim 1, wherein,
the initializing portion obtains the distance-shortest scanning angle, when the vehicle is determined to be in a stop state.
9. The obstacle detecting device according to claim 1, further comprising a position determining portion determining if the sensor is not mounted at the normal position.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An optical scanning device for scanning a plurality of light beams on one or more scanned surfaces, the optical scanning device comprising:
a light source for emitting said plurality of light beams;
a front optical system for receiving said plurality of light beams from the light source along an optical axis that extends within the optical scanning device;
a deflector for receiving said plurality of light beams from said front optical system and for deflecting said plurality of light beams in a first direction so that said plurality of light beams scan in said first direction;
a rear optical system for receiving said plurality of light beams from said deflector and for directing said plurality of light beams toward the one or more scanned surfaces so that said plurality of light beams are separated farther in a second direction that is orthogonal to said first direction within said rear optical system than at said deflector;
wherein
two light beams of said plurality of light beams are deflected by said deflector, and said two light beams travel parallel to one another in a plane that includes said second direction before said two light beams enter said rear optical system; and
other light beams of said plurality of light beams are deflected by said deflector and said other light beams progressively separate from one another in said plane before said other light beams enter said rear optical system.
2. The optical scanning device of claim 1, wherein:
said front optical system includes, in order from the light source side, a first optical system for collimating each of said plurality of light beams and a second optical system for converging each of said plurality of light beams at least in said second direction.
3. The optical scanning device of claim 1, wherein:
said rear optical system includes, in order from the light source side, a third optical system for converging in said first direction each of said plurality of light beams deflected from said deflector, a separation optical system for separating said plurality of light beams in said second direction after they pass through said third optical system, and a fourth optical system for converging each of said plurality of light beams at least in the second direction after they pass through said separation optical system.
4. The optical scanning device of claim 2, wherein:
said rear optical system includes, in order from the light source side, a third optical system for converging in said first direction each of said plurality of light beams deflected from said deflector, a separation optical system for separating said plurality of light beams in said second direction after they pass through said third optical system, and a fourth optical system for converging each of said plurality of light beams at least in the second direction after they pass through said separation optical system.
5. The optical scanning device of claim 4, wherein said third optical system includes at least one cylindrical lens having refractive power at least in said first direction.
6. The optical scanning device of claim 5, wherein said at least one cylindrical lens includes, in order from the light source side, a first cylindrical lens having negative refractive power in said first direction and a second cylindrical lens having positive refractive power in said first direction.
7. The optical scanning device of claim 6, wherein said other light beams intersect in said plane between said second optical system and said deflector.
8. The optical scanning device of claim 7, wherein said other light beams enter said rear optical system at positions in said plane that are outside said two light beams.
9. The optical scanning device of claim 8, wherein:
said deflector includes plural reflecting surfaces that deflect said plurality of light beams; and
said two light beams are reflected by said plural reflecting surfaces at right angles in said plane and enter said third optical system at right angles in said plane.
10. The optical scanning device of claim 8, wherein:
said plurality of light beams includes, in order in said second direction, first, second, third, and fourth light beams that are deflected by said deflector so that said second and third light beams are parallel in said plane;
said second cylindrical lens includes first and second lens parts that are adjacent to one another in said second direction;
the first lens part includes a first light incident surface that is inclined at an angle in said plane so that the sum of the absolute values of the angles that the first and second light beams make with said first light incident surface is equal to the sum of the absolute values of the angles that the first and second light beams would make with said first light incident surface if said first light incident surface were perpendicular to the center optical axis of said third optical system; and
the second lens part includes a second light incident surface that is inclined at an angle in said plane so that the sum of the absolute values of the angles that the third and fourth light beams make with said second light incident surface is equal to the sum of the absolute values of the angles that the third and fourth light beams would make with said second light incident surface if said second light incident surface were perpendicular to the center optical axis of said third optical system.
11. The optical scanning device of claim 8, wherein:
said plurality of light beams includes, in order in said second direction, first, second, third, and fourth light beams that are deflected by said deflector so that said second and third light beams are parallel in said plane;
said second cylindrical lens includes first and second lens parts that are adjacent to one another in said second direction;
the first lens part includes a first light incident surface that is inclined at an angle in said plane so that the first light beam produces a straight scanning line; and
the second lens part includes a second light incident surface that is inclined at an angle in said plane so that the fourth light beam produces a straight scanning line.
12. The optical scanning device of claim 4, wherein said fourth optical system includes a cylindrical mirror that has refractive power at least in said second direction.
13. The optical scanning device of claim 5, wherein said fourth optical system includes a cylindrical mirror that has refractive power at least in said second direction.
14. The optical scanning device of claim 6, wherein said fourth optical system includes a cylindrical mirror that has refractive power at least in said second direction.
15. The optical scanning device of claim 1, and further including a plurality of scanned surfaces wherein each scanned surface is on a different one of a plurality of photosensitive drums, and each of said plurality of light beams scans one of said plurality of scanned surfaces.
16. The optical scanning device of claim 2, and further including a plurality of scanned surfaces wherein each scanned surface is on a different one of a plurality of photosensitive drums, and each of said plurality of light beams scans one of said plurality of scanned surfaces.
17. The optical scanning device of claim 4, and further including a plurality of scanned surfaces wherein each scanned surface is on a different one of a plurality of photosensitive drums, and each of said plurality of light beams scans one of said plurality of scanned surfaces.
18. The optical scanning device of claim 5, and further including a plurality of scanned surfaces wherein each scanned surface is on a different one of a plurality of photosensitive drums, and each of said plurality of light beams scans one of said plurality of scanned surfaces.
19. The optical scanning device of claim 6, and further including a plurality of scanned surfaces wherein each scanned surface is on a different one of a plurality of photosensitive drums, and each of said plurality of light beams scans one of said plurality of scanned surfaces.
20. The optical scanning device of claim 7, and further including a plurality of scanned surfaces wherein each scanned surface is on a different one of a plurality of photosensitive drums, and each of said plurality of light beams scans one of said plurality of scanned surfaces.
21. An optical scanning device for scanning a plurality of light beams on one or more scanned surfaces, the optical scanning device comprising:
a light source for emitting said plurality of light beams;
a front optical system for receiving said plurality of light beams from the light source along an optical axis that extends within the optical scanning device;
a deflector for receiving said plurality of light beams from said front optical system and for deflecting said plurality of light beams in a first direction so that said plurality of light beams scan in said first direction;
a rear optical system for receiving said plurality of light beams from said deflector and for directing said plurality of light beams toward the one or more scanned surfaces so that said plurality of light beams are separated farther in a second direction that is orthogonal to said first direction within said rear optical system than at said deflector;
wherein
two light beams of said plurality of light beams are deflected by said deflector so that said two light beams travel parallel to one another in a plane that includes said second direction between said deflector and said rear optical system;
other light beams of said plurality of light beams that are deflected by said deflector enter said rear optical system so that other light beams progressively separate from one another in said plane;
said front optical system includes, in order from the light source side, a first optical system for collimating each of said plurality of light beams and a second optical system for converging each of said plurality of light beams at least in said second direction;
said rear optical system includes, in order from the light source side, a third optical system for converging in said first direction each of said plurality of light beams deflected from said deflector, a separation optical system for separating said plurality of light beams in said second direction after they pass through said third optical system, and a fourth optical system for converging each of said plurality of light beams at least in the second direction after they pass through said separation optical system;
said third optical system includes at least one cylindrical lens having refractive power at least in said first direction;
said at least one cylindrical lens includes, in order from the light source side, a first cylindrical lens having negative refractive power in said first direction and a second cylindrical lens having positive refractive power in said first direction; and
said other light beams intersect in said plane between said second optical system and said deflector.
22. The optical scanning device of claim 21, wherein said other light beams enter said rear optical system at positions in said plane that are outside said two light beams.
23. The optical scanning device of claim 22, wherein:
said deflector includes plural reflecting surfaces that deflect said plurality of light beams; and
said two light beams are reflected by said plural reflecting surfaces at right angles in said plane and enter said third optical system at right angles in said plane.
24. The optical scanning device of claim 22, wherein:
said plurality of light beams includes, in order in said second direction, first, second, third, and fourth light beams that are deflected by said deflector so that said second and third light beams are parallel in said plane;
said second cylindrical lens includes first and second lens parts that are adjacent to one another in said second direction;
the first lens part includes a first light incident surface that is inclined at an angle in said plane so that the sum of the absolute values of the angles that the first and second light beams make with said first light incident surface is equal to the sum of the absolute values of the angles that the first and second light beams would make with said first light incident surface if said first light incident surface were perpendicular to the center optical axis of said third optical system; and
the second lens part includes a second light incident surface that is inclined at an angle in said plane so that the sum of the absolute values of the angles that the third and fourth light beams make with said second light incident surface is equal to the sum of the absolute values of the angles that the third and fourth light beams would make with said second light incident surface if said second light incident surface were perpendicular to the center optical axis of said third optical system.
25. The optical scanning device of claim 22, wherein:
said plurality of light beams includes, in order in said second direction, first, second, third, and fourth light beams that are deflected by said deflector so that said second and third light beams are parallel in said plane;
said second cylindrical lens includes first and second lens parts that are adjacent to one another in said second direction;
the first lens part includes a first light incident surface that is inclined at an angle in said plane so that the first light beam produces a straight scanning line; and
the second lens part includes a second light incident surface that is inclined at an angle in said plane so that the fourth light beam produces a straight scanning line.
26. The optical scanning device of claim 21, and further including a plurality of scanned surfaces wherein each scanned surface is on a different one of a plurality of photosensitive drums, and each of said plurality of light beams scans one of said plurality of scanned surfaces.