Projection optical system and object detection device
A projection optical system includes a laser diode; a laser diode module having a plurality of the laser diodes one-line arranged; a light projecting lens to adjust spread of light emitted from the respective laser diodes; and an optical deflector to deflect light passing through the light projecting lens and irradiate a target with the deflected light. The laser diodes emit light such that the light spreads at a first angle in a first direction and spreads at a second angle being wider than the first angle in a second direction being perpendicular to the first direction. The laser diode modules are disposed such that an arrangement direction thereof coincides with the first direction and they are placed along the second direction and shifted in position relative to each other in the first direction. The light projecting lenses are disposed with corresponding to the laser diode modules.
1. A projection optical system comprising:
a laser diode, the laser diode being a light source;
a laser diode module having a plurality of the laser diodes arranged in a row;
a light projecting lens configured to adjust spread of light emitted from each of the laser diodes; and
an optical deflector configured to deflect light passing through the light projecting lens and irradiate a target with the deflected light,
wherein the laser diodes emit light such that the light spreads out at a first angle in a first direction and spreads out at a second angle in a second direction, the second angle being wider than the first angle and the second direction being perpendicular to the first direction,
wherein a plurality of the laser diode modules is disposed such that an arrangement direction of the laser diodes coincides with the first direction and that the laser diode modules are placed side by side in the second direction and shifted in position relative to each other in the first direction,
wherein a plurality of the light projecting lenses is disposed such that the light projecting lenses correspond to the laser diode modules, respectively, and
wherein the plurality of the laser diode modules is mounted separately on both surfaces of one substrate.
2. The projection optical system according to claim 1 , wherein the light projecting lenses are disposed so as to be placed side by side in the first direction and to be shifted in position relative to each other in the second direction.
3. An object detection device comprising:
a laser diode, the laser diode being a light source;
a laser diode module having a plurality of the laser diodes arranged in a row;
a light projecting lens configured to adjust spread of light emitted from each of the laser diodes;
an optical deflector configured to deflect light passing through the light projecting lens and irradiate a target with the deflected light; and
a light receiving element configured to receive light projected from the optical deflector and reflected off the target, the object detection device detecting whether there is the target, based on a light reception signal outputted from the light receiving element,
wherein the laser diodes emit light such that the light spreads out at a first angle in a first direction and spreads out at a second angle in a second direction, the second angle being wider than the first angle and the second direction being perpendicular to the first direction,
wherein a plurality of the laser diode modules is disposed such that an arrangement direction of the laser diodes coincides with the first direction and that the laser diode modules are placed side by side in the second direction and shifted in position relative to each other in the first direction,
wherein a plurality of the light projecting lenses is disposed such that the light projecting lenses correspond to the laser diode modules, respectively,
wherein the object detection device further comprises a substrate having a front surface and a back surface, and
wherein one of the laser diode modules is mounted on the front surface, and another one of the laser diode modules is mounted on the back surface.
4. The object detection device according to claim 3 , wherein the light projecting lenses are disposed so as to be placed side by side in the first direction and to be shifted in position relative to each other in the second direction.