A heads-up display (HUD) is a device that projects images such as a speedometer or lane change indicator onto the inside surface of a vehicle's windshield. The projected image is created by mirrors such that the driver perceives the projected image as floating in the air a short distance (1-2 meters) away from his or her eyes.
Prior art heads-up display systems that project the image onto a windshield are complicated by a windshield's curvature. In order to have the projected image appear without distortion on a curved surface, the projected image must be compensated by the image source and projecting mirrors to compensate or overcome image distortion caused by the windshield surface's curvature.
A combiner heads-up display (C-HUD) is a device that performs essentially the same function as a heads-up display that projects images onto a windshield, except that the projected image of a C-HUD is not on the windshield but on an acrylic plastic panel called a “combiner mirror.”
A disadvantage of a combiner heads-up display is that it must be moved upwardly from inside the dashboard when it is turned on. It must also be retracted back into the dashboard when it is turned off in order to reduce the likelihood of damage and reduce the aging effects caused by prolonged exposure to the sun. The extension and retraction of the C-HUD is provided by a 12V DC motor and gearbox.
In the prior art, a combiner mirror of a C-HUD is locked in an upward and extended position by a mechanical lock that does not allow the combiner mirror to be returned to its stowed position if the DC power source fails or is cut off. A combiner heads-up display (C-HUD) that enables the combiner mirror to be manually stowed, i.e., pushed back into the vehicle's dashboard, when the power is off would be an improvement over the prior art.
Each end 210, 212 of the combiner mirror holder 204 has two elevation pins 214A, 214B and 216A and 216B. The elevation pins 214A, 214B, 216A and 216B are “attached to” and extend from from the corresponding ends 210 and 212 of the mirror holder 204.
The elevation pins are preferably cylindrical or columnar. They are sized and shaped to freely slide up and down substantially vertical elevation slots 218 formed into two substantially parallel, substantially vertical, substantially planar support plates 220 and 222.
The space between the support plates 220 and 222 is slightly greater than the width of the mirror holder 204 but less than the combined width of the mirror holder 204 plus the elevation pins. The combiner mirror 202 can thus be raised and lowered between the support plates 220 and 222 by raising and lowering the combiner mirror holder 204 as the elevation pins 214A, 214B and 216A and 216B “ride” in the elevation slots 218.
The combiner mirror holder 204 is raised and lowered by two substantially parallel, substantially horizontal elevation arms 224 and 226 that engage the lifting arms 280 extending away from and toward main gears 234, 236. The elevation arms 224, 226 have first and second opposing ends, one of which is identified by reference numeral 228 and which is provided with cylindrical opening 230 sized, shaped and arranged to fit onto small shafts 232 that extend inwardly from opposing, spaced-apart main gears 234 and 236. The elevation arms 224 and 226 are fixed to the shafts 232 such that rotation of the main gears 234, 236 causes the elevation arms 224 and 226 to rotate with the main gears, 234, 236.
Short pins 238 at the second end 240 of the elevation arms 224, 226 are sized, shaped and arranged to engage opposing and substantially-horizontal lift slots 242 that are formed into the two, substantially parallel, substantially horizontal lifting arms 280 that extend away from the mirror holder 204. The lift slots 242 are sized shaped and arranged to allow the pins 238 to traverse laterally (substantially horizontally) in the lift slots 242 as the arms 224 and 226 rotate clockwise and counter-clockwise with the main gears. Rotation of the arms 224, 226 thus causes the pins 238 to move laterally and vertically relative to the lift slots 242. Vertical movement of the pins 238 causes the substantially horizontal lifting arms 280 and the mirror holder to which they are connected, to rise.
The main gears 234, 236 are rotatably fixed to the support plates 220 and 222. The main gears 234, 236 are driven by two smaller mating gears 243 that are attached to a rotating drive shaft 244 which is also rotatably fixed between the vertical support plates 220, 222. A small D.C. motor (not shown) which is of course reversible, is geared to the drive shaft 244. By energizing the motor and controlling the polarity of the voltage provided to it, the drive shaft and small gears 243 can be rotated in opposite directions causing the main gears to rotate in opposite directions causing the mirror holder 204 and mirror 202 to go up or down.
Manually operable and retractable lock mechanism assemblies 250 (one assembly 250 in each support plate 220, 222) comprise an essentially hollow “follower” body 252, two coil springs 254 inside the follower body 252, and a substantially square-shaped latch 256 having a beveled or “mitred” corner portion 265. A leaf spring assembly 258, separate and apart from the retractable lock assemblies 250, reduces vibration of corresponding retractable lock assemblies 250.
The retractable lock mechanism assemblies 250 fit slidably into a recess 262 formed near the top edge 263 of the support plates 220 and 222.
The right-side elevation arm 224, shown at an angle of approximately 45 degrees relative to horizontal, is extended laterally, partway along the slot 242 formed in the right-side of the combiner mirror holder 204.
Referring now to
A mitred or beveled corner portion 265 of the top 260 of the substantially square-shaped latch 256 is inclined at an angle (angle 270 is preferably between about 120 and 160 degrees) or “mitred” relative to the top 260 and the slot 218 (at different angles of course). The angle of the mitre permits the guide pin 214 to be slid downwardly in the elevation rail/slot 218 by pushing downwardly on the combiner mirror 202. The mitred or beveled portion 265 of the top 260 enables the latch 256 to move within the recess 262 formed in the support plate 220 and into and out of the follower body 252.
Finally,
Those of ordinary skill in the art should recognize that the spring-loaded, manually operable retractable lock mechanism of the a combiner heads-up display allows the combiner mirror to be pushed back down into the vehicle's dashboard manually, even when there might not be any power available and which would require the combiner mirror to remain in its upright position.
The foregoing description is for purposes of illustration only. The true scope of the invention is set forth in the following claims.