Apparatus for head up display comprising a parabolic reflective mirror

• US 5,504,622 A
• Filed: 03/17/1994
• Issued: 04/02/1996
• Est. Priority Date: 03/18/1993
• Status: Expired due to Fees

• Current Assignee: Kansei Company
• Original Assignee: Kansei Company
• Inventors: Ishikawa, Tomonari, Oikawa, Kohki
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): MACK, RICKY LEVERN
• Application Number:
  US08/214,264
• Time in Patent Office: 747 Days
• Field of Search: 359/630, 359/631, 359/632, 359/633, 359/634, 359/13, 359/14, 359/637, 359/838, 345/7, 345/9, 348/118
• US Class Current: 359/630
• CPC Class Codes: B60K 2360/334 Projection means
• CPC Class Codes: B60K 35/60 Instruments characterised by their location or relative disposition in or on vehicles arrangements of lighting devices on dashboards B60Q3/10
• CPC Class Codes: G01D 7/06 Luminous indications projected on a common screen
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 2027/0121 Parasitic image effect attenuation by suitable positioning of the parasitic images
• CPC Class Codes: G02B 2027/0129 comprising devices for correcting parallax
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 5/10 with curved faces

Abstract

The present invention provides an apparatus for a head up display for the use of a motor vehicle, which can make a presentation of an image information in a remote place and which can remove a height-wise positional displacement of a double image and distortion of the double image caused by the curved shape of a vehicle front glass to the extent possible. In the apparatus for a head up display for the use of a motor vehicle according to the present invention, a projector (3) has a middle mirror (6) for reflecting an image information (9) such as characters or marks toward a reflective face. The middle mirror (6) includes a portion (18) of the parabolic reflective face which is located away from a main axis of a parabolic mirror. The portion (18) of the parabolic reflective face includes a first curved surface having a small curvature, corresponding to that portion of a vehicle front glass (2) which has a large curvature, and a second curved surface having a large curvature, corresponding t that portion of the vehicle front glass (2) which has a small curvature, so that distortion of the image information due to difference in curvature of the vehicle front glass (2) is corrected and a height-wise positional displacement of a double image, which may occur when the image information is looked through a pair of eyes (10) and (11) of a person riding on the motor vehicle, is corrected.

Claims

1. An apparatus for a head up display for use in a motor vehicle, comprising:

a curved front glass;

a reflective surface formed in said curved front glass;

a projector for projecting image information, said image information projected by said projector being reflected on said reflective surface in a direction where said image information is seen by eyes of a person riding in the motor vehicle wherein said image information is presented forwardly of said front glass; and

a first mirror mounted on said projector for reflecting said image information toward said reflective surface, said first mirror including a portion of a parabolic reflective face located spaced away from a main axis of a parabolic mirror, wherein said portion of said parabolic reflective face includes a first curved surface having a smaller curvature, corresponding to a portion of said curved front glass which has a larger curvature, and a second curved surface having a larger curvature, corresponding to a portion of said curved front glass which has a smaller curvature.

2. An apparatus for a head up display for the use in a motor vehicle according to claim 1, further comprising an instrument panel, said projector being disposed inside said instrument panel.

3. An apparatus for a head up display for the use in a motor vehicle according to claim 1, wherein said reflective surface is semitransparent.

4. An apparatus for a head up display for the use in a motor vehicle according to claim 2, wherein said reflective surface is semitransparent.

5. An apparatus for a head up display for the use in a motor vehicle, comprising:

a curved front glass;

a semitransparent reflective surface formed in said front glass;

an instrument panel;

a projector disposed inside said instrument panel for projecting image information;

said image information being reflected on said reflective surface toward eyes of a person riding in the motor vehicle to present an image of said image information forwardly of said front glass in an overlapped relation to a foreground; and

a first mirror mounted on said projector for reflecting said image information toward said reflective surface, said first mirror including a portion of a parabolic reflective face which is located away from a main axis of a parabolic mirror;

said portion of said parabolic reflective face including a first curved surface having a smaller curvature, corresponding to a portion of said front glass which has a larger curvature, and a second curved surface having a larger curvature, corresponding to a portion of said front glass which has a smaller curvature, wherein distortion of said image information due to differences in curvature of said front glass is corrected and a height-wise positional displacement of a double image, which double image may occur when said image information viewed by a person riding in the motor vehicle, is corrected.