Rear view mirror with integrated matrix display

• US 6,106,121 A
• Filed: 07/10/1997
• Issued: 08/22/2000
• Est. Priority Date: 07/10/1997
• Status: Expired due to Term

• Current Assignee: Massachusetts Institute of Technology, FCA US LLC (Stellantis NV)
• Original Assignee: Massachusetts Institute of Technology, Chrysler Corporation (Stellantis NV)
• Inventors: McClanahan, Betty L., Buckley, Stephen J.
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): Robinson, Mark A.
• Application Number:
  US08/891,164
• Time in Patent Office: 1,139 Days
• Field of Search: 359/629, 359/630, 359/871, 359/839, 349/11, 349/195
• US Class Current: 359/839
• CPC Class Codes: B60R 1/12 Mirror assemblies combined with other articles, e.g. clocks
• CPC Class Codes: B60R 2001/1215 with information displays

Abstract

A rear view mirror includes a transparent front glass that covers a matrix display, for example an LCD display. The matrix display is translucent when activated and transparent when inactive, and behind the matrix display is a mirror-backed rear glass. Thus, light can pass through the matrix display and reflect back off the mirror-backed rear glass. Consequently, the rear view mirror can assume its conventional function of presenting images of objects that are behind the vehicle, while the pixels of the matrix display can be activated to superimpose alpha-numeric characters on the images. The characters can represent vehicle speed, time, radio station data, or other vehicle control data.

Claims

1. A rear view mirror for a vehicle, comprising:

a liquid crystal display selectively presenting a display image on a reflective layer, such that the display image is superimposed on the reflective surface and includes at least one alpha numeric character, the liquid crystal display includes pixels and defines an off state, in which the pixels are deenergized and transparent, the liquid crystal display also defining an on state, wherein at least some of the pixels are energized and the energized pixels are translucent;

a first transparent layer juxtaposed with the liquid crystal display rearward of the liquid crystal display;

a first inefficient polarizing layer juxtaposed with the first transparent layer rearward of the first transparent layer;

a second transparent layer juxtaposed with the liquid crystal display frontward of the liquid crystal display, the second layer holding the reflective layer; and

a second inefficient polarizing layer located between the second transparent layer and the liquid crystal display, the second inefficient polarizing layer rendering the altered light translucent.

2. A method for presenting data in a vehicle, comprising the steps of:

providing a reflective mirror;

orienting the mirror such that images of objects behind the vehicle appear in the mirror;

providing a display in the mirror such that the display is co-extensive with the mirror, the display having a liquid crystal display selectively presenting a display image on a mirror, the display having a first inefficient polarizing layer rearward of the liquid crystal display, and the display having a second inefficient polarizing layer located frontward of the liquid crystal display, the second inefficient polarizing layer rendering light translucent; and

selectively energizing the liquid crystal display to selectively superimpose alpha-numeric data on the images.