Arrangement of heating strips of defogger on vehicle window glass

• US 6,137,085 A
• Filed: 11/30/1998
• Issued: 10/24/2000
• Est. Priority Date: 12/02/1997
• Status: Expired due to Fees

• Current Assignee: Central Glass Company Limited
• Original Assignee: Central Glass Company Limited
• Inventors: Matsumoto, Akihiko, Nagaiwa, Hiroshi, Nakashima, Hiroshi
• Primary Examiner(s): Hoang, Tu Ba
• Application Number:
  US09/201,887
• Time in Patent Office: 694 Days
• Field of Search: 219/200, 219/201, 219/202, 219/203, 219/212, 219/213, 219/217
• US Class Current: 219/203
• CPC Class Codes: H05B 2203/002 Heaters using a particular layout for the resistive material or resistive elements
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]

Abstract

A vehicle window glass assembly comprises a window glass and a plurality of parallel, electric heating strips disposed on the window glass. The distance between adjacent two of the heating strips at least at portions thereof disposed in a central region of the window glass being in the range of 20 to 28 mm so that a quantity of heat generated by the heating strips per unit area can be smaller, i.e., 0.80 to 0.95 times of a reference electric power or a supply power for the heating strips can be 0.80 to 0.95 times of a reference electric power. The reference electric power is a power necessary for causing a surface temperature of a comparable window glass with comparable heating s trips to rise up to 90% of an equilibrium temperature in the range of 35 to 45° C., in 5 to 10 minute'"'"'s time after energizing of the comparable heating strips starts, under the condition where the distance between adjacent two of the comparable heating strips at portions thereof disposed in a central region of the comparable window glass is in the range of 29 to 33 mm, a room temperature is 20° C., and windless.

Claims

1. In a vehicle window glass assembly including a window glass and a plurality of parallel, electric heating strips disposed on the window glass, wherein when the heating strips are supplied with a reference electric power a predetermined quantity of heat per unit area sufficient to raise the surface temperature of the window glass in a windless environment from a room temperature of 20°

C. up to 90% of an equilibrium temperature in the range of 35 to 45°

C. is generated in 5 to 10 minutes after supply of the reference electric power to the heating strips starts where the distance between adjacent two of the heating strips at portions thereof disposed in a central region of the window glass is in the range of 29 to 33 mm, the improvement wherein the distance between adjacent two of said heating strips at least at portions thereof disposed in a central region of said window glass is modified to from 20 to 28 mm, and the resistance of said heating strips is modified so that an application of said reference electric power to said heating strips generates a reduced quantity of heat per unit area necessary for defogging and therefore to reduce a consumption of electric power which ranges from 0.80 to 0.95 times said predetermined quantity of heat per unit area at said central region.