Browse Prior Art Database

Prism Bulb for Fluorescent Lamp

IP.com Disclosure Number: IPCOM000117579D
Original Publication Date: 1996-Apr-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 75K

Publishing Venue

IBM

Related People

Momose, Y: AUTHOR [+3]

Abstract

Disclosed is a construction of light source for a backlight unit of Liquid Crystal Display (LCD). The main idea of this disclosure is to change the construction of the bulb of a fluorescent lamp from the one shown in Fig. 1 to the one shown in Fig. 2 to increase luminance / power efficiency of LCD module. Isosceles triangular sections should be added on the glass bulb. 1. The distributions of light intensity are changed by prism shape as shown in Fig. 3. The direction of light from the prism surface is shown in the next three patterns (Fig. 4). a. The light that does not reflect the adjacent prism surface goes within a-1 direction. b. Also the light reflected in the adjacent prism surface goes within b-1 direction. c.

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Prism Bulb for Fluorescent Lamp

      Disclosed is a construction of light source for a backlight
unit of Liquid Crystal Display (LCD).  The main idea of this
disclosure is to change the construction of the bulb of a fluorescent
lamp from the  one shown in Fig. 1 to the one shown in Fig. 2 to
increase luminance /  power efficiency of LCD module.  Isosceles
triangular sections should be  added on the glass bulb.
  1.  The distributions of light intensity are changed by prism shape
       as shown in Fig. 3.  The direction of light from the prism
       surface is shown in the next three patterns (Fig. 4).
      a.  The light that does not reflect the adjacent prism surface
           goes within a-1 direction.
      b.  Also the light reflected in the adjacent prism surface goes
           within b-1 direction.
      c.  The refractive index of bulb material is more than 1.5.  In
           this case, the light (c1) transmitted by the adjacent
prism
           surface does not transmit the next prism inner surface,
but
           reflects perfectly(c2).  The reflection loss is zero.  The
           light goes back to the phosphor plane to be defused and be
           reused (Fig. 5).
  By effect a. and b., the distribution of light intensity is
   changed - y is up.  And c. minimizes the loss.
  2.  When this lamp is used in a backlight unit of side light
...