JPS6391629A - Converging lighting device for back light of liquid crystal display panel - Google Patents

Abstract

PURPOSE:To improve the brightness of lighting by providing a condenser lens for converting external light, a convergence part which reflects the converged external light and guides it in one direction, an optical fiber which guides the converged external light to an optional position, and a back light house which is provided atop of the optical fiber and illuminates a liquid crystal display panel. CONSTITUTION:The convergence part is constituted by arraying a light guide plate 1 which has condenser lenses formed of glass or plastic on a surface where light is collected and also have external light incidence surface formed on its back surface in such a direction that they contact condenser lens surfaces. The projection surface 11 of the light guide plate is worked 2a in a lens shape and projection light is converged on the end surface 6b of the optical fiber 6, guides to the back light house 9 through the optical fiber 6, and made into plane light 8, which illuminate the liquid crystal display panel 7 from the back surface. Consequently, a light converging device is arranged at an optional position and the converged external light is utilized to improve the surface brightness of the liquid crystal display panel.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a backlight illumination device for a liquid crystal display panel, and in particular, by condensing and guiding external light, the condensing device can be placed at any position. The present invention also relates to a condensing lighting device for a backlight of a liquid crystal display panel that improves illumination brightness.

(Prior art) Liquid crystals change their transparency depending on the voltage applied to their electrodes and display characters, figures, etc. However, liquid crystals do not emit light by themselves, but instead use the reflection or transmission of external light. ing. Therefore, it cannot be displayed in a place without external light.
Requires illumination light for display.

The backlight method uses external light from the back to illuminate the liquid crystal display panel.

Conventionally, when using external light as a backlight light source, a method has been used in which the external light is used directly or the external light is made incident on the back surface of a liquid crystal display panel through a reflector.

[Problem to be solved]

In the case of the conventional method, it is necessary to orient the back surface of the liquid crystal display panel or the surface of the reflector to the incident direction of external light, which limits the viewing direction of the liquid crystal display panel. Also,
Since light can only be brought in within the area of the liquid crystal display panel or the area of the reflector, the surface brightness of the liquid crystal display panel that is determined by this area can only be obtained, and the surface brightness cannot be improved.

Therefore, in this invention, a light condensing section is configured of a condenser lens for condensing external light, a light guide plate that reflects the condensed external light and guides it in one direction, and By providing an optical fiber that can be guided to any position and a backlight house installed at the tip of the optical fiber to illuminate the liquid crystal display panel, the light condensing section can be installed at any position unrelated to the liquid crystal display device. An object of the present invention is to provide a condensing lighting device for a backlight that can improve the illumination brightness of a liquid crystal display panel.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a backlight device for illuminating a liquid crystal display panel used in a liquid crystal display device from the back using external light. A light guide plate that forms a reflective surface to reflect and guide the focused external light in one direction, an optical fiber that guides the reflected light, and converts the light into surface emitting light to illuminate the liquid crystal display panel. A liquid crystal display panel that is configured with a backlight house, allows the condensing device to be placed at any position, and uses the concentrated external light to improve the surface brightness of the liquid crystal display panel. A condensing lighting device for backlighting was constructed.

[Effect]

The condenser illumination device for a backlight of a liquid crystal display panel of the present invention includes a condenser lens for condensing external light and a light guide plate that reflects the condensed external light and guides it in one direction. The light section is connected to the backlight house that illuminates the liquid crystal display panel by an optical fiber that guides the focused light, so by increasing the number of condensing lenses and increasing the area of the light guide plate, the light concentrating It is possible to increase the amount of external light and improve the illumination brightness of the liquid crystal display panel. Further, since the light condensing section and the liquid crystal display panel side are coupled by an optical fiber, efficient light condensation can be performed by moving the light condensing section to a free position with respect to the liquid crystal display panel side.

(Example) Embodiments of the invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a light condensing section in an embodiment of the present invention;
FIG. 2 is also an external perspective view of the condensing section.

The light condensing unit has a plurality of condensing lenses made of a material such as glass or plastic arranged on the surface from which light is to be collected as shown in the figure, and the outside light incident surface is arranged on the back side in the direction in which it touches the condensing lens surface. It is configured by disposing a formed light guide plate 1.

External light 4 is focused by a condenser lens 1 and enters a light guide plate 2 . The light incident on the light guide plate is reflected by a reflecting surface 3 formed equivalently within the light guide plate, and is output in the same direction (light collection 5), that is, to the output surface of the light guide plate.

FIG. 3 is an external perspective view of the light guide plate 2. FIG. The light guide plate is made of a material such as glass or plastic, and the surfaces other than the external light entrance surface 10 and the exit surface 11 are formed to form total reflection surfaces. Light incident from the external light entrance surface 10 is emitted only to the exit surface 11, and equivalently operates in the same way as if the reflecting surfaces 3 were arranged in the direction as shown in FIG. Moreover, the height of this reflective surface is very small compared to the height of the light guide plate, and there is no fear that the reflective surface located in front of the output surface will interfere with the reflected light from the rear reflective surface.

FIG. 4 is a block diagram of an embodiment of the present invention.

The light emitting surface 11 of the light guide plate is processed into a lens shape (2a), and the emitted light is focused on the end surface (6b) of the optical fiber 6 and guided to the backlight house 9 through the optical fiber 6.
The liquid crystal display panel 7 is illuminated from the back.

Like the light guide plate, this backlight house emits incident light from one direction only in the other direction.

Although this embodiment has been described using a cylindrical lens as the condensing lens 1, the shape is not limited to this, and for example, circular convex lenses may be arranged.

〔effect〕

As explained above, according to the present invention, the condensing section is constituted by the condensing lens and the light guide plate, so it can be made thin. In addition, since the liquid crystal display section and the light collecting section can be housed separately, the light collecting section can be installed in any location, and the viewing direction of the liquid crystal display section will not be set in the direction of incidence of external light. .

Furthermore, by increasing the area of the light condensing section, a high-brightness backlight source can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a light condensing section in an embodiment of the present invention;
FIG. 2 is an external perspective view of the condensing section, FIG. 3 is an external perspective view of the light guide plate, and FIG. 4 is an overall configuration diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Condenser lens, 2... Light guide plate, 3... Reflective surface, 4... External light, 5... Light condensing, 6... Optical fiber, 7... Liquid crystal display panel, 8... Surface light emitting surface, 9... Backlight house, 10... Light guide plate incident surface, 11... Light guide plate exit surface. Applicant: NEC Home Electronics Co., Ltd. Agent Masuji Benkazu 1) Takeo Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. A backlight device that illuminates a liquid crystal display panel used in a liquid crystal display device from the back using external light, comprising: a condensing lens that collects external light; and a reflective surface formed inside. A light guide plate that reflects the collected external light and guides it in one direction, an optical fiber that guides the reflected light, and a backlight house that converts the light into surface emitting light and illuminates the LCD panel. The light condensing device can be placed at any position, and the condensed external light can be used to
A condensing lighting device for a backlight of a liquid crystal display panel, which is characterized by improving the surface brightness of the liquid crystal display panel.