JP2006276761A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which has a direct down type back light, can irradiates the back of a liquid crystal display panel uniformly with the light from the back light, and generates no luminance unevenness in display on the liquid crystal display panel. <P>SOLUTION: A light diffusion lens 3 which diffuses lights is provided between light emission bodies 4, 4, and 4 of the back light and the liquid crystal display panel 1, and lights emitted by the light emission bodies 4, 4, and 4 are diffused by the light diffusion lens 3 to uniformly irradiate the back of the liquid crystal display panel 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device including a transmissive liquid crystal display panel that transmits light emitted from a light emitter of a direct type backlight and displays characters or images.

  In an electric device such as a video deck or a DVD player, a liquid crystal display unit is provided on the front surface of the housing in order to inform the user of the operation status of the device, and characters or images can be displayed on the liquid crystal display unit. . Furthermore, in recent years, display devices using larger liquid crystals such as a liquid crystal display of a notebook personal computer or a liquid crystal television have become widespread.

  A liquid crystal display device includes a reflective type that displays light by reflecting light from the outside, and a transmissive type that includes a light source such as an LED or a lamp inside and transmits light from the light source for display. There is a transflective type having both functions of a reflective type and a transmissive type. The transmissive liquid crystal display device needs to have a light source inside as a backlight, but there is an advantage that the luminance of the display portion can be set appropriately by selecting the light source according to the use application of the device. .

  In addition, the backlight used in the transmissive liquid crystal display device has an edge type that places a light source on the side surface of a light guide plate arranged on the back surface of the liquid crystal display panel, and a light source that is arranged directly under the liquid crystal display panel. There is a direct type. The edge type has the advantage that the liquid crystal display device can be reduced in size, and the direct type has the advantage that the display brightness of the liquid crystal display panel can be increased.

A conventional transmissive liquid crystal display device, for example, a liquid crystal display device described in Patent Document 1, is provided with a liquid crystal panel, a plurality of fluorescent tubes provided as light sources, and a fluorescent tube interposed between the fluorescent tubes. It is a structure provided with a reflecting plate, a diffusion plate disposed between the liquid crystal panel and the fluorescent tube, an optical sheet that performs polarization, and a housing that houses these. The light emitted from the fluorescent tube forming the direct type backlight is diffused by the diffusion plate and irradiated to the liquid crystal panel, passes through the liquid crystal panel, and characters or images are displayed on the liquid crystal panel.
JP-A-2005-17414

  However, in the liquid crystal display device described in Patent Document 1, light emitted from a fluorescent tube is diffused by a diffusion plate and irradiated to the liquid crystal panel. The diffusion plate is a thin sheet of acrylic or polycarbonate. Therefore, the light diffusion efficiency is not high, and there is a difference in the amount of light that passes through the liquid crystal panel between the part that is far from the fluorescent tube and the part that is far from the fluorescent tube. There is a problem that occurs. When such luminance unevenness occurs, the visibility of characters or images displayed on the liquid crystal panel may be reduced.

  The present invention has been made in view of such circumstances, and the object of the present invention is to dispose a lens that diffuses light between a light emitter of a direct backlight and a liquid crystal display panel, An object of the present invention is to provide a liquid crystal display device capable of diffusing light emitted from a light emitter and uniformly irradiating the liquid crystal display panel.

  Another object of the present invention is to increase the luminance of the liquid crystal display panel by providing a plurality of light emitters and light diffusing lenses, and to add several light emitters for each light diffusing lens. When arranged in correspondence, the number of mounted lenses can be reduced, and when one light emitter is arranged corresponding to each light diffusion lens, light from the light emitter can be diffused efficiently. The object is to provide a liquid crystal display device.

  Another object of the present invention is to provide a liquid crystal display device capable of diffusing light from a light emitter by realizing a light diffusing lens with a concave lens.

  Another object of the present invention is to increase the luminance of the liquid crystal display panel by providing a plurality of light emitters, and to assemble the light diffusion lens by integrally including a plurality of lens portions. The present invention provides a liquid crystal display device that can simplify the process, and can efficiently diffuse light from the light emitter when one light emitter is arranged corresponding to each lens unit. is there.

  Another object of the present invention is to provide a liquid crystal display device capable of diffusing light from a light emitter by forming a lens portion of a light diffusing lens into a concave lens shape.

  Another object of the present invention is to provide a liquid crystal display device in which the number of components can be reduced by integrally forming a light diffusing lens portion in a covering portion that covers a light source of a light emitter. There is.

  The liquid crystal display device according to the present invention includes a liquid crystal display panel and a light emitter that is disposed on the back side of the display surface of the liquid crystal display panel and causes light to enter the liquid crystal display panel. A light diffusing lens for diffusing light emitted from the light emitter and irradiating the liquid crystal display panel is provided between the panel and the light emitter.

  In the present invention, a light diffusion lens for diffusing light is provided between the light emitter and the liquid crystal display panel, and the light diffuser lens diffuses the light emitted from the light emitter and uniformly irradiates the back surface of the liquid crystal display panel. Thereby, the luminance of the liquid crystal display panel becomes uniform.

  In addition, the liquid crystal display device according to the present invention includes a plurality of the light emitters and the light diffusion lenses, and the light emitters and the light diffusion lenses correspond to one or a plurality of the light emitters for each light diffusion lens. It is characterized by being arranged.

  In the present invention, a plurality of light emitters and light diffusion lenses are provided to further increase the luminance of the liquid crystal display panel. In particular, when several light emitters are arranged corresponding to each light diffusion lens, the number of light diffusion lenses is reduced, and one light emitter is made to correspond to each light diffusion lens. Can be diffused efficiently.

  The liquid crystal display device according to the present invention is characterized in that the light diffusion lens is a concave lens.

  In the present invention, the light diffusing lens is realized by a concave lens, and the concave lens diffuses light from the light emitter and uniformly irradiates the back surface of the liquid crystal display panel.

  The liquid crystal display device according to the present invention includes a plurality of the light emitters, and the light diffusing lens includes a plurality of lens portions formed integrally with a translucent member. Or the said light-emitting body and the said light-diffusion lens are arranged corresponding to the said several light-emitting body, It is characterized by the above-mentioned.

  In the present invention, a plurality of light emitters are provided to increase the brightness of the liquid crystal display panel, and a plurality of lens portions are integrally formed to manufacture a light diffusion lens, and the light diffusion lens is incorporated into a liquid crystal display device. Simplify. In addition, when one light emitter is disposed corresponding to each lens unit, light from the light emitter can be diffused efficiently.

  The liquid crystal display device according to the present invention is characterized in that the lens portion has a concave lens shape.

  In the present invention, the lens portion of the light diffusing lens is formed in a concave lens shape, and the plurality of lens portions diffuse light from the light emitter and uniformly irradiate the back surface of the liquid crystal display panel.

  The liquid crystal display device according to the present invention is a liquid crystal display device comprising: a liquid crystal display panel; and a light emitter that is disposed on a rear surface side of the display surface of the liquid crystal display panel and makes light incident on the liquid crystal display panel. The luminous body includes a light source, a translucent covering portion that covers the light source, and a light diffusion lens portion formed on the covering portion.

  In the present invention, the light diffusing lens portion is integrally formed on the covering portion that covers the light emitting source of the light emitter. As a result, the light emitter efficiently diffuses light and uniformly irradiates light to the back surface of the liquid crystal display panel, so there is no need to separately provide a lens for diffusing light.

  In the case of the present invention, by arranging a lens that diffuses light between the light emitter of the backlight and the liquid crystal display panel, the light emitted from the light emitter can be diffused and uniformly irradiated to the liquid crystal display panel. Further, luminance unevenness does not occur in the display of the liquid crystal display panel, and the visibility of characters or images displayed on the liquid crystal display panel can be improved.

  Further, according to the present invention, since the luminance of the liquid crystal display panel can be increased by providing a plurality of light emitters and light diffusing lenses, luminance unevenness does not occur in the display of the liquid crystal display panel. Visibility of displayed characters or images can be improved. In addition, when several light emitters are arranged corresponding to each light diffusion lens, the number of lenses can be reduced, so that the cost can be reduced, and one light emitter is provided for each light diffusion lens. Since the light from the light emitter can be diffused more efficiently, the visibility can be further improved.

  Further, in the case of the present invention, since the light from the light emitter can be diffused by realizing the light diffusing lens with a concave lens, luminance unevenness does not occur on the display of the liquid crystal display panel, and the characters displayed on the liquid crystal display panel are displayed. Or visibility of an image etc. can be improved.

  Further, in the case of the present invention, by providing a plurality of light emitters, the brightness of the liquid crystal display panel can be increased, and the light diffusion lens integrally includes a plurality of lens portions, so that the light diffusion lens in the manufacturing process can be integrated. Since the integration can be simplified, the manufacturing cost can be reduced. In addition, when one light emitter is arranged corresponding to each lens unit, the light from the light emitter can be efficiently diffused, so that luminance unevenness does not occur in the display of the liquid crystal display panel. The visibility of characters or images displayed on the display panel can be improved.

  In addition, according to the present invention, since the light from the light emitter can be diffused by forming the lens portion of the light diffusing lens into a concave lens shape, luminance unevenness does not occur in the display of the liquid crystal display panel, and the display is performed on the liquid crystal display panel. Visibility of printed characters or images can be improved.

  Further, according to the present invention, the light diffusing lens portion is integrally formed on the covering portion that covers the light source of the light emitter, so that the light emitter efficiently diffuses light and the light is uniformly distributed to the back surface of the liquid crystal display panel. Therefore, luminance unevenness does not occur in the display of the liquid crystal display panel, and the visibility of characters or images displayed on the liquid crystal display panel can be improved. Further, since it is not necessary to provide a lens for diffusing light separately, the number of parts can be reduced, and the cost can be reduced.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
(Embodiment 1)
FIG. 1 is a cross-sectional view showing the configuration of the liquid crystal display device according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view showing the configuration of the liquid crystal display device according to Embodiment 1 of the present invention. . In the figure, reference numeral 1 denotes a liquid crystal display panel. The liquid crystal display panel 1 is a publicly known one that performs display by controlling the light transmittance using the birefringence of a liquid crystal layer that can be controlled by an external electric field. is there.

  The liquid crystal display panel 1 has a substantially rectangular plate shape, and a display surface for displaying an image is provided on the surface. A diffusion sheet 2 for diffusing light incident from the back surface into the liquid crystal display panel 1 is attached to the back surface of the liquid crystal display panel 1. The holder 6 that supports the liquid crystal display panel 1 is a cylindrical body having a rectangular opening at one end that is substantially the same size as the liquid crystal display panel 1, and a step-like panel locking portion 6 a is formed on the inner periphery of the one end. The liquid crystal display panel 1 and the diffusion sheet 2 are fixed by being fitted to the panel locking portion 6a with the display surface of the liquid crystal display panel 1 facing outside.

  The opening on the other end side of the holder 6 has an opening area smaller than that on one end side, and the diameter of the holder 6 is tapered from the substantially center in the axial direction to the other end side. On the other end side of the holder 6, a substantially rectangular substrate 5 is fixed so as to cover and close the opening on the other end side of the holder 6. Three white LEDs 4, 4, 4 are juxtaposed in the longitudinal direction of the substrate 5.

  Near the center of the holder 6 in the axial direction, there is provided a light diffusing lens 3 in which three concave lens portions 3a, 3a, 3a are arranged in a longitudinal direction on a substantially rectangular translucent plate. The light diffusing lens 3 protrudes substantially at the center of the inner peripheral surface of the holder 6, and is fixed to a lens locking portion 6 b that contacts the peripheral edge of the light diffusing lens 3. The concave lens portions 3a, 3a, and 3a are biconcave lenses in which both front and back surfaces of a translucent plate are formed in a concave shape. The three concave lens portions 3a, 3a, 3a are respectively opposed to the three white LEDs 4, 4, 4 arranged on the substrate 5, and the white LEDs 4, 4, 4 are aligned with the optical axes of the concave lens portions 3a, 3a, 3a. It is. Further, when the concave lens portions 3 a, 3 a, and 3 a of the light diffusing lens 3 diffuse and emit the light emitted from the white LEDs 4, 4, 4 to the back surface of the liquid crystal display panel 1, the diffused light is emitted from the liquid crystal display panel 1 The distance between the liquid crystal display panel 1 and the light diffusing lens 3 and the distance between the light diffusing lens 3 and the substrate 5 having the white LEDs 4, 4, and 4 are set to appropriate distances so that the back surface is uniformly irradiated.

  In the liquid crystal display device having the above configuration, light emitted from the three LEDs 4, 4, 4 disposed on the substrate 5 is diffused by the three concave lens portions 3 a, 3 a, 3 a of the light diffusion lens 3. Since the light diffused by the light diffusing lens 3 is uniformly applied to the back surface of the liquid crystal display panel 1, the amount of light transmitted through the liquid crystal display panel 1 can be made uniform, and the display surface of the liquid crystal display panel 1 can be made uniform. In this case, luminance unevenness does not occur.

  In the first embodiment, the concave lens portions 3a, 3a, and 3a are configured as biconcave lenses, but may be single-concave lenses. In addition, a convex lens may be used instead of the concave lens for light diffusion. In addition, the light diffusion lens 3 has a configuration in which three concave lens portions 3a, 3a, and 3a are respectively formed on a translucent plate. However, the present invention is not limited thereto, and the concave surface is integrally concave in the longitudinal direction like a cylindrical lens. You may use the lens which formed. Further, the white light emitting diodes 4, 4, 4 may be either LED lamps or chip LEDs, and other white light sources without using LEDs as light emitting bodies. May be used. Moreover, although it was set as the structure which provides 3 each of the concave lens parts 3a, 3a, 3a and white LED 4, 4, 4, it is not restricted to this, The structure which provides 2 or less or 4 or more may be sufficient, The concave lens portions 3a, 3a, 3a and the white LEDs 4, 4, 4 may not be the same number. Moreover, although the configuration in which the concave lens portions 3a, 3a, and 3a and the white LEDs 4, 4, and 4 are arranged in a line in the longitudinal direction is shown, the present invention is not limited to this and may be provided in other arrangements such as a staggered arrangement. Further, the LED of the light emitter need not be white.

(Embodiment 2)
FIG. 3 is a cross-sectional view showing the configuration of the liquid crystal display device according to Embodiment 2 of the present invention. The liquid crystal display device according to the second embodiment has substantially the same configuration as the liquid crystal display device according to the first embodiment, but the configuration of the light diffusion lens is changed.

  In FIG. 3, reference numeral 13 denotes a light diffusing lens, in which both front and back surfaces of a translucent plate are formed in a concave shape to form one concave lens. Three light diffusion lenses 13, 13, 13 are juxtaposed in the longitudinal direction on a lens locking portion 6 b provided at a substantially central portion in the axial direction in the holder 6. The three light diffusion lenses 13, 13, 13 are respectively opposite to the three white LEDs 4, 4, 4 arranged on the substrate 5, and the white LEDs 4, 4, 4 coincide with the optical axis of the light diffusion lenses 13, 13, 13. I have to do it.

  In the case of a configuration in which a plurality of concave lenses are not integrally formed but are formed separately and arranged in parallel, the same effect as the liquid crystal display device of Embodiment 1 can be obtained. In this case, since a liquid crystal display device can be configured using a general-purpose light diffusion lens without manufacturing a dedicated light diffusion lens, the development cost can be reduced.

  Since the other configuration of the liquid crystal display device according to the second embodiment is the same as that of the liquid crystal display device according to the first embodiment, the corresponding portions are denoted by the same reference numerals and detailed description thereof is omitted. To do.

(Embodiment 3)
FIG. 4 is a cross-sectional view showing the configuration of the liquid crystal display device according to Embodiment 3 of the present invention. In the liquid crystal display device according to the third embodiment, the light diffusion lens is not provided at the center of the holder 6 but is provided integrally with the white LED that forms the backlight.

  In FIG. 4, reference numeral 14 denotes a white LED, and the white LED 14 includes a light source 14 a that emits light and a translucent covering portion 14 b that covers one surface side of the light source 14 a. On the surface of the covering portion 14b, a light diffusing lens portion 14c is provided by forming the covering portion 14b in a concave lens shape.

  Three white LEDs 14, 14, 14 are arranged in parallel in the longitudinal direction on the substrate 5. Further, when the light diffusing lens portions 14c, 14c, and 14c diffuse the light emitted from the light sources 14a, 14a, and 14a of the white LEDs 14, 14, and 14 and irradiate the back surface of the liquid crystal display panel 1, the diffused light is liquid crystal. The distance between the liquid crystal display panel 1 and the substrate 5 having the white LEDs 14, 14, 14 is set to an appropriate distance so that the back surface of the display panel 1 is uniformly irradiated.

  With the above configuration, the light emitted from the light sources 14a, 14a, and 14a is diffused by the light diffusion lens portions 14c, 14c, and 14c, and uniformly irradiated on the back surface of the liquid crystal display panel 1. Thereby, the amount of light transmitted through the liquid crystal display panel 1 can be made uniform, and luminance unevenness does not occur on the display surface of the liquid crystal display panel 1.

  In addition, since the other structure of the liquid crystal display device which concerns on Embodiment 3 is the same as that of the liquid crystal display device which concerns on Embodiment 1, the same code | symbol is attached | subjected to the same location and detailed description is abbreviate | omitted. To do.

It is sectional drawing which shows the structure of the liquid crystal display device which concerns on Embodiment 1 of this invention. It is a disassembled perspective view which shows the structure of the liquid crystal display device which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the structure of the liquid crystal display device which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the structure of the liquid crystal display device which concerns on Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 3, 13 Light diffusion lens 3a Concave lens part (lens part)
4, 14 White LED (light emitter)
14a Light source 14b Covering part 14c Light diffusion lens part

Claims (6)

In a liquid crystal display device comprising: a liquid crystal display panel; and a light emitter that is disposed on the back side of the display surface of the liquid crystal display panel and causes light to enter the liquid crystal display panel.
A liquid crystal display device comprising a light diffusing lens for diffusing light emitted from the light emitter and irradiating the liquid crystal display panel between the liquid crystal display panel and the light emitter. A plurality of the light emitters and the light diffusion lenses are provided,
The liquid crystal display device according to claim 1, wherein the light emitter and the light diffusion lens are arranged in correspondence with one or a plurality of the light emitters for each of the light diffusion lenses.   The liquid crystal display device according to claim 1, wherein the light diffusion lens is a concave lens. A plurality of the light emitters,
The light diffusing lens has a plurality of lens portions formed integrally with a translucent member,
The liquid crystal display device according to claim 1, wherein the light emitter and the light diffusing lens are arranged in correspondence with one or a plurality of the light emitters for each lens unit.   The liquid crystal display device according to claim 4, wherein the lens portion has a concave lens shape. In a liquid crystal display device comprising: a liquid crystal display panel; and a light emitter that is disposed on the back side of the display surface of the liquid crystal display panel and causes light to enter the liquid crystal display panel.
The light-emitting body includes a light source, a translucent covering portion that covers the light source, and a light diffusion lens portion formed on the covering portion.

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