WO2013058203A1 - Illumination device and display device provided therewith - Google Patents

Abstract

Provided is an illumination device that can be reduced in thickness while minimizing unevenness in the brightness of an illuminated member. This illumination device (10) is provided with the following: a plurality of light-emitting elements (11); diffusing lenses (13) that are disposed so as to cover the light-emitting elements and diffusely transmit light therefrom; and a diffuser plate (14) that is disposed so as to cover the light-emitting elements and diffusing lenses and diffusely transmits light from the diffusing lenses towards a display panel (2). The diffusing lenses are in contact with the diffuser plate.

Description

LIGHTING DEVICE AND DISPLAY DEVICE HAVING THE SAME

The present invention relates to a lighting device and a display device including the same, and more particularly to a lighting device including a plurality of light emitting elements and a display device including the same.

Since the display panel (illuminated member) is a non-light emitting type liquid crystal display device (display device), a backlight device (illumination device) that irradiates light to the display panel is usually mounted. As such a backlight device, a backlight device including a plurality of LEDs (light emitting elements) is known.

FIG. 7 is a cross-sectional view showing an example of the structure of a conventional display device having a plurality of light emitting elements. As illustrated in FIG. 7, the display device 1001 includes a liquid crystal panel (illuminated member) 1002 and a backlight device (illumination device) 1010 that illuminates the liquid crystal panel 1002. The backlight device 1010 includes a plurality of LEDs (light emitting elements) 1011, a mounting substrate 1012 on which the plurality of LEDs 1011 are mounted, a diffusion plate 1013 disposed so as to cover the LEDs 1011 and the mounting substrate 1012, and a diffusion plate 1013. A plurality of optical sheets 1014 to be arranged and a chassis 1015 for housing the LEDs 1011 and the mounting substrate 1012 are included.

The diffusion plate 1013 is disposed at a predetermined distance from the LED 1011. The back surface (the lower surface in FIG. 7) of the diffusion plate 1013 is supported by a plurality of support pins 1016. Further, the plurality of support pins 1016 suppresses the diffusion plate 1013 from being bent.

By the way, since the light emitted from the LED has high directivity, uneven brightness tends to occur in the liquid crystal panel. In the conventional display device 1001, unevenness in luminance of the liquid crystal panel 1002 is suppressed to some extent by providing a diffusion plate 1013 that diffuses light from the LED 1011 and transmits it to the liquid crystal panel 1002 side. In addition, when the distance from the LED 1011 to the diffusion plate 1013 is short, luminance unevenness is likely to occur in the liquid crystal panel 1002. For this reason, in the conventional display device 1001, unevenness in luminance of the liquid crystal panel 1002 is suppressed by ensuring a sufficient distance from the LED 1011 to the diffusion plate 1013.

In addition, the illuminating device of the above structures is disclosed by patent document 1, for example.

JP 2010-155853 A

In the conventional display device 1001, in order to suppress luminance unevenness of the liquid crystal panel 1002, it is necessary to secure a sufficient distance from the LED 1011 to the diffusion plate 1013. For this reason, there is a problem that it is difficult to make the backlight device 1010 thinner.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lighting device that can be thinned while suppressing unevenness in luminance of a member to be illuminated, and the same. It is to provide a display device.

In order to achieve the above object, an illumination device according to the present invention is an illumination device that illuminates a member to be illuminated, and is disposed so as to cover a plurality of light emitting elements and the light emitting elements, and diffuses light from the light emitting elements. A diffusing lens that is transmitted so as to cover the light emitting element and the diffusing lens, and a diffusing plate that diffuses light from the diffusing lens and transmits the light to the illuminated member side. The diffusing lens is in contact with the back surface of the diffusing plate. The diffusing lens is in contact with the back surface of the diffusing plate.

In this illumination device, as described above, the diffusion lens that diffuses and transmits the light from the light emitting element, and the diffusion plate that diffuses the light from the diffusion lens and transmits it to the illuminated member side are provided. As a result, the light emitted from the light emitting element can be sufficiently diffused, so that even when the diffuser plate is brought close to contact with the diffusing lens, the occurrence of uneven brightness in the illuminated member is sufficiently suppressed. can do.

Also, as described above, the diffusion lens is in contact with the diffusion plate. Thereby, since the distance from a light emitting element to a diffusion plate can be made small, an illuminating device can be reduced in thickness.

Further, as described above, since the diffusion lens is in contact with the diffusion plate, the diffusion plate can be supported by the diffusion lens. Thereby, since the support pin for supporting a diffusion plate can be eliminated, the number of parts can be reduced. Moreover, since it is possible to prevent the occurrence of luminance unevenness due to the support pins, it is possible to further suppress the occurrence of luminance unevenness in the illuminated member.

In the illumination device, preferably, a plurality of printing dots for diffusing light are provided on the front surface or the back surface of the diffusion plate. If comprised in this way, since light can be more fully diffused with a printing dot, it can suppress more fully that a brightness nonuniformity generate | occur | produces in a to-be-illuminated member.

In the illuminating device in which the printed dots are provided on the front surface or the back surface of the diffusion plate, preferably, the print dot formation density in the region on the light emitting element is the print dot formation density in the upper region between the light emitting elements. Higher than. If comprised in this way, since the light on the light emitting element which is the strongest light will be most diffused by a printing dot, the light radiate | emitted from the light emitting element can be diffused effectively.

In the illuminating device in which printing dots are provided on the front surface or the back surface of the diffusion plate, the printing dots may be directly formed on the surface of the diffusion plate.

The lighting device in which printing dots are provided on the front surface or the back surface of the diffusion plate may include a sheet member on which printing dots are formed, and the sheet member may be attached to the diffusion plate.

In the illumination device in which the printing dots are provided on the front surface or the back surface of the diffusion plate, the printing dots are preferably provided on the front surface of the diffusion plate. If comprised in this way, it can prevent that a printing dot contacts a diffuser lens and is damaged.

The illumination device preferably further includes a mounting substrate on which the light emitting element is mounted, and the diffusion lens is attached to the mounting substrate. If comprised in this way, a diffuser lens can be accurately positioned with respect to a light emitting element.

The display device of the present invention includes the illumination device having the above-described configuration and a display panel illuminated by the illumination device. If comprised in this way, the display apparatus which can be reduced in thickness can be obtained, suppressing the brightness nonuniformity of a display panel (illuminated member).

As described above, according to the present invention, it is possible to easily obtain an illuminating device that can be thinned and a display device including the illuminating device while suppressing luminance unevenness of a member to be illuminated.

It is sectional drawing which showed the structure of the display apparatus of 1st Embodiment of this invention. It is the top view which showed the light emitting element, mounting board | substrate, diffusion lens, and chassis of 1st Embodiment of this invention shown in FIG. It is the expanded sectional view which showed the state by which the printing dot was formed in the surface of the diffusion plate of 2nd Embodiment of this invention. It is the expanded sectional view which showed the state which affixed the sheet | seat member in which the printing dot was formed on the surface of the diffusion plate of 2nd Embodiment of this invention. It is the top view which showed the structure of the diffusion plate of 2nd Embodiment of this invention, and a printing dot. It is the top view which showed the light emitting element of the 3rd Embodiment of this invention, a mounting substrate, a diffusion lens, and a chassis. It is sectional drawing which showed the structure of an example of the conventional display apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In order to facilitate understanding, even a cross-sectional view may not be hatched.

(First embodiment)
With reference to FIG. 1 and FIG. 2, the structure of the display apparatus 1 by 1st Embodiment of this invention is demonstrated.

The display device 1 according to the first embodiment of the present invention is used in, for example, a television receiver. As shown in FIG. 1, the display device 1 includes a display panel 2 (illuminated member) and a lighting device 10 that is disposed on the back side of the display panel 2 and illuminates the display panel 2. Note that the “back side (lower side in FIG. 1)” of the “back side of the display panel 2” is an orientation concept that is also applied to other components.

The display panel 2 is composed of a liquid crystal display panel, and has two glass substrates that sandwich a liquid crystal layer (not shown). The display panel 2 displays an image by being illuminated by the illumination device 10.

The lighting device 10 is a direct type backlight device. In addition, the lighting device 10 includes a plurality of light emitting elements 11, a plurality of mounting substrates 12 on which the light emitting elements 11 are mounted, and a plurality of light emitting elements 11 disposed so as to cover the light emission side (upper side in FIG. 1). A diffusion lens 13, a diffusion plate 14 disposed so as to cover the light emitting element 11 and the diffusion lens 13, a plurality of optical sheets 15 disposed on the front surface (surface on the display panel 2 side) 14a of the diffusion plate 14, A metal chassis 16 that houses the light emitting element 11 and the mounting substrate 12 is included.

As shown in FIG. 2, the plurality of light emitting elements 11 are mounted on the mounting substrate 12 in rows (one row in this embodiment) at an equal pitch. The light emitting element 11 is composed of an LED, for example, and emits white light.

The mounting substrate 12 is disposed on the bottom surface portion 16 a of the chassis 16. A plurality of the mounting boards 12 are arranged in the longitudinal direction and the lateral direction of the chassis 16. Thus, the plurality of light emitting elements 11 are arranged in a matrix in the chassis 16. The plurality of light emitting elements 11 are arranged at an equal pitch in the longitudinal direction of the chassis 16 and are arranged at an equal pitch in the short direction of the chassis 16.

The diffusion lens 13 is formed of a light transmitting material (for example, resin or glass), and has a function of diffusing light from the light emitting element 11 and transmitting it to the display panel 2 side. The diffusion lens 13 is disposed so as to cover the light emitting element 11, and one diffusion lens 13 is provided for each light emitting element 11. The diffusion lens 13 is attached to a predetermined position of the mounting substrate 12 via an adhesive layer (not shown). The diffusion lens 13 is provided with an engaging portion (not shown) and the mounting substrate 12 is provided with, for example, a through hole (not shown), and the engaging portion is engaged with the through hole so that the diffusion lens 13 is mounted on the mounting substrate. 12 may be attached.

Although the figure shows an example in which the diffusing lens 13 is formed in a hemispherical shape, the diffusing lens 13 may be formed in another shape such as a combination of a convex shape and a concave shape. One diffusing lens 13 may be provided for the plurality of light emitting elements 11.

As shown in FIG. 1, the diffusion plate 14 is made of a resin plate-like member, and closes the opening of the chassis 16 on the display panel 2 side. That is, the diffusion plate 14 is disposed so as to cover the light emitting element 11 and the diffusion lens 13. The diffusion plate 14 has a function of diffusing light from the diffusion lens 13 and transmitting it to the display panel 2 side.

Here, the back surface (surface opposite to the display panel 2) 14b of the diffusion plate 14 is in contact with the plurality of diffusion lenses 13. That is, the diffusion plate 14 is pressed against the plurality of diffusion lenses 13 with a predetermined pressing force by the plurality of optical sheets 15, the display panel 2, and other members. The plurality of diffusion lenses 13 are in contact with the back surface 14 b of the diffusion plate 14 to support the diffusion plate 14, and the mounting substrate 12 is in close contact with the chassis 16. In the figure, the diffusion plate 14 and the plurality of optical sheets 15 are placed on the side wall portion 16b of the chassis 16, but the diffusion plate 14 and the plurality of optical sheets 15 are formed smaller than the chassis 16 to form the chassis 16. It may be stored inside.

The plurality of optical sheets 15 are made of a resin sheet-like member thinner than the diffusion plate 14 and are arranged on the display panel 2 side of the diffusion plate 14. The optical sheet 15 diffuses or collects light transmitted through the diffusion plate 14. Note that the type of the optical sheet 15 to be used can be changed according to the application.

In the present embodiment, as described above, the diffusion lens 13 that diffuses and transmits the light from the light emitting element 11 and the diffusion plate 14 that diffuses the light from the diffusion lens 13 and transmits it to the display panel 2 side are provided. . Thereby, since the light emitted from the light emitting element 11 can be sufficiently diffused, even if the diffusion plate 14 is brought close to contact with the diffusion lens 13, the occurrence of uneven brightness in the display panel 2 is sufficiently suppressed. be able to.

Further, as described above, the diffusion lens 13 is in contact with the diffusion plate 14. Thereby, since the distance from the light emitting element 11 to the diffusion plate 14 can be made small, the illuminating device 10 can be reduced in thickness.

Further, as described above, since the diffusion lens 13 is in contact with the diffusion plate 14, the diffusion plate 14 can be supported by the diffusion lens 13. Thereby, since the support pin for supporting the diffusion plate 14 can be eliminated, the number of parts can be reduced. Further, since the occurrence of uneven brightness due to the support pins can be prevented, the occurrence of uneven brightness in the display panel 2 can be further suppressed. In addition, since the diffusion plate 14 can be supported at more points (support points) than when the support pins are provided, the deflection of the diffusion plate 14 and the optical sheet 15 can be further suppressed. Thereby, display quality (luminance uniformity, light condensing characteristics, etc.) can be improved.

Also, by pressing the diffusion plate 14 against the diffusion lens 13, the adhesion between the mounting substrate 12 and the chassis 16 can be improved. Thereby, since the heat generated in the light emitting element 11 can be efficiently transmitted to the chassis 16 via the mounting substrate 12, the heat dissipation of the lighting device 10 can be improved.

Further, as described above, the diffusion lens 13 is attached to the mounting substrate 12. Thereby, the diffusion lens 13 can be accurately positioned with respect to the light emitting element 11.

(Second Embodiment)
In the display device 1 according to the second embodiment of the present invention, as shown in FIG. 3, a plurality of printing dots 17 are provided on the front surface 14 a of the diffusion plate 14. The printing dots 17 are directly formed on the front surface 14a of the diffusion plate 14 using a printing method. The printing dots 17 are formed of, for example, white ink and have a function of reflecting and diffusing light. As shown in FIG. 4, a sheet member 18 on which printing dots 17 are formed may be attached to the diffusion plate 14.

As shown in FIG. 5, the formation density of the printing dots 17 in the region S1 on the light emitting element 11 is higher than the formation density of the printing dots 17 in the other regions (the region S2 above between the light emitting elements 11). For this reason, the light on the light emitting element 11 is most diffused.

In FIG. 5, the formation density of the printing dots 17 in the region S1 is increased by making the arrangement pitch of the printing dots 17 in the region S1 smaller than the arrangement pitch of the printing dots 17 in the region S2. Although not shown, the formation density of the printing dots 17 in the region S1 may be increased by making the diameter (outer shape) of the printing dots 17 in the region S1 larger than the diameter (outer shape) of the printing dots 17 in the region S2.

Other structures of the second embodiment are the same as those of the first embodiment.

In the present embodiment, as described above, the surface of the diffusion plate 14 (front surface 14a) is provided with a plurality of printing dots 17 that diffuse light. As a result, the light can be more sufficiently diffused by the printing dots 17, so that the occurrence of uneven brightness in the display panel 2 can be further sufficiently suppressed.

As described above, the formation density of the printing dots 17 in the region S1 on the light emitting element 11 is higher than the formation density of the printing dots 17 in the region S2 between the light emitting elements 11. Thereby, since the light on the light emitting element 11 which is the strongest light is most diffused by the printing dots 17, the light emitted from the light emitting element 11 can be effectively diffused.

Further, as described above, the printing dots 17 are provided on the front surface 14 a of the diffusion plate 14. Thereby, it is possible to prevent the printed dots 17 from coming into contact with the diffusing lens 13 and being damaged.

Other effects of the second embodiment are the same as those of the first embodiment.

(Third embodiment)
In the display device 1 according to the third embodiment of the present invention, as shown in FIG. 6, unlike the first embodiment, the light emitting elements 11 are mounted on the mounting substrate 12 in three rows. That is, the light emitting elements 11 are arranged in a matrix on the mounting substrate 12.

In FIG. 6, a plurality of (6) mounting substrates 12 are provided, but only one mounting substrate 12 is provided in one display device 1, and all the light emitting elements 11 are mounted on the mounting substrate 12. Also good.

Other structures and effects of the third embodiment are the same as those of the first and second embodiments.

In addition, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims, and further includes meanings equivalent to the scope of claims and all modifications within the scope.

For example, in the above-described embodiment, an example in which the display panel is applied to a liquid crystal display panel has been described. However, the present invention is not limited thereto, and may be applied to a display panel other than the liquid crystal display panel.

Moreover, in the said embodiment, although the backlight apparatus which illuminates a display panel was demonstrated as an example of an illuminating device, this invention is applicable not only to this but the illuminating device which illuminates to-be-illuminated members other than a display panel. is there.

In the second embodiment, an example in which printing dots (or a sheet member on which printing dots are formed) is provided on the front surface of the diffusion plate has been described. However, the present invention is not limited to this, and printing dots (or printing dots) are provided. May be provided on the back surface of the diffusion plate.

In the above embodiment, an example in which the diffusion lens is attached to the mounting substrate has been described. However, the present invention is not limited thereto, and the diffusion lens may be attached to the light emitting element or the chassis.

In the above embodiment, the description has been made by omitting the reflective sheet that is normally disposed inside the chassis, but it is preferable to provide the reflective sheet inside the chassis. In this case, an opening may be formed in a portion corresponding to the diffusion lens in the reflection sheet, and the reflection sheet may be disposed on the mounting substrate. If comprised in this way, the utilization efficiency of light can be improved easily.

Further, a configuration obtained by appropriately combining the configurations of the above-described embodiments is also included in the technical scope of the present invention.

1 Display device 2 Display panel (illuminated member)
DESCRIPTION OF SYMBOLS 10 Illuminating device 11 Light emitting element 12 Mounting board 13 Diffusing lens 14 Diffusing plate 14a Front surface 14b Back surface 17 Print dot 18 Sheet | seat member S1 area | region (area | region on a light emitting element)
S2 region (region above between light emitting elements)

Claims (8)

An illumination device for illuminating a member to be illuminated,
A plurality of light emitting elements;
A diffusing lens that is disposed so as to cover the light emitting element and diffuses and transmits light from the light emitting element;
A diffusing plate that is disposed so as to cover the light emitting element and the diffusing lens, diffuses light from the diffusing lens and transmits the light to the illuminated member side;
With
The diffusion plate has a front surface disposed on the illuminated member side and a back surface disposed on the opposite side of the illuminated member,
The diffusing lens is in contact with the back surface of the diffusing plate. The lighting device according to claim 1, wherein a plurality of printing dots for diffusing light are provided on the front surface or the back surface of the diffusion plate. 3. The illumination device according to claim 2, wherein a density of formation of the print dots in a region on the light emitting element is higher than a density of formation of the print dots in an upper region between the light emitting elements. The lighting device according to claim 2 or 3, wherein the printing dots are directly formed on a surface of the diffusion plate. A sheet member having the printed dots formed on the surface thereof;
The lighting device according to claim 2, wherein the sheet member is attached to the diffusion plate. 6. The illumination device according to claim 2, wherein the printing dots are provided on a front surface of the diffusion plate. A mounting substrate on which the light emitting element is mounted;
The lighting device according to any one of claims 1 to 6, wherein the diffusion lens is attached to the mounting substrate. The lighting device according to any one of claims 1 to 7,
A display device comprising a display panel illuminated by the illumination device.

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