JPH08254618A - Edge light surface light source device - Google Patents

Abstract

PURPOSE: To prevent the degradation in luminance and to assure the uniformity of luminance by directing diffusion so as to supply the incident light from the effective light emitting part of a primary light source near to both ends of an incident end face where there is no supply of the incident light. CONSTITUTION: A primary light source 20 of a liquid crystal back light is formed by disposing respective lead terminal parts 22 so as to face respectively both longitudinal ends of the incident end face 13 of the edge light panel 10. As a result, a fluorescent tube part 21 of the glass tube part of the primary light source 20 is made to emit light and the incident light is supplied to the edge light panel 10 to effect the secondary surface light emission of the panel 10 by irregular reflection patterns 12. At this time, the fine mirror finished longitudinal grooves 16 of the incident end face 13 disperse and supply the incident light from the fluorescent tube part 21 of the effective light emitting part to sections 17, by which the function of the irregular reflection patterns 12 of the sections 17 is exhibited to completely eliminate the sections 17 of the degraded luminance. The high uniformity of the luminance is thus assured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edge light surface light source device used as a liquid crystal backlight, an illuminated display, an illuminated signboard, an illumination sign and the like.

[0002]

2. Description of the Related Art In this type of edge light surface light source device, an edge light panel is arranged between a diffusion sheet on the front side and a reflection sheet on the back side, and a linear (tube-shaped) length is formed on an incident end surface at one end or both ends. A primary light source, and the incident light from the primary light source is supplied from the incident end surface into the edge light panel, and the back surface thereof is screen-printed or integrally molded by a diffuse reflection pattern. The diffused reflection in the edge light panel is promoted, the incident light is guided, and the surface light source is illuminated with high brightness and high uniformity.

[0003]

The linear long primary light source used in this edge light surface light source device has a length which covers the incident end face of the edge light panel, and is generally a hot cathode or cold cathode fluorescent light. The former is often used for illuminated signboards and displays that use a relatively large edge light panel, and the latter is often used for LCD backlights.

However, the linear long primary light source is indispensably equipped with lead terminal portions for energization at both ends thereof.
Since the lead terminal portion is covered with a metal cap or a rubber holder as is well known, the effective light emitting portion of the primary light source is defined by both ends, but the lead terminal portion cannot emit light. To form. The length of the non-emissive portion is, for example, 1 cm or more for each cold cathode tube, and 2 to 3 cm or more for a hot cathode tube.

Therefore, the relationship between the edge light panel and the primary light source corresponds to the length of the incident end face of the edge light panel, and the primary light source having an effective light emitting portion for covering the edge light panel is used, and the lead terminal portion of the primary light source is used. The non-light-emitting part due to the installation should be positioned so as to project to both sides of the incident end face of the edge light panel.

Therefore, in the edge light surface light source device, the length of the incident end face, that is, generally the width of the edge light panel,
Since the width of the non-light-emitting portion is inevitably the width of both ends added to the both ends, the edge light surface light source device has been dimensionally expanded by providing the primary light source with the lead terminal portion. In addition to the above, an unnecessary dead space is generally formed in a portion other than the primary light source adjoining portion.

When the edge light surface light source device is used as an illuminated signboard, an illuminated display, a liquid crystal backlight, etc., the dimension of the illuminated surface and the area of the liquid crystal display surface are made as uniform as possible. It is preferable, however, that due to the size enlargement caused by the lead terminal portion of the primary light source, it is generally configured to have a size larger than these areas, so that there is a dimensional difference around the illuminated surface and the liquid crystal display surface. Accordingly, it is necessary to install a frame frame having a relatively large width, which may impair the appearance of the product. Especially, in the case of a liquid crystal electronic device in which the liquid crystal display surface is tilted, the width on the tilted side is increased. The edge light surface light source device determines the dimensions, which may hinder the compactness in the width direction.

On the other hand, if a primary light source having the same length as the incident end surface of the edge light panel is used in order to avoid the enlargement of the size of the edge light surface light source device, the incident light facing the non-light emitting portion by the lead terminal portion is used. In the vicinity of both ends of the end face, there is no supply of incident light, so that a large decrease in brightness occurs. In order to eliminate this decrease in brightness, for example, the irregular reflection pattern of the portion may be corrected in the direction of increasing the irregular reflection amount, or the side end face in the vicinity may be provided with a reflection improving means.
After all, the decrease in brightness is unavoidable because it is due to the fact that no incident light is supplied. Therefore, in this case, the parts where brightness is reduced in the vicinity of both ends are inevitable to be corrected.

The present invention has been made in view of such circumstances, and the first problem to be solved by the present invention is, firstly, the primary terminal including the lead terminal portions at both ends with respect to the length of the incident end face of the edge light panel. While making the length of the light source substantially the same,
An edge light surface light source device that simultaneously realizes both the same length and the brightness reduction in a contradictory relationship by eliminating the brightness reduction in the vicinity of both ends of the incident end surface which is a non-correctable part due to the non-light emitting part. Second, in addition to this, there is to provide an edge light surface light source device capable of further improving the brightness.

[0010]

According to the present invention, in accordance with the first problem, the length of the primary light source including the lead terminal portions at both ends in the longitudinal direction is determined based on the length of the incident end face of the edge light panel. On the other hand, the incident end face is made to have a fine pitch, and vertical fine mirror surface flutes are engraved continuously over the entire length in the longitudinal direction. Inwardly and inwardly, the end portions of the primary light source are continuously and partially engraved so that the incident light from the effective light emitting portion of the primary light source is supplied near both ends of the incident end surface where no incident light is supplied. It is designed to disperse and direct, and to effectively utilize the diffused reflection pattern of the region to prevent it from lowering the brightness, thereby ensuring uniform brightness. In other words, the fine mirror surface vertical groove on the incident end face is formed. Incident light capture means The present invention provides a dispersion directing means near both ends of the incident end face and a function demonstrating the function of the diffuse reflection pattern near the both ends, that is, the present invention provides claim 1 as an edge light panel for the above first problem. The edge light panel is provided with a primary light source having the same length as the incident end surface provided so as to face each of the lead terminal portions at both ends in the longitudinal direction of the incident end surface, and a fine pitch is provided on the incident end surface of the edge light panel. 3. An edge light surface light source device, characterized in that the vertical mirror grooves of the vertical direction are engraved continuously and over the entire length in the longitudinal direction. Instead of the vertical groove, the above-mentioned fine mirror surface vertical groove is continuously and partially engraved from both ends of the incident end surface of each lead terminal portion facing surface toward the inside in the opposite direction. And an edge light surface light source apparatus according to claim 1, is obtained by a means of the subject matter as the first problem solving invention these respectively.

According to the second problem, if the fine mirror surface vertical groove is additionally provided on the reflecting end face opposite to the incident end face in addition to the incident end face, the primary light source has the same length. Based on the finding that the illumination brightness is improved while ensuring the uniform brightness in the vicinity of the incident end face, this is used as the brightness improving means, that is, the present invention has the above-mentioned second problem. Is characterized in that the reflecting end face opposite to the incident end face is provided with fine mirror surface vertical grooves in the vertical direction, which are fine pitch mirror surfaces, and are continuously engraved in the entire length or in the longitudinal direction. The edge light surface light source device is provided as a means for solving the second problem as the gist of the invention.

Further, the fine mirror-like vertical grooves are V-shaped grooves of an isosceles triangle having a right angle or an acute angle, and the pitch thereof is 0.
Since it is easy to obtain a preferable result when it is made as small as 03 mm or more and 1 mm or less, the present invention makes this preferable for the first or second problem, and claims 4 to Is an isosceles triangle and has a V-shaped groove with an apex angle of right angle or acute angle and its engraving pitch is 0.03 mm or more 1
The edge light surface light source device according to any one of claims 1 to 3, which is less than or equal to mm, and which is a preferable means for solving the first or second problem as the gist of the invention.

In the present invention, it is assumed that the incident end surface of the edge light panel is provided with fine mirror surface vertical grooves as fine mirror surfaces of fine pitches, but the vertical grooves are not mirror surfaces. This is because it promotes diffused reflection of the incident light to disperse and supply the diffused reflection state at the time of incidence when the incident light is supplied to the edge light panel. Therefore, the fine specular flutes reflect the incident light and the incident light is reflected by the primary light source side. V-shaped groove with an isosceles triangle whose apex angle is a right angle or an acute angle (or something similar to this) so as to prevent reflection and return to the surface as much as possible and sufficiently capture the incident light. It is particularly preferable that, for example, the reflection recovery of the incident light increases as it spreads in the obtuse angle direction. Therefore, in order to suppress the loss of the incident light, for example, the apex angle is 1 even when the obtuse angle is set.
It is preferable to set it to 00 ° or less, preferably 95 ° or less. For example, the shape of the vertical groove can be a U-shape which is widened to the primary light source side, but it is preferably a V-shape groove. It should be approximated.

The fine mirror surface vertical groove of the present invention is a vertical vertical groove, and by doing so, the incident light is directed in the direction of the light source separation in the edge light panel and is directed to the vicinity of both ends of the incident end surface, thereby making This is because it is possible to prevent the directivity in the direction and to fully perform the function of the diffused reflection pattern of the edge light panel. Therefore, the angle of the vertical groove may be largely oriented in the falling direction, or the vertical groove may be replaced. ，
Use a lateral groove on the incident end face, roughen the incident end face,
Furthermore, even if the vertical groove is a roughened vertical groove instead of the mirror surface, it should be avoided that the directivity of the incident light in the light source separation direction is impaired. Since the incident light from the primary light source is omnidirectional in itself, the edge light panel may be supplied to the edge light panel in the in-plane horizontal direction of the light source separation direction without any directional property. This is because by not directing the light panel toward the front and back sides, it is possible to sufficiently diffusely reflect incident light and eliminate the decrease in brightness at both ends of the incident end face.

The fine mirror surface and the vertical groove of the incident end face are provided continuously and over the entire length in the longitudinal direction, and are provided continuously and partially at the end portion in the longitudinal direction (the middle portion thereof may be a flat surface, for example). Both are effective and preferable for eliminating the decrease in the brightness of the incident surface. However, if the former is provided over the entire length in the longitudinal direction, the trapping property as the trapping means of the incident light is enhanced depending on the diffused reflection pattern of the edge light panel, and, for example, the brightness on the incident end face side of the edge light panel is relatively improved. It tends to be easy to do. In this case, an improvement in average brightness can be seen when compared with the same one except that fine mirror vertical grooves are provided, but since the incident end face side may be slightly bright, for example, a liquid crystal backlight using a general diffuse reflection pattern. It may not always be suitable when it is used so as to gaze at the liquid crystal surface, such as the one for use. On the other hand, when the latter is partially provided in the longitudinal direction, the average luminance is slightly lower than that of the above-mentioned full length, but the incident light trapping property is sufficient, and the luminance is extremely averaged over the entire area. In the case of the above-mentioned liquid crystal backlight, it may be preferable to partially dispose in the longitudinal direction. In this case, the optimum average luminance can be obtained by about B
In the case of 5 sizes using cold cathode tubes and lengths of about 6 cm from both ends, in general, it is about 3 to 7 times longer than the non-light emitting part by the lead terminals.
It is preferable in terms of eliminating the decrease in the brightness of the incident end face and improving the average brightness, and it is particularly preferable that the length is about 5 ± 1 times. Incidentally, when the purpose is only to eliminate the decrease in the brightness of the incident end face, a corresponding effect can be obtained by, for example, making it twice or more the non-luminous portion.

The engraving pitch of the fine mirror surface vertical grooves on the incident end surface is
0.03 mm to 1 mm is preferable, 0.0
It is particularly preferable that the distance is 5 mm ± 0.01 mm. If the engraving pitch becomes coarser than 1 mm, the vertical groove of the above-mentioned preferable and particularly preferable embodiment becomes deep, and the effective illumination area of the edge light panel is narrowed, and the incident light is dispersed near both ends of the incident end face. This is because, while the supply becomes poor, the above-mentioned range can sufficiently secure the action and effect.

On the other hand, when a fine mirror surface vertical groove is provided on the reflecting end surface, the point that the incident light of the edge light panel is diffusely reflected toward the inside thereof is different from that of the above-mentioned incident end surface.
The remainder may be similar to that according to the fine mirror surface vertical groove on the incident end surface. Therefore, in addition to being provided continuously and over the entire length, it can be provided in the longitudinal direction part as needed, its shape,
Aspects such as angles can be the same as those described above.
In addition, since the fine mirror surface flutes on this reflection end surface are not essential,
Instead of this, other means such as making it a flat surface can be used.

The shape of the fine mirror surface vertical groove on the incident end face or the reflecting end face is formed by injection molding an edge light panel or its transparent substrate, or by cutting with an NC router or the like, a molding means or a secondary processing ( The post-processing) means, and the diffuse reflection pattern of the diffuse reflection means can be formed by a molding means such as halftone dots, dots, lines or a printing means by screen printing, while the primary light source has the same length as the incident end face. As long as it is made of a hot cathode or a cold cathode, a linear (tube-shaped) long one may be used.

The fact that the primary light source has the same length as the incident end face means that a slight dimensional difference is allowed to the extent that the size of the edge light surface light source device is not substantially enlarged and a dead space is not substantially formed. Used to mean substantially the same length.

[0020]

In the present invention, the fine mirror surface vertical grooves on the incident end face capture the incident light from the effective light emitting part of the primary light source as much as possible, and the primary light source near both ends of the incident end face. There is an incident light dispersion / pattern function exerting action that disperses and directs the incident light to a portion that cannot be corrected due to the non-light emitting portion and exerts the diffuse reflection pattern function of the portion.

Further, the fine mirror surface vertical grooves on the reflection end face prevent emission of the incident light reaching the reflection end face as much as possible, and specularly irregularly reflect inwardly into the edge light panel to illuminate as much as possible. It has a non-directional dispersion reflection effect that makes light.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described more specifically with reference to the drawings showing the following embodiments. In FIGS. 1 to 4, A is a liquid crystal backlight for one side light source, 10 is an edge light panel,
20 indicates a primary light source.

The edge light panel 10 is a transparent substrate 1 having high transparency such as a transparent plate made of acrylic resin.
1. A diffuse reflection pattern 12 is provided on the entire back surface of 1, and one end face is an incident end face 13, the other end face opposite to this incident end face is a reflection end face 14, and both end faces intersecting the incident end face 13 are mirror side reflection faces 15. It is configured as a thing. At this time, the irregular reflection pattern 12 is based on a halftone dot pattern formed by screen printing on the transparent substrate 11, and the halftone dot pattern is, for example, a halftone dot regularly arranged at a uniform interval of 1 mm pitch. The incident end face 1 has a maximum area at an intermediate position deviated from the center between the incident end face 13 and the reflective end face 14 to the reflective end face 14 side.
3. A halftone dot pattern in which the area gradually increases from the reflection end surface 14 toward the intermediate position of the deviation.

Further, the edge light panel 10 has the incident end face 13 and the reflecting end face 14 each of which is provided with fine mirror surface vertical grooves 16 in the vertical direction, which are mirror surfaces with a fine pitch and are continuously engraved over the entire length in the longitudinal direction. , In this example, each of the fine mirror surface longitudinal grooves 1 of the incident end face 13 and the reflecting end face 14
6 is a V-shaped groove which is an isosceles triangle and has a right apex angle, and its engraving pitch is 0.05 mm.

On the other hand, the primary light source 20 is a linear (tube-shaped) long one using a cold cathode fluorescent tube having a small diameter so as to have a diameter as close as possible to the thickness of the transparent substrate 11 in the edge light panel 10. The same length is used so that the total length including the lead terminal portions 22 of the rubber holder coating at both ends in the longitudinal direction thereof matches the length of the incident end surface 13 of the edge light panel 10.

In the liquid crystal backlight A, the primary light source 20 is provided such that the lead terminal portions 22 are respectively arranged face-to-face at both ends of the incident end face 13 of the edge light panel 10 in the longitudinal direction. The fluorescent tube portion 21 of the glass tube portion of the light source 20 is caused to emit light,
The incident light is supplied to the edge light panel 10 to cause secondary surface emission of the edge light panel 10 by the irregular reflection pattern 12.

At this time, the primary light source 20 has its fluorescent tube portion 21.
While the lead terminal portions 22 at both ends form non-light emitting portions, generally, the lead terminal portions 22 are arranged face-to-face, and are generally imaginary lines near both ends in the longitudinal direction of the incident end surface 13 of the edge light panel 10. Brightness reduction area 1 shown
However, in this example, the fine mirror surface vertical groove 16 of the incident end face 13 causes the incident light from the fluorescent tube portion 21 of the effective light emitting portion to be generated in the portion 17 of FIG. Is dispersed and supplied, and thereby the function of the diffused reflection pattern 12 of the portion 17 is exerted to completely eliminate the portion 17 where the luminance is lowered, and a high degree of uniformity of luminance is secured.

Further, while the fine mirror surface vertical groove 16 of the incident end face 13 enhances the trapping property of the incident light, it has a directing function of the incident light in the light source separating direction without directing the incident light in the front and back directions. Since the fine mirror surface vertical grooves 16 of the reflecting end surface 14 effectively and appropriately reflect the incident light reaching the reflecting end surface 14 to the inside of the edge light panel 10 in a non-directional diffused manner and use it as illumination light as much as possible. Due to the combined action of, the brightness is greatly improved.

The brightness (average brightness) of the liquid crystal backlight A of this example was improved by about 5% as compared with the case where the incident end face and the reflective end face were flat.

In the figure, 30 is a reflection sheet made of, for example, a low-foaming polyester white film, and 31 is a diffusion sheet made of, for example, a semitransparent polyester film.

FIGS. 5 to 7 show other examples, respectively. FIG. 5 shows the above-mentioned fine mirror surface vertical groove 16 and the incident end face 13.
This is an example in which the reflection end surface 14 is continuously provided along the entire length in the longitudinal direction and the reflection end surface 14 is a flat mirror surface. In this example, although there is some difference in brightness compared to the above example, Similarly, in addition to eliminating the problem, the brightness of the portion 17 was improved by about 20%.

In FIG. 6, instead of the one for one side light source,
A pair of incident end faces 13 facing the edge light panel 10.
, And each of them is provided with a minute mirror surface vertical groove 16, and primary light sources 20 of the same length are similarly provided respectively for the light sources on both sides, and the gradually increasing area dot pattern of the irregular reflection pattern 13 is used as the primary light source 20. This is an example in which the brightness is maximized in the middle of the interval, and at this time, the brightness is high so as to eliminate the brightness-reduced portions 17 that also appear in four places.

FIG. 7 shows that the fine mirror surface flutes 16 are continuously and longitudinally inward from both ends of the incident end surface 13 of the edge light panel 10 in the opposite direction, for example, a non-light emitting portion by a lead terminal portion. This is an example of engraving each with a length of 6 cm, which is 6 times as long as the above.
In addition, the luminance of the portion 17 is similarly improved by about 10%.

Although the illustrated example has been described above, each specific shape, structure, material, manufacturing method of the edge light panel surface light source device, the edge light panel, the diffused reflection pattern, the primary light source, the fine mirror vertical grooves, etc. The dimensions, the numbers, the relationship between them, additions to these, and the like can be in various forms unless they are against the gist of the above inventions.

[0035]

Since the present invention is constructed as described above,
According to claim 1 and claim 2, the fine mirror surface longitudinal grooves of the incident end face respectively capture the incident light from the effective light emitting portion of the primary light source as much as possible, and the primary light source near both ends of the incident end face. The incident light is dispersed and directed to a portion that cannot be corrected due to the non-light emitting portion, and the diffused light scattering / pattern function exerting the diffuse reflection pattern function of the portion is exerted, and the length of the incident end face of the edge light panel is increased. On the other hand, the length of the primary light source including the lead terminals at both ends is made substantially the same, and the decrease in brightness near both ends of the incident end face, which is a non-correctable part due to the non-light emitting part, is eliminated. , It is possible to provide an edge light surface light source device capable of making the brightness of the part uniform to the same extent as the part facing the effective light emitting part of the primary light source, and including the case of mounting on another device,
Based on the edge light panel, it can be made compact without any further enlargement or formation of dead space.

According to a third aspect of the present invention, in addition to this, the fine mirror surface longitudinal grooves on the reflection end face prevent emission of incident light reaching the reflection end face as much as possible, and the mirror surface is non-directionally mirrored inward of the edge light panel. It is possible to provide an edge light surface light source device which diffuses irregularly and serves as illumination light as much as possible to achieve a non-directional diffuse reflection effect, and at the same time improves brightness.

According to the fourth aspect, the above edge light surface light source panel can be surely realized and can be made extremely suitable.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a liquid crystal backlight.

FIG. 2 is a plan view showing a relationship between an edge light panel and a primary light source.

FIG. 3 is an enlarged perspective view showing a fine mirror surface vertical groove.

FIG. 4 is an enlarged plan view of a microscopic vertical groove.

FIG. 5 is a plan view showing the relationship between the edge light panel of another example and the primary light source.

FIG. 6 is a plan view showing the relationship between the edge light panel of another example and the primary light source.

FIG. 7 is a plan view showing the relationship between another example of the edge light panel and the primary light source.

[Explanation of symbols]

 A Liquid crystal backlight 10 Edge light panel 13 Incident end face 14 Reflective end face 16 Fine mirror surface vertical groove 20 Primary light source 21 Fluorescent tube part 22 Lead terminal part

Claims (4)

[Claims] 1. An edge light panel, and a primary light source having the same length as the incident end surface, which is provided so as to face each of the lead terminal portions at both ends in the longitudinal direction of the incident end surface of the edge light panel. An edge light surface light source device comprising a fine mirror surface vertical groove formed in a fine pitch on the incident end surface of the edge light panel in a continuous manner over the entire length in the longitudinal direction. 2. The fine mirror surface vertical grooves are continuous and extend in the opposite direction inward from both ends of the incident end surface of each lead terminal portion, instead of the series of longitudinal mirror length vertical grooves. 2. The edge light surface light source device according to claim 1, wherein the edge light surface light source device is provided by partially engraving. 3. The reflection end face opposite to the incident end face is provided with a fine pitch mirror surface in the vertical direction, which is continuously and additionally engraved in full or partially in the longitudinal direction. Edge light surface light source device characterized by. 4. The fine mirror surface vertical groove is an isosceles triangle and is a V-shaped groove having an apex angle of a right angle or an acute angle, and the engraving pitch is 0.03 mm or more and 1 mm or less. The edge light surface light source device of any one of 1 to 3.