KR940001116B1 - Panel in a source of flat light - Google Patents

Abstract

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Description

Surface light source panel

As the drawings show an embodiment,

1 is a perspective view of a word processor.

2 is an exploded perspective view of the main portion thereof.

3 is a front view of the photographing apparatus.

4 is a plan view of the diffusion sheet.

5 and 6 are plan views of surface light source panels, respectively.

* Explanation of symbols for main parts of the drawings

1: word processor 2: main unit

3: key board part 5: display part

7: display surface 8: see-through protection panel

9 liquid crystal panel 10 surface light source device

11: diffuse reflection sheet 12,32: surface light source panel

13: reflective back sheet 14: light source

15: end reflecting portion 16: transparent substrate

17,33: diffuse reflection layer 18,34: parallel pattern area

19,35: Adjustment pattern part 20: Photographing device

21: light box 22: light for illumination

23: glass panel 24: stand frame

25: transparent glass panel 26: camera

27: disc film 29: diffusion sheet

30: cut out portion 31: the second negative film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface light source panel for use in various lighting or for use in a surface light source device for various back lighting such as a liquid crystal backlight, a display stand, a display panel, and the like.

Instead of providing a plurality of fluorescent light sources horizontally or vertically on the back side of the conventional diffuse reflection panel, a surface light source device is proposed in which a light source is placed on an end surface of a surface light source panel.

However, while the surface light source device can be formed thinly and compactly, it is difficult to attain uniform luminance necessarily. For example, Japanese Patent Application Laid-Open No. 57-128383 includes a steplessly diffused reflection layer on a transparent substrate. By forming white paint, Japanese Patent Application Laid-Open No. 60-205576 forms the front diffuse reflection layer of the transparent substrate by white ink added with glass beads, and Japanese Patent Application Laid-Open No. 62-902 forms the diffuse reflection layer. This is solved by stacking a plurality of surface light source panels.

In addition, it is also difficult to solve this problem. In Japanese Patent Application No. 63-208670 proposed by the present inventors to obtain uniform and sufficient luminance, the diffuse reflection layer formed on the transparent substrate in the direction away from the light source. The sequential area ratio was changed stepwise to the increased state while the diffuse reflection layer was left in a dim light state, for example, by screen printing of a thin ink having a solid content of 13 to 30 μt%. It consists of a large number of diffuse reflection parts of fine point shape or linear shape with density of line to 65 line.For example, it is uniform with surface light source panel of A4 plate that each fluorescent lamp of 8W is arranged on the opposite end face, and brightness is up to 2000nit. Excellent results are obtained.

Although the surface light source panel according to the present inventors is practically practical in various surface light source devices, on the other hand, even when applied to a liquid crystal backlight, especially in a portable word processor, a computer, a television, etc., sufficient brightness as a whole can be obtained. For example, there is a case where a tendency that the vicinity of the light source is small but becomes bright is observed.

This tendency generally appears in the form of an acid, and especially when the diffuse reflection layer is formed close to the end edge of the transparent substrate, for example, at the end edge, it tends to appear relatively flat in a parallel or slightly acid shape.

Therefore, especially in a surface light source panel used under such a condition that high precision uniformity is required, if there is a part that is only bright and the luminance rises, a relatively sufficient standard luminance can be obtained even though The slight difference in contrast, which may appear in the part, also becomes particularly prominent, which acts to enlarge the disturbance as a whole and impair uniformity.

The present invention has been made in view of the above problems, and an object thereof is to provide a surface light source panel which can obtain uniformity of luminance with high accuracy regardless of conditions.

As a result of careful study according to the above object, in general, the change in the luminance of the mountain shape occurs because the incident light from the light source does not necessarily go straight through the transparent substrate, for example, it tends to be inclined mutually in a diagonal direction. In the case where the incident light is concentrated in the mountain-shaped portion at the tip as the base, the change in the area ratio of the diffuse reflection layer is increased in the in-plane direction away from the light source. As a result, the fact that the luminance change due to the concentration of the incident light cannot be absorbed as a result is found to be the fact that the darkness near the metallic members at both ends further enhances this tendency when the fluorescent light source is used. It was.

On the other hand, in the case where the diffuse reflection layer was formed close to the edge of the transparent substrate, the influence of the light source appeared directly on the surface light source panel, and similarly, it was found that the parallel pattern could not be absorbed.

The present invention has been made on the basis of such findings, and the present invention relates to a light source and a parallel pattern portion in which the diffuse reflection layer formed on the transparent substrate surface is changed in an area without increasing the area ratio in order from the light source to the in-plane direction in parallel. Surface light source panel (claim 1) and diffuse reflection characterized by comprising an adjustment pattern part which reduced the area ratio further on the mountain shape which has the edge which opposes the light source so that it may be surrounded by this parallel pattern part in the side. In a surface light source panel in which a layer is formed close to the edge of the transparent substrate, the diffuse reflection layer includes a parallel pattern portion in which the area ratio is increased in order in parallel and steplessly toward the in-plane direction from the light source, and the light source side. The area ratio is further reduced to a parallel or slightly mountainous shape near the edges of Relates to a surface light source panel was adjusted, characterized in that obtained by having a pattern region (claim 2), and each of them with a base.

In the present invention, the area ratio of each diffuse reflection layer is further reduced in the portion where the incident light is concentrated or directly affected by the incident light, so that the diffuse reflection of the adjustment pattern portion further secures sufficient light propagation in the in-plane direction. The brightness of the diffuse reflection layer due to the diffuse reflection is weakly suppressed to ensure uniformity of luminance between the parallel pattern portions.

EXAMPLE

In the following, according to the drawings showing an embodiment, the present invention will be described in which (1) is a word processor, which is a main body 2 having a key board portion 3 and a key board portion 3. ) Is housed in a shape that overlaps with each other.

It is comprised by the display part 5 which rises with respect to the main body 2, and falls freely.

The display portion 5 to be erected has a wide flat plate shape thinned by about 2/3 of its size with respect to a thickness of about 3 cm before and after the liquid crystal panel protected by the see-through protection panel 8 on its front face. The display surface 7 according to (9) is provided.

On the other hand, in this display part 5, the surface light source device 10 is assembled in the back surface side of this liquid crystal panel 9. As shown in FIG.

The surface light source device 10 stacks the transparent diffuse reflection sheet 11, the surface light source panel 12 and the reflective back sheet 13 made of the same milky white polyester film by the milky white polyester film on the surface thereof, and at the same time, the fluorescent lamp. The light source 14 and the end reflecting part 15 by the white tape formed over three end surfaces except the light source 14 side of the surface light source panel 12 are provided.

In addition, in the present example, the light source 14, which is a fluorescent lamp, exposes the surface light source panel 12 side of the glass tube in a slit shape while being transparent, while using an apertured tube that is internally or externally reflected on the remaining outer periphery. In this way, the total amount of emitted light can be supplied as incident light.

The surface light source panel 12 uses a transparent substrate 16, which is a single acrylic transparent resin plate thickened to a thickness of 6 mm while having a vertical and horizontal dimension of 130 x 240 mm, for example. A diffuse reflection layer 17 is formed on the entire surface by a large number of high density distributed dots.

The diffuse reflection layer 17 is provided with the parallel pattern part 18 and the adjustment pattern part 19, and the parallel pattern part 18 constitutes another part other than the adjustment pattern part 19 mentioned later. From 14), the area ratio is changed in increasing order in parallel steplessly toward the in-plane direction.

In this example, the change in the increased state is a pattern in which the position biased toward the end reflecting portion 15 from the center of the light source 14 and the upper end reflecting portion 15 of the surface light source panel 12 becomes the coverage area ratio portion. It is supposed to be done as.

This prevents the proximity of the end reflecting portion 15, which is the position spaced most apart from the light source 14, by the reflected light of the end reflecting portion 15 from becoming too bright, thereby preventing the occurrence of the parallel pattern portion 18. This is to ensure uniformity.

On the other hand, the adjustment pattern portion 19 itself has a diffuse reflection layer 17 in which the increase state is changed in parallel with the area ratio in the parallel pattern portion 18, and at the same time, the parallel pattern portion 18 The area ratio in the parallel pattern part 18 is further reduced by being formed in the part which shows the mountain shape which has the opposite end of the light source 14 as the base so that it may be enclosed.

It is preferable that the area ratio in the adjustment pattern portion 19 is generally about several percent to fifteen percent.

It is more preferable that the vicinity of the surrounding parallel pattern portion 18 is enlarged steplessly in the same manner. In this case, this increase state change is visually determined as the actual surface light source panel 12. It is relatively difficult to do.

Formation of the diffuse reflection layer 17 by the parallel pattern part 18 and the adjustment pattern part 19 was performed by screen printing and white printing as disclosed in Japanese Patent Application No. 63-208670 such as the inventors. Although sticking of a film or other well-known examples can be used such as shot blasting, in particular, screen printing or film sticking can be used with high precision to obtain a good result, and simple means can be used as follows. desirable.

That is, for example, when the diffuse reflection layer 17 is formed by screen printing, the parallel pattern portion 18 and the adjustment pattern portion (2) are placed on the second disc film 31 which ultraviolet-sensitive the diffuse reflection portion pattern to the printing PVA film. What is necessary is just to express the pattern of the diffuse reflection layer 17 with 19).

3 shows the photographing apparatus 20 of the second disc film 31, in which 21 is a light box, 22 is a light for illumination, and 23 is a top surface of the light box 21. As for the milky glass panel 24 used for the diffuse reflection use, the stand frame 26 which has the transparent glass panel 25 on the light box 21 on an upper surface is a camera.

The photographing of the second disc film 31 by the imaging device 20 is a disc film having a parallel pattern on the transparent glass panel 25, for example, by a dot pattern of a product made by a retreat fan. (27) and a rectangular diffusion sheet 28 made of, for example, a polyester milky film, are stacked and stacked.

In this photographing, as shown in FIG. 4, under the original film 27, as shown in FIG. 4, a portion corresponding to the adjustment pattern portion 19 forms the cutout portion 30 in the shape of a collar. The diffusion sheet 29 which is an ester milky white film is further laminated, and the diffusion sheet 29 is sandwiched between the transparent glass panel 25 and the original film 27.

When the parallel pattern of the original film 27 is photographed on the second original film 31 using this diffusion sheet 29, the light from the light for illumination at the cutout 30 is directly exposed to the remaining masking portion thereof. This diffusion sheet 29 weakens slightly, reaches the original film 27, and simultaneously records the pattern image on the second original film 31. FIG.

At this time, since the light of the cutout portion 30 is stronger in the masking portion, when the camera 26 is reached, the light proceeds as if it enters the halftone image of the original film 27 slightly, and the area ratio of each halftone point is compared with the masking portion. It becomes a result of recording in the reduced state, and it becomes possible to image the said parallel pattern part 18 and the adjustment pattern part 19 on the 2nd original film 31 simultaneously.

In addition, since the diffusion sheet 28 on the original film 27 diffuses the illumination light uniformly while maintaining the intensity of the illumination light, the parallel pattern is made by blurring the boundary line of the cutout portion 30 in the diffusion sheet 29 below. The portion 18 and the adjustment pattern portion 19 are changed into a stepless shape.

On the other hand, in place of the cutout portion 30 of the lower diffusion sheet 29, this is made into a transparent portion, and an intermediate pale masking portion is provided between this cutout portion or the transparent portion and the masking portion. In the latter case, the change in the stepless shape can be expressed more reliably.

Screen printing using the PVA film photosensitively produced by the second disc film 31 may be performed on the transparent substrate 16 by an ordinary method using the ink shown in Japanese Patent Application Laid-Open No. 63-208670.

In the surface light source device 10 according to the present embodiment, the liquid crystal panel 9 can be adjusted back uniformly by the incident light from the light source 14 so as to be very uniform. The change in luminance due to the change could be sufficiently solved.

6 is an example of the surface light source panel 32 of claim 2, and in this example, for liquid crystal backlight, such as the two-equalization provided on the opposite end surface of the light source 14, respectively. will be.

The diffuse reflection layer 33 in the surface light source panel 32 is formed by the same screen printing so as to leave the edge portion near the edges of both ends of the light source 14 side of the transparent substrate 16 and to be almost full. In addition, the diffuse reflection layer 33 changes the area ratio in increasing order in parallel in a stepless manner in the same manner as described above from the respective light sources 14 toward the spaced plane inward direction, and at the center position, The parallel pattern part 34 by the densities distributed by high density, and the adjustment pattern part 35 which reduced the area ratio in the substantially parallel state of the edge vicinity of the both ends are provided.

The adjustment pattern portion 35 is formed by using a diffusion sheet having a narrow width along both edge portions in the imaging of the second disc film, thereby masking the intermediate portion with respect to both edge portions. The illumination light is formed so as to directly contact, and the remaining part is the same as the above description, and the description thereof is omitted.

Also in the surface light source panel 32 according to the present example, the luminance change easily seen when the diffuse reflection layer is formed near the edges of this type is eliminated, and the entire liquid crystal panel can be rear-adjusted very uniformly. There is a number.

Although the example shown above was made as above, the diffuse reflection layer provided with the parallel pattern part and the adjustment pattern part in this invention expresses this in the formation process of an original film by carrying out computer design or correction | amendment of a pattern, etc. In this case, it is not necessary to use the lower diffusion sheet from the beginning.

Moreover, although this invention is very suitable when uniformity is requested | required with high precision, such as a liquid crystal backlight, it is also the surface light source device for display which illuminates the both image films which were attached, and the thing for other illumination, or The same applies to indoor or indoor installations that are used for lighting.

In these cases, unlike the above example, several surface light source panels may need to be laminated via a diffuse reflection film, or may be illuminated on both sides, and the surface light source panel may be curved. It is also possible to make a configuration.

As is clear from the above description, in the practice of the present invention, the specific materials, sizes, quantities, shapes, configurations, uses, etc. in the surface light source panel, the parallel pattern portion, the adjustment pattern portion, etc. do not contradict the gist of the invention. As long as it can be changed in many ways, it is not limited to the above illustration and description.

Since the present invention is configured as described above, in a surface light source device in which high precision uniformity is required, such as, for example, a liquid crystal backlight, the luminance near the light source is increased, and the relative luminance difference from the standard luminance of other parts is increased. It is possible to provide a surface light source panel having a high uniformity to reduce or eliminate the.

Therefore, an ideal surface light source device that realizes a thin, bright, uniform brightness of illumination or back illumination can be put into practical use, and has an excellent effect that the use of this type of surface light source device can be dramatically expanded.

Claims (2)

The light reflection layer 17 formed on the surface of the transparent substrate 16 has a parallel pattern portion 18 in which the area ratio is gradually increased in an increasing state in parallel to the in-plane direction spaced apart from the light source 14, and the light source. (14) a surface light source panel comprising an adjustment pattern portion 19 having a reduced area ratio again in a mountain shape with the end facing the light source downward so as to be surrounded by this parallel pattern portion 18. . In the surface light source panel in which the diffuse reflection layer 33 is formed near the end edge of the transparent substrate 16, the diffuse reflection layer 33 is arranged in parallel in an in-plane direction spaced apart from the light source 14 in a stepless manner. A parallel pattern portion 34 gradually changing the area ratio to an increased state, and an adjustment pattern portion 35 having the area ratio reduced to a parallel shape or a slightly mountainous shape near the end edge toward the light source 14. Surface light source panel, characterized in that.