TECHNICAL FIELD

The present invention relates to the field of optical thin films, in particular to a decorative sheet, an electronic apparatus cover plate and an electronic apparatus.

BACKGROUND

With the continuous development of science and technology, decorative sheets are widely used on the surfaces of electronic products such as cell phones and computers, household appliances such as refrigerators, air conditioners and washing machines and automobiles, in order to improve the aesthetic property of the products.

In the prior art, an intaglio printing technique is generally employed in making decorative sheets, which is, printing a graph-text structure layer having patterns or characters inside a film to thereby present various ornamental patterns or metallic feelings. However, the graph-text structure layer fabricated by the intaglio printing technique is usually a planar structure and cannot present a three-dimensional effect. Moreover, the graph-text structure layer fabricated by the intaglio printing technique has poor resolution, which makes the displayed graphs and text unclear.

In addition, in order to make the graphs and text of the decorative sheet bright and eye-catching so as to enable a user to see clearer and brighter graphs and text, in the prior art, in general, brightening inks will be used in intaglio printing, or shinning crystals will be added in the graph-text structure layer, such that the graphs and text of a device film will appear to be bright and eye-catching. However, the manufacture process will involve certain difficulty and material waste, which will increase the cost to a certain extent. The brightening inks will also cause pollutions to the environment. In addition, if the above materials are used to enhance the definition and lightness of the graphs and text, the longer the materials are used, the greater the oxidation degree of the materials will be, and as time passes the definition and lightness of the graphs and text will also decrease correspondingly.

SUMMARY

With respect to the above problem, the present invention is aimed at providing a decorative sheet, for forming a three-dimensional image to represent a three-dimensional material object. The decorative sheet comprises a transparent protective layer, a graph-text structure layer and a reflective layer. The graph-text structure layer and the reflective layer are located on a same side of the transparent protective layer. The graph-text structure layer comprises a number of graph-text sub-blocks which form the three-dimensional image, and each graph-text sub-block comprises a micro-structure that represents corresponding lightness of the three-dimensional material object.

Preferably, light rays reflected or refracted by the micro-structure to the graph-text sub-block represent the corresponding lightness of the three-dimensional material object.

Preferably, each graph-text sub-block represents the corresponding lightness of the three-dimensional material object based on a location of a light source.

Preferably, each graph-text sub-block represents the corresponding lightness of the three-dimensional material object based on a location of a receptor.

Preferably, the lightness of the image formed by the graph-text structure layer is related to one or a combination of two of a size, a shape, a spacing distance, a period, a height, arrangement density, material and an included angle with a horizontal direction of the graph-text sub-blocks.

Preferably, the lightness of the image formed by the graph-text structure layer is related to one or a permutation and combination of two or more of a size, a shape, a spacing distance, a period, a height, arrangement density, material and an included angle with a horizontal direction of the micro-structures.

Preferably, a lightness change of the image formed by every graph-text sub-block conforms to a lightness change of the three-dimensional material object.

Preferably, the included angles between the micro-structures in at least two graph-text sub-blocks and the horizontal direction are different, so that a dynamic and continuous image of the three-dimensional material object is obtained.

Preferably, the micro-structure is a convex structure and/or a concave structure.

Preferably, in a same graph-text sub-block, the graph-text sub-block comprises a plurality of identical micro-structures.

Preferably, a maximum radius of the graph-text sub-block is less than 100 μm; or the maximum radius of the graph-text sub-block is less than 80 μm; or the maximum radius of the graph-text sub-block is less than 50 μm.

Preferably, a cross-sectional shape of the graph-text sub-block includes round, triangular, square, rectangular and irregular polygonal shapes;

or a cross-sectional shape of the micro-structure includes round, triangular, square, rectangular and irregular polygonal shapes.

Preferably, a setting of plural micro-structures forms the image, and a change among the plural micro-structures represents the lightness change of the image.

Preferably, a change in one or more of the size, shape, spacing distance, period, height, arrangement density, material and included angle with the horizontal direction of the micro-structures represents the lightness of the image.

Preferably, a gray value of the three-dimensional material object presented at a predetermined angle corresponds to the setting of the plural micro-structures, one gray value corresponds to one micro-structure, the micro-structures are the same when the gray values are the same, and the micro-structures are different when the gray values are different.

Preferably, a spacing distance between two closely adjacent graph-text sub-blocks is from 0 to 200 μm; or the spacing distance between two closely adjacent graph-text sub-blocks is from 0 to 50 μm.

Preferably, the graph-text structure layer is provided between the transparent protective layer and the reflective layer.

Preferably, a face of the graph-text structure layer which has the micro-structures is facing towards the transparent protective layer.

Preferably, a bonding layer is also provided between the transparent protective layer and the graph-text structure layer.

Preferably, there is a refractive index difference between the bonding layer and the micro-structure.

Preferably, the decorative sheet further comprises a bearing layer and a polymer layer, the polymer layer is provided on a side of the bearing layer, and the graph-text sub-blocks are provided on the polymer layer.

Preferably, the reflective layer is located between the transparent protective layer and the graph-text structure layer.

Preferably, the reflective layer is located between the bearing layer and the polymer layer.

Preferably, the decorative sheet comprises a coloring layer which is provided on a surface of the reflective layer.

Preferably, the decorative sheet comprises a coloring layer, which is provided between the polymer layer and the bearing layer.

The present invention also provides an electronic apparatus cover plate, which is provided with a decorative sheet as described above.

The present invention further provides an electronic apparatus, which is provided with an electronic apparatus cover plate as described above.

Preferably, the electronic apparatus comprises consumer electronics and household appliances.

Advantageous effects of the present invention are as follows:

(1) The present invention provides a decorative sheet, which comprises a graph-text structure layer, the graph-text structure layer comprises a number of graph-text sub-blocks, and the graph-text sub-blocks in turn comprise a number of micro-structures. The parameters of the micro-structures of each graph-text sub-block are different, so that light rays emitted by each graph-text sub-block comprising the micro-structures have different lightness, and thus a change of lightness is produced among the graph-text sub-blocks. By using the lightness change among the graph-text sub-blocks to represent the lightness change of the three-dimensional material object in a natural state, the graphs and text displayed on the graph-text structure layer are enabled to have a three-dimensional effect.

(2) The present invention provides a decorative sheet. By adjusting the parameters of the micro-structures in the graph-text sub-blocks on the decorative sheet, an oriented brightness of the graph-text structure layer is enhanced, and graphs and text of different brightness can be presented when the observer observes the graphs and text from different visual angles.

(3) The present invention provides a decorative sheet, in which the graph-text structure layer is formed of graph-text sub-blocks. By adjusting the arrangement density and diameter of the graph-text sub-blocks, the graphs and text displayed on the graph-text structure layer are enabled to have higher resolution. No matter from which angle the observer observes the decorative sheet, the observer can see clearer graphs and text. In addition, the graphs and text have a visually continuous and three-dimensional effect, giving the observer a sense of reality, thereby achieving a good decorative effect.

(4) The present invention provides a decorative sheet, wherein the brightness of the graphs and text are adjusted by using the micro-structures, and no brightening ink or other material needs to be used, which saves costs and produces no pollution to the environment.

