PAPER FORMING MOLD, MOLD MANUFACTURING METHOD, AND PAPER MANUFACTURED BY FORMING MOLD

Abstract

A paper forming mold, comprising a roller (1). A number of through micropores are formed on a wall of the roller (1), and one or more patterns and characters of a normal watermark, a white watermark, a windowed security thread, and a paper marker are carved on the wall of the roller (1). The paper forming mold has a high reproducibility for an original watermark design draft, improves consistency, clarity, three-dimensionality, detail refinement and richness of the watermark in paper, and thus enhances the anti-counterfeiting function of the watermarked paper; the service life of the paper forming mold is prolonged; and the automation level of paper forming mold manufacturing is improved, and the labor intensity is greatly reduced.

Claims

1-30. (canceled)

31. A paper forming mold, wherein it comprises a roller (1) and a pattern and character block (2), wherein a number of through micropores, and a hollowed-out part where the pattern and character block (2) is mounted, are provided on a wall of the roller (1), and the pattern and character block (2) is detachably mounted to the hollowed-out part of the roller (1); and one or more patterns and characters of a normal watermark, a white watermark, a windowed security thread, and a paper marker are carved on the pattern and character block (2).

32. The paper forming mold of claim 31, wherein the hollowed-out part penetrates through the wall of the roller (1).

33. The paper forming mold of claim 31 wherein the pattern and character block (2) is in interference fit with and in embedded connection with the hollowed-out part of the roller (1); or the pattern and character block (2) is welded to the hollowed-out part of the roller (1); or the pattern and character block (2) is adhered to the hollowed-out part of the roller (1); or the pattern and character block (2) and the roller (1) are respectively provided with threaded holes and are connected to each other via screws (3).

34. The paper forming mold of claim 33, wherein the centre of the screw (3) is provided with a linearly-penetrating water filter hole; or the centre of the screw (3) is provided with an L-shaped water filter hole having an L-shaped flow passage.

35. The paper forming mold of claim 31, wherein the roller (1) is flush with a top surface of the pattern and character block (2), or the roller (1) and the top surface of the pattern and character block (2) are different in height.

36. The paper forming mold of claim 31, wherein the pore diameters of the number of micropores at the same height are all equal or not all equal.

37. The paper forming mold of claim 31, wherein the porosities of the micropores in different regions are not all equal.

38. The paper forming mold of claim 31, wherein the micropores are any one or a combination of cylindrical pores, corrugated pores and stepped pores.

39. The paper forming mold of claim 31, wherein passages of the micropores are arranged obliquely.

40. The paper forming mold of claim 31, wherein reinforcing ribs (4) are further arranged in the roller (1).

41. The paper forming mold of claim 40, wherein a spring (5) is arranged on the side of the reinforcing rib facing the roller (1), a distal end of the spring (5) is connected to the bottom of the pattern and character block (2), and the pattern and character block (2) is pressed into the hollowed-out part under an elastic force of the spring (5) compressed.

41. The paper forming mold of claim 31, wherein the pattern and character block (2) is a rectangular block with upper and lower ends having the same length, or the pattern and character block (2) is a wedge-shaped block with upper and lower ends having different lengths.

42. The paper forming mold of claim 31 wherein two or more pattern and character blocks (2) are arranged in one hollowed-out part.

43. The paper forming mold of claim 41, wherein one pattern and character block (2) is composed of two or more sub-modules, that is, the pattern and character block (2) is of a split-type structure.

44. A method for manufacturing the paper forming mold of claim 43, wherein a roller (1) is manufactured first, the paper forming mold is designed according to the characteristics of patterns and characters and requirements for water filtration, the micropores and the hollowed-out part are then created on a wall of the roller (1) according to the design, a pattern and character block (2) having patterns and characters is separately created, and finally, the created pattern and character block (2) is embedded in the hollowed-out part of the roller (1); and the creating of the micropores and the patterns and characters is not limited to a specific order.

45. A method for manufacturing the paper forming mold of claim 31, wherein the micropores and the patterns and characters are first created on a flat plate, and the flat plate is then curled to form a cylindrical shape; and the creating of the micropores and the patterns and characters is not limited to a specific order.

46. A paper made by using the paper forming mold of claim 31.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] FIG. 1 shows partial schematic diagrams of different paper forming tools having a first exemplary image, in which the left diagram shows a paper forming mold of the present invention, and the right diagram shows a watermark cylinder mold of the prior art;

[0049] FIG. 2 shows schematic diagrams of different paper forming tools having the first exemplary image in the event of filament breakage, in which the left diagram shows a paper forming mold of the present invention, and the right diagram shows a watermark cylinder mold of the prior art;

[0050] FIG. 3 shows effect diagrams of normal watermarks of the first exemplary image manufactured by using the different paper forming tools, in which the left diagram is an effect diagram of the normal watermark of the first exemplary image manufactured by using the paper forming mold of the present invention, and the right diagram is an effect diagram of the normal watermark of the first exemplary image manufactured by the watermark cylinder mold of the prior art; and

[0051] FIG. 4 is a partially enlarged schematic diagram of a watermark cylinder mold formed by weaving in the prior art.

[0052] FIG. 5 is a schematic diagram of nodes of warps and wefts of the watermark cylinder mold.

[0053] FIG. 6 is a schematic structural diagram of a roller formed with micropores according to the present invention.

[0054] FIG. 7 is a schematic diagram of a connecting structure for a roller and a pattern and character block in a split-type paper forming mold, in which the pattern and character block is a rectangular block.

[0055] FIG. 8 is a schematic diagram of a connecting structure for a roller and a pattern and character block in a split-type paper forming mold, in which the pattern and character block is a wedge-shaped block.

[0056] FIG. 9 is a schematic diagram of a connecting structure for a roller and a pattern and character block in a split-type paper forming mold, in which a hollowed-out part of the roller does not penetrate through a wall of the roller.

[0057] FIG. 10 is a schematic diagram of a connecting structure for a roller and a pattern and character block in a split-type paper forming mold, in which the top surface of the pattern and character block is higher than an outer wall surface of the roller.

[0058] FIG. 11 is a schematic diagram of a connecting structure for a roller and a pattern and character block in a split-type paper forming mold, in which the top surface of the pattern and character block is lower than an outer wall surface of the roller.

[0059] FIG. 12 is a schematic diagram of a connecting structure for a roller and a pattern and character block in a split-type paper forming mold, in which the pattern and character block is connected to the roller by means of screws.

[0060] FIG. 13 is a partially enlarged diagram of a connecting position between the roller and the pattern and character block in FIG. 12.

[0061] FIG. 14 shows schematic cross-sectional diagrams of screws with two water filter hole flow passage designs.

[0062] FIG. 15 is a schematic diagram of a connecting structure for a roller and a pattern and character block in a split-type paper forming mold, in which the pattern and character block is pressed into a hollowed-out part of the roller by means of a spring mounted on a reinforcing rib.

[0063] FIG. 16 is a schematic diagram of a connecting structure for a roller and a pattern and character block in a split-type paper forming mold, in which the pattern and character block is a wedge-shaped block, and the wedge-shaped block is embedded into the hollowed-out part from the interior of the roller.

[0064] FIG. 17 is a partial schematic structural diagram of a paper forming mold in which micropores are cylindrical pores.

[0065] FIG. 18 is a partial schematic structural diagram of a paper forming mold in which micropores are corrugated pores.

[0066] FIG. 19 is a partial schematic structural diagram of a paper forming mold in which micropores are stepped pores.

[0067] In the figures, 1. Roller; 2. Pattern and character block; 3. Screw; 4. Reinforcing rib; and 5. Spring.

DETAILED DESCRIPTION OF EMBODIMENTS

[0068] In order to better explain the technical features, objects and effects of the present invention, particular embodiments of the present invention will now be described herein with reference to the accompanying drawings.

Embodiment 1

[0069] This embodiment provides a paper-forming mold, the paper-forming mold, comprising: a roller 1. A number of through micropores are formed on a wall of the roller 1, and one or more patterns and characters of a normal watermark, a white watermark, a windowed security thread, and a paper marker are carved on the wall of the roller 1.

[0070] The main innovation points of the paper-forming mold provided in this embodiment lie in that the paper-forming mold is a roller 1 of a non-woven thin-walled structure, and the roller 1 has both micropores and patterns and characters recessed to different depths. The micropores and the patterns and characters are formed by processing a thin plate body, rather than separate components. Moreover, the heights of the micropores and the patterns and characters do not exceed a surface of the roller 1, and the surface of the roller 1 is free of projections.

[0071] A normal watermark and a white watermark described in this embodiment are both watermarks, but the two are not the same, and the differences between them are as follows.

[0072] Normal watermark: a mold has a transition region in a watermark region for creating a normal watermark and is provided with voids such as micropores having a water filtration function. In addition, the created normal watermark has a gray-scale and layered visual effect. In the prior art, a watermark region for creating a normal watermark is directly formed by pressing.

[0073] White watermark: a mold has no transition region in a watermark region for creating a white watermark and is not provided with voids such as micropores having a water filtration function. In addition, the created white watermark does not have a layered visual effect. In the prior art, a watermark region for creating a white watermark is formed by soldering a separately made metal film to a watermark cylinder mold.

[0074] In this embodiment, the micropores are penetrating pores through the wall of the roller 1, inlets of the micropores are located on an outer wall of the roller 1, and outlets of the micropores are located on an inner wall of the roller 1. The inlet of the micropore is in communication with the outlet of the micropore to form a through passage for drainage of a fiber suspension liquid.

[0075] Generally, a cross section of the micropore passage may be circular, elliptical, polygonal, crescent-shaped, etc. Different cross sections may be the same or different in shape, and the different cross sections may be the same or different in proportion. For example, when the cross section of the micropore passage is circular, the micropore passage may be a cylindrical space, that is, the micropore is a cylindrical pore, as shown in FIG. 17; the micropore passage may be a cone-shaped or frustum-shaped space, that is, the micropore is a conical pore; the micropore passage may be a space with an axial cross section in a corrugated shape, that is, the micropore is a corrugated pore, as shown in FIG. 18; or the micropore passage may be a stepped space with an axial cross section having different upper and lower widths, that is, the micropore is a stepped pore, as shown in FIG. 19. Furthermore, the micropores on one roller may be any one or a combination of cylindrical pores, conical pores, corrugated pores, and stepped pores. For example, all the micropores on one roller 1 are cylindrical pores; or all the micropores on one roller 1 are conical pores; or some of the micropores on one roller 1 are cylindrical pores, some are corrugated pores, and some are stepped pores.

[0076] In this embodiment, considering the feasibility of the creating of micropores and the controllability of drainage rate of the micropores, all the micropores on one roller 1 use an equal-diameter perforated structure with a circular cross section, that is, the micropore passages are cylindrical.

[0077] Further, the pore diameters of the number of micropores at the same height are all equal or not all equal. With regard to a structure with cylindrical micropore passages, the pore diameters of the number of micropores are equal or not all equal.

[0078] In another specific embodiment, micropores on one roller 1 are cylindrical pores of the same pore diameter. In this case, the micropores are cylindrical pores. Compared to a structure using conical pores, the cylindrical pores have the advantage that the pore diameters are consistent at the same height position relative to an outer wall surface or an inner wall surface of the roller 1, facilitating the calculation of the porosity to control the gray scale of the watermarks.

[0079] In this embodiment, the porosities of the micropores in different regions are not all equal.

[0080] In this embodiment, a solution in which the pore diameters of micropores are not all equal and the densities are not all equal is used to meet the requirements of watermark grayscale change, that is, the porosities of the micropores meeting the requirements of watermark grayscale change are used: the porosities of the micropores are small in a bright part of the watermark and the porosities of the micropores are large in a dark part of the watermark.

[0081] For example, when the pore diameters of the micropores are equal, the densities of the micropores are small and the micropores are dispersed in the bright part of the watermark; and the densities of the micropores are large and the micropores are compact in the dark part of the watermark.

[0082] For another example, when the micropores have the same density, the pore diameters of the micropores are small in the bright part of the watermark; and the pore diameters of the micropores are large in the dark part of the watermark.

[0083] Of course, it is also possible to consider that both the porosities of the micropores and the heights of carving lines of the patterns and characters affect the gray level of the watermark.

[0084] As shown in FIG. 1, the left diagram is a partial diagram of a watermark pattern having a first exemplary image carved on the wall of the roller 1 in this embodiment, and the right diagram is a partial diagram of a watermark pattern having the first exemplary image pressed on a watermark cylinder mold in the prior art. By contrast, the watermark pattern in the left diagram has a larger difference in line depth, rendering a more refined and three-dimensional pattern with more lines.

[0085] As shown in FIG. 2, the left diagram shows filament breakage of the paper forming mold in this embodiment, and the right diagram shows filament breakage of the watermark cylinder mold in the prior art. It can be seen that the filament breakage is very obvious in the right diagram, but is less obvious in the left diagram.

[0086] As shown in FIG. 3, the left diagram is an effect diagram of a watermark created using the paper forming mold described in the embodiment, and the right diagram is an effect diagram of a watermark created using a watermark cylinder mold in the prior art. Obviously, the watermark in the left diagram is clearer, the presented image is more three-dimensional, and details are more refined.

[0087] As shown in FIGS. 4 and 5, nodes of warps and wefts of the watermark cylinder mold in the prior art are formed by weaving an upper metal filament and a lower metal filament, so when a watermark pattern is pressed on the watermark cylinder mold, due to the influence of factors such as the structure and strength thereof, the line depth of a watermark is limited, and the filaments are very likely to be broken during the pressing.

[0088] It can be seen from the above-described content that the paper-forming mold disclosed in this embodiment has a high reproducibility for an original watermark draft, improves consistency, clarity, three-dimensionality, detail refinement, and richness of the watermark in paper. Thus it enhances the anti-counterfeiting function of the watermarked paper and the service life of the paper-forming mold is prolonged The automation level of mold manufacturing is improved and the labor intensity is greatly reduced.

[0089] Further, passages of the micropores are arranged obliquely. It is convenient to drain water during papermaking.

[0090] Further, the micropores are created using any one of a laser, an electric spark, and an electron beam, and the patterns and characters are created using a laser carving machine or a mechanical carving machine. In this embodiment, only common creating methods are listed, but the creating of the micropores and the patterns and characters is not limited to the above-mentioned creating methods.

[0091] As shown in FIG. 6, it is a schematic diagram of the roller 1 on which the micropores are created.

[0092] Further, the roller 1 is made of copper or nickel or an alloy or a hydrophobic plastic. The hydrophobic plastic may be selected from polytetrafluoroethylene or polyoxymethylene or polyurethane or polypropylene or polyvinyl chloride.

[0093] As shown in FIGS. 1-3, micropores are distributed in all watermark regions covered by the exemplary image, and in this case, the distribution positions of the watermark regions and the micropores are overlapped. When it is required to form a windowed security thread, the micropores are distributed only on the wall around the windowed security thread.

[0094] Further, in order to further improve the working strength of the roller 1, reinforcing ribs 4 are further arranged in the roller 1.

[0095] Further, the content of the normal watermark or the white watermark or the paper marker is any one or a combination of elements including patterns, letters, numbers, symbols, and characters.

[0096] This embodiment also provides a method for manufacturing the above-described paper-forming mold. The method mainly comprises manufacturing of a roller 1, three-dimensional pattern design of a watermark, carving, and perforation. The specific manufacturing method thereof lies in that a roller 1 is manufactured first, the paper forming mold is then designed according to the characteristics of patterns and characters and requirements for water filtration, and finally, micropores and the patterns and characters are created on a wall of the roller 1 according to the design.

[0097] The creating of the micropores and the patterns and characters is not limited to a specific order. That is, any one of the following modes can be used:

[0098] Mode 1: the micropores are created first, and the patterns and characters are then created;

[0099] Mode 2: the patterns and characters are created first, and the micropores are then created;

[0100] Mode 3: the creating of the micropores is performed concurrently with, separate from, and not interspersed with the creating of the patterns and characters; and

[0101] Mode 4: the creating of the micropores is performed concurrently with, and interspersed with the creating of the patterns and characters.

[0102] Generally, when the paper-forming mold is manufactured, patterns and/or characters of a normal watermark, a white watermark, a windowed security thread, etc. are directly carved on the roller 1 after micropores are made, or patterns and/or characters of a normal watermark, a white watermark, a windowed security thread, etc. are firstly carved on a pore-free roller 1, and then micropores are made on the roller 1 by applying laser or other techniques.

[0103] Further, during the design of the paper-forming mold, the pore diameters of individual micropores, the porosities of micropores in different regions, and lines of the patterns and characters are designed according to the characteristics of the patterns and characters and the requirements for water filtration.

[0104] By comparing the use effects of the paper-forming mold described in this embodiment and the watermark cylinder mold in the prior art through multi-group experiments, when being used for papermaking, the paper-forming mold provided in this embodiment has a high reproducibility for an original watermark design draft, improves consistency, clarity, three-dimensionality, detail refinement and richness of the watermark in paper, and thus enhances the anti-counterfeiting function of the watermarked paper. The service life of the paper forming mold is prolonged the automation level of watermark mold manufacturing is improved, and the labor intensity is greatly reduced.

Embodiment 2

[0105] This embodiment uses, on the basis of Embodiment 1, a structure in which a roller 1 is separated from a module having a normal watermark, a white watermark, a windowed security thread, and a paper marker.

[0106] This embodiment provides a paper-forming mold, comprising a roller 1 and a pattern and character block 2. A number of through micropores and a through hollowed-out part are provided on the wall of the roller 1, and the pattern and character block 2 is detachably mounted to the hollowed-out part of the roller 1. One or more patterns and characters of a normal watermark, a white watermark, a windowed security thread, and a paper marker are carved on the pattern and character block 2.

[0107] Further, the pore diameters of the number of micropores at the same height are all equal or not all equal.

[0108] Further, the porosities of the micropores in different regions are not all equal.

[0109] The main innovation points of the paper-forming mold provided in this embodiment lie in that the paper-forming mold comprises a roller 1 having a non-woven thin-walled structure and a pattern and character block 2. The roller 1 has the micropores and the hollowed-out part for installing the pattern and character block 2, and patterns and characters recessed to different depths are created on the pattern and character block 2.

[0110] The micropores are any one or a combination of cylindrical pores, corrugated pores and stepped pores.

[0111] Further, passages of the micropores are arranged obliquely.

[0112] In order to further improve the working strength of the roller 1, reinforcing ribs 4 are further arranged in the roller 1.

[0113] The roller 1 is made of copper or nickel or an alloy or a hydrophobic plastic. The hydrophobic plastic may be selected from polytetrafluoroethylene or polyoxymethylene or polyurethane or polypropylene or polyvinyl chloride.

[0114] Further, the content of the normal watermark or the white watermark or the paper marker is any one or a combination of elements including patterns, letters, numbers, symbols, and characters.

[0115] This embodiment also provides a method for manufacturing the above-described paper forming mold. The method mainly comprises manufacturing of a roller 1, three-dimensional pattern design of a normal watermark, carving and perforation. The specific manufacturing method thereof lies in that a roller 1 is manufactured first, the paper-forming mold is designed according to the characteristics of patterns and characters and requirements for water filtration, and the micropores and the hollowed-out part are then created on a wall of the roller 1 according to the design. pattern and character block 2 having patterns and characters is separately created, and finally, the created pattern and character block 2 is embedded in the hollowed-out part of the roller 1.

[0116] The creating of the micropores and the patterns and characters is not limited to a specific order. That is, any one of the following modes can be used:

[0117] Mode 1: the micropores are created first, and the patterns and characters are then created;

[0118] Mode 2: the patterns and characters are created first, and the micropores are then created;

[0119] Mode 3: the creating of the micropores is performed concurrently with, separate from, and not interspersed with the creating of the patterns and characters; and

[0120] Mode 4: the creating of the micropores is performed concurrently with, and interspersed with the creating of the patterns and characters.

[0121] The other parts of this embodiment are the same as those of Embodiment 1, and therefore, the description thereof will not be repeated.

Embodiment 3

[0122] This embodiment optimizes the connection between a pattern and character block 2 and a roller 1 on the basis of Embodiment 2.

[0123] With regard to a first connection, as shown in schematic diagrams of a connecting structure for a roller 1 and a pattern and character block 2 in a split-type paper forming mold illustrated in FIGS. 7, 8, 9, 10 and 11, the pattern and character block 2 and the roller 1 are welded or adhered to each other or are in embedded connection with each other only by means of an interference fit. Soldering is usually used for welding.

[0124] In FIGS. 7-11, as shown in FIGS. 7, 8, 10 and 11, a hollowed-out part on the roller 1 penetrates through the wall of the roller 1. In the examples shown in FIGS. 7 and 8, the pattern and character block 2 is substantially the same as the roller 1 in thickness, and the top surface of the pattern and character block 2 is substantially the same as an outer wall surface of the roller 1 in height. In the example shown in FIG. 10, the top surface of the pattern and character block 2 is significantly higher than the outer wall surface of the roller 1. In the example shown in FIG. 11, the top surface of the pattern and character block 2 is significantly lower than the outer wall surface of the roller 1.

[0125] In FIGS. 7-11, as shown in FIG. 9, the hollowed-out part on the roller 1 does not penetrate through the wall of the roller 1, the pattern and character block 2 is embedded in the hollowed-out part of the roller 1, and the top surface of the pattern and character block 2 is substantially the same as the outer wall surface of the roller 1 in height. Of course, in this case, the top surface of the pattern and character block 2 may also be slightly higher or slightly lower than the outer wall surface of the roller 1.

[0126] With regard to a second connection, as shown in a schematic diagram of a connecting structure for the roller 1 and the pattern and character block 2 in the split-type paper forming mold illustrated in FIG. 12, the pattern and character block 2 and the roller 1 have a partial structure overlap, and in this case, the pattern and character block 2 and the roller 1 are welded or adhered or connected by means of screws 3.

[0127] As shown in FIG. 13, the pattern and character block 2 is integrally connected to the roller 1 via the screws 3.

[0128] Further, as shown in FIG. 14, the screw 3 is provided with a water filter hole, and a water passage structure of the water filter hole has two types of “|” and “”. For example, the left in FIG. 14 is a linear water filter hole structure penetrating through the center of the screw 3, and the right diagram in FIG. 14 is an L-shaped water filter hole structure not penetrating through the center of the screw 3.

[0129] With regard to a third connection, as shown in a schematic diagram of a connecting structure for the roller 1 and the pattern and character block 2 in the split-type paper-forming mold illustrated in FIG. 15, the pattern and character block 2 is pressed into the hollowed-out part of the roller 1 by means of a spring 5 mounted on a reinforcing rib 4.

[0130] The other parts of this embodiment are the same as those of Embodiment 2, and therefore, the description thereof will not be repeated.

Embodiment 4

[0131] This embodiment optimizes the structure of the pattern and character block 2 on the basis of Embodiment 2 or Embodiment 3. As shown in FIG. 7, the pattern and character block 2 is a rectangular block with upper and lower ends having the same length. Alternatively, as shown in FIGS. 8, 15, and 16, the pattern and character block 2 is a wedge-shaped block with upper and lower ends having different lengths.

[0132] The other parts of this embodiment are the same as those of Embodiment 2 or Embodiment 3, and therefore, the description thereof will not be repeated.

Embodiment 5

[0133] This embodiment provides paper-forming molds of two structures.

[0134] The paper-forming mold of a first structure comprises a roller 1. A number of through micropores are formed on a wall of the roller 1, and one or more patterns and characters of a normal watermark, a white watermark, a windowed security thread, and a paper marker are carved on the wall of the roller 1.

[0135] The paper-forming mold of a second structure comprises a roller 1 and a pattern and character block 2. A number of through micropores and a through hollowed-out part are provided on the wall of the roller 1, and the pattern and character block 2 is detachably mounted to the hollowed-out part of the roller 1. One or more patterns and characters of a normal watermark, a white watermark, a windowed security thread, and a paper marker are carved on the pattern and character block 2.

[0136] In the paper-forming molds of the two structures described above, the pore diameters of the number of micropores at the same height are all equal or not all equal, and the porosities of the micropores in different regions are not all equal.

[0137] With regard to the paper-forming molds of the two structures described above, a manufacturing method is further provided on the basis of Embodiment 1 or Embodiment 2. The micropores and the patterns and characters are first created on a flat plate, and the flat plate is then curled to form a cylindrical shape, and the creating of the micropores and the patterns and characters is not limited to a specific order.

[0138] The other parts of this embodiment are the same as those of Embodiment 1 or Embodiment 2, and therefore, the description thereof will not be repeated.

Embodiment 6

[0139] According to any one of Embodiments 1-5, this embodiment provides paper made by the paper-forming mold disclosed in Embodiments 1-5. The paper is a security paper for anti-counterfeiting printing.

[0140] Those described above are merely preferred embodiments of the present invention and are not intended to limit the invention in any form, and any simple modifications and equivalent improvements made on the above embodiments according to the technical essence of the present invention shall fall within the scope of protection of the present invention.