Title: MAT CAPABLE OF CHANGING INTO SOFA Cross-reference to related application This application claims the benefit of Korean Patent Application No.10 5 2010-0075679, filed on August 5, 2010 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. Technical Field [1] The present invention relates to a mat capable of changing to a sofa, and more particularly, to a mat capable of changing to a sofa that is made of a io cushion material and that is unfolded on the floor to be used as a bottom mat for preventing a safety accident of toddlers and children and to be used for play and rest by changing to a shape of a sofa by stacking and filling. Background Art 15 [2] In general, at the floor of a playroom for toddlers and children, a safety mat for preventing a safety accident is provided. However, in a conventional floor mat, a pattern, a color, or simple studying contents in which children like are added, and the mat cannot be used for another play or rest, and thus there is a limitation in a use of the mat. 20 [3] 1 Disclosure Technical Problem [4] The present invention is made to overcome the above mentioned problems, and it is an object of the present invention to provide a mat capable 5 of changing to a sofa that is made of a cushion material and that is unfolded on the floor to be used as a bottom mat for preventing a safety accident of toddlers and children and to be used for play and rest by changing to a shape of a sofa by stacking and filling. [5] 10 Technical Solution [6] To achieve the above objects, there is provided a mat capable of changing to a sofa including: a frame sheet member in which a plurality of frame sheets are connected to be folded or unfolded in a multistage and that has a through-hole therein; and a block sheet member that is filled within the through 15 hole or disposed at one side of the frame sheet member and that is formed in various shapes that can be engaged to be filled without a gap within the through-hole. [7] In accordance with another aspect of the present invention, the frame sheet member includes a first frame sheet that is formed in a plate shape and 2 second and third frame sheets that are formed in a "--" shape and in which first and second through-holes, respectively, are formed. [8] In accordance with another aspect of the present invention, when the mat is changed to a sofa, the first frame sheet is disposed at a bottom surface, 5 the second and third frame sheets are sequentially stacked on the first frame sheet, the first and second through-holes are stacked in the same direction, and some of the plurality of block sheet members are selectively filled within the first and second through-holes, and the remaining block sheet members are selectively disposed at one side of the frame sheet member. 10 [9] In accordance with another aspect of the present invention, in the first frame sheet, a fourth frame sheet formed in the same plate shape as that of the first frame sheet is additionally connected. Advantageous effects 15 [10] As described above, a mat capable of changing to a sofa according to an exemplary embodiment of the present invention is made of a cushion material and is unfolded on the floor to be used as a bottom mat for preventing a safety accident of toddlers and children and to be used for play and rest by changing to a shape of a sofa by stacking and filling. 20 3 Brief Description of Drawings [11] FIG. 1 is a development view of a mat capable of changing to a sofa according to an exemplary embodiment of the present invention. [12] FIGS. 2a to 2c are perspective views illustrating a folded operation 5 of a frame sheet member of a mat capable of changing to a sofa according to an exemplary embodiment of the present invention. [13] FIG. 3 is a perspective view illustrating a filling operation of a block sheet member of a mat capable of changing to sofa according to an exemplary embodiment of the present invention. 10 [14] FIGS. 4 to 6 are perspective views illustrating a use state of a mat capable of changing to sofa according to an exemplary embodiment of the present invention. [15] FIG. 7 is a perspective view illustrating a use state of a mat capable of changing to sofa according to another exemplary embodiment of the present 15 invention. Best modes for carrying out the invention [16] [17] FIG. 1 is a development view of a mat capable of changing to a sofa 20 according to an exemplary embodiment of the present invention, FIGS. 2a to 2c 4 are perspective views illustrating a folded operation of a frame sheet member of a mat capable of changing to a sofa according to an exemplary embodiment of the present invention, FIG. 3 is a perspective view illustrating a filling operation of a block sheet member of a mat capable of changing to sofa according to an 5 exemplary embodiment of the present invention, FIGS. 4 to 6 are perspective views illustrating a use state of a mat capable of changing to sofa according to an exemplary embodiment of the present invention, and FIG. 7 is a perspective view illustrating a use state of a mat capable of changing to sofa according to another exemplary embodiment of the present invention. 10 [18] [19] A mat 1 capable of changing to sofa according to an exemplary embodiment of the present invention includes a frame sheet member 10 in which a plurality of frame sheets are connected to be stacked or unfolded in a multistage and that has a through-hole therein and a block sheet member 20 15 that is filled within the through-hole or is disposed at one side of the frame sheet member 10 and that is formed in various shapes that can be engaged to be filled without a gap within the through-hole. [20] [21] Here, in the frame sheet member 10, a plurality of frame sheets are 20 connected to be stacked or unfolded in a multistage, and a through-hole is 5 formed within the frame sheet member 10, and when the frame sheet member 10 is unfolded at the floor to be used as a bottom mat, the frame sheet member 10 forms the entire of a portion of the mat and a circumferential edge of another portion of the mat, and when the frame sheet member 10 is used as a sofa by 5 stacking, the frame sheet member 10 performs a function of forming the bottom and an outer frame of the sofa. [22] Such a frame sheet member 10 includes a plate-shaped first frame sheet 11 and second and third frame sheets 15 that have a "=" shape and in which first and second through-holes 17 and 19, respectively, are formed. 10 [23] That is, as shown in FIG. 1, the plate-shaped first frame sheet 11 is disposed at the rightmost, and at a left side corner thereof, a second frame sheet 13 is connected, and the first through-hole 17 is disposed toward a left direction, and similarly, at upper and lower corners of the left side of the second frame sheet 13 in which the first through-hole 17 is formed, the third frame 15 sheet 15 is connected, and the second through-hole 19 is disposed opposite to the first through-hole 17, and the first and second through-holes 17 and 19 form together a "-"-shaped through-hole. [24] Further, the frame sheet member 10 is stacked in an unfolded state, and as shown in FIG. 2, upper end portions of a connected corner of the first 20 and second frame sheets 11 and 13 are connected so that the second frame 6 sheet 13 is stacked on the first frame sheet 11, and lower end portions of a connected corner of the second and third frame sheets 13 and 15 are connected so that the third frame sheet 15 is folded to be stacked on the second frame sheet 13. 5 [25] Therefore, in a stacked state, the first frame sheet 11 is disposed at a lowest portion, and in an upper portion thereof, the second and third frame sheets 13 and 15 are sequentially stacked so that the first and second through holes 17 and 19 face toward the same direction, thereby forming a shape of a sofa. 10 [26] Such a frame sheet member 10 is formed with a filler of a cushion material having a restoring force of a compression sponge and an outer cover that encloses the filler from the outside and that has various designs, and when the frame sheet member 10 is used as a bottom mat or a sofa, the frame sheet member 10 prevents a safety accident that may occur to toddlers and children. 15 [27] Further, as shown in FIG. 7, a fourth frame sheet 30 formed in the same shape may be additionally connected to the first frame sheet 11, and when the fourth frame sheet 30 is used as a bottom mat, the fourth frame sheet 30 performs a function of enlarging an area of an entire mat, and when the fourth frame sheet 30 is used as a sofa by stacking, the fourth frame sheet 30 20 reinforces a cushion feeling of the first frame sheet 11, thereby performing a 7 function of providing a more comfortable impression. [28] The connection number of the first frame sheet 11 to the fourth frame sheet 30 may be changed according to various exemplary embodiments. [29] At the inside of the first and second through-holes 17 and 19 and 5 one side of the frame sheet member 10, the block sheet member 20 is provided, and when the frame sheet member 10 is unfolded at the floor, the block sheet member 20 fills the first and second through-holes 17 and 19 without a gap to complete a bottom mat, and when the frame sheet member 10 is used as a sofa by stacking, some of the block sheet member 20 is filled within the first and io second through-holes 17 and 19 and the remaining block sheet members 20 are put at one side of the stacked frame sheet member 10 to perform a function of completing a shape of a desired sofa. [30] When such a block sheet member 20 is filled within the first and second through-holes 17 and 19 of the frame sheet member 10 that is unfolded 15 or folded by stacking, the block sheet member 20 is formed in various shapes that can be engaged to be filled without a gap. [31] That is, the block sheet member 20 is formed in various shapes that can be engaged like a block used at "Tetris" game and is filled to be engaged without forming a gap or deviating to the outside within the first and second 20 through-holes 17 and 19. 8 [32] The block sheet member 20 is formed with a filler of a cushion material having a restoring force of a compression sponge like the frame sheet member 10 and an outer cover that encloses the filler from the outside and that has various designs, and when the block sheet member 20 is used as a bottom 5 mat or a sofa, the block sheet member 20 prevents a safety accident that may occur to toddlers and children. [33] [34] Hereinafter, as shown in FIGS. 4 to 6, an entire use method of the mat capable of changing to sofa 1 according to an exemplary embodiment of io the present invention will be described. [35] As shown in FIG. 1, when changing the mat 1 capable of changing to sofa unfolded at the floor to be used as a bottom mat to a sofa 1, as shown in FIG. 4, entire block mat members filled at the inside of the first and second through-holes 17 and 19 are first pulled out. 15 [36] Thereafter, the second frame mat is stacked on the first frame mat, and the third frame mat is sequentially stacked on the second frame mat, and in this case, the first and second through-holes 17 and 19 face the front side at a position at which the sofa is to be disposed. [37] Thereafter, a portion of the block mat member is filled within the first 20 through-hole 17 of a second frame mat 15 interposed between the first and the 9 third frame mats 11 and 15 to perform a sheet function of the sofa, and in this case, as shown in the drawing, the block sheet members 20 are engaged with each other to be completely filled without a gap within the first through-hole 17. [38] Thereafter, some of the remaining block sheet members are 5 disposed at the front side of the first frame mat 11 to be used as a leg support, and other block sheet members are disposed at an upper portion of the third frame mat to be used as a leg support or a neck support. [39] [40] As shown in FIG. 5, as the block mat member is disposed to be 10 engaged at the front side of first frame mat without being filled within the first through-hole 17, at the rear side, a sofa may be formed and at the front thereof, a bottom mat may be formed and used. [41] [42] As shown in FIG. 6, the block mat member forms a rectangular 15 shape by filling within the second through-hole 19 as well as the first through hole 17 and is thus used as an unbacked sofa. [43] [44] The foregoing invention has been described in terms of preferred embodiments. However, those skilled in the art will recognize that many 20 variations of such embodiments exist. Such variations are intended to be 10 within the scope of the present invention and the appended claims. [45] [46] [Description of symbols] [47] 1: mat capable of changing to sofa 5 [48] 10: frame sheet member [49] 11: first frame sheet [50] 13: second frame sheet [51] 15: third frame sheet [52] 17: first through-hole 10 [53] 19: second through-hole [54] 20: block sheet member [55] 30: fourth frame sheet [56] [57] 15 [58] 11