LIGHT-EMITTING BUILDING BLOCK HAVING ELECTRICITY CONNECTION UNIT AND POWER SUPPLY BASE F OR THE SANE BACKGROUND OF THE INVENTION 1. Field of the Ivention [00011 The present invention relates generally to a light-emitting building block, and in particular to the light-emitting building block having a light member and an electricity connection unit received therein and when multiple building blocks are connected to each other, the electricity connection units are connected to transfer power to the light members. 2. The Prior Arts [00021 Although modem toys or video games provide more vivid entertainment than traditional toys, some traditional toys, such as building blocks, still attract many parents and children. Playing the building blocks can improve hand-eye coordination of young children Moreover, the building blocks can be assembled and connected in many ways, which is fun. Children and adults both can use bricks in various shapes to create anything and everything, such as vehicles, buildings, and even robots, Therefore, the building block is still one of most popular toys across all ages. 100031 Although the conventional building blocks provide entertainment and stimulate creativity, the building blocks can be improved to attract more children to play. One of schemes to attract attention of the children is to provide a lightemitting building block. The improved building blocks can lluminate when they are connected to each other and still has a structure not too complicated, SUMMARY OF THE INVENTION [0004] A primary objective of the present invention is to provide a iight-emitting building block having a light member and an electricity connection unit received therein. When the building blocks are connected to each other, the electricity connection units form a circuit to supply power to the light members thereby enhancing entertainment [00051 In order to achieve the objective, a building block according to the present invention comprises a hollow and light transmittable brick. The brick has at least two studs extended from a top of the brick and at least two tubes corresponding to the studs defned in a bottom of the brick. At least two electricity connection units corresponding to the studs are disposed in the brick and each electricity connection unit has a positive conducting member and a negative conducting member. The positive conducting member has a fist positive contact and a second positive contact respectively located at two ends thereof and the negative conducting member respectively has a frst negative contact and a second negative contact located at two ends thereof. At least one light member is disposed in the brick and electrically connected with the electricity connection units A circuit board is disposed in the brick and the light member is assembled on the circuit board. Each electricity connection unit includes a rod. The positive conducting member and the negative conducting member are connected with the rod, and the positive conducting member is separated from the negative conducting member. The rod passes through the circuit board. Thus, the first posKivecontact and te second positive contact of the positive conducting member are respectively located at two sides f the circuit board, so that the first positive contact is disposed in the stud and the second positive contact is disposed in the tube. Similarly, the first negative contact and the second negative contact of the negative condAting member are respectively located at two sides of the circuit board, so that the first negative contact is disposed in the stud and the second negative contact is disposed in the tube. [0006] When the bricks are connected to each other by inserting the studs of one brick into the tubes of another brick, the first positive and negative contacts in the studs are in contact with the second positive and negative contacts in the tubes so as to form a circuit. When one of the bricks is electrically connected to a power supply or a power supply is built in the brick, all of the light members in the connected bricks are turned on, which increase the visual attraction. [0007] Another objective of the present invention is to provide a power supply base for supplying power to the building blocks. [0008] The hollow power supply base has at least one stud corresponding to the tube of the brick disposed on a top thereof T he stud of the power supply base has a positive electrode piece and a negative electrode piece, When the power supply base is engaged with the brick, the positive electrode piece and the negative electrode piece are electrically connected with the second positive contact and the second negative contact disposed in the tube of the brick respectively. The positive electrode piece and the negative electrode piece are electrically connected with at least one battery so as to provide power to the light member in the brick. [00091 The electric power of the battery disposed in the power supply base is transferred to the electricity connection units through the positive and negative electrode pieces so as to illuminate the light membersJin the bricks. BRIEF DESCRIPTI )N OF THE DR/AW WINGS [00101 The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiments thereof, with reference to the attached drawings, in which: 100111 Figure 1 is a perspective view showing a light-emitting building block in accordance with a first embodiment of the present invention; 100121 Figure 2 is another perspectiveview showing the building block in accordance with the first embodiment of the present invention; 100131 Figure 3 is a cross-sectional view showing the building block according to the first embodiment of the present invention; 10014] Figures 4A to 4C show various connections between electricity connection units and Light Emitting Diodes of the building blocks according to the present invention; 100151 Figure 5 is a cross sectional view showing the building blocks and a power supply base according to the first embodiment of the present invention connected to each other; 100161 Figure 6 is a cross-sectional view showing a building block according to a second embodiment of the present invention; [0017] Figure 7 is a cross sectional view showing the building blocks according to the second embodiment of the present invention connected to each other; jO0S Figure 8 is a perspective view showing a building block according to a third embodiment of the present invention; anid [0019j Figure 9 is a perspective view showing a building block according to a fourth embodiment of the present invention. DI-AILD DIF l)ESCR I'iWON OF TIHI PREFERRED EMBODI MENT .4 100201 With reference to the drawings and in particular to Figs I and 2, a lighbemitting building block according to a first embodiment of the present invention comprises a holow and light transmittable brick 10,. The rectangular brick 10 has at least two studs 11 extended from a top of the brick 10 and at least two tubes 12 defined in a bottom of the brick 10. The shape, size and the position of the tubes 1.2 are corresponding to the studs 11. The brick 10 according to the first embodiment has four studs I 1 and four tubes 12 arranged in a symmetric form of a 4 by 4 matrix [00211 As shown in Fig. 3, at least two electricity connection units are disposed in the brick 10. The number of the electricity connection units is the same as the number of the studs 11 and the positions of the electricity connection units are corresponding to the studs 11, and therefore the brick 10 according to the first embodiment has four electricity connection units received therein. Each electricity connection unit has an insulating rod 20. a positive conducting member 21 disposed inside and extended through the rod 20 and a negative conducting member 22 disposed outside ofthe rod 20. The rod 20 separates the positive conducing member 21 from the negative conducting member 22, and therefore the positive conducting member 21 is not contacted with the negative conducting member 22. The rod 20 according to the first embodiment includes an tpper fixing portion 201 and a lower fixing portion 202 disposed at an upper portion and a lower portion thereof respectively. An upper end of the rod 20 penetrates through the top of the brick 10 and the dis.kshaped upper fixing portion 201 of the rod 20 is contacted with an inner side of the top of the brick 10. 1 he lower fixing portion 202 of the rod 20 extends laterally from an outer surface of the lower portion of the rod 20 so as to fixing the negative conducting member 22.
[00221 The positive conducting member 21 has a first positive contact 211 and a second positive contact 212 disposed on two ends thereof respectively. According to the first embodiment, the positive conducting member 21 is a thin rod and is axially disposed in the rod 20. The first positive contact 211 of the positive conducting member 21 is a flat plate and located on a top the rod 20. The second positive contact 212 is shaped in a spiral and protruded out of a bottom of the rod 20 and located in the tube 12. [0023] The negative conducting member 22 has a first negative contact 221 and a second negative contact 222 disposed on two ends thereof respectively According to the first embodiment, the negative conducting member 22 is an elongated strip and the first negative contact 221 is shaped in a ring-shaped bowl having a central hole, The ring-shaped bowl of the first negative contact 221 includes an inner wall, an outer wall and a bottom between the inner and outer walls. The inner wall of the first negative contact 221 defines the centra hole of the ring-shaped bowl, and is corresponding to and sleeved on the upper end of the rod 20 The outer vail of the fist negative contact 221 is corresponding to and contacted with an inside of the stud 11. Because the outer wall of the first negative contact 221 is engaged with the inside of the stud 11 and the inner wall of the first negative contact 221 is sleeved on the upper end of the rod 20, the upper end of the rod 20 is fixed. The second negative contact 222 of the negative conducting member 22 is a flexible bent strip and located in the tube 12 and cloe to the inner periphery of the tube 12. 100241 The brick 10 has at least one light member located therein and the light member is electrically connected with the positive and negative conducting members 21, 22. Acording to the first enbodiment, the light member includes a Light Emitting Diode 31 (LED) which is connected to a circuit board 32. The circuit 6 board 32 has niore than one set of wires 33 connected to the positive arnd negative conducAting members 21, 22 of the electricity connection unts. As shown in Fig. 4A, the positive conducting members 21 are connected in parallel and the negative conducting members 22 are connected in parallel. Then, the parallel-connected positive conducting members 21 and the parallel-connected negative conducting members 22 are connected to the LED on the circuit board 32 in series. Therefore, when any one of the electricity connection units (including the positive and negative condo acting members 21 22) is connected with the power source, the LET) 31 on the circuit board 32 is tumed on. The rod 20 passes through the circuit board 32. [00251 The positive conducting members 215 the negative conducting members 22 and the LEDs 31 can also be connected by another ways described hereinafter. [00261 As shown in Fig. 4B, each of the electricity connection units is individually connected with one LED 31. For example, the brick 10 according to the first embodiment includes four electricity connection units and four LEDs 3 1 disposed in the brick 10, When any of the electricity connection units is connected with the power source, the corresponding LED 31 is turned on. [0027] As shown in Fig 4C, the electricity connection units is arranged in pairs and each pair of the electricity connection units is connected with one L"ED 3 1. For example, the four electricity connection units of the brick 10 according to the first embodiment are arranged in two pairs and the brick 10 has two LEDs 31. In each pair of the electricity connection units, the two positive conducting members 21 are connected in parallel, the two negative conducting members 22 are connected in parallel and then the positive and negative conducting members 2 1 22 and the LED 31 are connected in series. When the positive and negative conducting members 21, 22 of one of the electricity connection units in the brick 10 are connected with the power soure, the corresponding LED 31 is turned on, but the LED 31 connected with the other pair of the electricity connection unit is not turned on. 10028] In order to provide the power to the light members, the brick 10 includes at least one battery (not shown in the drawing) received therein and the battery may be counted to the circuit board 32. The brick 1.0 further includes a switch 34 to control the connection between the Light Emitting Diode 31 and the battery. The switch 34 may be disposed at an underside of the circuit board 32 and located corresponding to one of the tubes 12 in the bottom of the brick 10. Therefore, tbe user can operate the switch 34 through the tube 12 [00291 In addition to using the battery disposed in the brick 10 to supply power, the power supply may be disposed outside of the brick 10. According to another embodiment, the brick 10 connects with a power supply base 40 having a structure corresponding to the tubes 12 and the electricity connection units of the brick 10. Referring to Fig 5, a top of the power supply base 40 includes at least one stud 41 corresponding to the tubes 12 of the brick 10. Each stud 41 of the power supply base 40 has a positive electrode piece 42 and a negative electrode piece 43 disposed therein, The positive electrode piece 42 and the negative electrode piece 43 have structures the same as those of the first positive and negative contacts 211, 221, respectively. The positive electrode piece 42 and the negative electrode piece 43 are connected to at least one battery (not shown in the drawings) When the tubes 12 of the bricks 10 are engaged with the studs 41 of the power supply base 40, the second positive and negativcontacts 212., 222 in the tube 12 arc electrcally contacted with the positive and negative electrode pieces 42, 43 of the power supply base 40, respectively. therefore , the power supply base 40 provides power to the LEDs 31 in the brick 10 by the positive and negative electrode pieces 42, 43 of the power supply base 40 and the electricity connection units of the brick 10. [0030] Referring to Fig. 5, when the brick 10 is connected with another brick 10', the power supply base 40 supplies power to the LEDs 31 in the brick 10, and also supplies power to the LEDs 31 in the brick 10' through the electricity connection units of the briek 10. 100311 When the bricks 10 and 10, are connected to each other, the studs 11 of one brick are engaged with the tubes 12 of another brick and the electricity connection units of the bricks 10 and 10' are electrically connected. 'he light members can be turned on to provide the interlocking bricks 10 with the visual attraction. [00321 Figs. 6 and 7 show a brick 10 according to a second embodiment of the present invention, wherein the differences between the first and second embodiments areh the O fthe positive and negative conducting members of the electricity connection unit. 100331 The positive conductig member 51 and the negative conducting member 52 of the brick 10 according to the second embodiment are connected to a hollow rod 50. The positive conducting member 51 includes a top contact pin i1, a bottom contact pin 12 and a spring 513 disposed between the top and bottom contact pins 512, 513. Each of the top and bottom contact pins 511, 512 includes a first end and a second end. The first ends of the top and bottom contact pins 511, 512 are projected out of two ends of the rod 50 to form the first and second positive contacts, respectively. The spring 513 is compressed between the second ends of the top and bottom contact pins 5|11 512 and therefore the top and bottom contact pins 511 512 are movable by compressing the spring 51. Moreover, the top and bottom contact pins 511, 512 and the spring 513 forms a circuit to be electrically connected with the LED 31, [0034] The negative conducting member 52 includes a first negative contact 521 disposed at a first end thereof The first negative contact 521 is a conical coil and the diameter of the first negative contact 521 is gradually reduced from top to bottom thereof The top contact pin 511 is disposed inside of the first negative contact 521. A second end of the negative conducting member 52 is bent to form a flexible second negative contact 522 which is connected with the LED 31 on the circuit board 32 to form a circuit [0035] The connections of the positive and negative conducting members 51, 52 and the 1 4 E1)s 31 are the same as those disclosed in Figs 4A to 4C. [00361 The same as the first embodimentwhen the bricks 10 according to the second embodiment are connected to each other, the tubes 12 of the brick are engaged with the studs I1 of another brick and the bottom contact pin 512 and the second negative contact 522 of the brick are respectively connected with the top contact pin 511 and the first negative contact 521 of another brick. Therefore, the circuit is formed to tun on the LEDs 31 [0037] The bricks 10 can be rectangular cubes or another shapes of cubes and the number of the studs can also be adjusted. As shown in Figs. 8 and 9, the brick 10 are rectangular cube having two and eight studs 11 on the top thereof respectively. The structure inside the brick 1 0 is the same as the previous embodiments. [0038] Although the present invention has been described with reference to the preferred embodiments thereof it is apparent to those skiUed in threat that a variety of nodifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims I0