JP2006192610A - Blackboard device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blackboard device from the upper end side of a blackboard, a screen is lowered to start an image projection thereto immediately, when a video image is projected using a video projector or a slide projector is used in a classroom. <P>SOLUTION: This blackboard device comprises a roll-up projection screen 4 arranged on the upper end part of the blackboard 2 in the way that the screen 4 is movable in the longitudinal direction of the blackboard 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blackboard device in which a hoisting projection screen is installed on a blackboard.

  If you use a video projector to enlarge the video in a school classroom or use a slide projector, the classroom usually does not have a projection screen, so the projection screen appears on the blackboard installed in front of the classroom. Hook it with a hook, or attach a blank paper such as imitation paper to the blackboard, and use that white paper as a screen substitute, but each time you attach the projection screen to a position that is easy to see on the blackboard However, there are various problems such as that it takes a lot of time and white paper such as imitation paper makes the image appear worse.

  In view of the above-mentioned problems, the present invention allows a screen to be projected from the upper end side of the blackboard and immediately projected onto the screen when a video is projected by a video projector or a slide projector is used in a school classroom. An object of the present invention is to provide a blackboard device that can be used.

  Means for solving the above problems will be described with reference numerals in the embodiments described later. In the blackboard device of the invention according to claim 1, the hoisting projection screen 4 is placed on the upper end of the blackboard 2 in the longitudinal direction of the blackboard. It is characterized by being installed to be movable in the direction.

  In a second aspect of the present invention, the hoisting-type projection screen 4 is configured such that the winding projection screen 4 has a winding shaft 41 that is wound around a sheet-like screen body 40 in a roll shape and is supported in a screen case 42. Thus, the screen case 42 is movably supported by a guide rail 43 provided along the upper end portion of the blackboard 2.

  According to a third aspect of the present invention, in the blackboard device according to the first or second aspect, the blackboard 2 is held on the fixed frame 1 so as to be movable up and down via a lift driving means 3.

  According to a fourth aspect of the present invention, in the blackboard device according to the third aspect, the elevating drive means 3 includes a first drum 9 and a second drum 10 that are coaxially and integrally rotatable at the center of the fixed frame 1. The one end portions 11a and 12a of the pair of first cable bodies 11 and 12 are fastened to the outer periphery of the first drum 9 and wound in the same direction, and the other end portions 11b and 12b are at both left and right ends of the fixed frame 1 It fixes to the lower end part of the blackboard 2 via the guide pulleys 13 and 14 provided in the section, and the one end part 15a of the second cable body 15 is fixed to the outer periphery of the second drum 10, and the first cable bodies 11 and 12 are fixed. The other end 15b is connected to an output shaft 17 of a linear actuator 16 provided on the fixed frame 1, and the operation of the output shaft 17 raises and lowers the blackboard 2 and at an arbitrary height position. It is characterized by being made to stop.

  The fifth aspect of the present invention is the blackboard device according to the third aspect, wherein the elevating drive means 3 includes a disk-shaped first drum 9, a cam-shaped second drum 10, and a brake drum 60 at the center of the fixed frame 1. A pair of first ropes 11 and 12 are extended downwardly through guide pulleys 13 and 14 on the outer peripheral surface of the first drum 9, and one end thereof is fixed to the lower end of the blackboard 2, and the second One end of the second cable body 15 is fastened to the outer peripheral surface of the drum 10 and wound in the opposite direction to the first cable bodies 11 and 12, and the other end is connected to the balance spring mechanism 63, and the brake A brake band 66 that is biased by a brake spring 67 is attached to the outer peripheral surface of the drum 60, and a brake release lever 68 that releases the brake against the biasing force of the brake spring 67 is attached to the brake band 66. Become And wherein the door.

  The effect of the invention by the above-described solution means will be described with reference numerals of the embodiments described later. According to the blackboard device of the invention of claim 1, when the projection screen 4 is not used, the screen body 40 is rolled up. If so, the normal blackboard 2 can be used in that state, and when the video is enlarged and broadcast by a video projector in a school classroom or when a slide projector is used, the projection screen 4 is moved in the longitudinal direction of the blackboard 2 By doing so, for example, all the students in the classroom can be set at a position that is most easy to see.

  According to the blackboard device of the second aspect of the invention, the projection screen 4 can be easily and easily moved in the longitudinal direction of the blackboard 2, and the screen body 40 can be easily raised and lowered.

  According to the blackboard device of the third aspect of the invention, the height of the projection screen 4 can be set to a desired position by operating the elevating drive means 3 to raise and lower the blackboard 2.

  According to the blackboard device of the invention of claim 4, since the blackboard 1 is moved up and down and stopped at an arbitrary height position by the operation of the output shaft 17 of the linear actuator 16 by the lift driving means 3, the linear actuator If the 16 electric switches can be operated, the blackboard 1 can be freely moved up and down at any position regardless of the height, hand strength, and position of the operator. Can be operated by the person using the screen, and the height of the projection screen 4 can be adjusted easily and easily.

  In addition, since this linear blackboard device has only to be attached to the fixed frame body 4 with the linear actuator 16 having a very compact structure, the number of parts of the entire device is small, the structure is simple, the manufacture is easy, and the cost is low. In addition, it is possible to reduce the wear and damage of parts and to facilitate maintenance.

  According to the blackboard device of the invention according to claim 5, since the blackboard is moved up and down by the blackboard driving means using the balance spring mechanism, the blackboard is lifted and stopped easily by the user's manual operation. The height of the projection screen can be easily adjusted.

  A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 (a) is a front view of a blackboard device according to the present invention, (b) is a side view, and FIG. It is an XX line expanded sectional view of a). FIG. 3 is a front view showing the raising / lowering driving means 3 for raising and lowering the blackboard 2. This blackboard device includes a fixed frame 1 attached to a wall W of a classroom, a blackboard 2 held on the fixed frame 1 so as to be movable up and down, a lifting drive means 3 for driving the blackboard 2 up and down, and a blackboard 2 And a hoisting projection screen 4 movably installed in the longitudinal direction of the blackboard 2.

  As shown in FIG. 2, the blackboard 2 has a substrate 34 made of veneer plywood, for example, fixed to a wooden frame 33 made up of a peripheral frame 31 and an intermediate frame 32 therebetween by an adhesive or nailing. A surface material 35 made of a coated steel plate or a steel plate is attached to 34 with an adhesive. A material composed of the substrate 34 and the surface plate 35 attached thereto is referred to as a blackboard surface material 36.

  As shown in FIG. 2, the blackboard 2 is integrally attached to the elevating frame 37 by mounting brackets 44 and 45, and the elevating frame 37 can be raised and lowered to the fixed frame 1 through the elevating drive means 3. Retained. 2 and 3, the elevating frame 37 includes a pair of left and right elevating guide columns 5, 6 and upper and lower frames 38, 39 that connect the upper end portions and the lower end portions of the elevating guide columns 5, 6 respectively. The left and right lifting guide columns 5 and 6 pass through the guide holes 7 and 7 provided at the left and right ends of the fixed frame 1 and are driven up and down by the lifting drive means 3. ing.

  As shown in FIGS. 1 and 2, the projection screen 4 has a winding shaft 41 in which a winding shaft 41 for winding and pulling out a sheet-like screen body 40 in a roll shape is supported in a screen case 42. The screen case 42 is movably supported on a guide rail 43 provided along the upper end portion of the blackboard 2, and a bracket 46 is attached to the screen case 42. A plurality of support shafts 48 to which guide wheels 47 are attached are attached, and these guide wheels 47 are fitted into guide rails 43 at the upper end of the blackboard 2 so that they can be moved along the longitudinal direction of the blackboard 2.

  Although not shown, the take-up shaft 41 is pivotally supported by the screen case 42 while being urged in the direction to take up the screen main body 40 by a take-up spring. The screen main body 40 may be pulled downward against the urging force of the spring, and the screen main body 40 is appropriately held by a stopper in the pulled-out position.

  A round bar 50 is provided at the lower end of the screen body 40, and a handle 51 for pulling out the roll-shaped screen body 40 from the winding shaft 41 is attached to the center of the round bar 50. It is. Further, as shown in FIG. 2, the guide rail 43 is fixed to the upper side portion of the aluminum frame 49 attached to the peripheral frame 31 of the blackboard 2 by a fixing bracket 52. In FIG. 2, 53 is an aluminum powder receiver.

  Next, the raising / lowering drive means 3 which raises / lowers the blackboard 2 will be described with reference to FIG.

  A rotating shaft 8 orthogonal to the surface of the blackboard 2 is supported at the center of the fixed frame 1 so as to be able to rotate forward and backward by a bearing (not shown). 9 and the second drum 10 are fixed so as to be integrally rotatable in close proximity on the same axis. One end portions 11a and 12a of the pair of first rope bodies 11 and 12 are fixed to the outer peripheral surface of the first drum 9 at the point symmetrical positions, and the one end portions 11a and 12a side is the outer periphery of the first drum 9. The other end portions 11b and 12b are extended downward through guide pulleys 13 and 14 pivotally supported at both left and right end portions of the fixed frame body 4, respectively. Each is fixed to a lower frame 39 of an elevating frame 37 that is integral with the blackboard 2.

  One end 15a of the second cord 15 is fixed to the outer periphery of the second drum 10, and the one end 15a is wound around the outer periphery of the second drum 10 in the direction opposite to the first cords 11 and 12. The other end 15b is connected to the output shaft 17 of the linear actuator 16 also provided in the fixed frame 4 via a guide pulley 19 provided in the right end of the fixed frame 4. 18 are linked together.

  The linear actuator 16 includes a main body portion 20, a base tube portion 21 extending from the main body portion 20, and an output shaft 17 provided concentrically on the base tube portion 21. A drive mechanism (not shown) driven by the provided electric motor causes the output shaft 17 to perform a mechanical linear motion of a predetermined axial direction stroke. The blackboard 2 is moved up and down through the two drums 10, the first drum 9 and the first ropes 11 and 12, and the blackboard 2 is stopped at an arbitrary height position by the stopping operation of the output shaft 17.

  The linear actuator 16 is selected by balancing the relationship between the weight of the blackboard 2 and the thrust and holding force of the output shaft 17. The stroke length of the output shaft 17, the first cords 11, 12 are selected. In addition, the length of the second cable body 15 and the elevation distance of the blackboard 2 are set as appropriate, and then the main body 20 and the base tube 21 of the actuator 16 are fixed to the fixed frame 4. Yes.

  The first rope bodies 11 and 12 attached to the outer peripheral surface of the first drum 9 are made of wire, the second drum 10 is made of a sprocket, and the second rope body 15 attached to the outer circumference of the second drum 10 made of this sprocket. Consists of chains.

  A motor (not shown) of the linear actuator 16 is connected to a power source 24 by a connection cord 22 via a controller 23 for blackboard lifting operation. The controller 23 is provided with a push button switch a for raising the blackboard and a push button switch b for lowering the blackboard. When any one of the push button switches a or b is pressed, the linear actuator 16 is pressed. The output shaft 17 is moved in the contraction direction or the extension direction, the blackboard 2 is raised or lowered, and when the hand is released from the push button switch a or b, the output shaft 17 is stopped and the blackboard 2 is raised. Alternatively, the descent operation is stopped, and the blackboard 2 stops at an arbitrary height position. The output shaft 17 automatically stops at the contraction limit position and the extension limit position, so that the blackboard 2 stops at the ascending limit position and the descending limit position. In this case, the controller 23 may be connected wirelessly and remotely controlled by the push button switches a and b.

  1 and 3 show a state in which the blackboard 2 is stopped at the intermediate height position in the vertical direction. In this state, the output shaft 17 of the linear actuator 16 shown in FIG. 2 is at an intermediate position between the expansion limit position and the contraction limit position with respect to the base tube portion 21. If the output shaft 17 of the linear actuator 16 extends rightward from the position indicated by the solid line in FIG. 3 by pressing the blackboard lowering push button switch b of the controller 23, the output shaft 17 Since the second cord body 15 is loosened by the thrust in the extending direction, the second drum 10 together with the first drum 9 is counterclockwise due to the tension acting on the first cord bodies 11 and 12 due to the weight of the blackboard 2. Thus, the first cords 11 and 12 are unwound from the first drum 9, and the blackboard 2 is lowered from the intermediate height position shown by the solid line in FIG. If the hand is released from the push button switch b while the blackboard 2 is descending, the extension operation of the output shaft 17 is stopped and the holding force is applied to the output shaft 17. Are balanced, and the blackboard 2 stops at an arbitrary lowered position.

  Further, for example, when the blackboard 2 push button switch a is pushed from the state where the blackboard 2 is at the intermediate height position shown in FIG. 3, the output shaft 17 is contracted to the left from the position indicated by the solid line in FIG. The second cord 15 is pulled by the thrust in the contraction direction of the output shaft 17, and the second drum 10 rotates clockwise together with the first drum 9, whereby the first cords 11, 12 are moved to the first drum 9. The blackboard 2 goes up as it is wound up. If the hand is released from the push button switch a while it is rising, the contraction operation of the output shaft 17 stops, and the holding force acts on the output shaft 17. Therefore, the holding force and the weight of the blackboard 2 are balanced. The blackboard 2 stops at an arbitrarily raised position.

  The linear actuator 16 is connected to the output shaft 17 and the output shaft 17 because the output shaft 17 may slightly rotate when the output shaft 17 extends and contracts with respect to the base tube portion 21 extending from the main body portion 20. If the end 15b of the second cable body 15 is fixedly connected as it is, the second cable body 15 is twisted to cause a problem, but the end 15b of the second cable body 15 is Since the output shaft 17 is connected to the output shaft 17 via the connecting member 18 that does not transmit the rotating motion to the second cable body 15, the output shaft 17 is not twisted and does not cause a problem.

  When the roll-up projection screen 4 installed at the upper end of the blackboard 2 that can be driven up and down by the up-and-down drive means 3 configured as described above, the screen body 40 is wound around the take-up shaft 41 when not in use. In use, the screen case 42 is appropriately moved to the required position in the left-right direction along the guide rail 43 at the upper end of the blackboard 2, and the screen body 40 is pulled with the handle 51 at the lower end at that position. Just drop it down. Then, the height of the projection screen 4 can be freely set to a desired position by operating the above-described lifting drive means 3 to move the blackboard 2 up and down.

  In the blackboard device according to the present invention described above, the roll-up projection screen 4 is installed at the upper end of the blackboard 2 so as to be movable in the longitudinal direction of the blackboard 2. Therefore, when the projection screen 4 is not used, the screen body 40 is used. If you roll up the screen, you can use the normal blackboard 2, and when you use the video projector in the classroom to enlarge the video, project a movie with a projector, or use a slide projector, use the projection screen 4 on the blackboard 2. By moving in the longitudinal direction, all the students in the classroom can be set at a position that is most visible.

  The hoisting projection screen 4 is formed by supporting a take-up shaft 41 obtained by winding a sheet-like screen main body 40 in a roll shape in a screen case 42. Since it is movably supported by a guide rail 43 provided along the upper end of the blackboard 2, it can be easily moved in the longitudinal direction of the blackboard 2 and the screen body 40 can be easily raised and lowered. .

  Further, since the blackboard 2 is held by the fixed frame 1 so as to be able to move up and down via the lifting drive means 3, the height of the projection screen 4 can be set by moving the blackboard 2 up and down by operating the lifting drive means 3. Can be set to the position.

  As described above, the elevating drive means 3 is provided with the first drum 9 and the second drum 10 coaxially and integrally rotatable at the center of the fixed frame 1, and a pair on the outer periphery of the first drum 9. One end portions 11a and 12a of the first cable bodies 11 and 12 are fastened and wound in the same direction, and the other end portions 11b and 12b are guide pulleys 13 and 14 provided at both left and right end portions of the fixed frame body 1, respectively. Is fixed to the lower end portion of the blackboard 2 via the first end 15a of the second cord 15 around the outer periphery of the second drum 10 and wound in the opposite direction to the first cords 11 and 12, The other end 15b is connected to an output shaft 17 of a linear actuator 16 provided on the fixed frame 1, and the operation of the output shaft 17 of the linear actuator 16 causes the blackboard 1 to move up and down and stop at an arbitrary height position. The linear actuator If the electric switch 6 can be operated, it is possible to freely move the blackboard 1 up and down at any position regardless of the height, hand strength, and position of the operator, and thus the wheelchair. Can be operated by the person using the screen, and the height of the projection screen 4 can be adjusted easily and easily.

  FIG. 4 shows another embodiment of the raising / lowering drive means 3. The fixed frame 1 is provided with a rotating shaft 8 orthogonal to the surface of the blackboard 2, and a concentric disk shape on the shaft 8. The first drum 9, the cam-shaped second drum 10, and the brake drum 60 are integrally and sequentially shifted in parallel in the axial direction so that these members can rotate freely with respect to the fixed frame 1. A pair of first ropes 11 and 12, which are axially mounted and fixed at one end to a point-symmetrical position on the outer peripheral surface of the first drum 9, are lowered via guide pulleys 13 and 14 provided in the vicinity of both left and right ends. The other end of each is connected to the blackboard lower frame 39. Therefore, if the first drum 9 rotates counterclockwise as indicated by the arrow in the figure, the first cords 11 and 12 are pulled out downward and attached to the blackboard upper and lower frames 38 and 39, and therefore to this. The blackboard 2 is lowered by its own weight.

  On the other hand, the second cable body 15 having one end fixed to the cam-shaped second cable body 10 in a reverse direction to the winding of the first cable bodies 11 and 12 is connected to the balance spring mechanism 63. That is, the other end is connected to the spring mounting plate 61 via the guide pulley 19 on the upper right side in the drawing. A plurality of, in the drawing, three balance springs 63a to 63c are mounted in parallel between the spring mounting plate 61 connected to the second cable body 15 and the other spring mounting plate 62 opposite to the spring mounting plate 61. It has been. One end portion of the cable body for the frame body 64 is fixed to the spring mounting plate 62 on the other side, and the other end portion of the cable body 64 is connected to the lower end portion of the fixed frame body 1 via the guide pulley 65. . The rotational torque of the cam-shaped second drum 10 due to the urging force of the balance springs 63a to 63c that sequentially increases by the disk-shaped first drum 9 that rotates as the blackboard 2 is lowered is the weight of the blackboard 2. The cam surface of the cam-shaped second drum 10 is formed so as to be successively smaller in the radial direction so as to always coincide with the rotational torque of the disk-shaped first drum 9 according to the above. The balance springs 63a to 63c that resist are suspended and held by the urging force to obtain a mechanical equilibrium, and can be stopped at any position up and down, and is restricted by the brake means at the stop position. To be maintained.

  That is, a total of a plurality of, in the drawing, three balance springs 63a to 63c attached to the spring attachment plate 61 on the second cable body 15 side and the spring attachment plate 62 on the frame cable body 64 side, respectively. The urging force is adjusted to the urging force that obtains a mechanical balance with the weight of the blackboard 2.

  A brake band 66 is attached to the outer periphery of the brake drum 60, and a brake spring 67 and a brake release lever 68 are attached to one end of the brake drum 60. The brake release lever 68 is connected to a push-pull operating string 69 at one end. The other end portion of the operation string 69 is connected to a brake release lever 70 attached along the lower end portion of the blackboard 2.

  Accordingly, the rotation of the disc-shaped first drum 9 is restricted by the frictional force of the brake band 66 due to the urging force of the brake spring 67, and the vertical movement of the blackboard 2 is restricted, and the operation is performed by the release operation of the brake release lever 70. The brake release lever 68 transmitted via the string 69 loosely moves the brake band 66 around the shaft 71 in a direction against the urging force of the brake spring 67, thereby releasing the brake and releasing the disc-shaped first drum. The blackboard 2 interlocking with the rotation of the blackboard 9 is guided by the lifting guide columns 5 and 6 that pass through the guide holes 7 and 7 of the fixed frame 1 while maintaining the mechanical balance by the balance springs 63a to 63c. Lightly move up and down.

  In this way, the raising / lowering driving means 63 using the balance spring mechanism 64 can also raise and lower the blackboard 2 and can easily adjust the height of the projection screen.

  In the embodiment described above, the case where the projection screen 4 is installed on the blackboard 2 that is held up and down by the fixed frame 1 via the elevation drive means 3 has been described. However, the projection screen 4 according to the present invention does not move up and down. You may install in the upper end part of the fixed blackboard 2 so that the longitudinal direction movement is possible. The projection screen 4 may have any structure as long as it is a hoisting screen. Further, the projection screen 4 can be installed not only on the blackboard 2 of the new classroom but also on the blackboard 2 of the existing classroom.

(a) is a front view of the blackboard device according to the present invention, and (b) is a side view. It is the XX line expanded sectional view of (a) of FIG. It is a front view which shows the raising / lowering drive means for raising / lowering driving a blackboard. It is a front view which shows other embodiment of the raising / lowering drive means for raising / lowering driving a blackboard.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed frame 2 Blackboard 3 Elevating drive means 4 Projection screen 5, 6 Elevating guide support | pillar 8 Rotating shaft 9 1st drum 10 2nd drum 11, 12 1st rope 11a, 12a One end 11b, 12b of 1st rope Other ends 13 and 14 of the first rope 15 Guide pulley 15 Second rope 15a One end 15b of the second rope 15 Other end 16 of the second rope 15 Linear actuator 17 Output shaft 18 Connecting member 40 Screen body 41 Winding shaft 42 Screen case 43 Guide rail

Claims (5)

  A blackboard device, wherein a roll-up projection screen is installed at the upper end of the blackboard so as to be movable in the longitudinal direction of the blackboard.   The hoisting projection screen is formed by supporting a winding shaft obtained by winding a sheet-like screen main body in a roll shape in a screen case, and the screen case is provided along the upper end portion of the blackboard. 2. The blackboard device according to claim 1, wherein the blackboard device is movably supported on a rail.   The blackboard apparatus according to claim 1 or 2, wherein the blackboard is held on a fixed frame so as to be movable up and down via a lift drive means.   The elevating drive means is provided such that the first drum and the second drum are coaxially and integrally rotatable at the central portion of the fixed frame body, and one end portions of the pair of first rope bodies are fixed to the outer periphery of the first drum. The other end is fixed to the lower end of the blackboard via guide pulleys provided at the left and right ends of the fixed frame body, and one end of the second cord body is disposed on the outer periphery of the second drum. The other end is connected to the output shaft of the linear actuator provided on the fixed frame body, and the operation of this output shaft raises and lowers the blackboard and the desired height. 4. The blackboard device according to claim 3, wherein the blackboard device is stopped at the vertical position. The elevating drive means has a disk-shaped first drum, a cam-shaped second drum, and a brake drum attached to a central portion of the fixed frame body, and a pair of first ropes on the outer peripheral surface of the first drum. The lower end of the blackboard is fixed to the lower end of the blackboard, and the second end of the second cord is fixed to the outer peripheral surface of the second drum and wound in the opposite direction to the first cord. The other end is connected to a balance spring mechanism, and the brake drum is provided with a brake band urged by the brake spring on its outer peripheral surface, and the brake band is against the urging force of the brake spring. 4. The blackboard device according to claim 3, further comprising a brake release lever for releasing the brake.

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