JP2018189925A - Blackboard projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blackboard projection device in which a movable type projector is installed with respect to a curved blackboard so as to be movable integrally with a projection screen along a left and right direction of the blackboard, and in which the projection screen can be suitably stretched and expanded against any spot on a concavely curved blackboard surface.SOLUTION: The blackboard projection device includes: a blackboard body 1 in which at least one section of a blackboard surface 10 is concavely curved in a horizontal direction; a projector guide rail 2 arranged like a horizontal straight line along a wall surface W of a blackboard mounting part; and a screen guide rail 3 comprising a curved part 3a which is arranged along an upper edge of the blackboard surface 10 and corresponds to the concave curve. On the projector guide rail 2, a movable pedestal 4 loaded with a projector P is mounted in a travelable manner, whereas, on the screen guide rail 3, a winding retention frame 5 of a winding type projection screen S to be expanded and magnetically attached to the blackboard surface 10 is supported in a travelable manner. The winding retention frame 5 is engaged with the movable pedestal 4 via a slide mechanism 6A so as to be movable forward and backward.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a blackboard in which at least a portion of the blackboard surface is concavely bent in the horizontal direction, and a roll-up type projection screen that is stretched and magnetically attached to the blackboard surface, and a projector that projects an image on the projection screen. The present invention relates to a blackboard projection device that can move in the left-right direction.

  As a projector for a blackboard, there is a movable type that can change the projection position of an image in the horizontal direction of the blackboard. For example, in Patent Document 1 related to the present applicant, a guide rail is provided at the upper end of a blackboard (including a whiteboard) or above a blackboard installation portion on a building wall, and a mounting column frame (pedestal) of the projector is provided on the guide rail. It has been proposed that it can be moved left and right on the blackboard. Similarly, in Patent Document 2, a guide rail made of an aluminum extrusion mold member having a hollow portion continuous in the longitudinal direction on both the front and rear sides is disposed along the left and right directions of various display boards including a normal blackboard. The projector's movable pedestal is placed so that the front and rear support rollers roll on both hollow parts, and the upper end of the cable duct chain of the projector transmission cable is fixed to the movable pedestal and folded back into a U-turn shape. In addition, a configuration has been proposed in which the lower side of the cable duct chain is coordinated between both hollow portions of the guide rail.

  Therefore, guide rails used for movable projectors generally require sufficient support strength to support the weight of the projector (usually about 5 to 10 kg). In particular, a guide rail applied to a large blackboard with a wide left and right width is required to be highly rigid and excellent in strength because the entire length is increased. Therefore, a metal having a plurality of hollow portions as disclosed in Reference 2 What consists of an extrusion type | mold material is suitable.

  On the other hand, in a normal blackboard whose surface is dark green or black, a projection screen is used to project an image by a projector. This projection screen is a so-called magnet screen, which is held in a wound state when not in use, and is magnetically attached to the blackboard surface by a magnetic layer on the back side when it is spread on the blackboard surface during use. Yes. However, in the case of a movable projector, a projection screen is attached according to the projection position. However, with a separate projection screen as a single item, it is very large to position and expand on the blackboard surface each time it is used. In addition, it takes a lot of labor and time, and accurate positioning is difficult. Therefore, a means for attaching a winding holding frame of the projection screen to the movable pedestal of the projector and moving the projector and the projection screen integrally is assumed.

Japanese Patent Application Laid-Open No. 2014-083693 JP 2016-112817 A

  However, large blackboards with wide left and right widths often use so-called curved blackboards in which the left and right sides or the whole of the blackboard surface is concavely curved in the horizontal direction in order to increase visibility from students seated at the left and right ends of the room. ing. When a movable projector is provided on such a curved blackboard, it is desirable that the long guide rail for running the movable pedestal has high rigidity and excellent strength such as the above-described metal extruded mold having a plurality of hollow portions. However, with a highly rigid guide rail, bending to match the concave curve of a curved blackboard is extremely difficult, and multiple projector transmission cables are routed via a cable duct chain that folds up and down in a U-turn shape. When installing, since the linearity of the arrangement | positioning part is required, a horizontal linear guide rail must be employ | adopted. Therefore, as described above, the means for attaching the winding holding frame of the projection screen to the movable pedestal of the projector simply moves the winding holding frame linearly integrally with the projector along the horizontal linear guide rail. For this reason, the projection screen cannot be properly extended on the concavely curved blackboard surface.

  In view of the circumstances described above, the present invention is intended for curved blackboards, in which a movable projector is installed integrally with a projection screen so as to be movable along the left-right direction of the blackboard, and at any position on a concavely curved blackboard surface. The object of the present invention is to provide a blackboard projection device that can properly extend a projection screen.

  If the means for achieving the above object is shown with reference numerals in the drawings, the blackboard projection device according to the invention of claim 1 is a blackboard main body 1 in which at least a part of the blackboard surface 10 is concavely curved in the horizontal direction. And a guide rail 2 for the projector disposed in a horizontal straight line along the wall surface W of the blackboard installation portion, and a curved portion 3a disposed along the upper edge of the blackboard surface 10 and corresponding to the concave curve. The screen guide rail 3 includes a movable pedestal 4 on which the projector P is mounted. The screen guide rail 3 is stretched on the blackboard surface 10 and magnetically attached. The winding holding frame 5 of the winding type projection screen S to be driven is supported so as to be able to run, and the winding holding frame 5 is connected to the movable base 4 via a slide mechanism 6 so as to be movable back and forth.

  According to a second aspect of the present invention, in the blackboard projection device according to the first aspect, the winding holding frame 5 is pivotally attached to the sliders 60 and 66 of the slide mechanisms 6A to 6C so as to be horizontally rotatable at the center in the left-right direction. It is characterized by being.

  The invention of claim 3 is the blackboard projection device according to claim 1 or 2, wherein the winding holding frame 5 is supported by the screen guide rails 3 via the support frames 7 at the left and right positions, and each support frame. 7 is characterized in that the winding holding frame 5 is pivoted so as to be horizontally rotatable.

  According to a fourth aspect of the present invention, in the blackboard projection apparatus according to any one of the first to third aspects, the slide mechanisms 6B and 6C include a sliding guide rail 65 in the front-rear direction attached to the movable base 4 side, and the sliding guide rail 65. And a connecting member 67 having one end fixed to the slider 66 and the other end connected to the winding holding frame 5.

  According to a fifth aspect of the present invention, in the blackboard projection apparatus according to the fourth aspect, the projector guide rail 2 is attached to the wall surface W of the building frame so as to be spaced above the blackboard body 1 and the sliding guide rail 65 is a movable base. 4 is arranged below the projector guide rail 2 via a suspension member 46 suspended from the front portion of the projector 4.

  According to a sixth aspect of the present invention, in the blackboard projection apparatus according to any of the first to fifth aspects, the projector guide rail 2 is formed of a metal extrusion mold material having hollow portions 2a and 2b that are continuous in the longitudinal direction on both front and rear sides. A plurality of support rollers R1 and R2 provided on both front and rear sides of the movable base 4 on 2a and 2b roll, and a cable duct chain for holding a plurality of projector transmission cables C on the guide rail 2 8 is configured such that the upper end is fixed to the movable base 4 and is folded up and down in a U-turn shape.

  Next, the effects of the present invention will be specifically described with reference to the drawings. In the blackboard projection device according to the first aspect of the present invention, the movable pedestal 4 on which the projector P is mounted is mounted on the horizontal linear projector guide rail 2 so as to run freely, while the winding projection screen S is wound. The holding frame 5 is supported by the screen guide rail 3 having a curved portion 3a corresponding to the concave curve of the blackboard surface 10, but the winding holding frame 5 is mounted on the movable base 4 via the slide mechanisms 6A to 6C. Are connected to each other so that they can be moved back and forth, so that either of the movable pedestal 4 and the winding holding frame 5 can be moved to the left and right by moving the left and right sides of the blackboard 1 together. Since the winding holding frame 5 is automatically displaced back and forth in response to a change in the front and rear position due to the concave curvature of the blackboard surface 10, which position in the left-right direction on the concavely curved blackboard surface 10 Also And wound holding frame 5 and black-plate surface 10 is kept in the appropriate regular intervals, it is possible to properly to stretched always projection screen S with respect to black-plate surface 10 has.

  According to the second aspect of the present invention, the winding holding frame 5 is pivotally attached to the sliders 60 and 66 of the slide mechanisms 6A to 6C so as to be horizontally rotatable at the central portion in the left-right direction. Corresponding to the change in the surface direction due to the above, the winding holding frame 5 is always automatically rotated and displaced in the direction in which the projection screen S is placed along the blackboard surface 10, so that the projection can be performed at any position in the left-right direction on the blackboard surface 10. The screen S can be easily extended and magnetized.

  According to the invention of claim 3, the winding holding frame 5 is supported by the screen guide rail 3 via the support frame 7 at two places on the left and right, and is pivotally attached to each support frame 7 so as to be horizontally rotatable. As a result, the horizontal posture is maintained by supporting the left and right two points at any position in the left and right direction of the blackboard, so that no tilt occurs when the projection screen S is pulled out, and the projection screen S can be easily extended to the proper posture. it can.

  According to the invention of claim 4, the slide mechanisms 6 </ b> B and 6 </ b> C connect the winding holding frame 5 to the slider 66 fitted to the sliding guide rail 65 in the front-rear direction on the movable base 4 side via the connecting member 67. Therefore, there is an advantage that it is structurally simple and can be easily assembled to the movable base 4 and the winding holding frame 5.

  According to the fifth aspect of the present invention, the projector guide rail 2 is attached to the wall surface W so as to be spaced above the blackboard body 1, and the sliding guide rail 66 of the sliding mechanism 6 </ b> C defined in the fourth aspect is disposed in front of the movable base 4. The projector is arranged below the guide rail 2 for the projector via the suspension member 46 suspended from the section. Therefore, in the existing fixed type blackboard, particularly for the projector with respect to the top of the blackboard body in terms of its specifications and strength. Even if it is difficult to attach the guide rail 2, there is an advantage that the projection device for the blackboard can be applied without hindrance.

  According to the invention of claim 6, the projector guide rail 2 is made of a metal extrusion mold material having hollow portions 2a, 2b continuous in the longitudinal direction on both the front and rear sides, and the front and rear of the movable base 4 on both the hollow portions 2a, 2b. Since the plurality of support rollers R1 and R2 provided on both sides roll, even if the weight of the projector P is large and the guide rail 2 is long, the rigidity is high and sufficient support strength is maintained. Since a plurality of projector transmission cables C are held in the cable duct chain 8 arranged in a U-turn shape on the guide rail 2 up and down, the transmission cables C are less likely to deteriorate. The wiring work is facilitated and the appearance of the wiring part is also improved.

BRIEF DESCRIPTION OF THE DRAWINGS The whole projection apparatus for blackboard which concerns on 1st embodiment of this invention is shown, (a) is a top view, (b) is a front view. It is arrow sectional drawing of the AA line of Fig.1 (a). It is a front view which shows the arrangement | positioning part of the movable pedestal and winding holding frame in the projection device for blackboards. It is a partially broken front view which shows the driving | running | working part of the movable base of the projection apparatus for blackboards. It is a vertical front view which shows the rear side of the running part of the movable base. It is a perspective view which shows the winding holding frame and support frame of the projection apparatus for blackboards. It is sectional drawing of the BB line of FIG. It is sectional drawing of CC line of FIG. It is a top view which shows the state which has arrange | positioned the movable base and the winding holding frame in the blackboard left side part of the projection apparatus for blackboards. The slide mechanism in the projection apparatus for blackboards concerning 2nd embodiment of this invention is shown, (a) is a partially notched front view, (b) is a partially notched longitudinal side view. It is a vertical side view which shows the slide mechanism in the projection apparatus for blackboards concerning 3rd embodiment of this invention.

  Embodiments of a blackboard projection device according to the present invention will be specifically described below with reference to the drawings. Note that in the first to third embodiments, common components are denoted by the same reference numerals, and redundant description is omitted.

  In the blackboard projection device of the first embodiment shown in FIGS. 1 and 2, reference numeral 1 denotes a horizontally long large blackboard body, which is attached to a lifting device 11 fixed to the wall surface W of the building frame so that it can be raised and lowered on the back side. It has been. The blackboard surface 10 has a general dark green color and has magnetic attraction by a base steel plate, and the left and right side portions 10b and 10c continuous from the flat central portion 10a are concavely curved in the horizontal direction, The edge is the most forward. A horizontal linear projector guide rail 2 is attached to the top of the blackboard body 1 via a plurality of mounting brackets 12 so as to be positioned behind the blackboard surface 10, and the projector P is mounted on the guide rail 2. The movable pedestal 4 is placed so that it can run freely. Further, a screen guide rail 3 extending substantially along the upper edge of the blackboard surface 10 is fixed, and a winding holding frame 5 of the winding type projection screen S is supported on the guide rail 3 so as to be able to run. The winding holding frame 5 is connected to the movable base 4 so as to be movable back and forth via the slide mechanism 6A. The left and right side portions of the screen guide rail 3 are curved portions 3a corresponding to the concave curves of the left and right side portions 10b and 10c of the blackboard surface 10.

  The projector P is held on the distal end side of the mounting arm 42 that protrudes forward from the upper portion of the projector column 41 erected on the movable pedestal 4, and as shown by the phantom line in FIG. An image is projected onto a projection screen S that is drawn out and spread on the blackboard surface 10. Also, on the guide rail 2 for the projector, as shown by the phantom line in FIG. 1 (b), the cable duct chain 8 with the upper end fixed to the movable base 4 is folded up and down in a U-turn shape, and the lower end side Are arranged in a fixed manner on the guide rail 2. Reference numeral 12 denotes a brake operation handle attached to the lower center of the blackboard body 1. The blackboard body 1 can be moved up and down to the upper and lower limit positions by holding and raising and lowering, and the blackboard body 1 is braked by releasing it. Can be held in place.

  As shown in FIGS. 7 and 8, the projector guide rail 2 includes a rail body 20 made of an aluminum extrusion mold member having hollow portions 2 a and 2 b having a substantially rectangular cross section continuous in the longitudinal direction on both front and rear sides, and the rail body 20. And a cover plate member 21 made of an aluminum extrusion mold material that seals the wiring groove 2c formed between the hollow portions 2a and 2b. Then, on the hollow portion 2b on the rear side of the rail body 20, the channel-shaped traveling guide that is open upward and continuous in the longitudinal direction is provided by side wall portions 20a and 20b having inverted L-shaped cross-sections that are opposed to each other in the front-rear direction. A frame portion 22 is configured. As shown in FIGS. 7 and 8, the screen guide rail 3 is made of a substantially rectangular tube-shaped aluminum extrusion mold material, has a slit-like opening 31 that opens forward over the entire length, and has a hollow portion on the lower side. 32 and is screwed to the upper frame portion 14 of the blackboard body 1 at a plurality of locations in the longitudinal direction.

  As shown in FIGS. 3 to 5 and 8, the movable pedestal 4 is raised at the front and rear edges of a substantially rectangular base frame 40 in which the projector column 41 is erected on the front and rear edges 40 a and 40 b and the left and right edges. Wall portions 40c and 40d are integrally formed, and upright cross-shaped mounting plates 43 are screwed to the rising wall portions 40c and 40d at the left and right edges at the bottom. A roller mounting plate 44 having a reverse L-shaped longitudinal section is screwed to the lower surface of the front portion of the base frame 40, and a plurality of (four in FIG. 4) support rollers R1 are pivotally attached to the roller mounting plate 44. At the same time, a plurality of (five in FIG. 5) support rollers R2 are also pivotally mounted on the hanging wall portion 40b at the rear edge of the base frame 40, alternately arranged on the front side and the rear side. Further, horizontal pieces 40e are fixed to the left and right ends of the hanging wall portion 40b at the rear edge, and a horizontal rotation roller R3 is pivotally attached to the horizontal piece 40e.

  The movable pedestal 4 on the projector guide rail 2 has a front support roller R1 that rolls on the front hollow portion 2a of the rail body 20, while a lower portion of the hanging wall portion 40b travels along with the support roller R2 of the rail body 20. It arrange | positions in the guide frame part 22, and the support roller R2 rolls on the back side hollow part 2b. Further, as shown in FIGS. 5 and 8, left and right lateral rotation rollers R3 and R3 are also arranged in the travel guide frame portion 22, and the support roller R2 is supported by the travel guide frame portion 22 by the lateral rotation roller R3. The lateral rotation roller R3 is brought into contact with the inner side surface of the traveling guide frame portion 22 in a non-contact state, so that the movable pedestal 4 that moves on the guide rail 2 in the front-rear direction is moved. Misalignment is prevented.

  As shown in FIG. 4, the cable duct chain 8 is fixed to a mounting piece 43a whose upper end portion 8a protrudes laterally from the top end of the right mounting plate 43 provided on the movable base 4, and a lower end portion 8b. Is fixed to the lid plate member 21 via the mounting bracket 81 at an intermediate position of the projector guide rail 2 and is folded back on the lid plate member 21 in a U-turn shape. A plurality of projector transmission cables C drawn from the left end side of the guide rail 2 through the wiring groove 2c are led out from the wiring holes 6a provided in the cover plate member 6 and inserted into the cable duct chain 8, It is led out from the upper end 8a and introduced into the projector column 41.

  As shown in FIG. 3 and FIGS. 6 to 8, the winding holding frame 5 of the projection screen S is circular at both ends of a horizontally long cylindrical frame 50 made of an aluminum extruded mold having a substantially C-shaped cross section opened obliquely downward in the rearward direction. An end plate 51 is screwed using a plurality of (three in the figure) screw holes 50a provided on the inner periphery of the cylindrical frame 50, and has a horizontal winding shaft 52 at the inner center thereof, and an inner end portion. The projection screen S is wound around the winding shaft 52 and held through a winding mechanism (not shown) provided in the above. Further, a deep locking groove 50b continuous in the longitudinal direction is formed at the outer peripheral top of the cylindrical frame 50. The winding mechanism of the winding holding frame 5 is a well-known mechanism that urges the winding shaft 52 to rotate in the winding direction by a spring force.

  On the other hand, the projection screen S can be magnetically attached to the blackboard surface 10 by a magnetic layer on the back side as a so-called magnet screen, and an edge material 9 made of hard synthetic resin is fixed to the lower edge, and the upper edge side is It is connected to the winding shaft 52 via a mask sheet M having the same left-right width and a short vertical length. The mask sheet M is made of a black and flexible non-magnetic material. Further, as shown in FIG. 6, the edge material 9 has a strip-shaped magnet sheet 91 attached to a plurality of longitudinal positions on the back side, and a semicircular handle 92 at the center in the longitudinal direction as shown in FIG. Is fixed.

  As shown in FIG. 1, the winding holding frame 5 is supported by the screen guide rail 3 via the support frames 7 and 7 at two positions on the left and right sides. As shown in FIG. 6, each support frame 7 includes a holding frame main body 71 made of a substantially inverted T-shaped plate, a rectangular position adjusting plate 72 having a pair of longitudinal holes 72 a and 72 a, and a belt-like attachment. And a plate 73. The holding frame main body 71 has a pair of support rollers R4 and R4 and a pair of upper horizontal rollers R5 and R5 on the rear surface side of both side pieces 71a and 71a projecting to the left and right, and a lower portion on the rear surface side of the vertical plate portion 71b. The lower horizontal roller R7 is attached to a projecting piece portion 71c in which the intermediate horizontal roller R6 further extends obliquely rearward from the lower end of the vertical plate portion 71b. And the holding frame main body 71 is a bolt and nut type | mold of the connection piece 71d and the position adjustment board 72 in the state which accumulated on the position adjustment board 72 the connection piece 71d which protrudes ahead from the upper end of the vertical board part 71a. By being pivotally attached via a pivot pin 74, it is connected to the position adjustment plate 72 so as to be horizontally rotatable.

  In order to hold the winding holding frame 5 on the screen guide rail 3 via the two support frames 7 and 7, as shown in FIGS. 6 and 7, the belt-like mounting plate 73 of each support frame 7 is attached by a bolt b. The nuts 53 inserted into the locking grooves 50b of the winding holding frame 5 are screwed and fixed at predetermined positions, while the supporting rollers R4 and R4 of each holding frame main body 71 pivotally attached with the position adjusting plate 72 are connected to the upper horizontal. The rollers R5 and R5 and the intermediate horizontal roller R6 are fitted inward from one end side of the guide rail 3 for the screen, the holding frame body 71 is moved to the working position, and is pivotally attached to the holding frame body 71 at the working position. What is necessary is just to screw each volt | bolt b passed from the upper direction to each long hole 72a of the position adjustment board 72 to be fixed to the strip | belt-shaped attachment board 73 currently fixed to the winding holding frame 5 side. At this time, the front-rear position of the winding holding frame 5 can be adjusted within the range of the long hole 72 a of the position adjusting plate 72. As shown in FIG. 7, each support roller R <b> 4 of the holding frame body 71 rolls on the hollow portion 32 of the screen guide rail 3, but each upper horizontal roller R <b> 5 touches the inner wall surface on the back side of the guide rail 3. Each intermediate horizontal roller R6 is brought into contact with the inner wall surface on the front side of the guide rail 3 to prevent the front and rear positions of the support frame 7 from being displaced, and the lower horizontal roller disposed below the guide rail 3 Since R7 is in rolling contact with the blackboard surface 10, the forward tilt of the support frame 7 is also prevented.

  Thus, the winding holding frame 5 held on the screen guide rail 3 is connected to the movable base 4 on the projector guide rail 2 via the slide mechanism 6A as described above. As shown in FIGS. 3 and 8, the slide mechanism 6A has guide blocks 60, 60 fixed to the front and rear two positions on the inner side of the cross-shaped horizontal portion 43b of the left and right mounting plates 43, 43 on the movable base 4 side. A pair of left and right cross-sectional slide bars 61 and 61 fitted to the guide blocks 60 and 60 so as to be slidable back and forth, and an upwardly open U-shape that is held on the front side of both slide bars 61 and 61. The connecting frame 62 and a belt-like mounting plate 63 disposed on the lower surface side of the horizontal plate portion 62 a of the connecting frame 62.

  The connecting frame 62 is bolted to the slide bars 61, 61 through a pair of upper and lower elongated holes 62c, 62c provided in the both side plates 62b, 62b, respectively. An integral slider 60 is configured. Further, the belt-like mounting plate 63 is inserted into the locking groove 50b of the winding holding frame 5 by the bolt b at the central portion in the left-right direction of the winding holding frame 5 similarly to the belt-like mounting plate 73 in the support frame 7 described above. The nut piece 53 is screwed and fixed, and is connected to the horizontal plate portion 62a of the connecting frame 62 via a bolt / nut-type pivot pin 64 so as to be horizontally rotatable. Since the connecting frame 62 is bolted to the slide bars 61, 61 through the long holes 62c, 62c, the height of the winding holding frame 5 can be adjusted within the range of the long holes 62c.

  In the blackboard projection device having the above-described configuration, the winding holding frame 5 supported by the screen guide rail 3 has the slide mechanism 6 </ b> A with respect to the movable base 4 on which the projector P mounted on the projector guide rail 2 is mounted. Since it is connected to be movable back and forth, it is possible to move both the movable base 4 and the winding holding frame 5 to an arbitrary position in the left and right direction of the blackboard by simply moving the movable base 4 and the winding holding frame 5 left and right manually. The projection screen S is pulled out from the winding holding frame 5 at the moving position, and is spread and magnetized on the blackboard surface 10, and a required image can be projected onto the projection screen S by the projector P.

  In other words, the screen guide rail 3 is movable with respect to the linear projector guide rail 2 because the left and right side portions are curved portions 3a and 3a along the left and right side portions 10b and 10c of the blackboard surface 10, respectively. The distance between the pedestal 4 and the winding holding frame 5 is the minimum when it is located at the central portion 10a of the blackboard surface 10 shown by the solid line in FIG. The slider 60 of the slide mechanism 6A automatically slides back and forth in response to the increase / decrease of the interval, so that the connected state of the movable base 4 and the winding holding frame 5 is maintained. As a result, there is no hindrance to the integral movement of the movable base 4 and the winding holding frame 5. Accordingly, the winding holding frame 5 is kept at an appropriate fixed interval with respect to the blackboard surface 10 at any position in the left-right direction of the blackboard, so that the projection screen S is always easily extended on the blackboard surface 10. Thus, it is possible to properly magnetize.

  Further, in the left and right side portions 10b and 10c that are concavely curved on the blackboard surface 10, the direction of the winding holding frame 5 also needs to change inward in accordance with the surface direction. As shown, the position adjustment plates 72 in the left and right support frames 7 and 7 that support the winding holding frame 5 are connected to the holding frame main body 71 so as to be horizontally rotatable, and are similarly belt-like mounting plates of the slide mechanism 6A. Since 63 is also connected to the connecting frame 62 so as to be horizontally rotatable, the winding holding frame 5 is automatically rotated and displaced inwardly without difficulty. Therefore, the projection screen S can be easily extended and magnetized at any position in the left-right direction on the blackboard surface 10. In addition, since the winding holding frame 5 is supported by the guide rail 3 for the screen via the support frame 7 at two places on the left and right, the horizontal posture is maintained with the left and right two-point support at any position in the left and right direction of the blackboard. When the projection screen S is pulled out, no tilt occurs, and the projection screen S can be easily extended to an appropriate posture.

  On the other hand, as in this embodiment, a metal extrusion mold material having hollow portions 2a and 2b continuous in the longitudinal direction on both front and rear sides is used as the guide rail 2 for the projector, and both front and rear sides of the movable base 4 are placed on both hollow portions 2a and 2b. If a plurality of support rollers R1 and R2 provided on each of them are configured to roll, even if the weight of the projector P is large and the guide rail 2 is long, high rigidity and sufficient support strength are ensured. it can. Further, in the configuration in which a plurality of projector transmission cables C are held in the cable duct chain 8 that is arranged in a U-turn shape up and down on the guide rail 2 as in this embodiment, these transmission cables C are used. The wiring work is easy and the appearance of the wiring part is also good.

  As the blackboard body 1 to which the blackboard projection device of the present invention is applied, in the present embodiment, the left and right side portions 10b and 10c continuous from the flat central portion 10a of the blackboard surface 10 are illustrated as being concavely curved. It is sufficient that at least a part of the blackboard surface 10 is concavely curved in the horizontal direction, such as concavely curved over the entire length of the direction, or concavely curved on only one of the left and right sides. Moreover, although the blackboard of this embodiment is a raising / lowering type, this invention is applicable also to a fixed type blackboard. In the fixed blackboard, the projector guide rail 2 may be attached not to the blackboard main body 1 but to the building wall W as exemplified by a third embodiment to be described later.

  Furthermore, this invention is excellent also in the applicability with respect to the existing blackboard. That is, regardless of whether the existing blackboard is an elevating type or a fixed type, the guide rail 2 for the projector can be obtained simply by bending the screen guide rail 3 so as to have a curved portion corresponding to the concave curvature of the blackboard surface 10. The movable pedestal 4, the winding holding frame 5, and the slide mechanism 6A can use common parts even if the blackboard specifications are different. In addition, for the linear guide rail 2 for the projector, it is only necessary to cut a long raw material according to the horizontal length of the applied blackboard, and the screen guide rail 3 does not require high rigidity, so it can be easily bent. Raw materials can be used.

  Regarding the slide mechanism for connecting the winding holding frame 5 to the movable base 4 so as to be movable back and forth, in the first embodiment, the left and right slide bars 61 and 61 and the connecting frame 62 move back and forth integrally as a slider 60. Although illustrated, other various configurations are possible. For example, in the projection apparatus for blackboard of the following second embodiment and third embodiment, a simple slide mechanism including a slide guide rail and a slider attached to the movable base 4 side is employed.

  As shown in FIGS. 10 (a) and 10 (b), the projection apparatus for blackboard of the second embodiment is connected to the movable pedestal 4 on the guide rail 2 for the projector via the slide mechanism 6B. However, the rest is the same as the first embodiment described above. In this slide mechanism 6B, sliding guide rails 65 extending in the front-rear direction are ported to the left and right central portions of the lower surface side of the horizontal plate portion 45a of the rail holding frame 45 projecting forward from the movable base 4 in a shelf shape. A slider 66 having a substantially inverted convex cross section is inserted into a wide guide groove 65a opened below the moving guide rail 65 so as to be slidable back and forth, and the upper and lower parts are bent in two steps in a reverse U shape. A connecting member 67 made of a band plate is screwed to the lower surface of the slider 66 on the upper side, and a bolt-nut type is attached to the band-shaped mounting plate 63 whose lower side of the connecting member 67 is fixed to the winding holding frame 5 side. It is connected via a pivot pin 64 so as to be horizontally rotatable.

  In addition, the strip | belt-shaped attachment board 63 is bolted to the nut piece 53 inserted in the locking groove 50b in the both ends similarly to 1st embodiment. Further, the rail holding frame 45 on the movable pedestal 4 side is vertically long at two positions on the left and right mounting plates 43 and 43 of the movable pedestal 4 in the left and right side plate portions 45b and 45b extending rearward. Bolts are fastened through the holes 43c and 43c, and the height can be adjusted in the range of the long holes 43c.

  Also in the blackboard projection device of the second embodiment, the winding holding frame 5 supported by the screen guide rail 3 is movable back and forth with respect to the movable base 4 on the projector guide rail 2 via the slide mechanism 6B. Therefore, regardless of the change in the distance between the four and the five due to the concave curvature of the blackboard surface 10, both the four and the five can be moved together to an arbitrary position in the left-right direction of the blackboard by manual operation. . Further, since the winding holding frame 5 is pivotally attached to the slider 66 of the movable pedestal 4 so as to be horizontally rotatable, the winding holding frame 5 is always rotated along the blackboard surface 10 corresponding to the concave curvature of the blackboard surface 10. Dynamic displacement. Therefore, the projection screen S can be easily extended and magnetized at any position in the left-right direction on the blackboard surface 10.

  The blackboard projection device according to the third embodiment is applied to an existing fixed blackboard having a curved portion. As shown in FIG. 11, the blackboard body 1 in this case is fixed to the wall surface W of the building frame by a substantially inverted L-shaped mounting bracket 16 with a narrow spacer 15 interposed on the back side thereof. Since the space from the wall surface W to the blackboard surface 10 is narrow and the load bearing strength is insufficient, it is difficult to attach the projector guide rail 2 to the top. For this reason, as shown in the figure, the projector guide rail 2 is attached to the wall surface W via the wall mounting frame member 23 at a position spaced upward from the blackboard body 11. This wall-mounting frame member 23 is made of an aluminum extrusion mold material having two upper and lower hollow portions 23a, 23a, and is bolted to the wall surface W at mounting plate portions 23b, 23b extending vertically. The engaging portions 23c and 23d are respectively engaged with the upper and lower engaging pieces 20c and 20d on the rear end of the guide rail 2 for the projector, and the receiving pieces 23e protruding forward are overlapped on the lower surface of the rear portion of the guide rail 2. The guide rail 2 is stably and firmly supported by bolting.

  On the other hand, the screen guide rail 3 is disposed along the upper edge of the blackboard surface 10 as in the first and second embodiments described above, and the winding holding frame 5 is attached to the left and right sides of the screen rail 3. It is supported through the support frames 7 and 7 so as to be able to run as described above. The winding holding frame 5 is connected to the movable base 4 on the guide rail 2 for the projector via a slide mechanism 6C so as to be movable back and forth. That is, the basic structure of the movable pedestal 4 is the same as that of the first and second embodiments described above, but the suspension member made of an L-shaped plate on the hanging wall portion 40a at the front edge of the base frame 40. 46 is suspended, and a sliding guide rail 65 along the front-rear direction is bolted to the lower surface side of the horizontal plate portion 46b of the suspension member 46 disposed below the screen guide rail 3, Similarly to the slide mechanism 6B of the second embodiment, a connecting member 67 is screwed on the upper side to a slider 66 that is fitted to the sliding guide rail 65 so as to be slidable back and forth, and the lower side of the connecting member 67 is It is connected to a belt-like mounting plate 63 fixed to the winding holding frame 5 side via a bolt / nut-type pivot pin 64 so as to be horizontally rotatable.

  Accordingly, in the blackboard projection device of the third embodiment, the movable pedestal 4 and the winding holding frame 5 are integrated with the blackboard manually by hand regardless of the mutual change in the distance due to the concave curvature of the blackboard surface 10. Since the winding holding frame 5 can be moved to an arbitrary position in the left-right direction and is always rotated and displaced along the blackboard surface 10 in response to the concave curvature of the blackboard surface 10, the left-right direction on the blackboard surface 10 is The projection screen S can be easily extended and magnetically attached to any position at any position.

  Note that the suspension member 46 in the third embodiment is bolted to the base frame 40 of the movable pedestal 4 so that the height can be adjusted via a vertically elongated slot not shown in the upper portion of the vertical plate portion 46a. ing. In this way, including the above-described first and second embodiments, if the height of the winding holding frame 5 can be adjusted by the elongated holes in the vertical direction interposed in the connecting portions of the slide mechanisms 6A to 6C, Even if the height difference between the guide rail 2 for the projector and the guide rail 3 for the screen fluctuates due to the blackboard specifications or the like, it can be handled within the range of the long hole.

  In the projection apparatus for blackboard of the present invention, the cross-sectional shape of the guide rail 2 for the projector and the guide rail 3 for the screen, the form of the movable pedestal 4 and the winding holding frame 5, the structure and member configuration of the slide mechanism, the movable pedestal of the slide mechanism In addition to the embodiment, various design changes can be made to the detailed configuration such as the attachment and connection structure with respect to 4 and the winding holding frame 5 and the size and shape of the projector P and the projection screen S.

DESCRIPTION OF SYMBOLS 1 Blackboard main body 10 Blackboard surface 10a Center part 10b Left side part 10b Right side part 2 Projector guide rails 2a, 2b Hollow part 3 Screen guide rails 3a Curved part 4 Movable base 46 Suspension member 5 Winding holding frame 6A-6C Slide mechanism 60, 66 Slider 65 Sliding guide rail 67 Connecting member 7 Support frame 8 Cable duct chain C Transmission cable for projector P Projector S Projection screen W Wall surface R1, R2 Support roller

Claims (6)

A blackboard body with at least a part of the blackboard surface being concavely curved in the horizontal direction, a guide rail for the projector arranged in a horizontal straight line along the wall surface of the blackboard installation section, and an upper edge of the blackboard surface A screen guide rail having a curved portion corresponding to the concave curve,
A movable pedestal mounted with a projector is placed on the guide rail for the projector so that it can run freely, and a winding holding frame for the winding projection screen that is stretched and magnetically attached to the blackboard surface is run on the screen guide rail. Supported,
A blackboard projection apparatus, wherein the winding holding frame is connected to the movable pedestal through a slide mechanism so as to be movable back and forth.   2. The blackboard projection device according to claim 1, wherein the winding holding frame is pivotally attached to the slider of the slide mechanism so as to be horizontally rotatable at a central portion in the left-right direction.   The winding holding frame is supported by screen guide rails via support frames at two left and right positions, and the winding holding frame is pivotally attached to each support frame so as to be horizontally rotatable. The blackboard projection device according to claim 1 or 2.   The sliding mechanism includes a sliding guide rail in the front-rear direction attached to the movable pedestal side, a slider fitted to the sliding guide rail so as to be slidable in the front-rear direction, and one end side of the slider is fixed to the other end side. The blackboard projection device according to claim 1, comprising a connecting member connected to the winding holding frame.   The projector guide rail is spaced above the blackboard body and attached to the wall of the building housing, and the slide guide rail is suspended through a suspension member that is suspended from the front of the movable base. The blackboard projection device according to claim 4, wherein the projection device is disposed below the rail.   The projector guide rail is made of a metal extrusion mold material having hollow portions continuous in the longitudinal direction on both front and rear sides, and a plurality of support rollers provided on both front and rear sides of the movable base on both hollow portions roll, The cable duct chain for holding a plurality of projector transmission cables is arranged on the guide rail in such a manner that the upper end is fixed to the movable base and folded up and down in a U-turn shape. Projection device for blackboard as described in 1.

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