SCREEN FORMING APPARATUS

Abstract: A screen forming apparatus comprises a long pipe (1) of the predetermined length floatable in the water, a pump (2) for conveying the water through the pipe (1),a pipe (9) connecting the pipe (1) with the pump (2), an air-water device (24) provided with the pipe (9) for mixing the water with air, a number of nozzles (3, 4) disposed along the longitudinal direction of the pipe (1) at the predetermined intervals for injecting the water in the form of screen (13), and a device (62, 64) for producing air curtains (66) flowing along the front and the rear surfaces of the screen (13) in order to maintain the screen (13) substantially uniform in thickness.

Description: The present invention relates to a screen forming apparatus, according to the generic part of claim 1, 3 or 6. In outdoor movie theaters a solid movie screen is installed in the open air and a movie is projected thereon. The screen used for the outdoor movie theater is a sheet or a board which is similar to the screen used for the indoor movie theaters. The sheet or the board screen is hung down from or expanded over a supporting structure such as a scaffold of a predetermined height and width. The conventional outdoor movie theater usually has a projection screen standing on ground and a large size screen is necessary to entertain an audience with the movies. A large supporting structure is required to hold a large screen, and a considerable labor is required in assembling/disassembling such a supporting structure. Also, the conventional outdoor theater occupies a large space for both the screen and the audience since the screen entails a periphery construction and there must be some distance between the screen and the audience. There has been an idea to establish an outdoor movie theater which has a screen standing on the water with the audience having seats on the ground near the water. However, it is difficult to support the ordinary, large screen that is used in the indoor theaters on or above the water such as the sea, lake, river or pool. Only a small size screen can be employed for the on-the-water-screen theater. FR-A-1 075 481 discloses a screen forming apparatus comprising a pipe means of a predetermined length, a pump for conveying a screen forming fluid and large angle nozzle means for ejecting said screen forming fluid. US-A- 3 894 689 discloses in a strobe liquid display device a plurality of nozzles arranged along a pipe at predetermined intervals. One purpose of the present invention is to provide a liquid screen forming apparatus for forming a large fluid projection screen erecting on any place of water surface or the ground, so that a large outdoor movie theater or an advertisement installation can be built at a place, for instance, at the sea side or along the river side. Another purpose of the present invention is to provide a screen forming apparatus for forming a projection screen of liquid curtain having good projection qualities. Still another purpose of the present invention is to provide a screen forming apparatus for forming a gaseous screen which is easy to handle, and has a uniform quality in reflecting images sent from the projector so that the audience can enjoy a clear vision. Yet another purpose of the present invention is to provide a screen forming apparatus for establishing a screen of liquid which is uniform in thickness and is capable of creating an atmosphere different from the indoor movie theaters. To meet these purposes, the invention provides the features of claim 1, 3 or 6. Further developments are described in the subclaims. According to a first aspect of the present invention, there is provided a unique screen forming apparatus which comprises a water pipe of predetermined length, a water pump for supplying water to the water pipe, a number of first type nozzles fixed on the water pipe at regular intervals in the longidutinal direction of the pipe for forming plural, pie-like water curtains (screens) by spouting the water supplied from the pump, and a number of second type nozzles respectively placed between each two first type nozzles for forming plural, fan-like water curtains. According to this water screen forming apparatus, water compressed by the pump is sent into the water pipe and then sprayed from both the first and the second water nozzles, so that a water screen of predetermined size is created which extends along the lengthwise direction of the water conveyance pipe. When the water conveyance pipe is set on the water and the water pump starts supplying the water to the pipe, a large projection screen appears on the surface of the water. By providing a gas-water mixing device, for instance an air-water mixing device for mixing air bubbles with the water prior to sending the water to the pipe, there is created a whity, smog-like screen since air-bubble-containing-water is sprayed from the nozzles. Such a screen possesses a very low light transparency quality and a large light-scattering quality, so that a clear projected image can be expected thereon. In accordance with a second aspect of the present invention, there is provided another screen forming apparatus which comprises a gas ejection pipe equipped with gas nozzles for injecting whity gas made from dry ice or the like and a gas suction pipe so placed as to be opposed to the gas ejection nozzles for sucking the ejected gas, forming a projection screen between the gas ejection nozzles and the gas suction pipe. In this screen forming apparatus, whity gas ejects to the gas suction pipe. Gas so ejected is sucked into the gas suction pipe, thereby forming a gaseous curtain or screen between the gas ejection pipe and the gas suction pipe. Unlike the last mentioned screen forming apparatus, working medium such as water does not splash about in this apparatus. Therefore, a selection range in installing the screen forming apparatus is widened. According to a third aspect of the present invention, still another screen forming apparatus is provided, which apparatus comprises a water pipe for spraying water containing fluorescent dye and air ejection pipes so placed as to sandwich the water pipe between them, thereby forming air curtain flowing along the front and the back faces of the water curtain and keeping the thickness of the screen substantailly constant. According to this apparatus, fluorescent dye is contained in the ejected water, so that the light from the prejector is reflected clearly. Also, since the air ejection pipes are arranged in parallel relation with the water curtain (screen) forming pipe, and inject air or form air curtains which sandwich the water screen, the water screen is maintained substantially constant in thickness and the water does not disperse even at the region apart from the nozzles. The invention will now be further described with reference to the drawings. Specifically, Figure 1 shows a schematic view of a projection carried out using the screen forming apparatus of the first embodiment; Figure 2 is an enlarged view of a part of the water conveyance pipe shown in Figure 1; Figure 3 is a sectional view along the line III-III of Figure 2; Figure 4 is a schematic view showing a first water nozzle of Figure 3; Figure 5 schematically illustrates a second water nozzle of Figure 3; Figure 6 illustrates an outline of the water curtain defined by the apparatus of Figure 1; Figure 7 is a fragmentary sectional view showing another water nozzle; Figure 8 is a modification apparatus of Figure 1; Figure 9 is another modification of Figure 1; Figure 10 is a still another modification of Figure 1; Figure 11 depicts an overall view of projection with use of a screen forming apparatus according to a second embodiment; Figure 12 is a sectional view of an ejector of Figure 11; Figure 13 is conceptual view of the water screen defined by the apparatus of Figure 11; Figure 14 depicts an overall view of projection with use of a screen forming apparatus according to a third embodiment; and Figure 15 is a schematic view showing an arrangement of the gas injection pipe and the air injection pipe, and air curtains formed by these pipes. Embodiment 1 As shown in Figure 1, a screen forming apparatus mainly includes a water conveyance pipe 1 of predetermined length, which floats and is held on a water body surface W of, for example, a swimming pool, a water supply pump 2 for sucking up the water in the pool and supplying water under pressure to the water conveyance pipe 1, a plurality of first water spray nozzles 3 and second water spray nozzles 4, respectively installed on the water conveyance pipe 1. The length of the water pipe 1 is determined in accordance with that of a desired projection screen 13. Referring to Figure 2, the water pipe 1 is constituted by a plurality of pipe segments 1A made of metallic or plastic material. The pipe segments are connected to each other by flexible joint pipes 7. Returing to Figure 1, the water supply pump 2 is placed at a pool-side. An intermediate pipe 9 is connected to a discharge port of the water pump 2 at one end thereof and the same is connected to an inlet opening of the water pipe 1 at the other end. Referring to Figure 6, the first set of water spray nozzles 3 are placed spaced from each other in the longitudinal direction of the pipe 1 such that each first nozzle 3 spouts water upward creating a-piece-of-pie-like water screen A above the pipe 1 while the second set of water spray nozzles 4 are placed between each two first nozzles 3 such that they create fan-like water screens B between the screens A. The heights of the screens A and B depend on the water pressure given by the pump 2 and the pump capacity is determined in accordance with the size of the screen desired. The first nozzle 3, as illustrated in Figure 4, has a water injection port 11 whose water spraying angle α1 is about 20 degrees and the second nozzle 4, as illustrated in Figure 5, has a water injection port 12 whose water spraying angle α2 is about 170 degrees. Returning to Figure 6, the first nozzle 3 creates the water screen A taller than the water screen B created by the second nozzle 4. Also, the second nozzles 4 are positioned so as to form the water screens B in front of the water screens A. Therefore, the water curtains B are respectively formed between each two water curtains A in a manner such that the former curtains B cover the vacant spaces between the latter curtains A, i. e., the combination of two types of screens define one large screen 13 over the water pipe 1 along its longitudinal direction. As illustrated in Figure 3, each pipe segment 1A is provided with a buoyant member 10 along the longitudinal direction thereof, so that the water pipe 1 can float in the water. Where the projection screen 13 is to be made over the water of a swimming pool as shown in Figure 1, the water conveyance pipe 1 is set on the water and then the water pump 2 is switched on for pumping up the pool water into the pipe 1. Water thus supplied to the pipe 1 is ejected upward from the first and the second nozzles 3 and 4, thereby creating the water screen 13. In this case, water becomes small droplets as it spreads from the nozzles, and mix with the air, so as to form a fog-like screen. Accordingly, such a screen possesses a low light transparency quality as well as a large light-scattering quality. When the screen 13 is formed over the swimming pool water W, the projector 14 which is placed on the pool-side with a proper distance from the screen is started sending the image on the screen 13. Sound required to the projected image is given by speaker sets (not shown) disposed near the pool. Therefore, created is an outdoor theater of a mood different from the conventional outdoor theaters, and it is possible to entertain a large audience with an unique effect. As illustrated in Figure 7, the second nozzles 4 may be disposed at the front and the rear of the first nozzle 3 such that the water screens B are formed at the front and the rear of the water screen A. Figure 8 depicts a case where the water screen is formed on the sea, lake or river. The water pump 2 is disposed in a ship 8 which holds the water supply pipe 1. The projector 14 is placed in another ship 15 apart from the water screen 13 with a proper distance. It is of course that the projector 14 may be set on a ground such as the sea shore. The sound for the image may be produced by a speaker set installed on the ship 15 or the sea shore. A much higher screen can be built by several water conveyance pipes 1 arranged like a ladder as illustrated in Figure 9. In this case, a couple of vertical poles 17 stand on the ground, with horizontal bars 18 spanning therebetween. The water pipes 1 are supported by the horizontal bars 18. As the water is supplied to the pipes 1 by the pump 2, a water screen 13 of considerable and consisting of different portions 13A, 13B, 13C height is created. Each set of the horizontal bar 18, the water conveyance pipe 1, and the water nozzles 3 and 4 hide behind the water screen created by the other set just below , so that only the lowermost horizontal bar 18 and the pipe 1 are apparent to the audience, making a very tall screen. The water nozzles 3 and 4 may spout water also in horizontal directions and produce curtain portions 13A, 13B as depicted in Figure 10. The water pipes 1 extend vertically along the supporting poles 20 standing on a ground. In the above embodiment, only two types of nozzles 3 and 4 are employed. However, other types of nozzles may be provided. For instance, a bar-like nozzle which injects water higher and in a narrower angle than the first nozzle 3 in order to create a larger screen. Also, the first nozzles are not necessarily provided with the second nozzles, i. e., the first nozzles may be associated with the bar-like nozzles only. Embodiment 2 A second embodiment of the present invention will be described with reference to Figures 11, 12 and 13. The water conveyance pipe 1 in the screen forming apparatus of this particular embodiment ejects water downward for forming a water screen 13 under the water conveyance pipe 1 as illustrated in Figure 11. This apparatus includes a horizontal supporting member 18, a water curtain forming pipe 1 mounted on the supporter 18 for ejecting water downward and an ejector 24 for blending water with gaseous substance such as air, so as to generate a projection screen of air-bubble-containing water. The ejector 24 may be an air-water mixing device. Meantime, the water pipe 1, the pipe segments 1A, the joint pipe 7, the first nozzle 3 (nozzle angle 1 is also approximately 20 degrees) and the second nozzle 4 (nozzle angle 2 is also approximately 170 degrees) are almost the same as those described in the first embodiment and no explanations are given to these elements. Only the difference to be noted may be that the pipe segment 1A is not provided with the buoyant member since the pipe 1 does not float in this embodiment. An intermediate pipe 9 is connected to the inlet of the water curtain pipe 1 at one end thereof and to the discharge port 26 of the ejector 24 at the other end thereof. Referring now to Figure 12, the ejector 24 has a cylindrical shape and possesses an inlet port 28 at one end thereof and an outlet port 26 at the other end thereof. A suction pipe 30 which defines a suction port 68 for introducing the gaseous substance such as air is attached to the ejector 24 at the central part thereof. Inside the ejector 24, there is formed a nozzle section (throttling section) 34 at the upstream side (right hand in the drawing), and provided therein is a swirl blade 32 for injecting fluid such as water coming through the inlet port 28. At the downstream side in the ejector 24, there is defined a mixing section 36 for mixing the fluid ejected from the nozzle section 34 and gaseous substance sucked through the suction pipe 30. The mixing section 36 includes three continuous chambers, namely a mixing chamber 38 having a bore gradually reduced in diameter along the fluid flowing direction, a parallel chamber 40 of a uniform bore, and a diffusing chamber 42 having a bore gradually expanded from the parallel chamber 40. When a harmless fluorescent dye is mixed with water and supplied to the inlet port 28 of the ejector 24, the mixture is ejected into the mixing chamber 38 from the nozzle section 34 by the swirl blade 32. Then, air is sucked through the suction pipe 30 into the mixing chamber 38 due to negative pressure in the mixing chamber 38 by the jet stream of the mixture and resultantly it enters into the parallel chamber 40 together with the mixture. While flowing through the mixing chamber 38 and the parallel chamber 40, the air so introduced and the fluorescent dye-water mixture are blended, whereby a water containing air bubbles and fluorescent dye is obtained. Such a mixture regains pressure as it flows through the diffuser chamber 42 and then discharged from the discharge port 26, which is in turn supplied to the water pipe 1 via the connecting pipe 9. After conveyed to the water pipe 1, the water containing air bubbles is spouted downward from the first nozzles 3 as well as the second nozzles 4, thereby creating a whity, foggy screen 13 which scatters the light or hardly transmitts the light. Referring to Figure 13, the screen 13 is formed by the water curtains A and B. The water ejected from the first set of nozzles 3 defines the water curtains A at a relatively low part of the screen 13, whereas the water ejected from the second set of nozzles 4 defines the other water curtains B at a relatively high part of the screen 13 between each two water screens A. That is, the water curtain B covers the upper vacant space between each two water curtains A, so as to define a single screen 13. Since the fluid injected from the pipe 1 contains fluorescent dye, the reflection on the screen 13 is clearly generated. It is of course that harmless fluorescent dye has to be added to the water. Embodiment 3 Now, a third emodiment of the present invention will be explained with reference to Figures 14 and 15. As shown in Figure 14, the screen forming apparatus includes the supporter 18 held above substantially in horizon, a gas ejection pipe 52 attached to the underside of the supporter 18 and provided with a gas ejection nozzle 50 for jetting whity and less-transparent gas made from harmless gas such as dry ice, and a suction pipe 54 spacedly facing the gas ejection pipe 52 with a predetermined clearance for sucking the gas from the ejection pipe 52. The length of the gas ejection pipe 52 is determined according to the length of the gaseous screen 13 to be desired. A pump 56 for conveying the whity gas such as dry ice under the predetermined pressure is joined to the inlet of the gas ejection pipe 52. The gas ejection nozzle 50 is disposed on the lower face of the gas ejection pipe 52 along the longitudinal direction of the pipe 52 so as to eject gas downwardly. Beneath the gas ejection pipe 52, there is disposed a suction pipe 54 parallel to and spaced from the gas ejection nozzles 50 by a predetermined distance. The suction pipe 54 has substantially same length as the gas ejection pipe 52. A suction port 60 is formed along the upper face of the suction pipe 54 and a suction device 58 for sucking the gas into the suction pipe 54 is connected to one end of the suction pipe 54, so that the lower pipe 54 sucks the gas ejected from the upper pipe 52, thereby defining a gaseous projection screen 13 therebetween. Referring to Figure 15, there are provided air ejection pipes 62 which are mounted on the supporter 18 and extend in parallel with the ejection pipe 52. These air ejection pipes 62 are separated from the ejection pipe 52 with an equal distance (the supporter 18 is not shown in Fig. 15). The air ejection pipes 62 are also provided with nozzles 64 for forming air curtains. In other words, the air ejected from the air ejection nozzles 64 produces the air curtains 66 which flow along the front and the rear faces of the gaseous curtain formed between the gas ejection nozzle 50 and the suction port 60. The air curtains 66 sandwich the gaseous screen 13 so that they prevent the substance from dispersing, thereby maintaining the screen 13 uniform in thickness. An air suction pipe (not shown) is provided along the lower pipe 54 so as to produce stronger air curtains for surly confining the gas screen 13. The whity gas made of harmless dry ice is compressed to the gas ejection pipe 52 by the pump 56 and then ejected from the nozzle 50 of the pipe 52 toward the suction port 60 of the suction pipe 54. The interior of the suction pipe 54 is under a negative pressure due to a suction device 58. Therefore, the gas from the upper pipe 52 is effectively sucked into the lower pipe 54. Accordingly, a whity, uniform-in-thickness gaseous screen 13 is produced. As a result, even the audience having seats not in front of the screen 13 or having a small angle relative to the screen 13 can also enjoy a clear picture. A screen of different size is also formed by changing the distance between the two pipes 52 and 54 as well as the gas pressure sent to the gas ejection pipe 52 52. In other words, the size of the screen 3 can change freely. Due to the fact that the projection screen 13 is made of harmless, whity gas of, for example, dry ice, there is no danger to the audience. Accordingly, only small number of elements are necessary to establish the gaseous screen 13, i. e., the screen 13 can be built almost anywhere in a simple manner. For example, this type of screen 13 may be utilized even in the indoor theater. In this case, since the screen 13 is formed by injecting and sucking the working fluid, and it is easy to let it appear and disappear in a quick manner, the audience is amused with an atmosphere different from the ordinary indoor theaters. In the last mentioned embodiment, the gas is injected downward. However, it is not a limitation in carrying out the present invention. For instance, any arrangement of the gas injection and suction pipes are satisfactory as long as they are spaced by a proper distance, and one of them injects the gas while the other sucks the same, so as to form a screen therebetween. One simple example is an arrangement in which the pipes 52 and 54 stands vertically and the gas is supplied horizontally. Furthermore, where the distance between the gas ejection pipe 52 and the suction pipe 54 is small or the sucking pressure of the suction pipe 54 is sufficiently high, the elements for forming the air curtains are not necessary since the gas ejection pipe 52 and the suction pipe 54 produces a decent screen. Moreover, the working fluid is not limited to the whity gas such as dry ice. For instance, water mixed with the fluorescent dye in the order of several ppm may be employed. In this case, the gas ejection pipe 52 and the suction pipe 54 will be replaced by a water ejection pipe and a water receiving pipe.

Claims: An apparatus for forming a screen (13) for projecting images, comprising pipe means (1) of predetermined length, a pump (2) for conveying a screen forming fluid to said pipe means (1), nozzle means (3,4) for ejecting the screen forming fluid, characterised in that said nozzle means comprises a plurality of first (3) and second (4) nozzles arranged at regular intervals along said pipe means (1), the first nozzles (3) being arranged to generate first regions (A) of said screen (13), the second nozzles (4) being arranged to generate second regions (B) of said screen (13), sections of the second regions (B) being outside of the first regions (A), the ejection angle (α1) of the first nozzles (3) being smaller than the ejection angle (α2) of the second nozzles (4). An apparatus according to claim 1, wherein the first nozzles (3) and the second nozzles (4) are arranged so as to generate the first regions (A) of the screen in front of or behind the second regions (B). An apparatus for forming a screen (13) for projecting images, comprising pipe means (1) of predetermined length, a pump (2) for conveying a screen forming fluid to said pipe means (1), nozzle means (3,4) for ejecting the screen forming fluid, characterised in that said pipe means comprises a plurality of pipes (1) having said predetermined length, said pipes being arranged in parallel to each other, each pipe having a plurality of nozzles arranged at regular intervals along said pipe to generate regions of said screen, each said pipe covering a different portion (13A, 13B, 13C) of said screen (13). An apparatus according to claim 3, including supporting poles (17) for supporting said pipes (1) and for conveying said fluid to said pipes, wherein said pipes are arranged substantially in vertical position. An apparatus according to anyone of the previous claims, including means (54, 58, 60) for recovering said screen forming fluid from said screen (13). An apparatus for forming a screen (13) for projecting images, comprising pipe means (1) of predetermined length, a pump (2) for conveying a screen forming fluid to said pipe means (1), nozzle means (3,4) for ejecting the screen forming fluid, characterised in that said pipe means comprises a plurality of pipes (1) having said predetermined length, said pipes being arranged parallel to each other, and means (54,60) are provided for recovering said screen forming fluid from said screen (13). An apparatus according to anyone of the previous claims, wherein said pipe (1) is constructed by a plurality of segments (1A) and these segments (1A) are connected to each other by flexible pipes (7). An apparatus according to claim 7, wherein said segments (1A) are provided with buoyant members (10) for allowing said segments (1A) to float in the water. An apparatus according to anyone of claims 1 to 8, wherein said screen forming fluid is water. An apparatus according to claim 9, wherein said screen forming fluid contains fluorescent dye. An apparatus according to anyone of claims 1 to 8, wherein said screen forming fluid is whity gas. An apparatus according to anyone of claims 1 to 8, wherein said screen forming fluid is dry ice. An apparatus according to claim 9, including an air-water mixing device (24) for mixing water with air prior to ejection through the nozzles (3,4). A screen forming appratus according to claim 13, wherein said air-water mixing device (24) comprises: a body provided with a round, water inlet port (28), an air introduction port (68), and a round, water-air discharging port (26); a nozzle section (34) defined in said body and gradually reduced in diameter from said water inlet port (28) in the direction toward said water-air discharging port (26), air introduced through said air introduction port (68) being supplied to the downstream end of the nozzle section (34); a swirl blade (32) provided in the body ; a mixing chamber (38) defined in the body, spaced from the nozzle section (34) in the direction toward the discharging port (26) and gradually reduced in diameter for mixing water supplied from said nozzle section (34) with air introduced through said air introduction port (68); a parallel chamber (40) defined in the body and continuous from the mixing chamber (38) toward the discharging port (26) with an unchanged diameter; and a diffuser section (42) defined in the body, continuous from the parallel chamber (40) to the discharging port (26) and progressively enlarged in diameter for discharging a water-air mixture from the body. An apparatus according to any of claims 5 or 6, wherein said means (54,60) for recovering said screen forming fluid includes means (58) for sucking said screen forming fluid from said screen (13). An apparatus according to any of claims 5 or 6, wherein said pipe (1) and said recovering means (54,60) include tubular members (52,54). An apparatus according to any claims 6 or 7, wherein said pipe (1) has gas ejection nozzles (50) while said recovering means (54,60) has an opening for recovering said screen forming fluid from said screen (13). An apparatus according to anyone of the previous claims, including means (62,64) for generating an air curtain (66) flowing along the front and the rear surfaces of the screen (13) formed by said screen forming fluid.

Inventors: ARAKI, TOSHIMITSU, KAMATA, TOSHIO, KAWAMATA, FUMIHIKO, MIYAGAWA, HITOSHI, MIYASHITA, KUNIHIRO, OGINO, MASAYUKI, WATANABE, MITSUO
Applicants: ISHIKAWAJIMA-HARIMA HEAVY INDUSTRIES CO., LTD.
Application year: 1989
Main classification: G03B21
IPC codes: F21S8, A63J5, G03B21, A63J25, A63J99