Mist screen forming device and mist screen forming system

Abstract

To solve the problem that when a mist screen forming device is installed in a passage or the like, it is necessary to perform construction such as burying the device in a floor or installing a slope in front of and behind the device.SOLUTION: A mist screen forming device 100 comprises a box-shaped and vertical housing 1; a recovery unit 2 that is installed inside and at the bottom of the housing 1, and recovers mist having turned into water droplets; a plurality of fans 7 arranged vertically on both sides; and a straightening plate 6 arranged on the front. The mist screen forming device 100 is arranged vertically near a wall on the lateral side of a corridor, for example. Therefore, there is no need to perform any construction on a floor surface of the corridor. In addition, installation and movement of the device are very easy because it is completed just by placing it.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mist screen forming device and a mist screen forming system that are installed vertically and spray a screen-shaped mist in the horizontal direction. [Background technology]

[0002] A sprayer such as that described in Patent Document 1 has been known for some time. This sprayer, a mist screen forming device, forms a mist screen above the device and is composed of a mist generator that generates mist using water supplied from a water tank, a mist rectifier that rectifies the generated mist, a mist guide that sprays the rectified mist upward in a predetermined shape, and an air jetting device that sprays air upward and has air guides on both sides of the mist guide that spray the air in a predetermined shape. The mist screen formed is formed by spraying mist in a screen-like or film-like shape above the device and spraying film-like air on both sides, forming a three-layer structure consisting of an air layer, a mist layer, and another air layer in the screen thickness direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-184768 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned conventional sprayers spray mist upward, so they need to be installed on the floor. Therefore, when installing them in a passageway, they have to be buried in the floor or have slopes installed in front of and behind the device, which is a problem. The present invention has been made to solve these problems. [Means for solving the problem]

[0005] The present invention comprises a self-supporting vertical box-shaped housing, an air supply port provided on the side of the housing, a mist supply port provided on the back of the housing, an opening provided on the front of the housing, and a straightening plate consisting of a number of holes provided in the opening, wherein a partition plate is arranged on the housing at a position separating the air supply port and the mist supply port and together with the back forms a substantially closed mist supply area, the edges of the partition plate are close to each other to form a long and narrow opening from which mist is sprayed, a plate body acting as an air filter is arranged at a position separating the air supply port and the opening, and the side surface, the partition plate and the plate body form an air supply area, and a space is formed between the straightening plate and the plate body. Furthermore, one end of a mist supply pipe may be connected to the mist supply port, and the other end may be connected to a mist generator that generates mist. Furthermore, a water droplet collection section may be provided at the bottom of the housing. In addition, a mist screen forming system may be formed by providing multiple mist screen forming devices as described above and connecting one end of each of the air supply means, the number of which is less than the number of the mist screen forming devices, to the air supply means and branching the other end and connecting it to the housing of the mist screen forming device. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a perspective view showing a mist screen forming device (sprayer) according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a horizontal cross-sectional view of FIG. 1. [Figure 3] FIG. 2 is an explanatory diagram showing the internal configuration of the lower part of the housing. [Figure 4] FIG. 10 is a perspective view showing the state in which the door is closed. [Figure 5] FIG. 2 is a cutaway view of the mist screen forming device. [Figure 6] 1 is a perspective view showing the overall configuration of a mist screen forming device. FIG. [Figure 7] FIG. 2 is a plan view showing an example of the arrangement of the mist screen forming device. [Figure 8]FIG. 10 is an explanatory diagram showing a modified example of the mist screen forming device. [Figure 9] FIG. 10 is an explanatory diagram showing a modified example of the mist screen forming device. [Figure 10] FIG. 10 is an explanatory diagram showing a modified example of the mist screen forming device. [Figure 11] FIG. 10 is an explanatory diagram showing a modified example of the mist screen forming device. [Figure 12] FIG. 10 is a perspective view showing a configuration for swinging the head in the up and down direction. [Figure 13] 13 is an explanatory diagram showing the operation of the mist screen forming device shown in FIG. 12. FIG. [Figure 14] FIG. 10 is a perspective view showing the configuration of the device when a mist collection device is added. [Figure 15] FIG. 10 is an explanatory diagram showing a modified example of the mist screen forming device. [Figure 16] FIG. 5 is a configuration diagram showing a mist screen forming device according to a second embodiment of the present invention. [Figure 17] FIG. 10 is a perspective view showing a mist screen forming device according to a third embodiment of the present invention. [Figure 18] FIG. 10 is a configuration diagram showing a mist screen forming system according to a fourth embodiment of the present invention. [Figure 19] FIG. 10 is a partially enlarged view showing a mist screen forming device according to a fifth embodiment of the present invention. [Figure 20] FIG. 20 is a cross-sectional view showing the mist screen forming device shown in FIG. [Figure 21] 20A to 20C are component diagrams of the mist screen forming device shown in FIG. 19, where (a) is a front view, (b) is a top view, and (c) is a side view. DETAILED DESCRIPTION OF THE INVENTION

[0007] (Embodiment 1) FIG. 1 is a perspective view showing a mist screen forming device (sprayer) according to a first embodiment of the present invention. FIG. 2 is a horizontal cross-sectional view of FIG. 1. FIG. 3 is an explanatory diagram showing the internal configuration of the lower part of the housing. FIG. 6 is a perspective view showing the overall configuration of the mist screen forming device. This mist screen forming device 100 comprises a box-shaped, vertical housing 1, a collection unit 2 installed inside and below the housing 1 and collecting mist that has turned into water droplets, multiple fans 7 installed vertically in series on both side surfaces, and a rectifying plate 6 located on the front.

[0008] A box-shaped collection section 2 is provided at the bottom of the housing 1. A tray 3 is provided above the collection section 2 at the bottom inside the housing 1. A drain hose 4 is connected to a part of the tray 3, and this drain hose 4 is connected to the collection section 2. The collection section 2 is a tank that stores water inside. When necessary, the drain hose 4 is removed by unplugging the drain hose 4 and opening a door 18 provided on the front of the housing 1, and the water inside can be drained to the desired location. The door 18 of the collection section 2 is preferably provided on the front of the housing 1. By providing it on the front, the tank of the collection section 2 can be easily removed even when it is installed close to the wall of the installation location. Figure 4 is a perspective view showing the state with the door 18 closed.

[0009] The housing 1 is made of sheet metal. The housing 1 is a vertically elongated box-like body with an opening 5 on the front side, in which a honeycomb-structured straightening plate 6 is placed. Numerous holes (air supply ports) are formed on both sides, and multiple fans 7 are installed in the holes. A mist supply port 9 is provided on the back panel 8. A partition plate 10 is arranged vertically inside the housing 1 between the holes and the mist supply port 9 to separate them. The partition plate 10 is formed to have a substantially triangular shape in cross section, including the back side, forming a substantially closed triangular prism-shaped space. As shown in the cutaway view of Figure 5, the edge on the front side forms a long, narrow opening 11 from which mist is sprayed. This triangular space is referred to as the mist supply area 51.

[0010] Furthermore, a coarse-meshed air filter-like plate 12 made of fiber is placed on the front side of the interior. This plate 12, the partition plate 10, and the side surface on which the fan 7 is installed form a triangular shape in cross section. This triangular area is the air supply area 52. The plate 12 uniformly straightens the air supplied from the fan 7. The straightening plate 6 placed on the front has a honeycomb structure and straightens the mist through each hole before spraying it. Note that the straightening plate 6 is not limited to a honeycomb structure, as long as it is a plate-like body with a large number of holes of a predetermined length formed on its surface.

[0011] The back panel 8 that constitutes the mist supply area 51 is provided with two mist supply ports 9, one at the top and one at the bottom, and these mist supply ports 9 are connected to the mist supply pipes 20. A shielding plate 91 is provided in front of the mist supply ports 9 to prevent the mist from traveling in a straight line. The mist supply pipes 20 are connected to the mist generator 30. The mist generator 30 has a water tank inside, and the ultrasonic generator is located at the bottom of the tank (not shown). The ultrasonic generator generates ultrasonic waves using a piezoelectric element. The mist generator 30 is also provided with a fan (not shown) for sending the mist generated inside through the mist supply pipes 20. Two mist supply pipes 20 extend from the top of the mist generator 30, and their ends are connected to the mist supply ports 9. The ends of the mist supply pipes 20 open into the water tank of the device main body, and mist separated from the water surface by the ultrasonic generator in the water tank is supplied to the mist supply area 51 via the mist supply pipes 20. From the viewpoint of construction, it is preferable that the mist supply pipe 20 is a pipe that can be deformed flexibly.

[0012] A certain space 13 is provided between the straightening plate 6 and the plate 12. The supplied air and mist merge in this space 13. A long, narrow opening 11 is formed on the front side of the mist supply area 51, and air is evenly pushed out from the plate 12 into the space 13 through the air supply area 52. The mist sprayed out by the air pressure reaches the straightening plate 6 in a layered form. Furthermore, the air seeps out evenly into the space 13 through the sponge-like plate 12, suppressing the mist flow forcefully sprayed out from the opening 11 on both sides. Furthermore, because the air is supplied evenly, no turbulence is caused in the mist flow. Therefore, the mist maintains its spraying state from the opening 11 and reaches the straightening plate 6, where it is sprayed out to the front.

[0013] The mist condenses in the space 13 mainly on the straightening plate 6, turning into droplets that fall downward. It also turns into droplets that fall downward in other areas. These droplets fall into the tray 3 and flow to the collection section 2 via the drain hose 4. The housing 1 is placed on a base 15. The base 15 is a substantially circular plate-like body with a predetermined thickness. A plurality of feet (not shown) are provided on the bottom surface of the base 15.

[0014] This mist screen forming device 100 is installed in a desired location. For example, it can be installed on the side of a corridor, with the mist generator 30 placed next to it. FIG. 7 is a plan view showing an example of the placement of the mist screen forming device 100. By placing this mist screen forming device 100 near the wall W on the side of the corridor R, there is no need to perform any construction work on the floor F of the corridor R. Furthermore, since it can be installed simply by placing it, installation and movement are extremely easy. Note that a projector P can project moving images onto the mist screen S formed by the mist screen forming device 100 from a predetermined location (installed on the ceiling, etc.), or predetermined information can be projected by irradiating it with a laser beam. In this way, desired information can be displayed on the mist by projecting light that reflects off the mist screen.

[0015] Next, when moving the installed mist screen forming device 100, the mist generator 30 is removed from the housing 1 and transported. The mist generator 30 is also relatively small and can be transported easily. This mist screen forming device 100 forms a mist screen in the horizontal direction using the vertical housing 1, so no construction work is required on the floor of the installation location, making it easy to install and move. Furthermore, spraying mist in the horizontal direction makes it easier to collect the mist, as will be described later.

[0016] 8, the base 15 may also be a rotating table 40. By using the rotating table 40, the direction in which the mist screen is formed can be freely changed. The rotating table 40 may be configured so that a rotating table 42 is attached to a base plate 41 via a rotation shaft so that it can be rotated manually, and the housing 1 is placed on the rotating table 42. A motor drive unit (not shown) may also be attached to the base plate 41 to rotate the rotating table 42 to a desired angle in the left-right direction so that it can be rotated automatically by a predetermined angle.

[0017] The mist screen can be used as a mist door by being rotatable. For example, when a person is detected by a sensor (not shown), the motor drive unit is activated to rotate the housing 1, opening the mist screen door. When the person passes through, the rotary table 42 is rotated to close the mist screen door.

[0018] Furthermore, as shown in Fig. 9, the collection unit 2 may be configured to be installed outside the housing 1. In this case, the capacity of the tank of the collection unit 2 can be increased, allowing for extended use. Also, as shown in Fig. 10, the drain hose 4 may be connected to a water tank in the main body of the mist generator 30 to return the water. In this way, the collected water can be reused to generate mist.

[0019] Furthermore, as shown in FIG. 11, the mist generator 30 may be installed at the bottom of the housing 1, the collection unit 2 may be omitted, and the collected water may be returned to the water tank of the mist generator 30. Specifically, the drain hose 4 is connected to the water tank of the mist generator 30, and the water collected in the tray 3 is returned to the water tank. In this configuration, the mist supply pipe 20 extends from the mist generator 30 and is connected to the back panel 8 of the housing 1 in the same manner as above. This makes the entire system compact and reduces the installation area. This increases the flexibility of the installation location. Furthermore, the collection unit 2 is not necessary, and the collected water can be returned and reused as mist.

[0020] Figure 12 is a perspective view showing a configuration for swinging up and down. Figure 13 is an explanatory diagram of the operation of the mist screen forming device shown in Figure 12. The base 55 of this mist screen forming device 100 is composed of a rectangular tilting table 56, a cylindrical body 57 that serves as a rotation fulcrum for the tilting table 56, and a frame 58 that supports the tilting table 56 in the front-to-rear direction of the tilting table 56. In the normal state (when the mist screen is sprayed horizontally), the tilting table 56 is supported by the cylindrical body 57 and the front and rear frames 58, so the housing 1 itself remains upright, and as a result, the mist screen that is sprayed is horizontal.

[0021] Next, when the frame 58 is removed and the tilting table 56 is linearly supported by the cylinder 57, the tilting table 56 tilts in one direction. Specifically, one side of the tilting table 56 touches the floor, and a portion of the tilting table 56 touches the cylinder 57 linearly. In this state, the housing 1 is tilted, and as a result, the mist screen sprays out at an angle. Because the cylinder 57 is not supported in a fixed position, the tilt can be adjusted by changing the position of the cylinder 57. The cylinder 57 is fixed between the tilting table 56 and the floor by friction. Note that a non-slip surface such as rubber may be provided on the surface of the cylinder 57 to prevent slipping. A similar non-slip surface may be provided on the underside of the tilting table 56.

[0022] In this way, with this mist screen forming device 100, the vertical tilt of the housing 1 can be adjusted with a simple structure. Furthermore, tilting can be easily achieved in a short amount of time. In addition to this configuration, the tilting means may also be a known arrangement in which screwed feet are attached to the four corners of the tilting table 56 (not shown).

[0023] FIG. 14 is a perspective view showing the configuration of an apparatus when a mist collection device is added. As shown in the figure, a mist collection device 70 may be added to the mist screen forming apparatus 100. The mist collection device 70 has a housing 71 that is the same height as the housing 1, and the front of this housing 71 (the surface facing the mist screen forming apparatus 100) is open, leaving the interior hollow. Multiple holes are provided on the back side of the housing 71, to which mist collection pipes 72 are connected. A suction device 73 and a condenser 74 are connected to the mist collection pipe 72, and the mist sucked by the suction device 73 is converted into water inside the condenser 74. The condenser 74 is connected to the water tank of the mist generator 30 of the mist screen forming apparatus 100 by the mist collection pipe 72, so the condensed water returns to the water tank.

[0024] A tray is provided at the bottom of the housing 71, and the mist solidified on the inner surface of the housing 71 flows downward and is collected in the tray. A drain hose 75 is provided on the tray. The drain hose 75 is connected to the mist collection pipe 72.

[0025] Alternatively, as shown in Figure 15, a mesh or nonwoven fabric water absorbent 76 may be installed on the front of the housing 71, and mist may collide with and adhere to the water absorbent 76, resulting in water droplets being collected. In this case, the water droplets flow downward. The suction device and condenser can be omitted. A collection unit 77 consisting of a tank for collecting water is installed at the bottom of the housing 71. In this case, pipes connecting to the housing 71 are omitted, allowing for independent installation. Water that falls into the tray of the housing 71 falls through a drain 78 in the tray into the collection unit 77 and is collected. Note that the water absorbent 76 can be made of a highly absorbent material, such as microfiber cloth. When the mist collides with the water absorbent 76, the water absorbs the water, which then moves downward and is collected in the collection unit 77. The collected water is returned to the water tank of the mist generator in the mist screen forming device for reuse.

[0026] The mist screen forming device 100 equipped with this mist collection device 70 prevents an increase in humidity in the installation location by collecting mist, and the water used for the mist can be recycled and reused, reducing water consumption. Furthermore, because the mist screen forming device 100 forms a mist screen horizontally, the mist collection device 70 can be installed vertically. This allows for greater freedom in installation location.

[0027] (Embodiment 2) Fig. 16 is a structural diagram showing a mist screen forming device according to embodiment 2 of the present invention. This mist screen forming device 200 has a structure in which a shutter 201 is provided on the front side of the mist screen forming device 100 according to embodiment 1. The shutter 201 is divided into two pieces (shutter 201a and shutter 201b), which are provided in that order from the bottom up on the front side of the housing 1. The shutter 201 is made of a metal plate and is detachable from the housing 1. In the example shown in the figure, the top of the front side is open, and the shutter 201 closes from approximately the center to the bottom.

[0028] In areas where the shutter 201 is closed, the mist is blocked by the shutter 201, so a mist screen is not formed in that area, and the mist sent to the space 13 turns into water droplets and falls downward. The water droplets are collected in the tray 3 and then collected in the collection section 2. The collected water is periodically removed and disposed of. From the front where the shutter 201 is not closed, a normal mist screen S is formed horizontally. Furthermore, if the upper shutter 201a is opened, the vertical width of the mist screen S will increase accordingly. Since water droplets fall, it is preferable to install the shutters 201 from the bottom up.

[0029] The shutter 201 may be of an openable / closable type like a door (not shown). Furthermore, a partition plate may be provided inside the space 13 at the boundary between the shutters 201a and 201b to separate the space into upper and lower sections (not shown). A drain hole is provided in part to allow water droplets to fall. By providing the partition plate, it is possible to prevent the flow of mist in the space 13 from changing and affecting the open section when the shutter 201 is installed. The space 13, which is almost closed by the partition plate, becomes filled with mist and turns into water droplets, which fall into the tray 3.

[0030] (Embodiment 3) FIG. 17 is a perspective view showing a mist screen forming device according to a third embodiment of the present invention. This mist screen forming device 300 has a structure in which the housing 301 is vertically divided and connectable. In the example shown in the figure, it has a three-part structure, and when connected, it has approximately the same configuration as the mist screen forming device 100 shown in the first embodiment. Note that in the figure, the top plate of the upper housing 301 has been omitted for ease of explanation. Each housing 301 has the same structure as in the first embodiment. Furthermore, although not shown, additional housings 301 can be added to extend the system upward. Insertions are provided at the connecting portions between the housings 301, and the housings are connected by inserting one edge into the other edge.

[0031] Similar to the first embodiment, each housing 301 has an internal partition plate 10, a plate body 12, a fan 7, a mist supply port 13, and a front straightening plate 6. The mist supply area 51 and the air supply area 52 are internally connected and integrated when each housing 301 is connected. The mist supply port 9 on the back panel 8 is provided in each housing 301, but can be omitted. With this divided configuration, the housing 301 can be extended or shortened to the desired height. This allows a mist screen of the required area to be formed.

[0032] (Fourth embodiment) Figure 18 is a configuration diagram showing a mist screen forming system according to embodiment 4 of the present invention. The mist screen forming system 400 is configured by connecting multiple mist screen forming devices 100. In this mist screen forming system 400, a mist generator 30 is connected to each mist screen forming device 100. Air is supplied from an air supply device 401 through an air supply pipe 402. Each mist screen forming device 100 does not have the fan 7 on the side of the housing 1, and instead receives air from the air supply device 401.

[0033] The air supply device 401 is equipped with a large fan inside a large box-shaped housing 402, which has an air inlet from the outside and a filter (these are well-known elements and are therefore not shown). An air supply pipe 402 is connected to the top of the box-shaped housing 401. It is preferable to use a flexible pipe for the air supply pipe 402. The air supply pipe 402 branches at the tip and each branch is connected to the housing 1 of a different mist screen forming device 100.

[0034] According to the mist screen forming system 400, the mist screen S is formed in three layers. Furthermore, since the mist generators 30 are provided individually, the type of mist can be changed. For example, the mist from the first mist screen forming device 100 can be mixed with a deodorizer, the mist from the second mist screen forming device 100 can be a liquid with a sterilizing effect, and the mist from the third mist screen forming device 100 can be ordinary water. Furthermore, the mist from the mist screen forming devices 100 at both ends can be ordinary water mist screens S that function as shutters, while the central mist screen forming device 100 can be a mist screen S with a virus-removing effect. In this way, the mist screen S can be formed in a way that traps the components of the central mist.

[0035] In the mist screen forming system 400, the mist generator 30 may be shared by each housing 1. In that case, the mist supply pipe is connected to each housing using a pipe that branches into three. In particular, when multiple mist screen forming devices 100 are installed, the cost of the entire system can be reduced by sharing the mist generator 30 and / or air supply device 401. Note that the system may include four or more mist screen forming devices.

[0036] (Embodiment 5) FIG. 19 is a partially enlarged view showing a mist screen forming device according to embodiment 5 of the present invention. FIG. 20 is a cross-sectional view showing the mist screen forming device shown in FIG. 19. FIG. 21 is a component diagram of the mist screen forming device shown in FIG. 19, with (a) being a front view, (b) being a top view, and (c) being a side view. This mist screen forming device 500 is similar to the mist screen forming device 100 according to embodiment 1, but differs in that it is provided with a rectifier 501 in the opening 11. The honeycomb-shaped rectifying plate 6 is not provided in front of the opening 11. In other words, the rectifying plates 6 are arranged on both the left and right sides of the opening 11.

[0037] The rectifier 501 has a plurality of fins 503 arranged at equal intervals in a row on a rectangular plate 502, with each fin 503 inclined diagonally downward. This inclination causes water droplets that condense on the fins 503 to flow down along the inclination. The water then moves to the partition plate 10, which forms the opening 11, and flows downward. The water that flows down is collected in the tray 3 and then collected in the collection section 2. The inclination also allows the water droplets to flow quickly in one direction, preventing them from flying away with the mist. The fins 503 are particularly well-suited to flowing water droplets because they are attached to a single plate 502 and open on the other side. A rectangular plate 504 is placed on the other side. A small gap is formed between the edge of the fin 503 and the plate 504.

[0038] Furthermore, the fins 503 are rectangular and arranged in a roughly horizontal direction with a tilt in the direction of their short sides, and the short side downstream of the mist flow is cut at an angle, so that water droplets flow along the edge while being carried by the mist flow, preventing the water droplets from being detached from the fins 503 and being blown away by the mist flow.

[0039] Furthermore, the straightener straightens the mist that is sprayed out in a fixed direction. The mist from the openings 11 is guided to the front, so a neat mist screen is formed. Note that fins 503 that are longer than the thickness of the straightening plate 6 (the length that contributes to straightening) may be used (not shown). In this case, the straightening plate 6 can be left as is and only the openings 11 can have a high straightening effect. Furthermore, by providing the fins 503 so that they have a cross-sectional area smaller than the cross-sectional area of the flow paths (each honeycomb portion) of the straightening plate 6, the straightening effect can be enhanced.

[0040] The plate is attached to the opening 11 by sticking it to the tip of the partition plate 10, and is easy to replace.

[0041] In the above embodiment, the recovery unit 2 may be connected to a drainage pump instead of a tank to drain the water inside (not shown). Alternatively, the drainage pump may be connected to the tank. In this way, the effort of removing the tank and manually draining the water can be eliminated. [Explanation of symbols]

[0042] 100 Mist screen forming device 1 chassis 2. Recovery Section 3 saucers 4 Drain hose 5 Opening 6 Rectifier plate 7 Fan 11 Aperture 20 Mist supply pipe 30 Mist Generator

Claims

1. A self-standing vertical box-shaped housing, an air supply port provided on a side surface of the housing; a mist supply port provided on the rear surface of the housing; an opening provided on a front surface of the housing; a current plate formed of a number of holes in the opening, a partition plate is disposed in the housing at a position separating the air supply port and the mist supply port, and together with the rear surface, forms a substantially closed mist supply area, and edges of the partition plate are close to each other to form an elongated opening through which mist is sprayed; a plate body serving as an air filter is disposed at a position separating the air supply port from an opening provided on the front surface of the housing, and an air supply area is formed by the side surface, the partition plate, and the plate body; A mist screen forming device characterized in that a space is formed between the straightening plate and the plate body.

2. 2. The mist screen forming device according to claim 1, further comprising a mist supply pipe having one end connected to the mist supply port and the other end connected to a mist generator for generating mist.

3. 3. The mist screen forming device according to claim 1, further comprising a water droplet collection section provided at a lower portion of the housing.

4. A mist screen forming system having a plurality of mist screen forming devices according to claim 1, and a number of air supply means less than the number of said mist screen forming devices, one end of which is connected to said air supply means and the other end of which is branched and connected to the housing of said mist screen forming device.

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