JPH0464251B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhibition case used for displaying various exhibits for viewing.

[Prior Art] For example, as an exhibition case used in a museum, art gallery, etc., there is a base having a display floor on the upper surface, and a display case on the base so as to surround an exhibition space formed on the floor. A device is known that includes a case body installed in the case body.

In this type of display case, the displayed items in the display space arranged on the base can be viewed from the outside of the case body. Therefore, there are many cases in which most of the case body is made of a glass plate to improve visibility.

In such a display, one of the glass plates can be opened and closed so that the displayed items can be arranged on the floor or replaced.

[Problems to be solved by the invention] However, with such a structure, it is not possible to rigidly connect all the glass plates surrounding the exhibition space, so it is difficult to ensure the rigidity of the entire exhibition case and the airtightness of the exhibition space. difficult to do. In addition, if the glass plate to be opened is large, a great deal of effort and care is required to open and close it, especially if the glass plate is opened against gravity. There is also the risk that the supports that hold the glass panes in the open position will come loose during the replacement process, causing a catastrophe.

The present invention aims to solve these problems.

[Means for Solving the Problems] In order to achieve the above objects, the present invention employs the following configuration.

That is, the first invention (the invention described in claim 1; the same applies hereinafter) provides a base having an opening on the top surface and at least one surface other than the top surface that can be opened and closed, and an opening on the top surface of the base. an elevating floor that is disposed in the section and can be lowered into the base; and an elevating floor that is installed on the base and fixed to the base so as to surround the entire circumference of an exhibition space formed above the elevating floor. between a case body that can be viewed internally and which is equipped with a transparent wall body such as a glass plate, and a position where the elevating floor is used facing the opening and a position where exhibits can be installed and removed, which is set in the base; It is characterized by comprising an elevating mechanism that performs elevating and lowering operations.

Further, the second invention (the invention described in claim 2, hereinafter the same) has all of the first invention as its main part. The case body is airtightly installed on a base, and a sealing means is provided between the elevating floor and the periphery of the opening of the base to seal the gap therebetween by utilizing the rising movement of the elevating floor. It is characterized by:

Furthermore, the third invention (the invention described in claim 3; the same applies hereinafter) has all of the first invention as its main parts. The case body is airtightly installed on a base, and a sealing means is provided between the elevating floor and the periphery of the opening of the base to seal the gap therebetween by utilizing the rising movement of the elevating floor. ing. Furthermore, a lighting fixture is provided inside the case body, and an exhaust port is provided above the lighting fixture, and an air supply port is provided below the lighting fixture.

[Operation] According to the first invention, if the elevating floor in the use position is lowered by the action of the elevating mechanism to the position in the base where exhibits can be installed and removed, and one side of the base is opened,
Exhibits can be placed and exchanged on the elevating floor. If the elevating floor is raised to the use position by the action of the elevating mechanism, the elevating floor will face the upper opening of the base, and the exhibits placed on it will be exposed to the case body. It will be displayed in an enclosed exhibition space. Therefore, there is no need to provide any opening/closing portion in the case body. The transparent walls that make up this case body are fixed to the base, and there is no need for opening/closing, raising/lowering, or movement when replacing exhibits. Therefore, it becomes possible to rigidly connect the transparent wall bodies or the transparent wall body and other wall bodies, and the strength of the case body can be easily increased. Therefore,
The usable area of the transparent wall such as a glass plate can be designed to be as large as possible, and the function as an exhibition case can be maximized. Also,
In this exhibition case, the largest external part that is easily accessible to people approaching the display case does not operate at all, and only the internal elevating floor that is difficult for people to access operates, so there is a possibility that hands or clothing may get caught. is extremely low, and there is no fear that the transparent wall, such as a heavy glass plate, will lose its support and unexpectedly fall.

Further, according to the second invention, in addition to the effect obtained by the first invention, the effect that the exhibition space can be completely sealed is obtained. That is, when the elevating floor is raised to the use position, the gap between the periphery of the elevating floor and the periphery of the opening of the base is sealed by the lifting action by the sealing means. Since the case body is airtightly installed on the base, the exhibition space is hermetically sealed in the exhibition state.

Furthermore, according to the third invention, in addition to the effect obtained by the first invention, there is obtained the effect that the exhibition space can be ventilated. That is, the air in the exhibition space heated by the lighting equipment rises due to convection and is discharged from the exhaust port. Then, corresponding outside air is sequentially introduced into the exhibition space from the air supply ports. Furthermore, airtightness is maintained between the elevating floor and the base, and between the base and the case body in the display state. Therefore, by selecting the flow path resistance of the supply/exhaust ports, it is possible to control the ventilation rate relatively accurately.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

Embodiment 1 (Figures 1 to 7) The display case 1 of this embodiment is intended to be installed in, for example, an art museum or a museum, and a base 2 is fixed to the floor F of these buildings. It is designed to display items on display.

The base 2 has an upper frame 3 and a lower frame 4 which are horizontally connected at the upper and lower parts to form a rectangular shape, and are supported by supports 5.
It is a hexahedral shape formed by connecting the top and bottom of the
Its four vertical sides are each surrounded by metal decorative panels 6, and the top and bottom surfaces are left open. The front part of the decorative panel 6 has its lower end connected to the lower frame 4 via a hinge 7, and forms a door panel 6a whose upper part can be opened and closed around the hinge 7. At the lower end of the lower frame 4, there are a plurality of casters 8 and a plurality of adjusters 9 for fixing the base 2 to the floor surface F of the building and adjusting its inclination at the same time.
are arranged. An inner frame 10 is fixed to the upper end of the upper frame 3 with their inner surfaces flush with each other, and this frame 10
A locking collar 10a is formed by projecting an upper end portion inward.

An elevating floor 11 that can be lowered into the base 2 is disposed in the upper opening 2a of the base 2 surrounded by the inner frame 10. The elevating floor 11 is for placing exhibits, and is connected to the upper frame 3 and the inner frame 10.
It is formed of a rectangular pedestal 11a that is loosely fitted with a small gap S therein, and a decorative floor 11b whose upper surface is covered with cloth and which is held on the pedestal 11a.
The use position of the elevating floor 11 is such that the upper peripheral edge of the pedestal 11a abuts the lower end surface of the locking collar 10a, and the upper surface of the decorative floor 11b and the upper surface of the inner frame 10 are flush with each other. Furthermore, a humidity control agent M for controlling the humidity in the exhibition space A formed above the pedestal 11a and the decorative floor 11b is housed.

The exhibition space A is surrounded by a case body B installed on a base 2, and this case body B has a transparent wall body 12 that can be seen from the outside and a lid that is airtightly attached to the upper end of this transparent wall body 12. It is equipped with a ceiling 15. The transparent wall body 12 is formed of a plurality of glass plates 12a surrounding the exhibition space A from all sides. Each glass plate 12a is formed vertically,
Both side edges of each are rigidly connected with adhesive. The lower ends of all of them are airtightly fitted and held in a groove 14 formed between a frame 13 fixed to the outside of the upper frame 3 and the inner frame 10.

That is, the transparent wall body 12 of this case body B is
It is immovably fixed to the base 2.

The ceiling 15 includes a lighting box 16 that is fixed to the upper end of the glass plate 12a and has its top and bottom open, a lighting equipment inspection door 17 that closes the upper part of the lighting box 16 so that it can be opened and closed, and a lighting box 16 that has a horizontal position at the lower end of the lighting box 16. The louver 18 is held at the louver 18. The lighting equipment inspection door 17 is formed in two rectangular shapes arranged in the front and back, and one side of each is attached to the upper end of an intermediate frame 16a that extends from side to side over the upper end of the lighting box 16 via a hinge 17a. It is supported so that it can be opened and closed, and the other side is hooked to the upper end surface of the lighting box 16. Louver 18
The light box 16 is made of resin and has a mesh shape.
The lower end of the holder is bent upward inward and held at its tip. Note that a transparent glass plate 40 is provided between the lower end of the lighting box 16 and the louver 18.
is interposed. A sealing material 41 is provided between the glass plate 40 and the lower end of the lighting box 16 to seal the upper part of the exhibition space A.

On the other hand, in the base 2, there is provided a lifting mechanism 19 for raising and lowering the lifting floor 11 between an upper usage position and a lower display item loading/unloading position.

That is, as shown in FIGS. 3 to 7, a horizontal member 21 that opens downward is installed in the center of the lower frame 4 of the base 2 in the front-rear direction, and both left and right ends of this horizontal member 21 and A channel-shaped protection column 20 opening inward is erected between the base 2 and the upper frame 3,
The main parts of the elevating mechanism 19 are housed inside the protective column 20 and the horizontal member 21.

The elevating mechanism 19 is constructed by disposing feed screws 23 in each of the protection columns 20 and screwing nuts 22 fixed to both left and right ends of the elevating floor 11 into these feed screws 23. By rotating the feed screws 23 synchronously and screwing together the nuts 22 at the same speed, the elevating floor 1 is
1 can be raised and lowered. The structure of this elevating mechanism 19 will be specifically explained below.

The feed screw 23 is a trapezoidal single thread screw, and its upper end is supported by the lower end of the upper frame 3 via a radial bearing 24, as shown in FIG. Also. The lower end of the feed screw 23 is supported on the horizontal member 21 via a radial bearing 25, and is passed through the horizontal member 21 to connect to the input end 23.
It constitutes a. Both feed screws 23 can be rotated in forward and reverse directions by the rotational motion applied to each input end 23a. Each input end 23a
A crank arm 26 is fixedly attached to each of the crank arms 26, and these crank arms 26 are respectively connected to one end of a long flat crank lever 27 disposed within the horizontal member 21 via a crank pin 28. The inner ends of both crank levers 27 are connected to a crank arm 30 via a single crank pin 29, as shown in FIG.
0 is fixed to the lower end of a vertical driven shaft 32 supported on the horizontal member 21 via a radial bearing 31. As shown in FIG. 7, between the driven shaft 32 and the driving shaft 33 arranged in a horizontal position at the bottom of the front side of the base 2, there is a pair of bevel gears 34a with a smaller diameter on the driving shaft 33 side. 34b is provided. The base end of the driving shaft 33 is rotatably supported by a support plate fixed to the lower frame 4 on the front side, and has a rectangular cross section that fits inside the detachable operating handle 35.

The end of the nut 22 projects inward from the base 2 from the opening of the protection column 20, and the projecting end holds the pedestal 11a of the elevating floor 11 from the left and right through a connecting plate 36. . In addition, the protection pillar 20
Guide columns 37 fixed to the upper frame 3 and the lower frame 4 are provided in front and rear of the platform, and these guide columns 37 assist in holding the vicinity of the four corners of the elevating floor 11. That is, holding plates 38 are fixed to the lower ends of the pedestals 11a near the four corners of the elevating floor 11, and a plurality of radial bearings 39 are provided on these holding plates 38. Each holding plate 38 is provided so as to sandwich the end face of the guide post 37 from two sides, and the outer race of the radial bearing 39 is brought into rolling contact with each of the two faces of the guide post 37.

On the other hand, below the exhibition space A, there is a sealing means for sealing the exhibition space A from below by closing the gap between the elevating floor 11 and the upper opening 2a of the base 2 by using the rising movement of the elevating floor 11. 42 are provided. The sealing means 42 is a locking collar 1 formed on the inner frame 10 of the base 2.
A convex sealing material 43 made of urethane rubber or the like is fixed to the lower end surface of the elevator floor 1 in a circular manner.
1 rises to the use position, its pedestal 11
The upper end peripheral edge of a is configured to come into pressure contact with the sealing material 43.

Although FIG. 1 shows a side cross section of the display case 1, the elevating mechanism 19 is omitted in this drawing. Details of the lifting mechanism 19 are shown in Figures 4 to 7.
As shown in the figure. That is, FIG. 4 shows a part of the elevating mechanism 19 as a cross section on the right side of the base 2 and the elevating floor 11, and FIG. 5 shows a part of the elevating mechanism 19 from the bottom side of the base 2. Further, FIG. 6 shows a main part of the elevating mechanism 19 in an enlarged view in a front cross section of the base 2, and FIG. 7 shows a part of the elevating mechanism 19 in a right cross section.

If the configuration is like this, the door panel 6
Open a and attach the operating handle 35 to the base end of the driving shaft 33.
When the operating handle 35 is rotated, the rotational power is transmitted to the driven shaft 32 via the bevel gears 34a and 34b, and from the crank arm 30 fixed to the lower end of the driven shaft 32, the crank levers 27 on both sides are rotated. transmitted to. When the crank arm 26 rotates due to the sliding and rotational movement of each crank lever 27, each feed screw 23 connected to the crank arm 26 at the input end 23a rotates. the result,
Each nut 22 connected to the elevating floor 11 is screwed into each feed screw 23 and advances and retreats, thereby moving the elevating floor 11 from the use position to the exhibit loading/unloading position at the bottom (6th
(see imaginary line in the figure), the operating handle 3
The robot moves up and down within the base 2 by an amount corresponding to the input amount added to the base 2.

On the other hand, the exhibition space A is sealed from the periphery and above by the glass plate 12a, the lighting box 16, and the glass plate 40 at the lower end of the lighting box 16, etc., by airtight rigid connections. Then, when the elevating floor 11 rises from below to the use position and stops,
The upper end peripheral edge of the pedestal 11a presses against the sealing material 43 at the lower end of the locking collar 10a, closing the gap S between the elevating floor 11 and the upper end opening 2a of the base 2, and cutting off communication between the exhibition space A and the outside. It turns out.

Therefore, if the configuration is like this,
When displaying or exchanging exhibits, the work can be done safely and easily below the display case 1 by the mechanical operation of the elevating floor 11, and when the operation handle 35 is removed, the feed screw 23, nut 22, etc. By this function, the elevating floor 11 can be reliably locked in the use position. Therefore, each member such as the glass plate 12a surrounding the exhibition space A is brought into rigid contact with each other, increasing the rigidity of the entire exhibition case 1. It is also unnecessary to provide a lock mechanism or the like.

Furthermore, since the transparent wall 12 can be free of pillars that obstruct the view, or the transparent wall 12 can be made of a single glass plate, a good display case can be created that can improve the visibility of the exhibits. Can be provided.

In addition, the exhibition space A can be easily made completely sealed depending on the degree of elevation of the elevating floor 11, so there is no need to distinguish between display cases and storage cases as in the past. That is, with this kind of display, the interior of the exhibition space A can be made either airtight or airtight, making it possible to control the quality of the exhibit in an optimal manner depending on the exhibit.

Embodiment 2 (Fig. 8) The exhibition case 1 shown in this embodiment has the same basic configuration as that of Embodiment 1, and is designed to actively ventilate the exhibition space A. . Note that the same reference numerals are given to the same or corresponding parts as in the above embodiment, and detailed explanation thereof will be omitted.
Exhibition space A is the case body B installed on base 2.
The case body B includes a transparent wall 12 that can be viewed from the outside, and a transparent wall 1
2 and a ceiling 15 airtightly attached to the upper end thereof. That is, the opposite edges of the glass plates 12a constituting the transparent wall 12 that surrounds the exhibition space A from all sides are rigidly and airtightly connected to each other, and the lower ends are inserted into the grooves 14 formed on the upper frame 3 of the base 2. It is kept airtight. Furthermore, the upper end of a lighting box 16 of a ceiling 15 that closes off the upper part of the exhibition space A is hermetically joined to the upper end of the glass plate 12a. A rubber gasket 44 is interposed in a circumferential manner between the upper end surface of the lighting box 16, the upper end surface of the intermediate frame 16a, and the lower end surface of the lighting equipment inspection door 17 that is attached to the lighting box 16. The gap C between them is sealed.

On the other hand, below the exhibition space A, there is a seal that seals the exhibition space A from below by closing the gap S between the elevating floor 11 and the upper opening 2a of the base 2 using the rising movement of the elevating floor 11. Means 42 are provided. The sealing means 42 includes a convex sealing material 43 made of urethane rubber or the like fixed in a circumferential manner to the lower end surface of the locking collar 10a formed on the inner frame 10 of the base 2. When the pedestal 11a rises to a certain level, the upper peripheral edge of the pedestal 11a presses against the sealing material 43.

In addition, the lighting equipment inspection door 17 and the lighting box 1
A lighting fixture 45 is disposed between the louver 18 held at the lower end of the lighting fixture 45, and an exhaust port 46 and an air supply port 47 are provided above and below the lighting fixture 45, respectively. The exhaust port 46 is opened between the central portion of the intermediate frame 16a and the lighting equipment inspection door 17, and the air supply port 47 is formed by vertically penetrating the peripheral end portion of the elevating floor 11. In addition, an air filter 48 is interposed therein.

With such a configuration, the above-mentioned Example 1
In addition to the operation achieved by this, the interior of exhibition space A will be forcibly ventilated. That is, the exhibition space A is viewed from the surroundings and above by the glass plate 12.
A, the lighting box 16, and the like are sealed by an airtight rigid connection, and a rubber gasket 44 provided between the lighting box 16 and the lighting equipment inspection door 17.

Furthermore, in the lower part, the gap between the base 2 and the glass plate 12a is closed by the airtight rigid contact between the base 2 and the glass plate 12a. Then, when the elevating floor 11 has risen to the use position and stopped, the upper peripheral edge of the pedestal 11a is attached to the locking collar 1.
The sealing material 43 at the lower end of 0a is pressed to close the gap S between the elevating floor 11 and the upper opening 2a of the base 2.

As a result, communication between exhibition space A and the outside is cut off except for the exhaust port 46 and the intake port 47.
Exhibition space A heated by lighting of lighting equipment 45
The air inside rises and is discharged from the exhaust port 46. Along with this, the lower air supply port 47
From then on, new outside air corresponding to the amount of exhausted air is introduced into the exhibition space A via the air filter 48.

Therefore, if the configuration is like this,
It becomes unnecessary to keep the glass plate 12a in an open state when replacing an exhibit or the like. That is, when replacing an exhibit, the exhibit can be easily and safely replaced by operating the elevating floor 11.

Since each member such as the glass plate 12a that surrounds the exhibition space A from all four sides can be brought into rigid contact with each other, the rigidity of the entire exhibition case 1 is increased, and at the same time, the glass plate 12a and the like are equipped with a complicated butterfly holding mechanism and anti-theft mechanism. It becomes unnecessary to provide a locking mechanism or the like.

Moreover, by selecting the flow path resistance of the exhaust port 46 and the air supply port 47, such as the opening area and the air permeability of the air filter 48, it becomes possible to provide optimal ventilation for the exhibit. Therefore, the exhibition case 1
It can be effectively used not only as a display case but also as a storage case.

Embodiment 3 (FIGS. 9 and 10) The display case 1 according to this embodiment is used, for example, when one side of the display case 1 is placed close to the wall of a floor of a museum, etc., and is horizontally long. A case body B is provided on a base 2. Case body B
It comprises a transparent wall body 12 that can be viewed from the outside, and a ceiling 15 held in an inclined state at the upper end portion of the transparent wall body 12.

The transparent wall body 12 is configured by arranging glass plates 12a on the front and both sides, and arranging a metal rear wall 12b on the rear side. Both sides of the glass plate 12a are rigidly and airtightly connected to each other, and the lower end thereof is airtightly held in a groove 14 formed in the upper end surface of the inner frame 10 of the base 2. The lower end of the rear wall 12b is airtightly fixed to the upper end surface of the upper frame 3, and its upper front end is bent slightly downward, and a ceiling made of a glass plate is formed between this bent portion 12c and the upper end of each glass plate 12a. The circumferential edge of 15 is kept airtight.

Further, a lighting fixture 45 is provided on the rear wall 12b in close proximity to the inner surface thereof, and an exhaust port 46 and an air supply port 47 are located above and below this lighting fixture 45.
is provided. The exhaust port 46 is opened at the upper end of the rear wall 12b, and the air supply port 47 is opened at the peripheral end of the elevating floor 11, and an air filter 48 is provided therein.

Therefore, this device can also obtain the same functions and effects as those of the second embodiment.

Note that the present invention is not limited to the embodiments described above, and various other modifications are possible. for example,
The transparent wall that surrounds the exhibition space from the periphery is not limited to glass plates, but may also be composed mainly of acrylic, etc.
Alternatively, it may be formed into a cylindrical shape.

Further, the elevating mechanism is not limited to a manual type, but may be an electric type using a motor or the like. In that case, by stopping the power supply to the motor, the elevating floor can be fixed at the use position and the exhibition space can be locked.

[Effects of the Invention] Since the present invention has the above configuration, the following effects can be obtained.

According to the first invention, when display items are placed or replaced, the elevating floor is raised and lowered by the action of the elevating mechanism, so that the work can be carried out safely and easily. That is, in the display case of the present invention, the largest external portion that is easily touched by humans does not operate at all, and only the internal elevating floor that is difficult for humans to access operates, so there is no risk of hands being stuffed or clothes getting caught. Furthermore, there is no fear that the transparent wall such as a heavy glass plate will lose its support and unexpectedly fall. Then,
High safety can be ensured. Furthermore, all of the case bodies that surround the exhibition space can be joined or integrated, increasing the rigidity of the entire display case, and allowing the case body to have a relatively free shape, providing a good-looking display case. can. That is, in the display case of the present invention, the transparent wall body is fixed to the base,
Even when changing exhibits, there is no opening/closing, lifting/lowering, or movement involved. Therefore,
It becomes possible to rigidly connect the transparent walls to each other or to other walls, and the strength of the case body can be easily increased. Therefore, the usable area of the transparent wall such as a glass plate can be designed to be as large as possible, and the function as an exhibition case can be maximized.

According to the second invention, in addition to the above-mentioned effects, when the elevating floor is raised to the use position, the exhibition space can be easily almost completely sealed, so that the exhibition case can be used only for display purposes. figure,
It can also be used to store exhibits.

Further, according to the third invention, in addition to the effects obtained by the first invention, the amount of air circulation in the exhibition space can be adjusted, so that the quality of the exhibit can be controlled in an optimal state depending on the exhibit. .

[Brief explanation of the drawing]

1 to 7 show an embodiment of the present invention,
Figure 1 is a side sectional view of the exhibition case, Figure 2 is an exploded perspective view of the elevating floor, Figure 3 is a plan view of the base,
Figure 4 is a sectional view taken along the - line in Figure 3, Figure 5 is a bottom view of the base, and Figure 6 is a - line sectional view in Figure 3.
7 is an enlarged sectional view partially schematically showing the cross section taken along the line - in FIG. 3. FIG.
FIG. 8 is a side sectional view of a display case showing another embodiment. FIG. 9 is a side sectional view of a display case showing still another embodiment, and FIG. 10 is a front view of the display case shown in FIG. DESCRIPTION OF SYMBOLS 1... Exhibition case, 2... Base, 2a... Top opening, 11... Lifting floor, 12... Transparent wall, 12a... Glass plate, 15... Ceiling, 19... Lifting mechanism, 42... Sealing means, 43... Sealing material , 45...Lighting equipment, 46
...Exhaust port, 47...Air supply port, A...Exhibition space, B...Case body, S, C...Gap.

Claims (1)

[Claims] 1. A base having an opening on its top surface and at least one surface other than the top surface can be opened and closed, and an elevating floor disposed in the opening on the top surface of the base and capable of being lowered into the base. , an internally viewable case body comprising a transparent wall body installed on the base and fixed to the base so as to surround the entire circumference of the exhibition space formed above the elevating floor; and an elevating mechanism for elevating and lowering the elevating floor between a use position facing the opening and a position set in the base where exhibits can be installed and removed. 2. A base having an opening on its top surface and at least one side other than the top surface that can be opened and closed; an elevating floor disposed in the opening on the upper surface of the base and capable of being lowered into the base; and an elevating floor above the elevating floor. an internally visible case body comprising a transparent wall body airtightly installed on the base and fixed to the base so as to surround the entire circumference of an exhibition space formed in the exhibition space; an elevating mechanism that moves up and down from a use position facing the opening to a position set in the base where exhibits can be installed and removed; and a lifting mechanism that utilizes the lifting movement when the elevating floor rises to the use position. and sealing means for sealing a gap between the elevating floor and the periphery of the opening of the base. 3. A base that has an opening on the top surface and at least one side other than the top surface can be opened and closed, an elevating floor that is disposed in the opening on the upper surface of this base and can be lowered into the base, and an upper part of the elevating floor. an internally visible case body comprising a transparent wall body airtightly installed on the base and fixed to the base so as to surround the entire circumference of an exhibition space formed in the interior; a lighting fixture provided inside, an exhaust port located above the lighting fixture, and a position where exhibits can be installed and removed from a usage position where the elevating floor faces the opening and is set within the base. and an airtight seal that seals a gap between the elevating floor and the periphery of the opening of the base by utilizing the elevating movement when the elevating floor rises to the use position. and an air supply port provided at a position lower than the lighting equipment in the exhibition space.