Surface Cleaning Equipment

Abstract

To provide a surface washing device capable of quickly deactivating or reducing, pathogen organisms adhered to the surface of a handle (grip), a door knob, or the like of a toilet room or the like which is commonly used by unspecified people, for recovering a clean state of the grip surface until a next user touches the same grip.SOLUTION: A thin film covering the grip surface is caused to travel and retreat, then the thin film is heated for sterilization at a high temperature in a state in which, the thin film does not contact the grip body, then, the thin film is caused to cover the grip surface again, for substantially cleaning the grip surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus for inactivating or reducing pathogens (bacteria, viruses, etc.) attached to the surface of an object. [Background technology]

[0002] Even in Japan, where sanitation conditions are considered relatively good compared to other countries, there is a steady stream of infections caused by seasonal influenza and norovirus every year. In recent years, the outbreak of new strains of influenza and the novel coronavirus has also posed new threats to humanity. While the routes of infection for these diseases vary widely, one common route is contact infection. Pathogens on the hands of a carrier can adhere to surfaces such as doorknobs and handrails when the carrier touches them, resulting in indirect contact infection when a healthy person then touches the surface.

[0003] The primary method traditionally used to prevent contact infection is disinfection by wiping with chemicals such as ethanol or sodium hypochlorite. However, chemical disinfection is ineffective against pathogens that do not fit within the disinfectant spectrum of the chemical, and it takes a certain amount of time (tens of seconds to several minutes) for the chemical to disinfect the pathogens. In fact, frequent disinfection methods, such as disinfecting a doorknob with a chemical wipe every time a user touches it, are not a rational method from an efficiency standpoint.

[0004] Another conventional technology addressing this issue is the introduction of surface treatment products that claim to have antibacterial or antiviral properties. Many of these use silver ions or special polymers. However, most of these only have the ability to slightly inhibit the proliferation of attached pathogens compared to untreated surfaces, or only to slowly reduce pathogens over several hours to several tens of hours. Therefore, even when applied to frequently used shared areas such as doorknobs, they cannot be expected to have much of an effect in inhibiting contact infection.

[0005] As such, there are no existing technologies or products that can rapidly inactivate or reduce pathogens on the surface of objects where pathogens are likely to frequently adhere, such as doorknobs, in a matter of a few to a few tens of seconds. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] "Viruses Contained in Droplets Applied on Warmed Surface Are Rapidly Inactivated", Fiquet S. et al., 2014 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved is to inactivate or reduce pathogens attached to the surface of an object, and to make the surface of the object clean before the next use of the object. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following device.

[0009] The surface of the object to be used in a clean state is temporarily moved away from the usage position and then heated in that position. The heating conditions (temperature, heating time, etc.) are determined arbitrarily depending on the type of pathogen to be inactivated or reduced and the degree of reduction required.

[0010] In terms of sheltering the object surface, it is possible to consider a configuration in which the object surface is covered with a cover or the like during heating.

[0011] Generally, the higher the heating temperature of an object's surface, the shorter the time it takes to inactivate pathogens. While it's tempting to increase the heating temperature, in most cases the temperature at which the object is used is too high. For example, heating a doorknob to 200°C for 10 seconds will kill or inactivate most pathogens, but people cannot touch it until it returns to room temperature.

[0012] Therefore, the main focus of this invention is to limit the heat capacity of the surface of the object to be thermally sterilized to the minimum necessary. The minimum necessary heat capacity means heating a thin material such as a film or thin plate. This device heats only this thin material, and once the desired inactivation or reduction has been achieved, it places this thin material on a substrate or framework with the required rigidity.

[0013] With this device, the thin material used for sterilization has only the minimum necessary heat capacity, so there is no risk of burns even if a person touches it immediately after it has been heated to a high temperature. Furthermore, even when cooling after high-temperature heating, the amount of stored heat is small, so heat dissipation (cooling) occurs as quickly as during heating. Furthermore, because thin materials have a large surface area exposed to the outside air, they quickly return to room temperature simply by being exposed to room-temperature air after heating. Therefore, by selecting a material with the appropriate specific heat and thickness, setting the heating temperature, and setting the cooling time before a person touches the heated surface, there is no risk of burns to people after high-temperature heating.

[0014] Furthermore, heating only a thin material requires very little energy. For example, the amount of heat required to raise the temperature of 100 μm of water by 9°C is enough to raise the temperature of 10 μm of SUS304 foil by 188°C. If the room temperature is 23°C, raising the temperature by 188°C to 211°C will neutralize most pathogens within 10 seconds.

[0015] To rephrase the previous paragraph, even if you touch 10μm thick SUS304 foil heated to 211℃ at room temperature of 23℃ with your fingers, you will not get burned. The reason is that the amount of heat stored when 10μm thick SUS304 foil rises by 1℃ is only 0.05 times the thickness of the 100μm thick keratin on your fingers, and even if you were to divide the heat stored in the 211℃ SUS foil between the SUS foil and the keratin until they reached the same temperature, it would only reach 45℃. This means that it would feel like holding a teacup of lukewarm water.

[0016] In this way, when heat disinfecting the surface of a structure, separating the surface as thinly as possible and then heat disinfecting only the separated surface at a high temperature is an extremely effective method in terms of both disinfection efficiency and energy conservation.

[0017] Here we will discuss heating temperatures and times. Qualitatively speaking, there is no doubt that heating at the highest possible temperature for the longest possible time will result in the inactivation and reduction of pathogens. However, in actual product design, efficiency and economics should be taken into consideration when determining and designing the required specifications of the equipment. However, as a guideline, if the goal is sterilization, heating should be done above the boiling point of water. Bacteria, unlike viruses, are microorganisms that store water within their cell walls. Therefore, if bacteria are heated above the boiling point, they will expand the moment the water evaporates, causing the cell walls to be destroyed by internal pressure, making them unable to survive. Therefore, heating above the boiling point of water, i.e., above 100°C at atmospheric pressure, will instantly kill any attached bacteria if they can be heated to above 100°C.

[0018] On the other hand, this is not necessarily the case with viruses. Because viruses and phages are not living organisms but merely chemical substances, they may retain their molecular structure for a while even in environments above 100°C. Therefore, the heating temperature and time can be determined taking into account the heat resistance temperature of the metal foil or resin film used, the temperature of the heater, economy, and safety.

[0019] Here are some specific examples. There are viruses that have a membrane called an envelope and those that do not. For example, influenza viruses and coronaviruses are enveloped viruses, while norovirus is a non-enveloped virus. Intuitively, it may seem that viruses with a membrane have better resistance to external influences, but this is not actually the case. This is because enveloped viruses can be inactivated if the envelope is broken. On the other hand, non-enveloped viruses cannot be inactivated unless their structure itself is destroyed. Therefore, enveloped viruses can be heated above the boiling point of water, similar to the heat disinfection of bacteria, and the water inside the envelope will evaporate, destroying the envelope from the inside.

[0020] Here we quote a scientific paper that supports this theory. Non-Patent Document 1 conducts an experiment to measure the degree of reduction in infectivity of enveloped and non-enveloped viruses when heated at high temperatures, along with the heating time. According to this, when an enveloped virus is heated at 100°C, its infectivity is reduced to one-ten-thousandth of its initial level in one second (below the detection limit). On the other hand, when a non-enveloped virus is heated at 100°C, it takes nine seconds. When heated at 130°C, it is reduced to the detection limit in two seconds.

[0021] As such, heating conditions (temperature and time) vary depending on the type of pathogen to be reduced and to what extent, and therefore cannot be generally defined in this invention. However, considering rapidity and effectiveness, the lower limit temperature is likely to be 100°C (the boiling point of water), at which point bacteria and enveloped viruses are instantly killed or inactivated. Meanwhile, the upper limit must be such that the material does not burn a person when touched while stored at that temperature (depending on the thickness, specific heat, and thermal conductivity of the material), the thin film material does not deteriorate significantly even when repeatedly heated to that temperature, the time required to reach that temperature is not excessively long, and the voltage and current required to reach that temperature are acceptable from the standpoint of safety and economy. While there are currently not many materials that meet these conditions, we will describe them in the examples. [Effects of the Invention]

[0022] According to the present invention, the surfaces of objects requiring cleaning can be disinfected and detoxified quickly, energy-efficiently, and automatically, thereby meeting the social needs for cleaning frequently contaminated surfaces such as doorknobs and handrails whenever they become contaminated. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a representative diagram of the present invention, showing an external view of the device and a central cross-sectional view. [Figure 2] FIG. 2 is an external view of the device of the present invention with the cover part half-cut. [Figure 3] FIG. 10 is a diagram showing the state of the device of the present invention during maintenance. [Figure 4] FIG. 3 is a diagram showing the state of the device of the present invention during maintenance (viewed from the opposite side of FIG. 3). [Figure 5] FIG. 10 is a diagram showing the state of the device of the present invention during maintenance. [Figure 6] FIG. 2 is a cross-sectional view of a base device portion of the device of the present invention. [Figure 7] FIG. 3 is a cross-sectional view for explaining a rotation drive unit. [Figure 8] 1 is a flowchart of software for driving the device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] The core of this invention is that only the minimum surface thickness of the functional structure (doorknob, handrail, etc.) to be cleaned is heated and disinfected. However, if the area to be cleaned is made too thin or small, problems with rigidity and durability may arise. Conversely, if it is made too thick, it will take a long time to heat and cool, making it unsuitable for frequent use and requiring a large amount of energy.

[0025] Therefore, the thickness and structure of the device must satisfy the heating conditions based on the design requirements of how much pathogens must be reduced within how many seconds before the device can be restored to a reusable state, and there are countless ways to achieve this design, so it is not possible to generalize. The following example shows only one example using the present invention among the configurations that can withstand these actual designs. [Example]

[0026] Figure 1 shows an external view and a central cross-section of an apparatus according to an embodiment of the present invention. In Figure 1, thin film 107 travels in the direction of rotation arrow 108, driven by the driving force obtained by the rotation of drive shaft 109. If drive shaft 109 is considered the starting point, the thin film passes through heat disinfection zone 110, exits the front side (outside) of the apparatus, passes through driven rotation shafts 111, 112, 113, and 114 in order, re-enters the apparatus, has its surface wiped by scraper 118 and wiping paper 119, and then returns to drive shaft 109.

[0027] Since drive shaft 109 needs to have the function of feeding out thin film 107, it is equipped with friction resistor 115 with an appropriate friction coefficient integrated on its outer periphery. In addition, drive shaft 109 generates tension in the upward direction in the figure using a spring to remove slack in thin film 107 and to obtain an appropriate friction force between thin film 107 and friction resistor 115. This structure will be described later with reference to Figure 6.

[0028] The thin film 107 is required to be heat-resistant to at least 100°C in the heat disinfection zone 110. Considering economic efficiency and thin film availability, a polyimide or PTFE thin film is desirable for this thin film 107. A thickness of 5 μm to 12.5 μm is desirable from the standpoints of availability and the required heating time. Thinner films require shorter heating times, which is desirable in terms of both energy input and required time, but a 5 μm polyimide film, for example, is brittle and easily torn. Depending on the customer's required specifications, a 7.5 μm or 12.5 μm polyimide film provides a good balance of device performance when durability and availability are the primary considerations.

[0029] The heat disinfection zone 110 generates heat through electrical resistance. Therefore, essentially, any material that heats when electricity is passed through it will do. Examples of readily available materials include nichrome wire and stainless steel plate. Tests were conducted with several different materials and shapes, and when the heat disinfection zone 110 was made of SUS304 and had a width of 3 mm, a thickness of 0.01 mm, and a length of 160 mm, 7.8 V was applied to the entire zone, including the conductors connected to both ends of the heating zone, and 1.3 A flowed.

[0030] In this case, if the volume resistivity of SUS304 is 93 μΩcm, the density is 7.93 g / cm^3, and the specific heat is 280 J / kg·℃, the heating disinfection zone 110 will consume 8.4 W, and if there is no heat dissipation or heat transfer, the temperature will rise by 788°C per second.

[0031] The thin film 107 is made to travel in contact with this heat disinfection zone 110. If the thin film travels at a speed that allows it to pass through the 3 mm wide heat disinfection zone 110 in 0.2 seconds, then, based on the calculation in the previous paragraph, the thin film will receive the energy equivalent to the temperature rise of the heat disinfection zone 110 to 158°C during this time. Of course, not all of the energy is transferred from the heat disinfection zone 110 to the thin film 107. The situation will also differ depending on the environmental temperature (room temperature), but as a guideline, specifications and design can be set based on these levels of voltage, current, and passage time.

[0032] As the thin film 107 passes through the heat disinfection zone 110, the thin film position sensor 116 detects the thin film position mark 705. The thin film position mark 705 is a mark on the surface of the thin film 107 and is coated with heat-resistant paint. The thin film position sensor 116 is a reflective photoreflector that reads the increase or decrease in the reflected light from the thin film position mark 705. By installing this sensor and mark on both ends of the gripping device, the running status of the thin film 107 can be confirmed in the same way as the A and B phases of an encoder. Specifically, if the sensor does not respond within a certain period of time, it is possible that the thin film is stalled due to some kind of problem, or that the thin film is damaged or contaminated. In this case, the device can be stopped and an error message can be issued. Alternatively, by determining the position where the sensors on both ends of the grip are ON as the reset position, the starting point of one rotation of the thin film 107 loop can be reliably reproduced.

[0033] Both ends of the driven rotation shafts 111 to 114 are supported by rotation bearings so that the thin film 107 can move smoothly. Furthermore, if the fixed support structure 117 does not rotate but has a large frictional resistance, it may be smoothed by being covered with a heat-shrinkable fluororesin tube or the like.

[0034] The scraper 118 and the wiping paper 119 are placed to remove dirt and water droplets adhering to the surface of the thin film 107. Even if large water droplets adhere to the thin film 107 and pass through the heat disinfection body 110, the heat generated will not be enough to evaporate the entire droplet, so the purpose of this is to remove large particles in advance. The scraper 118 functions like a wiper, scraping off water droplets adhering to the surface, and is suitably made of a thin film resin material such as polyimide film. The wiping paper 119 must also be water-absorbent. While ordinary absorbent paper or nonwoven fabric can be used, it is desirable for the wiping paper 119 to be elastic so that it can be pressed against the thin film 107 with a constant force. Therefore, in consideration of economy, a felt material was used in the prototype, and good results were obtained.

[0035] The above describes how the loop material of the thin film 107 is disinfected by going around in one direction. Next, we will explain the entire device that contains this structure.

[0036] We will now explain the overall view of this device in Figure 1. This device is broadly divided into three parts: base part 105, which is fixed to a door or doorknob, gripping part 103, which disinfects while rotating thin film 107, and fixing parts 102 and 104, which fix it. Since the overview of the gripping part was explained in the previous paragraph, from here on, we will mainly describe the other parts.

[0037] FIG. 2 shows a diagram in which the cover 201 of the fixed parts 102 and 104 has been cut in half. This is what the inside of the device looks like. Note that various wiring has been omitted to simplify the illustration. In this diagram, it is divided into a motor / gear support part 202, a central shaft support part 203, and a rotation drive part support part 204. In addition, a human sensor is provided, divided into a human sensor light source 205 and a human sensor 206, which can detect when a human hand or the like approaches the grip part 207. Note that in this diagram, a photointerrupter is intended as the human sensor, but an ultrasonic sensor can also be used in the same way.

[0038] Figure 3 shows the maintenance procedure for replacing consumable parts. The rotary drive unit 301 is a replaceable unit in case of deformation due to unexpected load. The scraper and wiping cloth unit 302 can be removed as a single unit, allowing for easy replacement if contamination becomes severe. Figure 4 also shows a view from the opposite side.

[0039] Furthermore, since the total perimeter of the loop of the thin film 501 is longer than the total external dimension of the rotation drive unit 502, the loop of the thin film 501 can be replaced individually. This is illustrated in Figure 5. When the rotation drive unit 502 is docked to the device body, it is nested with the drive shaft unit and scraper / wiping cloth unit, so the rotation drive unit 502 has a butterfly structure that opens and closes as shown in the figure.

[0040] Next, to make it easier to understand the device structure, the structure of each unit will be explained below. First, a cross-sectional view of fixed base part 601 is shown in Figure 6. Motor gear support part 602 is supported by spring 603 with a preload applied upward in the figure. Note that the movement direction is restricted to the vertical direction by guide shaft 604 that passes through the inside of spring 603 and motor gear support member 602.

[0041] Motor 605 is equipped with encoder 606, which allows it to monitor its driving status by itself. In other words, it can monitor overload conditions, such as when the motor is not rotating despite current being applied, thereby preventing overheating. Gear 607, which is directly connected to the motor shaft, transmits rotation to gear 609 via intermediate gear 608. Each gear is supported by rotary bearings 610 to ensure smooth rotation.

[0042] Gear 610 is directly connected to drive shaft 611 and serves as the power source for rotating drive shaft 611. The opposite support portion of drive shaft 611 is similarly supported by rotary bearing 612, and drive shaft 611 is preloaded upward by spring 613 via this rotary bearing, as before. In other words, the force of the springs on both sides applies tension to thin film 107 via the drive shaft, removing slack.

[0043] The drive shaft 611 is provided with a friction resistor 614 in its center. The loop of the thin film 107 receives its driving force by coming into contact with this friction resistor 614. However, the friction coefficient of the friction resistor 614 does not necessarily have to be large. If the friction coefficient is too small, the frictional resistance (grip force) generated by the springs 603 and 613 on both sides plus the friction coefficient cannot overcome the rotational and frictional resistance of the other driven shafts and the wiping cloth, resulting in free rotation between the thin film and the drive shaft. Conversely, if the friction coefficient of the friction resistor 614 is too large, when a person forcibly presses down with their hand while the thin film loop is rotating, the resistance will prevent the friction resistor 614 from rotating, which will ultimately prevent the motor 605 from rotating, causing the motor to overheat and break.

[0044] Thus, an appropriate setting range is required for the frictional force of friction resistor 614 and the setting values ​​of springs 603 and 613. This can be set experimentally, although it also depends on the balance with other frictional elements (resistance of the driven shaft, wiping cloth, etc.).

[0045] In FIG. 6, friction resistor 614 is shown as a group of five divided hollow cylindrical parts, but this is for convenience in prototyping; it could, of course, be a single hollow cylindrical part, or simply a tape-like part with an appropriate friction coefficient.

[0046] Continuing the explanation, in the center of Figure 6, a sensor / wiping cloth paper fixing rod 615, consisting of a two-tiered round shaft, is placed like a bridge. This fixing rod does not move and remains fixed at all times. A thin film position sensor 616, which reads the position of the thin film, is fixed to this fixing rod. Furthermore, because this fixing rod has a two-tiered structure, upper and lower, its elasticity in the vertical direction can be used to attach and detach the scraper / wiping cloth paper unit 302 with a single snap.

[0047] Next, we will explain the rotation drive unit 701. Figure 7 shows a cross-sectional view and an isometric projection of one side. In the prototype, the heat disinfection zone 702 is made of SUS304 foil, and can be rapidly heated to a high temperature by passing an electric current through it. When heated, the heat disinfection zone 702 stretches due to thermal expansion, and if left as is, it will no longer be in contact with the thin film 703. Therefore, tension (preload) is constantly applied from both sides by springs 704. Of course, this spring 704 can also be applied on only one side. Outside the heating range, the heat disinfection zone 702 is connected to a conductor with low resistance (aluminum foil or copper foil) (not shown). This structure makes it possible to apply high-temperature heating to only the minimum necessary areas. Also, a plurality of thin film travel limiting pieces 706 are provided on both ends to prevent the thin film loop from shifting in a direction perpendicular to the travel direction (ie, in the longitudinal direction of the device) while it is traveling.

[0048] Having explained the hardware of the device of the present invention above, we will now describe the software required to effectively operate this device.

[0049] FIG. 8 shows a flowchart of the disinfection drive operation when the device is in a standby state (a state where the device has been disinfected and is waiting to be used) and is used by a person, or when the device has not been used for a certain period of time. As shown in the figure, when the human sensor detects contact with a human hand during standby and then detects that the human hand has been removed, the disinfection drive will begin. Also, if the standby state continues for a long time, the disinfection drive will also begin after a predetermined time has passed. The principle of operation is that no human hands should touch the device during disinfection operation, but if human hands touch the device while it is running, the motor and heating zone will immediately stop operating, protecting the safety of people and the device and giving priority to human use. After the person has finished using the device, that is, after the human sensor has turned off, the disinfection drive will start again. Note that if the previous disinfection drive did not completely go around the thin film loop once, an extra run will be made (not shown). Also, an emergency stop during disinfection drive will occur not only due to detection by the human sensor, but also due to operational inconsistencies or timeouts of the thin film encoder, or operational inconsistencies or timeouts of the motor encoder (not shown).

[0050] As described above, the device of the present invention makes it possible to quickly disinfect and inactivate the grip surface on which pathogens have adhered.

[0051] Although not shown in the figure, the thin film disinfection device does not necessarily have to be a heating body. For example, a cloth soaked in disinfectant (alcohol, sodium hypochlorite solution, etc.) can be placed on the front side of the thin film at the position where the heating zone is placed, and the cloth can be run so that it comes into contact with the thin film, thereby achieving a similar disinfection effect. [Industrial Applicability]

[0052] It can be used for a wide range of structural surfaces that require constant cleanliness. Typical applications include cleaning devices for door knobs, handles, handrails, straps, and other items that are frequently touched by an unspecified number of people in a short period of time.

[0053] It is also useful for medical equipment. In general hospital wards, it can be used for door handles and bed rails in patients' rooms to prevent hospital-acquired infections. It can also be used for handholds in toilets. It can also be used for structures that must be touched or gripped while wearing gloves that require cleanliness during surgery, such as the grip part of a surgical operating lamp.

[0054] In this way, the possibilities for industrial application are expanding in a wide range. [Explanation of symbols]

[0055] 101 Overall device of the present invention 102 Fixed part 103 Gripping part 104 Fixed part 105 Base 106 Motion Sensor Light Source 107 Thin Film 108 Thin film rotation arrow 109 Drive shaft 110 Heat disinfection zone 111 Driven rotating shaft 112 Driven rotating shaft 113 Driven rotating shaft 114 Driven rotating shaft 115 Frictional resistor 116 Thin Film Position Sensor 117 Fixed support structure 118 Scraper 119 Wipe paper 201 Cover 202 Motor and gear support 203 Center shaft support part 204 Rotation drive unit support 205 Motion Sensor Light Source 206 Human Sensor 207 Grip 301 Rotation drive unit 302 Scraper and Wiping Cloth Paper Section 501 Thin Film 502 Rotation drive unit 601 Fixed base part 602 Motor gear support 603 Spring 604 Guide shaft 605 Motor 606 Encoder 607 Gears 608 Intermediate gear 609 Gears 610 Rotary bearing 611 Drive shaft 612 Rotary bearing 613 Spring 614 Friction resistor 615 Sensor and cleaning cloth paper fixing rod 616 Thin Film Position Sensor 701 Rotation drive unit 702 Heat disinfection zone 703 Thin Film 704 Spring 705 Thin Film Position Mark

Claims

1. A rotary drive unit; an annular thin film having a predetermined circumferential length and covering an outer periphery of the rotation drive unit; a fixed base portion for mounting the rotation drive portion; Equipped with the rotary drive unit has a disinfection unit for disinfecting the thin film, the disinfection unit has a heating disinfection zone for heating the thin film, The fixed base portion has a drive shaft that rotates the thin film along the outer periphery of the rotation drive portion, causing the thin film to pass through the disinfection portion in sequence. Purification equipment.

2. The rotation drive unit has an opening / closing structure that opens and closes so that the circumferential length of the rotation drive unit changes. The purification device of claim 1 .

3. When the opening / closing structure is in a closed state, the perimeter of the thin film is greater than the perimeter of the flange of the rotation drive unit. The purification device according to claim 2 .

4. When the opening / closing structure is open, the perimeter of the thin film is larger than the perimeter of the outer periphery of the rotation drive unit covered with the thin film. The purification device according to claim 2 .

5. When the opening / closing structure is closed, the drive shaft rotates the thin film, and the disinfection unit disinfects the thin film. The purification device according to claim 4.

6. the thin film has a thin film position mark for detecting the position of the thin film; a thin film position sensor for detecting the thin film position mark and detecting rotational movement of the thin film; The purification device of claim 1 .

7. The heat disinfection zone heats the thin film to 100°C or higher. The purification device of claim 1 .

8. A tensioning section is provided for tensioning the heat disinfection zone to compensate for thermal elongation of the heat disinfection zone. The purification device of claim 1 .

9. A wiping unit is provided for removing water droplets or dirt adhering to the surface of the thin film. The purification device of claim 1 .

10. The fixed base portion has a position control portion for controlling the position of the drive shaft to apply tension to the thin film. The purification device of claim 1 .

11. The fixed base portion has a position control portion for controlling the position of the drive shaft to apply tension to the thin film. The purification device according to claim 8.

12. A human presence sensor is provided to detect the use of the purification device. The purification device of claim 1 .

13. When the human presence sensor detects a person during the rotational movement of the thin film, the rotational movement of the thin film is stopped. The purification device of claim 12.

14. When the human sensor does not detect a person for a predetermined period of time, the thin film is driven to disinfect intermittently. The purification device of claim 12.

15. The drive shaft has a friction resistor that rotates the thin film by friction with the thin film. The purification device of claim 1 .

16. A thin film travel limiting piece is provided to limit the deviation of the thin film in a direction perpendicular to the driving direction. The purification device of claim 1 .

17. The thickness of the thin film is 20 μm or less. The purification device of claim 1 .

18. A doorknob equipped with the cleaning device according to claim 1.

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