Drying device

Abstract

The invention provides a drying device. The drying device dries a recording medium on which an image is formed while conveying the recording medium. The drying device is provided with a conveying component, a heating device, a drying chamber and a channel. The transport member supports a recording medium and transports the recording medium in a predetermined transport direction. The heating device heats the recording medium conveyed by the conveying member in a high-temperature environment. The drying chamber is disposed on an upstream side of the heating device in a transport direction of the recording medium, and is configured to pre-dry the recording medium transported by the transport member. And the heating device is communicated with the drying chamber through the channel. Accordingly, the recording medium can be appropriately dried without increasing the size and the cost.

Description

Technical Field

[0001] The present invention relates to a drying apparatus for drying a recording medium having an image formed thereon by an inkjet method while conveying the recording medium. Background Art

[0002] An image forming system including an inkjet image forming apparatus includes a drying device for drying an image formed on a recording medium using ink. The drying device generally includes a heater that radiates infrared rays. For example, the drying device may include a first drying mechanism and a second drying mechanism that radiate infrared rays. The first drying mechanism and the second drying mechanism are sequentially arranged along a conveying direction of a sheet (recording medium). Based on information related to the sheet, the drying efficiency is improved by selectively irradiating the sheet with the first heating mechanism.

[0003] However, in the above-mentioned drying device using infrared rays, when the recording medium is irradiated with infrared rays rapidly, rough cracks such as bubbles bursting due to ink boiling may occur. Alternatively, the surface of coated paper may crack due to rapid evaporation and expansion of water contained in the recording medium. In addition, the temperature difference around the through-holes of the conveyor belt may cause unevenness of the belt holes.

[0004] Therefore, the drying device is usually configured to reduce the output of the heater and extend the conveying distance of the recording medium without rapidly drying the recording medium. However, this structure has the following problems: the cost and power consumption increase due to the large size of the drying device or the increase in the number of heaters. Summary of the invention

[0005] In view of the above problems, an object of the present invention is to provide a drying device that can appropriately dry a recording medium without increasing the size or cost.

[0006] The drying device of the present invention dries a recording medium having an image formed thereon while conveying it. The drying device comprises a conveying member, a heating device, a drying chamber, and a passage. The conveying member supports the recording medium and conveys it in a predetermined conveying direction. The heating device heats the recording medium conveyed by the conveying member under a high temperature environment. The drying chamber is arranged at a position upstream of the heating device in the conveying direction of the recording medium, and is used to pre-dry the recording medium conveyed by the conveying member. The passage connects the heating device and the drying chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1This is a front view showing the interior of a drying device according to an embodiment of the present invention.

[0008] Figure 2 This is a front view for explaining the flow of air in a drying chamber of the drying device according to one embodiment of the present invention. DETAILED DESCRIPTION

[0009] Below, while referring to the attached Figure 1 A drying device according to an embodiment of the present invention will be described.

[0010] First, refer to Figure 1 , the overall structure of the drying device 1 is described. Figure 1 It is a front view which shows the inside of the drying device 1. L and R shown in each figure respectively show the left side and the right side of the drying device 1.

[0011] The drying device 1 includes a conveying device 3, a heating device 5 and a drying chamber 7, wherein the conveying device 3 conveys a recording medium on which an image is formed by an inkjet method; the heating device 5 dries the image (ink) formed on the recording medium conveyed by the conveying device 3 in a high temperature environment; and the drying chamber 7 pre-dries the recording medium before drying the ink by the heating device 5.

[0012] First, the conveying device 3 is described. The conveying device 3 includes a conveying belt 11, a conveying plate 13, a suction device 15, and front and rear side plates 17. Figure 1 The recording medium is transported in a transport direction X from right to left; the transport plate 13 is used to support the conveyor belt 11; the suction device 15 adsorbs the recording medium to the conveyor belt 11; the front and rear side plates 17 support the conveyor belt 11, the transport plate 13 and the suction device 15.

[0013] First, the front and rear side plates 17 are described. The front and rear side plates 17 are plate-like members that are long in the width direction (the direction intersecting the conveying direction X, the left and right direction), and are arranged at intervals in the front and rear direction. Two chambers 19 arranged in the conveying direction X are formed in the lower part of the space between the front and rear side plates 17.

[0014] A driving roller 21 and a driven roller 23 are supported between the front and rear side plates 17. The driving roller 21 is rotatably supported at the end (left end) on the downstream side of the conveying direction X of the front and rear side plates 17. The driven roller 23 is rotatably supported at the end (right end) on the upstream side of the conveying direction X of the front and rear side plates 17. The driving shaft of the driving roller 21 is connected to a motor (not shown).

[0015] Next, the conveyor belt 11 is described. The conveyor belt 11 is an endless belt, and a plurality of through holes are formed on the entire surface thereof and penetrate the belt in the thickness direction. The conveyor belt 11 is wound around the driving roller 21 and the driven roller 23. The driving roller 21 is driven by a motor to rotate, and the conveyor belt 11 is moved along the conveyor belt 11. Figure 1 The conveyor belt 11 circulates in a counterclockwise direction. The surface of the conveyor belt 11 along the outer side of the upper track is a conveying surface for conveying recording media. Thus, the conveyor belt 11 is an example of a conveying member for conveying recording media in the present invention.

[0016] Next, the conveyor plate 13 is described. The conveyor plate 13 is supported by the front and rear side plates 17 in a manner that contacts the inner peripheral surface (the surface on the back side of the conveyor surface) of the conveyor belt 11 that travels along the upper track. When the conveyor belt 11 travels, the inner peripheral surface of the conveyor belt 11 slides along the upper surface of the conveyor plate 13. The conveyor plate 13 has a plurality of through holes that penetrate in the thickness direction formed on the entire surface.

[0017] Next, the suction device 15 will be described. The suction device 15 is respectively disposed in two chambers 19 formed between the front and rear side plates 17. By driving the suction device 15, air is sucked into the through holes of the conveyor belt 11 and the through holes of the conveyor plate 13. As a result, the recording medium on the conveying surface of the conveyor belt 11 is attracted to the conveyor belt 11.

[0018] Next, the heating device 5 will be described. The heating device 5 includes two heater units 31 , two fans 33 provided in each of the heater units 31 , and a housing 35 that houses the heater units 31 and the fans 33 .

[0019] The housing 35 is formed in a box shape with an open bottom surface. The bottom surface opening is covered with a protective net 37. An upper opening 39 and a lower opening 41 are formed at the upper and lower parts of the side plate (right side plate) on the upstream side in the conveying direction X of the housing 35, respectively.

[0020] Two heater units 31 are arranged in a row in the hollow part of the housing 35 along the conveying direction X. Each heater unit 31 has a plurality of infrared heaters 43 arranged in a row along the conveying direction X, and a reflector 45 for reflecting infrared rays emitted by each infrared heater 43. The infrared rays emitted by the infrared heater 43 are reflected by the reflector 45 and irradiated downward. The upper opening 39 formed in the right side plate of the housing 35 is arranged above the heater unit 31. On the other hand, the lower opening 41 formed in the right side plate of the housing 35 is arranged below the heater unit 31.

[0021] Two fans 33 are provided on the upper surface (top) of each heater unit 31. The fans 33 suck air in the housing 35 and blow it downward. The air blown downward passes through the heater unit 31 and is heated, thereby generating warm air blowing downward.

[0022] The heating device 5 is disposed at a portion on the downstream side in the conveying direction X above the conveying surface of the conveyor belt 11 of the conveying device 3 at a predetermined distance from the conveying surface.

[0023] Next, refer to Figure 2 The drying chamber 7 will be described. Figure 2 : is a front view showing the drying chamber 7. The drying chamber 7 is formed in a box shape whose height and length (length along the conveying direction X) are smaller than the housing 35 of the heating device 5 and whose lower surface is open. The opening of the lower surface is covered by a protective net 51. An upstream opening 53 and a downstream opening 55 are respectively formed at the lower part of the side plate on the upstream side (right side) and the downstream side (left side) in the conveying direction of the drying chamber 7. The upstream opening 53 and the downstream opening 55 are opposite to each other in the conveying direction X.

[0024] The drying chamber 7 is arranged at a position on the upstream side of the conveying direction relative to the heating device 5, above the conveying surface of the conveyor belt 11 of the conveying device 3, and at a predetermined interval from the conveying surface. In this way, the drying chamber 7 and the heating device 5 are arranged in sequence along the conveying direction X. The upstream opening 53 of the drying chamber 7 is connected to the upper opening 39 of the outer shell 35 of the heating device 5 via the upper duct 57. The upper duct 57 extends horizontally from the upper opening 39 to the upstream side above the ceiling of the drying chamber 7, and then bends downward along the upstream side plate of the drying chamber 7, thereby connecting to the upstream opening 53. In addition, the downstream opening 55 of the drying chamber 7 is connected to the lower opening 41 of the outer shell 35 of the heating device 5 via the lower duct 59. In this way, the upper duct 57 and the lower duct 59 are an example of the upper channel and the lower channel in the present invention that connect the heating device 5 and the drying chamber 7.

[0025] An upper air-sending fan 61 is provided at the inlet of the upper duct 57. A lower air-sending fan 63 is provided at the lower duct 59.

[0026] The drying operation of the drying device 1 having the above-mentioned structure is described. In the conveying device 3, the driving roller 21 is driven to rotate, so that the conveying belt 11 moves. Then, the recording medium on which the image is formed by the inkjet method is conveyed to the conveying surface of the conveying belt 11. In addition, the suction device 15 is driven. Accordingly, as described above, the air in the through holes of the conveying belt 11 and the through holes of the conveying plate 13 is sucked, and the upper part of the conveying surface of the conveying belt 11 becomes negative pressure. Accordingly, the recording medium is adsorbed on the conveying surface. In this way, the recording medium is conveyed along the conveying direction X while being adsorbed on the conveying surface.

[0027] Furthermore, the heater unit 31 and the fan 33 of the heating device 5 are driven. As described above, the infrared rays emitted by the infrared heater 43 are reflected by the reflector 45 and irradiated downward. In addition, the air blown downward by the fan 33 passes through the heater unit 31 and is heated, thereby generating downward warm air. In this way, the heating device 5 blows the heated air (warm air) downward. In addition, by driving the heater unit 31, the temperature inside the housing 35 of the heating device 5 rises.

[0028] Furthermore, the upper air supply fan 61 and the lower air supply fan 63 are driven. Figure 2 As shown by the arrow, the air in the upper space in the housing 35 (the space above the heater unit 31) enters the upper duct 57 from the upper opening 39 through the upper air supply fan 61, and flows into the drying chamber 7 from the upstream opening 53 through the upper duct 57. In addition, the heated air in the space below the heater unit 31 enters the lower duct 59 from the lower opening 41 through the lower air supply fan 63, and flows into the drying chamber 7 through the downstream opening 55. Accordingly, the temperature in the drying chamber 7 rises. However, since the temperature of the upper space in the housing 35 is lower than the temperature of the space below the heater unit 31, the temperature in the drying chamber 7 is lower than the temperature of the warm air blown out from the heating device 5.

[0029] In addition, since the upstream opening 53 and the downstream opening 55 are arranged opposite to each other, the air flowing in from the upstream opening 53 (the outlet of the upper duct 57 to the drying chamber 7) and the downstream opening 55 (the outlet of the lower duct 59 to the drying chamber 7) collides at the central portion of the drying chamber 7, thereby reducing the wind speed of the two air flows. Accordingly, the inflowing air is easy to stay in the drying chamber 7. In addition, the heated air flowing into the drying chamber 7 leaks downward from the drying chamber 7.

[0030] Then, the recording medium conveyed to the conveying surface of the conveyor belt 11 first contacts the leaked heated air, and the ink of the recording medium is pre-dried. The temperature of the heated air is not high enough to boil the ink, and the wind speed is slower than the warm air blown from the heating device 5, so the ink is auxiliary dried. Then, the recording medium is conveyed from the bottom of the drying chamber 7 to the bottom of the heating device 5. Accordingly, the pre-dried ink is completely dried.

[0031] As can be seen from the above description, according to the drying device 1 of the present invention, since the ink can be dried without rapidly increasing its temperature, the above-mentioned problems (rough cracks, surface cracks of coated paper, or uneven perforations) can be reduced. Furthermore, since there is no need to extend the length of the conveying surface of the conveyor belt 11, the drying device 1 can be prevented from being enlarged. Furthermore, since the number of heater units 31 can be reduced, the cost and power consumption can be reduced.

[0032] Furthermore, since the temperature of the air in the drying chamber 7 can be raised to an appropriate temperature by the air whose temperature is raised by the heating device 5 , there is no need to separately provide a mechanism for raising the temperature of the air in the drying chamber 7 .

[0033] Furthermore, as described above, since the temperature of the air leaking from the drying chamber 7 is lower than the temperature of the warm air blown from the heating device 5 and the wind speed is slower than the wind speed of the warm air blown from the heating device 5, the ink can be dried without rapidly increasing its temperature. In addition, since the air flowing into the drying chamber 7 is not easy to escape from the drying chamber 7, pre-drying can be performed effectively.

[0034] In addition, a temperature sensor 65 (see Figure 1 ), and controls the driving of the upper air supply fan 61 and the lower air supply fan 63 according to the temperature measured by the temperature sensor 65. For example, when the temperature in the drying chamber 7 is lower than a predetermined temperature, the rotation speed of the lower air supply fan 63 is increased so that more air with a higher temperature below the heater unit 31 enters the drying chamber 7.

[0035] The present invention describes specific embodiments, but the present invention is not limited to the above embodiments. The above embodiments can be variously changed, replaced, and deformed without departing from the scope and gist of the present invention, and the technical solution includes all embodiments that can be included in the scope of the technical idea.

Claims

1. A drying device for drying a recording medium having an image formed thereon while conveying the recording medium, It is characterized in that It has a conveying part, a heating device, a drying chamber and a channel, wherein: The conveying member is used to support the recording medium and convey it along a specified conveying direction; The heating device heats the recording medium conveyed by the conveying member under a high temperature environment; The drying chamber is arranged at an upstream side of the heating device in the conveying direction of the recording medium, and is used to pre-dry the recording medium conveyed by the conveying member; The passage connects the heating device and the drying chamber.

2. The drying device according to claim 1, characterized in that: The heating device comprises a fan, a heater and a housing, wherein: The fan sucks air from the outside and blows it onto the recording medium transported by the transport member; The heater is arranged at a position downstream of the fan in the blowing direction of air, and is used to irradiate infrared rays to the recording medium transported by the transport member; The housing is provided with the fan at the top and accommodates the heater. The channel includes an upper channel and a lower channel, wherein The upper passage connects the space of the housing on the upstream side of the fan in the blowing direction with the drying chamber; The lower passage connects the space between the heater and the conveying member and the drying chamber. An outlet of the upper passage to the drying chamber and an outlet of the lower passage to the drying chamber are opposite to each other.

3. The drying device according to claim 1, characterized in that: A fan is provided in the passage, and the fan is used to send air from the heating device to the drying chamber.

4. The drying device according to claim 1, characterized in that: A temperature sensor is provided, the temperature sensor being used to detect the temperature inside the drying chamber, The amount of air sent into the drying chamber is controlled according to the temperature in the drying chamber detected by the temperature sensor.

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