JP6287235B2 - Moisture content meter and image forming device - Google Patents

Description

  The present invention relates to a moisture meter for measuring the moisture content of a member to be measured, and an image forming apparatus including the moisture meter.

  2. Description of the Related Art Conventionally, an image forming apparatus is known in which the water content of a sheet member is obtained for the purpose of improving image quality (see Patent Document 1).

  Such an image forming apparatus is provided with a heat-conducting humidity sensor in the vicinity of the surface of the conveyed sheet member, obtains the ambient environmental humidity and the humidity in the vicinity of the sheet member, and calculates the sheet from the maximum change in the humidity difference. The water content of the member is obtained.

  However, in such an image forming apparatus, there is a problem that the humidity detected by the heat conduction type humidity sensor is affected by the surrounding environment and the accuracy is lowered, so that the moisture content with higher accuracy cannot be detected. there were.

  An object of the present invention is to provide a moisture meter that can measure the moisture content of a member to be measured without being affected by the surrounding environment.

The invention of claim 1 includes a closed space forming member that forms a closed space having an opening, and humidity detecting means for detecting the humidity of the closed space,
Closing the opening by bringing the member to be measured into contact with the opening of the closed space forming member, detecting the humidity of the closed space by the humidity detecting means, and measuring the moisture content of the member to be measured ,
The member to be measured is transported while being in contact with a surface having an opening of the closed space forming member, and the closed space is a groove extending in the transport direction of the member to be measured, and the groove is formed in the transport direction. The rear part on the downstream side is wide .

  According to this invention, the moisture content of the member to be measured can be measured without being affected by the surrounding environment.

It is the bottom view which showed the moisture content measuring device which concerns on this invention. It is sectional drawing which shows the structure of the moisture content measuring device shown in FIG. It is explanatory drawing which showed the method of measuring the moisture content of a sheet | seat member using the moisture content measuring device shown in FIG. It is explanatory drawing which shows notionally a mode that a water molecule is diffused from a sheet | seat member, or the water molecule in air is adsorb | sucked by the sheet | seat member SH. It is explanatory drawing which showed notionally the adsorption / desorption of the water molecule in the closed space of the recessed part, and the state of diffusion when the opening of the recessed part of the closed space formation member was block | closed with the sheet | seat member. It is explanatory drawing which showed the state where the closed space of the recessed part of the closed space formation member was conditioned to the humidity equilibrated with the moisture content of a sheet | seat member. It is the graph which showed the relationship between the humidity of closed space, and the moisture content of a sheet | seat member. It is the side view which showed schematic structure of the image forming apparatus provided with the moisture content measuring device shown in FIG. FIG. 2 is a block diagram showing a configuration of a control system of a moisture meter installed in the image forming apparatus shown in FIG. 1. It is explanatory drawing which showed the moisture content measuring device of 2nd Example. It is explanatory drawing which showed the usage method of the moisture content measuring device of 2nd Example. It is the perspective view which showed the moisture content measuring device of 3rd Example. It is a side view of the moisture content measuring device shown in FIG. It is a bottom view of the moisture content measuring device shown in FIG. It is a right view of the moisture content bundle container shown in FIG. It is explanatory drawing which showed an example which provided the moisture content measuring device in the conveyance roller of the image forming apparatus. It is the block diagram which showed the structure of the control system of the moisture content meter of 4th Example. It is explanatory drawing which showed an example which provided the moisture content measuring device in the link member of the endless track zone of an image forming apparatus. It is explanatory drawing which showed the structure of the endless track zone shown in FIG.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments that are embodiments of a moisture meter according to the present invention and an image forming apparatus equipped with the moisture meter will be described below with reference to the drawings.

[First embodiment]
1 and 2 show a moisture content measuring device 10 of the moisture meter 30 (see FIG. 9) of the first embodiment. The moisture content measuring device 10 includes a closed space forming member 11 made of foamed resin, and a humidity detection unit (humidity detection means) 20 that detects humidity.

  The closed space forming member 11 forms a circular recess (closed space) 12. That is, the closed space forming member 11 forms a closed space having an opening 12A that is circular in plan view. The diameter of the recess 12 is about 3.5 mm, and the depth of the recess 12 is about 1.3 mm.

  The inner wall surface 13 of the recess 12 is coated with fluororesin or metal plating, and a humidity detection unit 20 is implanted in the center of the upper wall 12B of the recess 12, so that the humidity in the recess 12 that is a closed space is provided. Is supposed to be detected. Reference numeral 22 denotes a signal cable.

The humidity detection unit 20 includes a thermal conductivity detection sensor 21 that detects the thermal conductivity of the recess 12, and obtains humidity from the thermal conductivity detected by the thermal conductivity detection sensor 21. The principle is the same as that described in the patent publication of Japanese Patent No. 2889909, and the description thereof is omitted.
[Measuring method]
As shown in FIG. 3, the moisture content measuring device 10 is placed on the sheet member (member to be measured) SH so as to close the opening 12 </ b> A of the recess 12 of the closed space forming member 11. That is, the inside of the recess 12 is closed by closing the opening 12A of the recess 12 of the closed space forming member 11 with the sheet member SH.

  Incidentally, the sheet member SH contains moisture, and as shown in FIG. 4, the water molecules M are diffused from the sheet member SH, or the water molecules M in the air are adsorbed to the sheet member SH. When the opening 12A of the recess 12 of the closed space forming member 11 is closed with the sheet member SH, as shown in FIG. 5, the adsorption / desorption of water molecules M in the closed space of the recess 12 without being affected by the surrounding environment. And diffusion. Finally, as shown in FIG. 6, the humidity in the recess 12 is adjusted to a humidity that balances the moisture content of the sheet member SH. By detecting the humidity at this time, the moisture content of the sheet member SH can be obtained without being affected by the surrounding environment.

  Here, the structure of the closed space in the recess 12 is shallow, has a wide opening with respect to the surface to be measured in order to reduce the adsorption / desorption error, and the inner peripheral surface having a small surface area is circular. Therefore, the response speed for detecting the humidity of the moisture content measuring instrument 10 can be increased. Moreover, if the shape of the closed space in the concave portion 12 is a conical shape or a spherical shape, the response speed can be further improved.

  Further, since the inner wall surface 13 of the recess 12 of the closed space forming member 11 is coated with fluororesin or metal plating, the humidity detection error due to the adsorption / desorption of the water molecules M can be reduced. Further, since the closed space forming member 11 is made of foamed resin, the heat conduction capacity is small, and therefore, condensation due to temperature change before and after closing the opening 12A of the recess 12 by the sheet member SH is minimized. It can be suppressed and condensation can be eliminated in a short time.

Incidentally, as shown in FIG. 7, since there is a hysteresis in the relationship between the moisture content and the humidity, it is desirable to consider which side the change is from high humidity / low humidity.
[Image forming apparatus]
FIG. 8 shows an inkjet image forming apparatus 100 including a moisture meter 30 (see FIG. 9).

The image forming apparatus 100 includes a paper feed mechanism 120, a carriage 105 having a print head 110, a drive mechanism 130 for moving the carriage 105, a transfer mechanism 140, and a moisture meter 30 (which measures the moisture content of the sheet member SH). 9) and the like.
[Paper feeding mechanism and transfer mechanism]
The paper feed mechanism 120 includes a paper feed roller (not shown) and a paper presser roller 101 for feeding the sheet member SH placed on the paper feed tray 109 to the image forming unit 50.

The transport mechanism 140 includes a pair of transport rollers 141A and 141B that transport the sheet member SH fed by the paper feed mechanism 120 to the image forming unit 50, and a sheet discharge roller (not shown) that transports the sheet member SH on which the image has been formed. And a pair of transfer rollers 142A and 142B.
[Print head]
The print head 110 has a nozzle hole (not shown) for ejecting ink and a piezoelectric element for ejecting ink from the nozzle hole, and the configuration thereof is the same as the conventional one. Therefore, the explanation is omitted.
[carriage]
The carriage 105 is movably provided along a main shaft 104 provided along a direction orthogonal to the sheet discharge direction of the sheet member SH (a direction orthogonal to the paper surface of FIG. 1). An ink cartridge 106 is detachably attached to the carriage 105, and the ink cartridge 106 is provided with ink of four colors, for example, cyan, magenta, yellow, and black.
[Drive mechanism]
The drive mechanism 130 includes a drive motor 102, a drive belt 103, and the like, and the carriage 105 is moved along the main shaft 104 by rotating the drive belt 103 by the drive motor 102. Yes.
[Control system]
FIG. 9 is a block diagram showing the configuration of the moisture meter 30. The moisture content meter 30 includes a moisture content measuring device 10, a storage unit 18 for storing a table F1, which will be described later, an image formation condition control unit (image formation condition control means) 15, a drying condition control unit 16, and a control unit. (Calculation means) 17.

  The storage unit 18 stores various data obtained by the control unit 17 in addition to storing the table F1.

  As shown in FIG. 7, the table F1 is graphs G1 and G2 showing the relationship between the humidity of the recess 12 of the closed space forming member 11 and the moisture content of the sheet member SH.

  The control unit 17 controls the humidity detection unit 20, the storage unit 18, the image forming condition control unit 15, the drying condition control unit 16, and the like of the moisture content measuring device 10.

The control unit 17 is controlled by the control device 117 of the image forming apparatus 100, and the control device 117 controls the paper feed mechanism 120, the drive mechanism 130, the transfer mechanism 140, and the like. Reference numeral 19 denotes a signal line.
[Operation]
Next, the operations of the moisture meter 30 and the image forming apparatus 100 configured as described above will be briefly described.

  First, as shown in FIG. 8, the sheet member SH placed on the paper feed tray 109 is fed to the image forming unit 50 by the control device 117. Before the droplets are discharged from the print head 110 onto the fed sheet member SH, the moisture content of the sheet member SH is measured by the moisture meter 30 (see FIG. 9).

  That is, the moisture content measuring device 10 of the moisture meter 30 is placed on the sheet member SH as shown in FIG. 3, and heat conduction is performed by the thermal conductivity detection sensor 21 of the humidity detection unit 20 of the moisture content measuring device 10. The rate is detected, and the control unit 17 obtains the humidity from the detected thermal conductivity. In this case, the humidity is obtained from the thermal conductivity when the humidity in the recess 12 of the closed space forming member 11 of the moisture content measuring device 10 is adjusted to a humidity balanced with the moisture content of the sheet member SH. That is, the humidity is obtained from the thermal conductivity when the detected thermal conductivity is constant.

  The moisture content measuring instrument 10 may be placed on the sheet member SH by an unillustrated vertical mechanism, or when the sheet member SH is fed to the image forming unit 50, the sheet member SH forms a closed space. You may comprise so that the opening 12A of the recessed part 12 of the member 11 may be plugged up.

  The control unit 17 obtains the moisture content of the sheet member SH from the obtained humidity based on the table F1 of the storage unit 18, and stores the moisture content in the storage unit 18.

  As described above, since the opening 12A of the recess 12 of the closed space forming member 11 is closed with the sheet member SH, the moisture content of the sheet member SH can be obtained without being affected by the surrounding environment.

  The control unit 17 sets the image processing condition or the drying condition based on the relationship between the moisture content of the sheet member SH and the image forming condition or the drying condition.

  That is, the image forming condition control unit 15 sets image forming conditions such as the amount and size of droplets as the image forming conditions of the image forming apparatus 100 based on the moisture content of the sheet member SH. Thereby, the image quality of the image formed by the image forming apparatus 100 can be improved.

  Based on the moisture content of the sheet member SH, the drying condition control unit 16 sets, for example, a drying condition such as temperature, air volume, or conveyance speed as the drying condition of the image forming apparatus 100. Accordingly, it is possible to stabilize the drying of the image formed by the image forming apparatus 100, and it is possible to prevent image quality deterioration due to picking.

As described above, since the moisture content of the sheet member SH can be obtained without being affected by the surrounding environment, the image quality of the image formed by the image forming apparatus 100 can be sufficiently enhanced.
[Second Embodiment]
FIG. 10 shows a moisture content measuring device 210 of the second embodiment. This moisture content measuring device 210 includes an auxiliary closed space forming member 211 made of foamed resin in addition to the moisture content measuring device 10.

  Similar to the closed space forming member 11 of the moisture content measuring device 10, the auxiliary closed space forming member 211 has a concave portion 212 having an opening 212 </ b> A that forms a circular auxiliary closed space in plan view, and the inner wall surface of the concave portion 212. 213 is coated with fluororesin or metal plating. The size of the recess 212 is set to be the same as the size of the recess 12 of the closed space forming member 11, but it is not necessarily the same size.

  As shown in FIG. 11, the moisture content of the sheet member SH is measured by making the opening 212 </ b> A of the closed space forming member 11 and the opening 212 </ b> A of the auxiliary closed space forming member 211 face each other. Measurement is performed by sandwiching the sheet member SH between the forming member 11 and the auxiliary closed space forming member 211.

  According to the second embodiment, the moisture content of the sheet member SH can be measured while minimizing the influence of the environment on the lower surface (back surface) side of the sheet member SH.

Further, a humidity detection unit (auxiliary humidity detection means) 220 similar to the humidity detection unit 20 shown in FIG. 2 is provided in the auxiliary closed space forming member 211 as shown in FIG. May be. Then, after the ink (droplet) is attached to the sheet member SH, based on the humidity detected by the humidity detection unit 20 and the humidity detected by the humidity detection unit 220, the degree of drying of the attached ink is obtained. A more accurate degree of drying can be determined.
[Third embodiment]
12 to 15 show a moisture content measuring device 310 of the third embodiment. The moisture content measuring device 310 includes a closed space forming member 311 having a rectangular shape in plan view, and a humidity detecting unit 20 that detects humidity. The closed space forming member 311 is made of foamed resin.

  The closed space forming member 311 includes an inclined guide surface 312 formed on one end side that is upstream in the conveying direction of the sheet member SH, and a groove 313 that is formed on the bottom surface 311b and extends in the conveying direction and forms a closed space. have. The inner wall surface of the groove 313 is coated with fluororesin or metal plating.

  The groove 313 is formed from the guide surface 312 to the rear end 311a of the closed space forming member 311. The rear portion 313A of the groove 313 is expanded so as to increase in width toward the rear portion.

  A humidity detector 20 is provided at a position (upstream side) adjacent to the rear portion 313A of the groove 313, and the humidity detector 20 detects the humidity in the groove 313.

  The sheet member SH is configured to move in the arrow direction P1 while being in contact with the bottom surface 311b of the closed space forming member 311.

  When the sheet member SH is conveyed in the arrow direction P1 while contacting the bottom surface 311b of the closed space forming member 311, a gas flow is generated in the conveying direction, and the rear portion 313A of the groove 313 is expanded. The gas flow increases, and a negative pressure is generated in the groove 313 which is a thin portion. The negative pressure causes the gas on the surface of the sheet member SH to move in the groove 313 in synchronization with the conveyance speed of the sheet member SH. Since the gas moves in accordance with the movement of the sheet member SH, the same effect as in the closed space can be obtained, and the humidity in which the moisture content in the gas and the moisture content of the sheet member SH are parallel can be measured.

  According to the third embodiment, the moisture content of the sheet member SH being conveyed can be measured without moving the moisture content measuring device 310.

In this embodiment, the rear portion 313A of the groove 313 is expanded. However, if the width of the rear portion 313A is increased, the rear portion 313A may not necessarily be expanded.
[Fourth embodiment]
FIG. 16 shows an example in which the moisture content measuring device 10 is provided on the conveying roller 500 of the image forming apparatus. In the fourth embodiment, the moisture content of the sheet member SH conveyed by the conveying roller 500 can be measured.

  FIG. 16A shows the configuration of the control system of the moisture meter 730 of the image forming apparatus 700 of the fourth embodiment. The moisture meter 730 is configured such that a transmission / reception device 731 is provided on the conveyance roller 500 and a transmission / reception device 732 is provided on a main body (not shown) of the image forming apparatus 700.

The moisture content meter 730 wirelessly transmits the humidity data measured by the moisture content measuring device 10 of the conveyance roller 500 via the transmission / reception devices 731 and 732 (radio waves and infrared rays) and controls the control unit 17 of the main body of the image forming apparatus 700 and the drying conditions. The data is transmitted to the control unit 16 and the image forming condition control unit 15. Others are the same as in the first embodiment, and a description thereof will be omitted.
[Fifth embodiment]
FIG. 17 shows an example in which the moisture content measuring device 10 is provided on the flat link member 601 of the endless track 600 of the image forming apparatus.

  As shown in FIG. 18, the endless track band 600 includes a plurality of pins 603 and a plurality of link members 601 and 602 engaged with the pins 603. Bearing portions 601A, 601B, 602A, and 602B are formed at both ends of each link member 601 and 602, and pins 603 are inserted into the bearing portions 601A and 602A and the bearing portions 601B and 602B, respectively. The link members 601 and 602 are rotatable around the pin 603.

  An opening 601H is formed in one of the plurality of link members 601, and the lower part of the closed space forming member 11 (see FIG. 2) of the moisture content measuring instrument 10 is inserted into the opening 601H, as shown in FIG. A moisture content measuring device 10 is attached.

  As shown in FIG. 17, the endless track band 600 is wound around the driving roller 610 and the driven roller 611, and is rotated counterclockwise by the rotation of the driving roller 610 in the direction of the arrow P <b> 2. The sheet member SH is conveyed in the direction of the arrow P3 by the rotational movement of the endless track 600.

  In the fifth embodiment, the moisture content of the sheet member SH conveyed by the rotational movement of the endless track band 600 can be measured.

  In the fifth embodiment, similarly to the fourth embodiment, a control system similar to the moisture meter 730 of the image forming apparatus 700 is provided.

  In the above embodiment, the case where the moisture content of the sheet member SH is measured has been described. However, the present invention is not limited to this, and the moisture content of other objects (members to be measured) may be measured. Moreover, although the closed space forming members 11 and 311 and the auxiliary closed space forming member 211 are made of foamed resin, they are not necessarily made of foamed resin, and may be made of other materials having low thermal conductivity.

  The inner wall surfaces 13 and 213 of the recesses 12 and 212 of the closed space forming member 11 and the auxiliary closed space forming member 211 and the inner wall surface of the groove 313 of the closed space forming member 311 are coated with fluororesin or metal plating. There is no need to coat with resin or metal plating.

  Further, although an ink jet image forming apparatus provided with the moisture content measuring device 10 has been described, the present invention is not limited thereto. For example, other image forming apparatuses such as a copying machine, a printer, a facsimile machine, and a multi-function machine including these components can be provided in the same manner.

  Further, although the moisture content of the sheet member SH is measured by detecting the thermal conductivity, the moisture content of the sheet member SH may be measured by detecting the humidity using a humidity sensor.

  As mentioned above, although the Example of this invention was described, the numerical value, material, arrangement | positioning, number, etc. in the said Example are examples, and this invention is not limited to these. Various modifications can be made within the scope of the present invention described in the claims, and design changes and additions are permitted without departing from the spirit of the invention of the claims.

10 Moisture content measuring device 11 Closed space forming member 12 Recessed portion (closed space)
12A Opening 20 Humidity detection part (humidity detection means)
30 Moisture content meter 100 Image forming apparatus SH Sheet member (Measuring member)
210 Moisture content measuring device 211 Auxiliary closed space forming member 212 Recessed portion (auxiliary closed space)
220 Humidity detector (auxiliary humidity detector)
311 Closed space forming member 313 Groove (closed space)

Japanese Patent No. 5211821

Claims (9)

A closed space forming member that forms a closed space having an opening, and humidity detecting means for detecting the humidity of the closed space,
Closing the opening by bringing the member to be measured into contact with the opening of the closed space forming member, detecting the humidity of the closed space by the humidity detecting means, and measuring the moisture content of the member to be measured ,
The member to be measured is conveyed while contacting the surface having the opening of the closed space forming member,
The moisture content meter , wherein the closed space is a groove extending in the conveyance direction of the member to be measured, and a width of a rear portion of the groove on the downstream side in the conveyance direction is widened . A closed space forming member that forms a closed space having an opening, and humidity detecting means for detecting the humidity of the closed space,
Closing the opening by bringing the member to be measured into contact with the opening of the closed space forming member, detecting the humidity of the closed space by the humidity detecting means, and measuring the moisture content of the member to be measured ,
The member to be measured is a sheet member,
An auxiliary closed space forming member that forms an auxiliary closed space having an opening;
The opening of the auxiliary closed space forming member is opposed to the opening of the closed space forming member, and the moisture content of the sheet member is measured by sandwiching the sheet member between the auxiliary closed space forming member and the closed space forming member. Moisture content meter characterized by that. A closed space forming member that forms a closed space having an opening, and humidity detecting means for detecting the humidity of the closed space,
Closing the opening by bringing the member to be measured into contact with the opening of the closed space forming member, detecting the humidity of the closed space by the humidity detecting means, and measuring the moisture content of the member to be measured ,
The moisture content meter , wherein the closed space forming member is made of foamed resin, and an inner wall surface of the closed space is coated with a fluororesin or metal plating . The closed space is circular in plan view,
The moisture content meter according to any one of claims 1 to 3, wherein the humidity detecting means is arranged in a circular central portion of the closed space. The member to be measured is a sheet member,
An auxiliary closed space forming member that forms an auxiliary closed space having an opening;
The opening of the auxiliary closed space forming member is opposed to the opening of the closed space forming member, and the moisture content of the sheet member is measured by sandwiching the sheet member between the auxiliary closed space forming member and the closed space forming member. The moisture content meter according to claim 4 . An auxiliary humidity detecting means for detecting the humidity of the auxiliary closed space is provided,
The degree of drying of the droplet is obtained based on the humidity detected by the humidity detecting unit and the humidity detected by the auxiliary humidity detecting unit after the droplet is attached to the sheet material. Item 6. A moisture meter according to Item 5 . The water content according to any one of claims 4 to 6 , wherein the closed space forming member is made of foamed resin, and an inner wall surface of the closed space is coated with fluororesin or metal plating. A meter. The moisture meter according to claim 7 , wherein the auxiliary space forming member is made of foamed resin, and an inner wall surface of the auxiliary closed space is coated with fluororesin or metal plating. An image forming apparatus comprising the moisture meter according to any one of claims 1 to 8 .