CN219096309U - Image forming apparatus having a plurality of image forming units - Google Patents

Abstract

The utility model provides an image forming apparatus which solves the problem of size increase caused by complicated structure of a control heater. The image forming apparatus includes: a conveying unit that conveys a medium; a liquid ejecting section that ejects liquid toward a medium; and a drying unit that dries the medium from which the liquid is ejected, the drying unit including an air blowing unit that blows air toward the medium, and a heating unit that includes a positive temperature coefficient element that heats the air.

Description

Image forming apparatus having a plurality of image forming units

Technical Field

The present utility model relates to an image forming apparatus.

Background

Conventionally, as shown in patent document 1, there is known an apparatus for drying ink discharged onto a recording medium by air heated by a nichrome wire heater.

Since the temperature of a heater such as a nichrome wire heater continuously rises when the heater is energized, a control board or the like for controlling the temperature by detecting the temperature by a sensor is required, and the device is complicated in structure and also increases in size.

Patent document 1: japanese patent application laid-open No. 2019-64169

Disclosure of Invention

The image forming apparatus includes: a conveying unit that conveys a medium; a liquid ejecting section that ejects a liquid to the medium; and a drying unit that dries the medium from which the liquid is ejected, the drying unit including a blower that blows air toward the medium and a heating unit that includes a positive temperature coefficient element that heats the air.

In the image forming apparatus according to the present utility model, it is preferable that the ptc element has a characteristic that the temperature of the ptc element is constant at a predetermined temperature when the temperature is increased by energization.

In the image forming apparatus according to the present utility model, it is preferable that the heating section has a heat sink arranged along a blowing direction in which the air is blown by the blowing section.

In the image forming apparatus of the present utility model, it is preferable that the plurality of heat radiating fins be arranged on both sides across the ptc element.

In the image forming apparatus according to the present utility model, it is preferable that the air blowing portion has an air outlet that diffuses the air in a direction intersecting a conveying direction in which the medium is conveyed by the conveying portion.

In the image forming apparatus according to the present utility model, it is preferable that the ptc element is covered with a heat sink plate in addition to being covered with an insulating material.

In the image forming apparatus according to the present utility model, it is preferable that the energization of the ptc element is controlled at a timing different from a timing of turning on or off a power supply of the image forming apparatus.

In the image forming apparatus according to the present utility model, it is preferable that the energization of the ptc element is controlled based on at least one of an installation environment temperature and humidity of the image forming apparatus.

In the image forming apparatus according to the present utility model, it is preferable that the energization of the ptc element is controlled based on at least one of a material and a shape of the medium.

According to the present utility model, it is possible to provide an image forming apparatus that solves the problem of an increase in size caused by a complicated structure of a control heater.

Drawings

Fig. 1 is a block diagram showing a configuration of an image forming apparatus.

Fig. 2 is a schematic view of the image forming apparatus as seen from above.

Fig. 3 is a schematic diagram of the image forming apparatus as seen from the side.

Fig. 4 is a schematic view of the heating section as seen from the side.

Detailed Description

1. First embodiment

1-1 Structure of image Forming apparatus

Hereinafter, an image forming apparatus 1 according to an embodiment will be described with reference to fig. 1 to 4. The directions in the drawings will be described with reference to a three-dimensional coordinate system. For convenience of explanation, the positive direction of the Z axis is referred to as upper or upper only, the negative direction is referred to as lower or lower only, the positive direction of the X axis is referred to as right or right only, the negative direction is referred to as left or left only, the positive direction of the Y axis is referred to as front or front only, and the negative direction is referred to as rear or rear only.

As shown in fig. 1, the image forming apparatus 1 includes a control unit 10, a storage unit 20, a printing unit 30, a conveying unit 40, and a drying unit 50. The drying section 50 includes an air blowing section 60 and a heating section 70.

The control unit 10 is configured to include a CPU (Central Processing Unit: central processing unit) that integrally controls the respective portions of the image forming apparatus 1, a UART (Universal Asynchronous Receiver Transmitter: universal asynchronous receiver transmitter) that manages input and output, an FPGA (Field Programmable Gate Array: field programmable gate array) or a PLD (Programmable Logic Device: programmable logic device) that are logic circuits, and the like. The CPU is also referred to as a processor. The storage unit 20 is configured to include a flash ROM (Flash Read Only Memory: flash read only memory) as a rewritable nonvolatile memory, a RAM (Random Access Memory: random access memory) as a volatile memory, and the like.

The CPU of the control unit 10 reads a program such as firmware stored in the flash ROM of the storage unit 20, and uses the RAM of the storage unit 20 as a work area to execute the program.

The image forming apparatus 1 can be mounted with, for example, ink cartridges or ink tanks storing ink of ink colors of CMYK (Cyan: cyan, magenta, yellow, black).

As shown in fig. 2, the printing section 30, which is a liquid ejecting section, includes a head having nozzle rows in which a plurality of nozzles ejecting ink are arranged in a nozzle arrangement direction, which is a left-right direction. One nozzle row corresponds to one ink color. In the case of the above-described four-color ink colors, the nozzle rows are arranged such that CMYK four rows are arranged in the front-rear direction.

The printing unit 30 includes a supply mechanism that supplies ink from an ink cartridge or the like to the head. The supply mechanism supplies ink of each color from an ink cartridge or the like to a corresponding nozzle row.

Under the control of the control unit 10, each nozzle of the nozzle array of the head of the printing unit 30 ejects ink onto the medium P to form an image. In the example of fig. 2, the nozzle row of the head faces downward, and each nozzle can eject ink downward toward the medium P.

The ink color may be any combination of four or more colors including, for example, a gradation of CMYK. Further, the medium P includes: paper including photo paper, synthetic paper, resin such as film, fiber, etc.

As shown in fig. 2, the conveying section 40 is located downstream of the printing section 30 in the conveying direction of the medium P, i.e., in the F direction. The F direction is also the front of the image forming apparatus 1.

As shown in fig. 3, the conveying section 40 is configured to include: a first roller 41 and a second roller 42 that face each other, and a conveyance guide 43 that supports the medium P. The first roller 41 and the second roller 42 sandwich the medium P and convey the medium P along the conveyance guide 43 in the direction F, which is the conveyance direction of the medium P.

Further, the conveying section 40 may be located upstream of the printing section 30 in the conveying direction of the medium P, that is, in the F direction.

As shown in fig. 2 and 3, the drying section 50 is located downstream in the F direction with respect to the printing section 30, and upstream in the F direction with respect to the conveying section 40. The blower 60 of the drying unit 50 includes a fan 61, an air inlet 62, a blower path 63, and an air outlet 64.

The air blowing path 63 extends from the air inlet 62 in the rightward direction, i.e., in the W1 direction, and then extends in the downward direction, i.e., in the W2 direction, toward the air outlet 64. In this way, the air blowing path 63 has a tubular shape in the shape of an L.

The blower 60 blows air sucked through the air inlet 62 along the air blowing path 63 by the fan 61, first in the first air blowing direction W1, and then in the second air blowing direction W2, and then from the air outlet 64 toward the medium P. The air blowing path 63 may include, for example, a plate-like airflow direction control member that controls the flow direction of air.

The W1 direction is also the width direction of the medium P. The W2 direction is also a direction toward the face of the medium P. The W2 direction is also a direction in which the nozzles of the head of the printing unit 30 eject ink toward the medium P. The W1 direction and the W2 direction are directions intersecting each other.

The outlet 64 has a rectangular shape and extends in the lateral direction, i.e., the width direction of the medium P. The air outlet 64 has a shape capable of blowing air across the entire width of the medium P. In other words, the outlet 64 extends in a direction intersecting the F direction in which the medium P is conveyed by the conveying unit 40. The direction in which the blow-out port 64 is expanded is also the W1 direction.

In this way, the air outlet 64 is configured to expand in the width direction of the medium P and to be able to blow air across the entire width of the medium P to be conveyed.

In addition, in the case where the space in the image forming apparatus 1 is reduced, a case wall, not shown, may be disposed in the vicinity of the air inlet 62. Further, there are cases where a space for the air blown out from the air outlet 64 to flow in the image forming apparatus 1 cannot be sufficiently ensured. These loads act as air blowing for the air blowing unit 60. As a result, the blower 60 may not blow sufficient air to the medium P.

Accordingly, an additional fan for discharging the air blown out from the air outlet 64 may be separately provided in the air blowing unit 60. For example, the additional fan is disposed at a position on the right side of the air outlet 64 opposite to the fan 61, whereby an increase in space in the image forming apparatus 1 can be suppressed.

Even when there is a load of air blowing as described above, the additional fan can be provided to discharge the air blown out from the air outlet 64, and as a result, the air blowing unit 60 can blow out sufficient air to the medium P.

As shown in fig. 2, the heating unit 70 of the drying unit 50 is disposed in the air blowing path 63 of the air blowing unit 60. Specifically, the heating portion 70 is located at a position adjacent to the right side with respect to the fan 61, and is located downstream in the W1 direction.

When the air sucked from the air inlet 62 of the air blowing unit 60 is blown in the W1 direction along the air blowing path 63 by the fan 61, the air is heated by the heating unit 70, blown in the W2 direction, and blown out toward the medium P from the air outlet 64.

The air heated by the heating unit 70 of the drying unit 50 and blown by the blowing unit 60 can dry the medium P on which the ink is ejected.

In this way, the medium P is blown with the heated air from the drying section 50 while being conveyed in the F direction by the conveying section 40, and is dried together with the ejected ink.

As shown in fig. 4, the heating portion 70 includes a positive temperature coefficient (Positive Temperature Coefficient, PTC) element 71, a heat sink 72, an insulating material 73, and a heat sink 74.

For example, the heating portion 70 has a so-called Sheath Heater (shielded Heater) in which the PTC element 71 is covered with a heat radiation plate 74, i.e., a Sheath layer (shielded) of metal such as aluminum.

As shown in fig. 4, the PTC element 71 has a flat shape that expands in the front-rear-left-right direction, and the heat dissipation plate 74 also has a flat shape that covers the PTC element 71.

The heating portion 70 uses magnesium oxide (MgO) having high insulation resistance and good heat conduction even at high temperature as the insulating material 73 between the PTC element 71 and the heat dissipation plate 74.

But magnesium oxide has hygroscopic properties. In order to prevent the magnesium oxide from absorbing moisture, openings at both ends of the heat sink 74 where the magnesium oxide is exposed are further sealed with an insulating material 73 having insulating properties such as epoxy resin or silicone resin.

In addition, a polyimide resin, a polyimide film, or the like having a low linear expansion coefficient, excellent flame retardancy, and high insulation properties may be used instead of magnesium oxide. By using a flame retardant material for the insulating material 73, an effect of suppressing an influence of a lightning surge or the like can be also achieved.

In this way, the PTC element 71 is covered with the heat dissipation plate 74 on the basis of being surrounded with the insulating material 73. In this way, the heating portion 70 can mount the PTC element 71 by the insulating material 73 so as not to be exposed to the outside.

The PTC element 71 is made of barium titanate (BaTiO ₃ ) A semiconductor ceramic element as a main component, and a resistor element having PTC characteristics.

The PTC element 71 can set a resistance value that increases sharply at a predetermined temperature (curie temperature) when the temperature rises by being energized from a power source and a cable, not shown, of the image forming apparatus 1. The PTC element 71 is an element that heats air by using the curie temperature.

In this way, the PTC element 71 has a characteristic that the resistance value increases when the temperature rises upon being energized, and the temperature of the PTC element 71 is constant at a predetermined temperature. The predetermined temperature is, for example, 40 ℃ to 50 ℃.

As a result, the PTC element 71 is controlled to a predetermined temperature by itself, unlike a nichrome wire heater or the like, without detecting the temperature by a temperature sensor and controlling the temperature by an external control such as a control board or the like. Further, since the PTC element 71 is constant when the predetermined temperature is reached, the power consumption can be reduced.

As described above, the PTC element 71 is covered with the insulating material 73 and covered with the heat dissipation plate 74. The PTC element 71 and the heat dissipation plate 74 have flat shapes.

The heat sink 72 is configured to be in contact with the heat sink 74 and to radiate heat of the PTC element 71 through the heat sink 74. The heat sink 72 is made of metal such as aluminum.

The plurality of fins 72 are provided, and the first fins 72a and the second fins 72b are disposed on both upper and lower sides so as to sandwich the PTC element 71. The first heat sink 72a and the second heat sink 72b are mounted in contact with each other on the upper and lower surfaces of the heat sink 74 having a flat shape.

The heat sink 72 is formed of a plurality of plates, a plate folded a plurality of times, or the like. The fin 72 is disposed along the direction W1 in which the air is blown so as to be in contact with the air blown by the blower 60 for as long as possible. Specifically, a plurality of plates or plates folded a plurality of times constituting the heat sink 72 are arranged along the W1 direction.

In this way, the fins 72 are configured to be in contact with the air blown by the blower 60 for as long a time as possible with a surface area as possible. The heat sink 72 can efficiently transfer heat of the PTC element 71 to air to heat it.

The temperature of the air heated by the heating portion 70 and blown by the blowing portion 60 to the medium P is higher than the ambient temperature of the image forming apparatus 1 and lower than the set temperature of the PTC element 71, that is, a predetermined temperature.

Here, an operation of the image forming apparatus 1 will be described. When a power supply, not shown, of the image forming apparatus 1 is turned on, power is supplied to each portion including the control section 10 by the power supply, and power is also supplied to the PTC element 71. The control unit 10 causes the transport unit 40 to transport the medium P and causes the printing unit 30 to eject ink onto the medium P based on information from an external device, not shown, to form an image on the medium P. The control unit 10 causes the drying unit 50 to supply heated air to the medium P in accordance with image formation on the medium P, thereby drying the medium P.

As described above, the image forming apparatus 1 of the present embodiment includes: a conveying unit 40 that conveys the medium P; a liquid ejecting section, i.e., a printing section 30 that ejects ink as a liquid onto the medium P; and a drying unit 50 for drying the medium P from which the ink is discharged. The drying section 50 includes an air blowing section 60 that blows air toward the medium P, and a heating section 70 that includes a PTC element that heats the air.

As a result, the image forming apparatus 1 does not need a control board or the like for detecting and controlling the temperature of the heating portion 70 by a sensor or the like, and thus the apparatus can be simply structured and can be miniaturized.

Although the present embodiment has been described in detail with reference to the drawings, the specific configuration is not limited to the embodiment, and changes, substitutions, deletions, and the like may be made without departing from the gist of the present utility model.

For example, the PTC element 71 of the heating section 70 may be energized by the power supply without the timing at which the power supply of the image forming apparatus 1 is turned on.

That is, the image forming apparatus 1 may be provided with a switch such as a transistor that turns on/off the energization from the power source to the PTC element 71. The control unit 10 is interlocked with the operations of the printing unit 30 and the conveying unit 40, and turns on the switch to energize the PTC element 71 when the heating unit 70 starts to be used. When the use of the heating unit 70 is completed, the control unit 10 turns off the switch, and cuts off the power supply to the PTC element 71. When the heating unit 70 is not used, the image forming apparatus 1 can save energy by turning off the switch.

The image forming apparatus 1 may be provided with a sensor for detecting temperature and humidity, and may be configured to detect the temperature and humidity of the installation environment of the image forming apparatus 1 by the sensor, and to not apply current to the PTC element 71 when it is determined that the air blown to the medium P does not need to be heated. In this configuration, since the image forming apparatus 1 performs heating only in a necessary environment, energy can be saved.

In addition, in the image forming apparatus 1, when the medium P is made of a specific material or shape, the medium P may be blown with unheated air without conducting electricity to the PTC element 71. For example, in the case where the medium P is a sheet of paper, the image forming apparatus 1 does not perform energization to the PTC element 71. In this configuration, the image forming apparatus 1 can blow air at a temperature that matches the characteristics of the medium P, and can suppress warping or the like of the medium P, for example, damage or jam of the head of the printing portion 30, and degradation of the quality of an image formed on the medium P.

Symbol description

1 … image forming apparatus; 20 … storage; 30 … print; 40 … conveying part; 50 … dry part; 60 … air supply part; 64 … blow-out port; 70 … heating part; 71 … PTC element; 72 … heat sink; 73 … insulating material; 74 … heat sink; p … medium.

Claims (9)

1. An image forming apparatus, comprising:

a conveying unit that conveys a medium;

a liquid ejecting section that ejects a liquid to the medium;

a drying unit that dries the medium from which the liquid is ejected,

the drying section has an air blowing section that blows air toward the medium, and a heating section that includes a positive temperature coefficient element that heats the air.

2. The image forming apparatus according to claim 1, wherein,

the positive temperature coefficient element has a characteristic that the temperature of the positive temperature coefficient element is constant at a predetermined temperature when the positive temperature coefficient element is energized to increase in temperature.

3. The image forming apparatus according to claim 1, wherein,

the heating unit has cooling fins arranged along a blowing direction in which the air is blown by the blowing unit.

4. The image forming apparatus according to claim 3, wherein,

the heat sink is provided in plurality and is disposed at both sides across the ptc element.

5. The image forming apparatus according to claim 1, wherein,

the air blowing portion has an air outlet that diffuses the air in a direction intersecting a conveying direction in which the medium is conveyed by the conveying portion.

6. The image forming apparatus according to claim 1, wherein,

the positive temperature coefficient element is covered by a heat radiation plate on the basis of surrounding of the positive temperature coefficient element is covered by an insulating material.

7. The image forming apparatus according to claim 1, wherein,

the energization of the positive temperature coefficient element is controlled at a timing different from the timing of turning on or off the power supply of the image forming apparatus.

8. The image forming apparatus according to claim 1, wherein,

the energization of the positive temperature coefficient element is controlled based on at least one of a set ambient temperature and humidity of the image forming apparatus.

9. The image forming apparatus according to claim 1, wherein,

the energization of the ptc element is controlled based on at least one of the material and the shape of the medium.

Images