JP2009012289A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus wherein the total amount of its power consumption is suppressed by downsizing a structure to promote ink curing after printing is made to a recording medium, and its overall structure is also reduced in size and weight. <P>SOLUTION: An inkjet printer 100 is provided with a recording head unit 107 consisting of: a recording head 108 to attach ultraviolet ray curable ink on the surface of a recording medium WK; and a first ultraviolet ray irradiating device 109 to irradiate the attached ultraviolet ray curable ink with an ultraviolet ray. The inkjet printer 100 is also provided with a second ultraviolet ray irradiating device 111 to irradiate, with ultraviolet ray, a range smaller than the one displaceable of the recording head unit 107, on the downstream side of the recording head unit 107 in the conveying direction of the recording media WK. The second ultraviolet ray irradiating device 111 is supported by a supporting guide 112, and is displaced in the width direction of the recording media WK by an optical source displacement drive motor 113. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image by attaching ink to the surface of a recording medium.

2. Description of the Related Art Conventionally, there are image forming apparatuses that form a desired image by attaching ink to the surface of a recording medium such as paper. For example, Patent Document 1 below discloses an ink jet printer that forms a desired image using ink that is cured by irradiation with ultraviolet rays (hereinafter referred to as “ultraviolet curable ink”). Patent Document 2 below discloses an ink jet printer that forms a desired image using ink that is cured by receiving heat (hereinafter referred to as “thermosetting ink”).
JP2003-200244A Japanese Patent Laid-Open No. 10-86353

  In such an image forming apparatus, the image formation accuracy, that is, the image quality is improved by promptly fixing the ink adhered to the recording medium to the recording medium. For example, in the inkjet printer disclosed in Patent Document 1, the surface opposite to the surface on which the ultraviolet curable ink is attached on the recording medium is irradiated with ultraviolet rays during printing (immediately after printing) and after printing, The ultraviolet curable ink attached to the surface of the recording medium is fixed at an early stage by irradiating the surface of the recording medium to which the ultraviolet curable ink is attached with ultraviolet rays after printing. In the ink jet printer disclosed in Patent Document 2, the surface opposite to the surface on which the thermosetting ink is attached on the recording medium is heated before printing, during printing (immediately after printing) and after printing, respectively. The thermosetting ink adhering to the surface of the recording medium is fixed early.

  That is, in these image forming apparatuses, the ink curing is promoted by applying ultraviolet rays or heat to the ink not only during printing on the recording medium (immediately after printing) but also after printing. However, such an image forming apparatus is configured to collectively apply ultraviolet rays and heat to the entire surface in the width direction of the recording medium after printing. For this reason, an ultraviolet irradiation device and a heating element corresponding to the entire surface in the width direction of the recording medium are required, and the power consumption of the image forming apparatus is increased, and the configuration of the image forming apparatus is enlarged to make it difficult to reduce the size. was there. In addition, a configuration for shielding leakage and transmission of ultraviolet rays and heat for curing each ink becomes large, and there is a problem that it is further difficult to reduce the size of the configuration of the image forming apparatus.

  The present invention has been made to address the above-described problems, and its purpose is to reduce the total power consumption of the image forming apparatus by reducing the configuration for promoting ink curing after printing on a recording medium. An object of the present invention is to provide an image forming apparatus capable of reducing the overall configuration of the image forming apparatus in size and weight.

  In order to achieve the above object, the present invention is characterized in that, in an image forming apparatus, a recording medium conveying means for conveying a recording medium on a platen, and a recording medium while being displaced in a direction orthogonal to the direction in which the recording medium is conveyed. A recording head for adhering ink to the surface of the recording medium, a first curing accelerating means for accelerating the curing of the ink adhering to the surface of the recording medium, and a first curing accelerating means in the recording medium transport direction. A second curing accelerating means for accelerating the curing of the ink adhering to the recording medium in a range smaller than the displaceable range of the head, and the second curing accelerating means are displaced in a direction perpendicular to the direction in which the recording medium is conveyed A displacement means.

  In this case, for example, the recording head attaches ultraviolet curable ink that is cured by being irradiated with ultraviolet rays to the recording medium, and the first curing accelerating unit and the second curing accelerating unit are light sources that emit light including ultraviolet rays. May be provided, and the surface of the recording medium may be irradiated with light rays including ultraviolet rays, respectively.

  Alternatively, for example, the recording head attaches a thermosetting ink that is cured by receiving heat to the recording medium, and the first curing accelerating unit and the second curing accelerating unit include a heating element that generates heat. Each may be provided and the surface of the recording medium may be heated.

  According to the feature of the present invention configured as described above, the second curing accelerating unit that irradiates the ultraviolet ray in a range smaller than the range in which the recording head can be displaced is displaced in the width direction of the recording medium WK while being displaced on the recording medium WK. The ink is cured. That is, the range for curing the ink in the second curing accelerating unit is extremely small as compared with the conventional technique in which the entire surface in the width direction of the recording medium WK is collectively cured. For this reason, the second curing accelerating means can use a device (for example, a light source or a heat source) with a smaller output than the prior art, and can reduce power consumption, and the physical configuration of the second curing accelerating means can also be reduced. Can be small. As a result, the total amount of power consumption of the image forming apparatus can be suppressed, and the entire configuration of the image forming apparatus can be reduced in size and weight.

  Another feature of the present invention is that the image forming apparatus further comprises a displacement control means for controlling the operation of the displacement means so as to displace the second curing accelerating means within the width of the recording medium. . According to this, it is possible to prevent the second curing accelerating means from being displaced to a portion where there is no recording medium in the width direction on the platen, and it is possible to save the power consumption required for the displacement of the second curing accelerating means.

  Another feature of the present invention is that the image forming apparatus further controls the operation of the second curing accelerating unit and the displacing unit so that the ink adhesion density on the surface of the recording medium is equal to or greater than a predetermined value. A control means for accelerating the curing of the attached ink is provided. According to this, a portion on the recording medium WK where the ultraviolet curable ink is not attached, or a portion where the density of the ultraviolet curable ink is less than a predetermined value (that is, a portion where the amount of attached ink is small). The displacement of the second curing accelerating means can be prevented, and the power consumption required for the displacement of the second curing accelerating means can be saved.

  Hereinafter, an embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the entire inkjet printer 100 according to the present invention. FIG. 2 is a schematic cross-sectional view schematically showing a cross section of the inkjet printer 100 taken along the line AA shown in FIG. FIG. 3 is a block diagram of a control system that controls the operation of the inkjet printer 100 shown in FIG. The ink jet printer 100 attaches droplets of ink that is cured by ultraviolet rays (hereinafter referred to as “ultraviolet curable ink”) to the surface of the sheet-like recording medium WK and ultraviolet curing that adheres to the surface of the recording medium WK. The image forming apparatus prints an image of a desired character, symbol, figure, or the like on the recording medium WK by irradiating the ink droplets with ultraviolet rays and curing them.

  The ink jet printer 100 includes a platen 101 having a flat surface portion and curved at both ends of the flat surface portion in the front-rear direction of the ink jet printer 100. The platen 101 is a mounting table on which the recording medium WK is mounted on the flat portion, and is formed to extend in the horizontal direction in the figure. A cylindrical grid roller 102 is provided at the center of the platen 101 along the horizontal direction in the drawing with its upper surface exposed. The grid roller 102 is rotationally driven by an X-axis direction feed motor 121 whose operation is controlled by a controller 120 described later.

  A long guide rail 103 is provided above the platen 101 so as to be parallel to the platen 101. Under the guide rail 103, two pinch rollers 104a and 104b each having a cylindrical portion facing the grid roller 102 are provided in a displaceable manner along the guide rail 103. The grid roller 102 and the pinch rollers 104a and 104b convey the sheet-like recording medium WK in the front-rear direction shown in the figure while being sandwiched from the vertical direction in the figure. That is, the grid roller 102 and the pinch rollers 104a and 104b correspond to the recording medium conveying unit according to the present invention. Here, the front-rear direction in the drawing for conveying the recording medium WK is the X-axis direction, and the left-right direction in the drawing orthogonal to the X-axis direction is the Y-axis direction.

  The guide rail 103 supports the recording head unit 107 via a linear motion rail 105 and a linear motion block 106 (not shown in FIG. 1). The linear motion rail 105 is a single rail fixed to the guide rail 103 along the Y-axis direction in the figure. The linear motion block 106 is a moving body that slides along the linear motion rail 105, and is fixed to the back surface of the recording head unit 107. That is, the recording head unit 107 is guided in the Y-axis direction in the drawing along the linear motion rail 105 (guide rail 103).

  The recording head unit 107 includes a recording head 108 and a first ultraviolet irradiation device 109. Among these, the recording head 108 introduces each ultraviolet curable ink from an ink tank (not shown) in which ultraviolet curable inks of four different colors are stored, and drops the respective ultraviolet curable ink droplets onto the recording medium WK. Exit toward The first ultraviolet irradiation device 109 is formed in a box shape extending in the vertical direction, and includes a light source (not shown) that emits ultraviolet light having a wavelength for curing the ultraviolet curable ink. The first ultraviolet irradiation device 109 is disposed on both sides of the recording head 108 in such a direction as to irradiate ultraviolet rays onto the platen 101 immediately below, and irradiates the ultraviolet rays onto the recording medium WK located on the platen 101 (in FIG. 2). Curing of the ultraviolet curable ink adhering to the surface of the recording medium WK is promoted. That is, the first ultraviolet irradiation device 109 corresponds to the first curing promoting means according to the present invention.

  A part of the drive belt 110 that is installed along the Y-axis direction in the figure is fixed to the upper back of the recording head unit 107. The drive belt 110 is displaced in the Y-axis direction in the figure by the rotational drive of the Y-axis direction scan motor 122 whose operation is controlled by the controller 120. In other words, the recording head unit 107 is displaced in the Y-axis direction on the linear motion rail 105 by the Y-axis direction scan motor 122 via the drive belt 110. In the present embodiment, the displaceable range of the recording head unit 107 in the illustrated Y-axis direction is 1400 mm.

  A second ultraviolet irradiation device 111 is provided on the front side of the inkjet printer 100 so as to face the curved portion on the front side of the platen 101. The second ultraviolet irradiation device 111 is formed in a box shape extending in the horizontal direction, and cures the same ultraviolet light as that of the light source built in the first ultraviolet irradiation device 109, that is, ultraviolet curable ink. A light source (not shown) that emits ultraviolet light having a wavelength is provided. The second ultraviolet irradiation device 111 is supported by a support guide 112 in a direction to irradiate ultraviolet rays onto the curved portion on the front side of the platen 101, and ultraviolet rays are formed on a recording medium WK located on the curved portion by the control of the controller 120. (Indicated by a broken line in FIG. 2) to accelerate the curing of the ultraviolet curable ink adhering to the surface of the recording medium WK. In this case, the irradiation range of the ultraviolet rays irradiated from the second ultraviolet irradiation device 111 has a substantially rectangular shape of about 100 mm in the illustrated X-axis direction and about 50 mm in the illustrated Y-axis direction. That is, the second ultraviolet irradiation device 111 corresponds to the second curing accelerating means according to the present invention.

  The support guide 112 is installed in a state parallel to the guide rail 103 (Y-axis direction in the drawing), and supports the second ultraviolet irradiation device 111 in a slidable state in the Y-axis direction in the drawing. Specifically, a drive belt (not shown) is installed in the support guide 112 along the Y-axis direction in the drawing, and the back surface of the second ultraviolet irradiation device 111 is fixed to a part of the drive belt. A light source displacement drive motor 113 (broken line) is provided at one end (right side in the figure) of the support guide 112. The light source displacement drive motor 113 is an electric motor whose operation is controlled by the controller 120 and drives the drive belt in the support guide 112 to displace the second ultraviolet irradiation device 111 along the Y-axis direction in the figure. In this case, the displacement range of the second ultraviolet irradiation device 111 is the same as the displacement range of the recording head unit 107 (1400 mm in this embodiment). That is, the support guide 112 and the light source displacement drive motor 113 correspond to the displacement means according to the present invention.

  Above the recording head unit 107, a long upper cover 114 that constitutes the upper housing of the inkjet printer 100 is provided. Further, side covers 115 </ b> R and 115 </ b> L constituting the casings on both sides of the inkjet printer 100 are provided on both sides of the platen 101 and the upper cover 114, respectively. Among these, on the front surface of the side cover 115R, an operation panel 116 is provided for giving an instruction to the ink jet printer 100 (controller 120) and displaying information from the ink jet printer 100 (controller 120). Further, a stand 117 is provided below the platen 101 to support the inkjet printer 100 and to move the inkjet printer 100 to a position desired by the operator.

  The ink jet printer 100 has a built-in controller 120 constituted by a microcomputer including a CPU, a ROM, a RAM, and the like. The controller 120 controls various operations of the ink jet printer 100 by executing a program stored in advance in a storage device such as a ROM in accordance with an instruction from the operator. Specifically, the controller 120 follows the instruction from the external computer device 130 via the interface 123, the X-axis direction feed motor 121, the Y-axis direction scan motor 122, the recording head unit 107, the second ultraviolet irradiation device 111, and Each operation of the light source displacement drive motor 113 is controlled. The external computer device 130 is a personal computer (so-called personal computer) including an input device 131 composed of a keyboard and a mouse and a display device 132 composed of a liquid crystal display.

  Next, the operation of the ink jet printer 100 configured as described above will be described. First, the worker connects the external computer device 130 and the inkjet printer 100 via the interface 123, and turns on the power of the external computer device 130 and the inkjet printer 100, respectively. As a result, the external computer device 130 enters a standby state in which it waits for the input of a command from the operator by executing a predetermined program (not shown). In addition, the inkjet printer 100 executes a predetermined program (not shown) stored in advance in the ROM in the controller 120 to return the recording head unit 107 and the second ultraviolet irradiation device 111 to the origin, and then the external computer device A standby state is waited for an instruction from 130. In this case, the origins of the recording head unit 107 and the second ultraviolet irradiation device 111 are one of the displaceable limit positions (the rightmost end in the drawing) within the respective displacement ranges of the recording head unit 107 and the second ultraviolet irradiation device 111. is there.

  Next, the operator sets the sheet-like recording medium WK on the platen 101 and then operates the input device 131 of the external computer device 130 to instruct the inkjet printer 100 to print an image. In response to this instruction, the inkjet printer 100 starts printing an image on the recording medium WK based on the image data output from the external computer device 130. Specifically, the controller 120 built in the ink jet printer 100 controls the operation of the X-axis direction feed motor 121 and the Y-axis direction scan motor 122 to control the relative positional relationship between the recording head unit 107 and the recording medium WK. While changing the above, the operation of the recording head 108 is controlled to emit ultraviolet curable ink droplets toward the recording medium WK. In addition, the controller 120 causes the first ultraviolet irradiation device 109 to irradiate ultraviolet rays together with the emission of the ultraviolet curable ink.

  Thereby, the droplets of the ultraviolet curable ink adhere to the position on the surface of the recording medium WK based on the image data, and the curing of the attached ultraviolet curable ink is promoted. In this case, a part of the ultraviolet curable ink adhering to the surface of the recording medium WK is cured, but a part having a large amount of the ultraviolet curable ink attached is not completely cured. Next, the controller 120 drives the light source displacement drive motor 113 in a state where the second ultraviolet irradiation device 111 is irradiated with ultraviolet rays, thereby repeatedly reciprocating the second ultraviolet irradiation device 111 in the Y-axis direction in the drawing.

  In this case, the controller 120 controls the rotation of the light source displacement drive motor 113 so that the second ultraviolet irradiation device 111 is reciprocated once until the recording head unit 107 reciprocates once. As a result, the ultraviolet curable ink adhering to the surface of the recording medium WK located on the displacement line of the second ultraviolet irradiation device 111 is irradiated with ultraviolet rays to accelerate curing. By the irradiation of the ultraviolet rays by the second ultraviolet irradiation device 111, the ultraviolet curable ink attached to the recording medium WK becomes substantially cured and is fixed on the surface of the recording medium WK.

  The controller 120 sequentially sends the recording medium WK on the platen 101 to the front side of the ink jet printer 100 while applying the ultraviolet curable ink to the surface of the recording medium WK and irradiating the ultraviolet curable ink with the ultraviolet curable ink. Execute. Then, when printing is performed for all of the image data, the controller 120 returns to the origin of the recording head unit 107 and the second ultraviolet irradiation device 111 and then waits for an instruction from the external computer device 130 again. Become. The operator removes the recording medium WK from the platen 101, stops the operations of the ink jet printer 100 and the external computer device 130, and ends the printing operation.

  As can be understood from the above description of the operation, according to the embodiment, the second ultraviolet irradiation device 111 that irradiates ultraviolet rays in a range smaller than the displaceable range of the recording head unit 107 is displaced in the width direction of the recording medium WK. The recording medium WK is configured to irradiate with ultraviolet rays. That is, the range in which the second ultraviolet irradiation device 111 irradiates the ultraviolet rays is extremely small compared to the conventional technique in which ultraviolet rays are radiated all over the recording medium WK in the width direction. For this reason, the second ultraviolet irradiation device 111 can use an ultraviolet light source having a smaller output than that of the prior art, can reduce power consumption, and can also reduce the physical configuration of the second ultraviolet irradiation device 111. Can do. Moreover, the structure which shields the leakage of the ultraviolet-ray from the 2nd ultraviolet irradiation device 111 can also be reduced in size. As a result, the total amount of power consumption of the inkjet printer 100 can be suppressed, and the overall configuration of the inkjet printer 100 can be reduced in size and weight.

  Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

  In the embodiment described above, the range in the width direction in which the second ultraviolet irradiation device 111 irradiates ultraviolet rays is set to 100 mm. However, the ultraviolet irradiation range of the second ultraviolet irradiation device is not limited to this as long as it is appropriately set within a range smaller than the range in which the recording head unit 107 can be displaced. For example, the range in the width direction for irradiating ultraviolet rays in the second ultraviolet irradiation device 111 may be 100 mm or more. According to this, the second ultraviolet irradiation device 111 can be displaced in the width direction of the recording medium WK to reduce the amount, and the ultraviolet curable ink can be irradiated with ultraviolet rays for a longer time. Further, the range in the width direction in which the second ultraviolet irradiation device 111 irradiates ultraviolet rays may be less than 100 mm. According to this, the 2nd ultraviolet irradiation device 111 can be constituted more compactly.

  In the embodiment, the range in which the second ultraviolet irradiation device 111 is displaced is configured to be the same as the range in which the recording head unit 107 is displaced. However, since it is only necessary to irradiate the ultraviolet curable ink attached on the recording medium WK with ultraviolet rays, the range in which the second ultraviolet irradiation device 111 is displaced is not necessarily configured to be the same as the range in which the recording head unit 107 is displaced. Absent. For example, the second ultraviolet irradiation device 111 may be displaced within the range of the width of the recording medium WK. In this case, the width of the recording medium WK may be configured such that, for example, an operator inputs to the controller 120 via the operation panel 116, or a sensor for detecting the width of the recording medium WK is provided in the recording head unit 107. It may be configured to detect the width of the recording medium WK. Then, the second ultraviolet irradiation device 111 may be displaced using the input width of the recording medium WK or the detected width of the recording medium WK.

  Further, for example, the second ultraviolet irradiation device 111 may be displaced within a range where the ultraviolet curable ink in the width direction of the recording medium WK is adhered, or the ultraviolet curable type in the width direction of the recording medium WK. The second ultraviolet irradiation device 111 may be displaced only in a portion where the density of the ink attached is equal to or higher than a predetermined value to irradiate the ultraviolet rays. In this case, the controller 120 outputs an image output from the external computer 130 in the width direction of the recording medium WK to which the ultraviolet curable ink is attached and a portion where the density of the ultraviolet curable ink is attached is a predetermined value or more. Can be identified based on the data. According to these, effects similar to those of the above-described embodiment can be expected, and a portion where there is no recording medium WK in the width direction (Y-axis direction in the drawing) on the platen 101, and UV curable ink on the recording medium WK are attached. It is possible to prevent the second ultraviolet irradiation device 111 from being displaced to a portion having no density or a portion where the density of the ultraviolet curable ink is less than a predetermined value (that is, a portion where the amount of the deposited ultraviolet curable ink is small). It is possible to save power consumed by the displacement of the second ultraviolet irradiation device 111.

  In the above embodiment, the present invention is applied to the ink jet printer 100 that forms a desired image by adhering ultraviolet curable ink to the recording medium WK. However, the present invention can be appropriately changed according to the suitability of the ink to be used. For example, the present invention may be applied to an ink jet printer that forms a desired image by attaching a thermosetting ink that is cured by receiving heat to the recording medium WK. In this case, the 2nd ultraviolet irradiation device 111 should just be provided with the infrared light source (for example, halogen lamp) which irradiates infrared rays instead of an ultraviolet light source. Further, in the case of using anaerobic ink that is cured by being combined with oxygen, a fan for sending air to the second ultraviolet irradiation device 111 may be provided. Also by these, the same effect as the above embodiment can be expected.

1 is a schematic perspective view showing an entire inkjet printer according to an embodiment of the present invention. It is a schematic sectional drawing which shows typically the cross-sectional shape which looked at the inkjet printer shown in FIG. 1 from the AA line direction. It is a block diagram which shows the outline of the control system which controls the action | operation of the inkjet printer shown in FIG.

Explanation of symbols

WK: Recording medium, 100: Inkjet printer, 101: Platen, 102 ... Grid roller, 103 ... Guide rail, 104a, 104b ... Pinch roller, 105 ... Linear motion rail, 106 ... Linear motion block, 107 ... Recording head unit, 108 DESCRIPTION OF SYMBOLS ... Recording head 109 ... 1st ultraviolet irradiation device, 110 ... Drive belt, 111 ... 2nd ultraviolet irradiation device, 112 ... Support guide, 113 ... Light source displacement drive motor, 114 ... Upper cover, 115R, 115L ... Side cover, 116 ... Operation panel, 117 ... Stand, 120 ... Controller, 130 ... External computer device.

Claims (5)

A recording medium conveying means for conveying the recording medium on the platen;
A recording head that attaches ink to the surface of the recording medium while being displaced in a direction perpendicular to the direction in which the recording medium is conveyed;
First curing accelerating means for accelerating curing of ink attached to the surface of the recording medium;
Second curing acceleration that is disposed downstream of the first curing accelerating means in the conveyance direction of the recording medium and accelerates the curing of ink adhered on the recording medium in a range that is smaller than the displaceable range of the recording head. Means,
An image forming apparatus comprising: displacement means for displacing the second curing accelerating means in a direction orthogonal to a direction in which the recording medium is conveyed. The image forming apparatus according to claim 1,
The recording head is attached to the recording medium with ultraviolet curable ink that is cured by being irradiated with ultraviolet rays.
The first curing accelerating unit and the second curing accelerating unit each include a light source that emits a light beam including ultraviolet rays, and irradiates the surface of the recording medium with the light beam including the ultraviolet rays. The image forming apparatus according to claim 1,
The recording head attaches a thermosetting ink that is cured by receiving heat to the recording medium,
The image forming apparatus for heating the surface of the recording medium, wherein each of the first curing accelerating unit and the second curing accelerating unit includes a heating element that generates heat. The image forming apparatus according to claim 1, further comprising:
An image forming apparatus comprising: a displacement control unit that controls an operation of the displacement unit so as to displace the second curing accelerating unit within a width of the recording medium. 5. The image forming apparatus according to claim 1, further comprising:
An image having control means for controlling the operation of the second curing accelerating means and the displacing means to promote the curing of the ink adhering to the portion where the ink adhesion density on the surface of the recording medium is a predetermined value or more. Forming equipment.

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