JP2007118206A - Process for manufacturing ink jet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for manufacturing an ink jet recorder in which recording quality is improved by suppressing impact position gap of an ink drop on a recording medium. <P>SOLUTION: The process for manufacturing an ink jet recorder comprises: a recording medium conveyance means having such a configuration as a conveyance belt provided with a linear scale is stretched between a drive roller 4, a driven roller 5 and a tension roller 6 and conveying a recording medium by driving the conveyance belt; a means for detecting the scale formed on the linear scale; and a recording head for recording on the recording medium conveyed by the recording medium conveyance means by ejecting ink drops, based on detection results from the scale detection means. The process also comprises: a step for stretching a base layer 3a becoming the substrate of the conveyance belt between the rollers; and a step for sticking a base layer 3b on which the scale is formed to the base layer 3a stretched between the rollers. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an ink jet recording apparatus.

The ink jet recording apparatus includes a transport belt that transports a recording medium placed on the outer peripheral surface, and a plurality of nozzles that eject ink droplets have a width dimension of the recording medium in a direction that intersects the transport direction of the recording medium. There is an ink jet recording apparatus that can complete recording without moving the recording head by the recording heads arranged over the covered distance.
In such an ink jet recording apparatus, in order to ensure good recording quality, there is one in which a recording position of a recording medium is detected, and ink droplets are ejected based on the conveying position to perform recording.

In the detection of the recording medium conveyance position, a configuration in which a linear scale is provided on the belt and a timing mark (scale) of the linear scale is detected by an encoder (see, for example, Patent Document 1) can be used.

JP 2004-69933 A

As a method of providing a linear scale on the conveyor belt, the following three methods, Method 1 to Method 3, are conceivable.

(Method 1) A scale is directly formed on a belt base material developed in a sheet form, and then both ends of the sheet-like belt base material are joined to form an endless transport belt. In this method 1, first, a scale is formed on the surface of a sheet-like belt base material by using, for example, a photolithography technique and an etching technique on a metal thin film formed by a vapor deposition technique or the like. Next, end portions of the sheet-like belt base material are joined together to form an endless conveyance belt.

(Method 2) A scale is formed directly on the outer peripheral surface of a seamless endless conveyor belt. In this method 2, first, a metal thin film is formed on the outer peripheral surface of the endless conveyor belt by, for example, a vapor deposition technique. Next, a scale is formed by utilizing a photolithography technique and an etching technique.
Here, in the photolithography technique, there is generally a step of exposing a resist film using a flat plate photomask. With this flat photomask, the endless conveyor belt cannot be exposed simultaneously over the entire circumference. Therefore, it is necessary to perform the exposure in a plurality of times. That is, the outer periphery of the conveyor belt is divided into areas that can be covered by the photomask, and exposure is performed for each area.

(Method 3) A tape-like linear scale is attached to an endless transport belt without a joint. In this method, a tape-like linear scale on which a scale is formed in advance is attached to the outer peripheral surface of one side edge portion of an endless conveyance belt.

However, the transport belt formed by the method 1 has a joined portion obtained by joining the end portions of the belt base material. The conveying belt formed by this method 1 is stretched between a plurality of rollers to constitute a recording medium conveying device in an ink jet recording apparatus, and when the recording medium conveying device is driven, the joint portion of the conveying belt gets over the rollers. Sometimes it induces vibrations and undulations on the conveyor belt.

In the conveyance belt formed by the method 2, the position of the photomask must be changed every time a plurality of exposures are performed. That is, in the conveyance belt formed by this method 2, the gap between the scales is likely to be shifted at the boundary portion between a plurality of exposures.

When the conveyance belt formed by the method 3 is stretched between a plurality of rollers to constitute a recording medium conveyance device in the ink jet recording apparatus, a difference occurs in the elongation of both side edges of the conveyance belt. That is, in the conveyance belt formed by this method 3, the elongation of one side edge portion to which the linear scale is attached is smaller than the elongation of the other side edge portion. Therefore, when the recording medium conveying apparatus is driven, the conveying belt is likely to meander.

That is, in the conveyance belt formed by the above-described methods 1 to 3, there is an unsolved problem that the landing position of the ink droplet is shifted from an appropriate position and it is difficult to improve the recording quality.

The present invention has been made paying attention to this unsolved problem, and provides an ink jet recording apparatus manufacturing method that can suppress landing position deviation of ink droplets on a recording medium and improve recording quality. With the goal.

In order to solve the above-mentioned problems, a first invention according to the present invention has a configuration in which an endless conveyance belt provided with a linear scale is stretched between a plurality of rollers, and drives the conveyance belt. A recording medium conveying means for conveying a recording medium; a scale detecting means for detecting a scale formed on the linear scale; and a detection result of the scale detecting means on the recording medium conveyed by the recording medium conveying means. A recording head that performs recording by ejecting ink droplets based on the above, a step of stretching the endless conveyance belt between the plurality of rollers, and the plurality of the recording heads To the conveyor belt stretched between the rollers,
And a step of attaching the linear scale. A method of manufacturing an ink jet recording apparatus is provided.

In the first aspect of the invention, the linear scale is attached to the conveyor belt in a state where the endless conveyor belt is stretched between a plurality of rollers in the recording medium conveyor means, that is, in a state where a necessary tension is applied to the conveyor belt. . In other words, the linear scale attached to the conveyor belt
Since tension does not act, the difference in elongation between the part where the linear scale is affixed to the conveyor belt and other parts can be kept low, and ink droplets can be landed at appropriate positions, thereby improving the recording quality. It is possible to manufacture an inkjet recording apparatus that can be used.

In a second aspect based on the first aspect, the linear scale is set such that a width in a direction orthogonal to a conveyance direction of the recording medium is set to a dimension equal to or larger than the width of the recording medium. In the step of attaching the linear scale, the linear scale having the width dimension is attached to a position where the entire area of the width of the previous recording medium can be placed on the linear scale. Provide a method.

In the second invention, a linear scale having a width set to a dimension equal to or larger than the width of the recording medium,
Affixed to the conveyance belt at a position where the entire width of the recording medium can be placed. That is, in the ink jet recording apparatus manufactured by this method, the recording medium can be transported while being placed on the linear scale.

Here, when a conveyor belt stretched between a plurality of rollers is driven, a tension side and a loose side are generated in the conveyor belt. Due to the difference between the tension side and the loose side, the conveyance belt may rotate while repeating expansion and contraction, and uneven conveyance speed may occur. If the recording medium can be transported in a state of being placed on the linear scale, even if the transport speed varies, the relative position between the recording medium and the scale of the linear scale does not occur.
That is, in the second invention, the relative positional deviation between the recording medium and the linear scale when the conveying belt is driven can be suppressed low, and ink droplets can be landed at an appropriate position, thereby further improving the recording quality. It is possible to manufacture an ink jet recording apparatus that can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1A, which is a plan view, and FIG. 1B, which is a front view, the inkjet recording apparatus 1 according to the present embodiment includes a gate roller 10, a paper feed motor 9, and a paper transport unit 40.
A linear encoder 7 and a recording head 2. In FIG. 1, the X direction indicates the conveyance direction of the recording paper 14, and the Y direction indicates a direction orthogonal to the X direction. Further, in FIG. 1A, some components are omitted for easy viewing.
The inkjet recording apparatus 1 is a so-called line head type inkjet recording apparatus that completes recording without moving the recording head 2 during recording.

Here, the detail of each said structure is demonstrated.
As shown in FIGS. 1A and 1B, the gate roller 10 is disposed on the upstream side of the paper transport unit 40, and sandwiches the recording paper 14 fed from a paper feed unit (not shown). And a pair of rotatable rollers. This gate roller 10 is driven by the power from the paper feed motor 9,
After performing skew correction for correcting the inclination of the recording paper 14 with respect to the X direction and the positional deviation in the Y direction, the recording paper 14 is supplied to the paper transport unit 40.

As shown in FIG. 2, the paper transport unit 40 includes a transport motor 12 that generates power for driving the paper transport unit 40, a drive roller 4 to which power is transmitted from the transport motor 12, and an X of the drive roller 4. Driven roller 5 disposed upstream in the direction, endless conveying belt 3 stretched between driving roller 4 and driven roller 5, tension roller 6 for applying tension to conveying belt 3, and pressure roller 11 and a belt charging unit 50.

The tension roller 6 is disposed between the driving roller 4 and the driven roller 5, is inscribed in the conveyance belt 3, and applies tension to the conveyance belt 3 by a spring force.
The pressure roller 11 is disposed immediately above the driven roller 5 with the conveyor belt 3 interposed therebetween, and is in contact with the conveyor belt 3.

The belt charging unit 50 includes a charging roller 8 and a charging power source 15. The charging roller 8 is disposed below the driven roller 5 on the upstream side in the X direction with the conveyance belt 3 interposed therebetween, and is in contact with the conveyance belt 3. The charging power supply 15 is electrically connected to the charging roller 8 and applies an AC voltage to the charging roller 8.
As shown in FIG. 2, the driven roller 5 is grounded and serves as a counter electrode with respect to the charging roller 8 facing the conveyance belt 3.

In the belt charging unit 50, the charging power supply 15 supplies charges to the transport belt 3 via the charging roller 8 to charge the transport belt 3. An alternating charge pattern corresponding to the AC voltage from the charging power source 15 is formed on the charged transport belt 3. Then, dielectric polarization occurs in the recording paper 14 placed on the charged transport belt 3, and an electrostatic adsorption force acts between the recording paper 14 and the transport belt 3.

The pressure roller 11 transfers the recording paper 14 placed on the charged conveyance belt 3 to the conveyance belt 3.
To increase the adhesion of the recording paper 14 to the transport belt 3.

As shown in FIG. 1A, a plurality of scales 3 c are formed on the outer peripheral surface of the transport belt 3. These scales 3c are made of a material that reflects detection light of a linear encoder 7 described later, and are formed at a predetermined interval H in the X direction as shown in FIG. 3 which is an enlarged view of a portion A in FIG. Has been. In the present embodiment, the plurality of scales 3c are 180 LPI (
Lines Per Inch), and the interval H shown in FIG. 3 is about 0.141 mm.

As shown in FIG. 4, which is a cross-sectional view taken along the line BB in FIG.
And a linear scale layer 3b. The scale 3c described above is formed on the outer peripheral surface of the linear scale layer 3b. In FIG. 4, each configuration is exaggerated for easy understanding.

The linear scale layer 3b is made of a synthetic resin such as PET (polyethylene terephthalate), PTFE (polytetrafluoroethylene), or PEI (polyetherimide). The base layer 3a is made of the above synthetic resin or a synthetic resin such as an elastomer.

Here, the charge supplied from the belt charging unit 50 to the transport belt 3 is stored in the linear scale layer 3b. In order to keep the leakage of the charge stored in the linear scale layer 3b low, the base layer 3a is made of a material having a volume resistivity smaller than that of the linear scale layer 3b, and the charge is stored in the linear scale layer 3b during charging. It is preferable to use a material having an appropriate volume resistivity so as not to flow too much.

Further, as shown in FIG. 4, the linear scale layer 3b has a Y-direction width that is set to the same dimension as the base layer 3a. The base layer 3a and the linear scale layer 3b have a width in the Y direction larger than that of the recording paper 14, and the entire width of the recording paper 14 can be placed.

As for the thickness of the linear scale layer 3b, from the standpoint of electrostatic attraction force, the smaller the thickness, the larger the capacitance and the more electric charge is stored. However, from the viewpoint of rigidity, the thicker one is elastically deformed. Is small and hardly affected by the elongation of the material. Therefore, it is necessary to set in consideration of the balance between the two.

The thickness of the base layer 3a needs to be set with emphasis on the rigidity and durability as the base member of the transport belt 3. In the present embodiment, the linear scale layer 3b is set to about 50 to 100 μm and the base layer 3a is set to about 100 to 200 μm from the above viewpoint.

The sheet conveying section 40 having the above configuration is rotationally driven counterclockwise as viewed in FIG. 2 by the power from the conveying motor 12 to which the conveying belt 3 is transmitted via the driving roller 4, as shown in FIG. Then, the recording paper 14 placed on the outer peripheral surface of the transport belt 3 is transported in the X direction.

The linear encoder 7 is composed of a reflective optical sensor having a light emitting element and a light receiving element, and is applied to the scale 3c of the linear scale layer 3b of the conveyor belt 3 as shown in FIGS. 1 (a) and 1 (b). It is disposed with a gap between it and the linear scale layer 3b at the facing position.
When the linear encoder 7 detects the scale 3c, the detection light output from the light emitting element toward the transport belt 3 is reflected by the scale 3c, and the reflected detection light is input to the light receiving element.

That is, the output signal from the linear encoder 7 (hereinafter referred to as an encoder signal) changes from the Lo level to the Hi level in a pulse shape and is turned on when the detection light is input to the light receiving element. When the detection light deviates from the scale 3c and is diffusely reflected by the linear scale layer 3b or absorbed by the linear scale layer 3b, the encoder signal is shifted from the Hi level to Lo.
The level changes in a pulse shape and becomes an OFF state. The linear encoder 7 has 18
It has two output channels of A phase and B phase that have a phase difference of 90 electrical degrees with a resolution of 0 LPI.

As shown in FIGS. 1A and 1B, the recording head 2 includes a yellow recording head 2a that ejects yellow (Y) ink droplets and a magenta (M) ink droplet that ejects magenta ink droplets. The recording head 2 b includes a cyan recording head 2 c that discharges cyan (C) ink droplets, and a black recording head 2 d that discharges black (K) ink droplets.

In the recording heads 2 a, 2 b, 2 c, and 2 d for each color, a plurality of nozzles that eject ink droplets onto the nozzle surface 21 are arrayed over a length that is greater than or equal to the width in the Y direction of the recording paper 14. These recording heads 2a, 2b, 2c, and 2d are provided with a paper transport unit 40 as shown in FIG.
The nozzle surface 21 is directed toward the recording paper 14 and a gap is provided between the nozzle surface 21 and the recording paper 14. Here, an electrostatic actuator method, a piezo method, a film boiling method, or the like can be adopted as the ink droplet ejection method of the recording head 2.

Further, as shown in FIG. 6, the ink jet recording apparatus 1 includes a control circuit 30 that controls the operation of each configuration described above. The control circuit 30 includes an interface 37 and a CPU (Centra
l Processing Unit) 31, paper feed motor control unit 32, charging power source control unit 33, discharge signal generation unit 34, transport motor control unit 35, and recording head control unit 36.

The interface 37 connects the inkjet recording apparatus 1 and the external device 20 such as a digital camera or a personal computer. The CPU 31 functions to issue an operation command to each control unit. The paper feed motor control unit 32 controls the paper feed motor 9, and the charging power source control unit 33
The charging power source 15 is controlled. The conveyance motor control unit 35 controls the conveyance motor 12, and the recording head control unit 36 controls the recording head 2.

The discharge signal generator 34 receives an encoder signal from the linear encoder 7 and generates a discharge signal based on the encoder signal.

Here, generation of the ejection signal will be described.
Each time the conveyor belt 3 is driven to rotate and the linear encoder 7 detects the scale 3c one by one, the encoder signals E ₁ and E ₂ in the A phase and B phase of the linear encoder 7 are as shown in FIG. In addition, an ON state and an OFF state occur alternately. At this time, B
The phase encoder signal E ₂ has a delay of 90 degrees in electrical angle from the phase A encoder signal E ₁ . The ON state in encoder signals E ₁ and E ₂ is called a scale detection pulse.

In the discharge signal generation unit 34, the ON state and O in each of the encoder signals E ₁ and E ₂
Based on the FF state, the ejection signal TS shown in FIG. 5 is generated. That is, the ejection pulse TS ₁ of the ejection signal TS is turned ON based on the scale detection pulse S1 ₁ rising edge of the encoder signal E _1, OFF state based on the scale detection pulse S2 ₁ rising edge of the encoder signal E ₂ It becomes. The discharge pulse TS ₂ is turned ON based on the falling edge of the scale detection pulse S1 ₁ in the encoder signal E _1, based on the scale detection pulse S2 ₁ falling edge of the encoder signal E ₂ O
It becomes FF state. Thereafter, the discharge signal TS is generated by this repetition.

As a result, the interval corresponding to the recording resolution of 720 dpi (dot per inch) (about 0.035).
mm), an ON state and an OFF state can be alternately generated in the ejection signal TS. Therefore, by counting the ON state and OFF state of the ejection signal TS, the transport position of the recording paper 14 can be grasped, and ink droplets are ejected from the recording head 2 based on the rising edge and the falling edge of the ejection pulse. The recording resolution is 720dp
i can be realized.

A recording operation flow in the inkjet recording apparatus 1 having the above-described configuration will be described.
When the control circuit 30 receives recording information from the external device 20 such as a digital camera or a personal computer via the interface 37, the ink jet recording apparatus 1 receives the CPU 3
1 starts the recording process, and the recording operation starts.

When the recording operation starts, first, the CPU 31 outputs a conveyance command to the conveyance motor control unit 35 to drive the conveyance motor 12 and drives the conveyance belt 3 via the driving roller 4.
Next, the CPU 31 outputs a charging command to the charging power source control unit 33 to cause the charging power source 15 to generate a voltage. At this time, the transport belt 3 is charged by being supplied with charge via the charging roller 8.

Next, the CPU 31 outputs a recording paper supply command to a paper supply unit (not shown), and causes the paper supply unit to supply one sheet of recording paper 14 to the gate roller 10. At this time, the recording paper 14 is supplied so as to be abutted between the pair of rollers of the gate roller 10 and the skew is corrected.

Next, the CPU 31 outputs a paper feed command to the paper feed motor control unit 32 and drives the paper feed motor 9 to rotate the gate roller 10 and supply the skew-corrected recording paper 14 to the paper transport unit 40. Let

The recording paper 14 supplied to the paper transport unit 40 is pressed by the pressure roller 11 and is attracted to the transport belt 3. At this time, the CPU 31 starts counting the ON state and the OFF state in the ejection signal TS.

Next, when the transport position of the recording paper 14 grasped based on the count values of the ON state and the OFF state in the ejection signal TS reaches the recording position of the yellow recording head 2a, the CPU 31 detects the yellow recording head 2a. Outputs the recording start command at.
At this time, the ejection of ink droplets by the yellow recording head 2a is permitted based on the rising edge and the falling edge of the ejection pulse in the ejection signal TS described above.

Next, the CPU 31 sequentially issues a recording start command for the magenta recording head 2b, a recording start command for the cyan recording head 2c, and a recording start command for the black recording head 2d, in the same manner as the recording start command for the yellow recording head 2a. The data is output to the recording head controller 36 in a timely manner.

Next, the CPU 31 outputs a paper discharge command to a paper discharge unit (not shown), and discharges the recording paper 14 downstream in the X direction. This completes the recording operation for one recording sheet 14.

Here, a method for manufacturing the paper transport unit 40 will be described.
In the manufacturing method of the paper transport unit 40, first, as shown in FIG.
The driven roller 5, the tension roller 6, and the transport motor 12 are disposed at predetermined positions.

Next, as shown in FIG. 7B, the drive roller 4, the driven roller 5, and the tension roller 6
A base layer 3a on which the linear scale layer 3b is not provided is stretched. At this time, the height position of the tension roller 6 is adjusted so that the tension acting on the base layer 3a is equal to the tension acting on the transport belt 3 in a state where the paper transport section 40 is completed. That is, the tension required for the conveyance belt 3 as the sheet conveyance unit 40 is determined at this time.

Next, as shown in FIG. 7C, the linear scale layer 3b on which the scale 3c is formed in advance.
The end portion 60 on the downstream side in the X direction is attached to the outer peripheral surface of the base layer 3a using an adhesive member 13 such as a double-sided pressure-sensitive adhesive sheet.

Then, an end 61 on the upstream side in the X direction of the linear scale layer 3b so as not to stretch and sag.
, The base layer 3a is gradually rotated counterclockwise, and the linear scale layer 3b is gradually attached to the outer peripheral surface of the base layer 3a.

After the linear scale layer 3b is attached to the base layer 3a, the belt charging unit 50 and the pressure roller 11 are disposed at predetermined positions, respectively, thereby completing the paper transport unit 40 shown in FIG.

In the present embodiment, the paper transport unit 40 corresponds to a recording medium transport unit, the recording paper 14 corresponds to a recording medium, the linear scale layer 3b corresponds to a linear scale, and the linear encoder 7
Corresponds to the scale detection means.

According to the manufacturing method described above, the base layer 3a is in a state where tension is applied to the base layer 3a.
Since the linear scale layer 3b is affixed to the outer peripheral surface, no tension acts on the linear scale layer 3b when the inkjet recording apparatus 1 is completed. That is, there is no difference in the distance H between the scales 3 c before and after the manufacture of the inkjet recording apparatus 1.

Therefore, in the ink jet recording apparatus 1, ink droplets can be landed on the recording paper 14 at an accurate interval corresponding to the recording resolution, and the recording quality can be improved.

Further, in the ink jet recording apparatus 1, the width dimensions of the linear scale layer 3 b and the base layer 3 a in the Y direction are equal and larger than the width of the recording paper 14. That is, the recording paper 14 is transported by placing the entire width in the Y direction on the outer peripheral surface of the linear scale layer 3b.

Therefore, in the paper transport unit 40, even if the transport speed of the transport belt 3 varies, the relative position shift between the scale 3c and the recording paper 14 is suppressed. Thereby, the recording quality can be further improved.

In the present embodiment, the ink jet recording apparatus 1 which is a line head type ink jet recording apparatus has been described as an example. However, the present invention is not limited to this, and a serial type ink jet recording apparatus that performs recording while scanning the recording head 2 in the Y direction. It can also be applied to. Further, although the case where the number of colors of the recording head 2 is four has been described, the present invention is not limited to this, and the number of colors such as one color or six colors may be arbitrary.

Moreover, although the double-sided adhesive sheet was demonstrated to the example as the adhesive member 13, the adhesive member 13 is not limited to this, You may use a liquid or paste-form adhesive agent.

Further, the example using the electrostatic adsorption force as the force for holding the recording paper 14 on the outer peripheral surface of the conveyance belt 3 has been described. However, the present invention is not limited to this. For example, a plurality of spurs are provided above the conveyance belt 3. In addition, a so-called friction feed method may be used in which the recording paper 14 is conveyed by a frictional force acting between the recording paper 14 and the conveying belt 3 by pressing the recording paper 14 against the outer peripheral surface of the conveying belt 3 with a spur.

1 is an external view showing a main configuration of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 3 is a front view illustrating a paper transport unit of the ink jet recording apparatus according to the embodiment of the invention. The A section enlarged view in Fig.1 (a). BB sectional drawing in Fig.1 (a). FIG. 4 is a diagram illustrating generation of an ejection signal of the ink jet recording apparatus according to the embodiment of the present invention. 1 is a block diagram illustrating a main configuration of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 4 is a diagram illustrating a method for manufacturing a paper transport unit of the ink jet recording apparatus according to the embodiment of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inkjet recording device, 2 ... Recording head, 3 ... Conveyor belt, 3a ... Base layer, 3
b ... Linear scale layer, 3c ... Scale, 7 ... Linear encoder.

Claims (2)

An endless conveyance belt provided with a linear scale is stretched between a plurality of rollers, and a recording medium conveyance unit that conveys a recording medium by driving the conveyance belt; and formed on the linear scale Scale detecting means for detecting a scale that is present, and a recording head that performs recording by discharging ink droplets to the recording medium conveyed by the recording medium conveying means based on the detection result of the scale detecting means. A method of manufacturing an ink jet recording apparatus,
An inkjet comprising: a step of stretching the endless conveyance belt between the plurality of rollers; and a step of attaching the linear scale to the conveyance belt stretched between the plurality of rollers. A method for manufacturing a recording apparatus. In the linear scale, a width in a direction perpendicular to the conveyance direction of the recording medium is set to a dimension equal to or larger than the width of the recording medium,
2. The step of attaching the linear scale, wherein the linear scale having the width dimension is attached to a position where the linear scale can place the entire width of the recording medium. A method for producing the ink jet recording apparatus according to claim 1.

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