JPH08276636A - Recording apparatus - Google Patents

Abstract

PURPOSE: To provide a recording apparatus in which the distance between a recording head and a recording medium can be kept appropriately. CONSTITUTION: A recording apparatus which performs recording on a recording medium with a recording head supported by a recording head supporting means (carriage C) moving on the recording medium is equipped with a recording head moving means (vertical movement part 18) which transfers the recording head corresponding to the variation of the carriage C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus, and more particularly to a recording apparatus for recording while a recording head mounted on a guide rail moves on a recording medium.

[0002]

2. Description of the Related Art FIG. 9 is a plan view of a conventional ink jet recording apparatus.

As shown in FIG. 9, in the conventional ink jet recording apparatus, a recording head 1 for ejecting ink from an ejection port to perform recording on a recording medium (recording material) 7 can be moved laterally on a guide rail 2. Is attached to. Both ends of the guide rail 2 are held by holding members 3 and are fixed to the housing 4. The recording head 1 is attached to a belt 6 that is driven by a carriage driving motor 5, and recording is performed on a recording medium 7 while moving on the guide rail 2 as the carriage driving motor 5 rotates.

When the recording of the entire width of the recording medium 7 (or one line of the designated recording width) is completed, the conveying roller 8 holding the recording medium 7 is driven by the conveying roller motor 9 to perform recording. The medium 7 is moved by one line in the direction perpendicular to the moving direction of the recording head 1. After that, the recording head 1 again moves on the guide rail 2 to perform recording for one line. Recording is performed on the recording medium 7 by repeating this operation.

In the ink jet recording apparatus having such a structure, the distance between the recording head 1 and the recording medium 7 is usually set to 1.2 mm, for example, but this distance has a great influence on the image quality.

That is, as shown in FIG. 10, if the interval is too large, the deviation of the ink droplets ejected at a constant angle θ on the image due to the manufacturing variation α of each nozzle is emphasized. As a result, the ink droplets cannot be recorded at the intended position on the recording medium, the accuracy of the position of the ink droplets recorded on the recording medium deteriorates, and the misalignment direction of each nozzle causes a straight line. What should have become a curve or becomes discontinuous, and the printing quality is greatly impaired.

On the contrary, if the distance is too close, the rebound of the ink that has collided with the recording medium adheres to the vicinity of the ejection port of the recording head to prevent the normal ejection state, and in the worst case, the ink ejection is unsuccessful. It will be possible.

Therefore, in the conventional ink jet recording apparatus, a highly accurate dimension is required for the distance between the recording head 1 and the recording medium 7. For example, the permissible value is ±.
It is desired to be within the range of 0.1 mm.

As described above, if the distance between the recording head and the recording medium is not kept within an appropriate range, the printing quality will be greatly reduced.

Particularly in a recording apparatus for drawing output which uses a large-sized recording medium, the guide rail inevitably becomes long, and the guide rails supported only at both ends are bent by their own weight. When the recording head moves on the bent guide rail, the distance between the recording head and the recording medium is wide at both ends and narrow at the central portion. Therefore, the positional accuracy of printing may be reduced at both ends of the guide rail, and abnormal discharge may occur at the center due to stains on the recording head.

When using a recording medium that is particularly thicker than plain paper (for example, polyester film), the position of the recording head must be changed in order to keep the distance between the recording head and the recording medium within an appropriate range. . For this reason, some recording devices have a means for the user to manually adjust the interval.

Therefore, as an example of countermeasures against the bending of the guide rail, for example, the diameter of the guide rail is increased to increase the mechanical strength of the guide rail itself and suppress the bending amount to a predetermined value or less. Further, as another example, FIG.
As shown in FIG. 1, both ends of the guide rail 2 are attached to the holding member 3
In addition to supporting the recording head 1, the holding member 10 is provided in the central portion, and the holding member 10 is provided with a height adjusting mechanism 11 to correct the bending of the guide rails 2 and correct the recording head 1 and the recording medium 7. I try to keep the interval between and within the proper range. Further, as described above, a means for manually adjusting the distance between the recording head and the recording medium is also used.

[0013]

However, if the diameter of the guide rail is increased as the guide rail deflection preventing means, the device itself is inevitably increased, and in order to sufficiently suppress the deflection, the diameter is simply increased. It was difficult to do just that. In addition, in the deflection correcting means in which a holding member is added to the center of the rail, it is difficult to guarantee the accuracy of the holding member parts, and the number of parts for adjustment addition increases, and the adjustment for ensuring the distance between the recording head and the recording medium is made. This requires a process, complicates the manufacturing process, and has a problem in terms of cost.

Further, when printing on a recording medium thicker than plain paper, the distance between the recording head and the recording medium must be adjusted each time, which is troublesome and there is a problem in operability of the apparatus.

Therefore, an object of the present invention is to provide a recording apparatus capable of properly ensuring the distance between the recording head and the recording medium.

[0016]

In order to solve the above-mentioned problems, the invention according to claim 1 performs recording on a recording medium while a recording head supported by recording head supporting means moves on the recording medium. The apparatus is characterized by comprising recording head moving means for moving the recording head according to a variation amount of the recording head supporting means.

The invention according to claim 2 is characterized in that the recording head moving means is interlocked with the movement of the recording head supporting means.

According to a third aspect of the present invention, there is provided a fluctuation amount detecting means for detecting a fluctuation amount of the recording head supporting means, and the fluctuation amount detecting means detects the fluctuation amount of the recording head supporting means according to the fluctuation amount of the recording head supporting means. It is characterized in that the recording head moving means is driven.

[0019]

According to the first aspect of the invention, the recording head moving means moves the recording head according to the amount of fluctuation of the recording head support means. Therefore, for example, when the guide rail which is the recording head supporting means is bent, the absolute value is the same as the bending amount and the recording head is moved in the opposite direction to cancel the bending amount, and the recording head and The distance to the recording medium is maintained at an appropriate value.

Further, according to the second aspect of the invention, since the deflection amount of the guide rail is determined by the positions from both ends of the guide rail, the recording head is moved in association with the movement of the recording head supporting means in the guide rail direction. Let Then, the bending amount can be canceled and the gap between the recording head and the recording medium can be maintained at an appropriate value.

According to the third aspect of the invention, the fluctuation amount detecting means detects, for example, the bending amount of the guide rail. The recording head moving means cancels the bending amount by moving the recording head in the opposite direction, which has the same absolute value as the bending amount detected by the fluctuation amount detecting means (bending amount detecting means), and cancels the bending amount. Maintain a proper distance from the recording medium.

[0022]

The present invention will be described below with reference to the illustrated embodiments. In addition, in each of the following embodiments, the same reference numerals are given to the portions already described, and the duplicated description will be omitted.

(1) First Embodiment FIG. 1 is an enlarged perspective view of an essential part of the first embodiment.

As shown in FIG. 1, a carriage C, which is a "recording head supporting means", has a carriage body 12 movably mounted on a guide rail 2 and a vertically moving part on which a recording head (not shown) is mounted. 18 and.

The carriage body 12 is driven along the guide rails 2 by a carriage driving means (not shown). A gear 13 is formed along the longitudinal direction of the guide rail 2, and a spur gear 14 corresponding to the gear 13 is rotatably attached on the carriage body 12. Since the spur gear 14 is meshed with the gear 13, the spur gear 14 rotates when the carriage body 12 moves along the guide rail 2.
A worm gear 15 is formed on the central axis of the spur gear 14,
The worm gear 15 is meshed with a gear 16. Here, when the carriage body 12 moves over the entire width of the guide rail 2, the worm gear 15 is rotated so that the gear 16 makes one rotation.
And the gear ratio of the gear 16 is set. The shaft of the gear 16 is connected to the eccentric cam 17.

On the front side surface of the carriage body 12, there is provided an up-and-down moving portion 18 which is a "recording head moving means" provided with a recording head holding mechanism and a connecting portion (not shown) for a print signal line to the recording head. It is installed. Vertical movement part 18
Are slidably connected to the carriage body 12 through guide grooves 19 in the vertical direction. Further, the vertically moving portion 18 is biased downward by a spring (not shown), and the stopper 34 provided on the right side surface of the vertically moving portion 18 is provided with a stopper 34.
Is in contact with the cam surface of.

Next, the operation will be described.

When the carriage 12 starts moving from the end of the guide rail 2, the spur gear 14 is rotated,
The worm gear 15 and the gear 16 are rotated to rotate the eccentric cam 17
Is rotated. According to the rotation of the eccentric cam 17, the stopper 34
The up-and-down moving unit 18 is driven up and down via the. Here, the eccentric cam 17 is configured to rotate once by moving the entire width of the guide rail 2 of the carriage 12. Therefore, the up-and-down moving portion 18 moves while moving between both ends on the guide rail 2,
It moves up and down according to the shape of the eccentric cam 17.

Further, as shown in FIG. 2, the vertical operation amount 20 (Y-axis direction) of the eccentric cam 17 is determined by the guide rail 2
The deflection amount 21 of the guide rail 2 at the position of the upper carriage 12 (X-axis direction) is set to be equal. That is, the length, thickness, material, etc. of the guide rail 2 are known, and the weight of the carriage C is also known. Therefore, the operation amount (deflection amount) of the carriage C according to the existing position on the guide rail 2 can be obtained by calculation and experiment, and the characteristic diagram shown in FIG. 2 can be obtained in advance.

Therefore, no matter where the vertical moving part 18 exists on the guide rail 2, it can be moved upward by the rotation of the eccentric cam 17 by the amount of downward bending of the guide rail 2. The distance 22 between the recording head 1 and the recording medium 7 on the vertical movement unit 18 is always kept constant.

As is clear from the above configuration and operation, it is possible to secure sufficient accuracy without adjustment, without increasing the cost of the guide rail due to the use of a thick member and without complicated adjustment during manufacturing. Is possible,
It is possible to prevent deterioration of image quality.

(2) Second Embodiment FIG. 3 is an enlarged perspective view of the essential parts of the second embodiment.

The difference between this embodiment and the first embodiment is that a variation amount detecting means is provided, and in the first embodiment, a gear or an eccentric cam is used as the driving means for the vertical moving portion. As opposed to
In this embodiment, a motor is used.

As shown in FIG. 3, the carriage C1 comprises a carriage body 12 and a vertically moving portion 18. The carriage main body 12 is moved along a guide rail 2A by a carriage driving means (not shown), and a linear scale 23 having a strip shape longer than the moving distance of the carriage is arranged parallel to the guide rail 2A.
As the material of (1), a thin metal plate or a material formed in a strip shape by Mylar having a metal deposited on the surface thereof is suitable. The linear scale 23 is fixed to the main body of the recording apparatus and functions as a reference member in the height direction as described below, so that the linear scale 23 is configured so as not to bend or bend.

As shown in FIG. 4, the conventional linear scale 23A is provided with the first pulse generating means 24 in the guide rail direction, and the first pulse generating means 24 includes slits, electrodes, magnetism and the like. ing. The first pulse generator 24 generates a pulse signal based on information detected by a sensor (not shown) mounted on the carriage, and the pulse signal functions as position information of the carriage C1 in the guide rail direction. To do.

On the other hand, the linear scale 2 of this embodiment
As shown in FIG. 5, 3 is a conventional first pulse generating means 2
4 in addition to the strip-shaped second parallel to the guide rail 2A.
A pulse generating means 26 is formed. The second pulse generating means 26 is detected by a vertical direction sensor 27 which is a "variation amount detecting means" arranged on the carriage body 12, and the sensor 27 generates a pulse signal.

When the guide rail 2A is bent, the vertical direction sensor 27 is also lowered at the same time. Therefore, the second pulse generating means 2 which is the height reference member.
A positional deviation with respect to 6 is detected. Information corresponding to this positional deviation is output from the vertical direction sensor 27 as a pulse signal.

This pulse signal is input to a control unit (not shown) in the main body of the recording apparatus, and the guide unit 2A of the carriage main body 12 based on the input pulse signal in the control unit.
The amount of movement in the direction perpendicular to is calculated. Reference numeral 28 is a pulse motor, reference numeral 29 is a pinion gear connected to the pulse motor 28, and reference numeral 30 is a pinion gear 2.
It is a rack that meshes with 9.

Next, the operation will be described.

As described above, the guide rail 2A bends due to the weight of the guide rail 2A itself and the weight of the carriage. When the guide rail 2A is bent, the carriage body 12 is lowered and the distance between the recording head and the recording medium is narrowed.

However, since the linear scale 23 itself is very lightweight and is attached by applying tension in the longitudinal direction at the time of attachment, almost no bending occurs. Therefore, the linear scale 23 is moved relatively upward with respect to the carriage body 12, and the vertical direction sensor 27 provided on the carriage body 12 detects the amount of vertical movement of the carriage body 12.

A control unit (not shown) calculates the amount of movement of the carriage body 12 based on the detected signal, and calculates the amount of drive (pulse number) of the pulse motor 28. The driving amount of the pulse motor 28 is equal to the detected vertical movement amount of the carriage body 12, and is opposite to the vertical movement direction of the carriage body 12. The control unit outputs the calculated movement amount and movement direction to the pulse motor 28. The pulse motor 28 rotates according to the input movement amount and movement direction. As a result, the pinion gear 29 rotates and drives the rack 30 provided in the vertical movement unit 18. As a result, the up-and-down moving unit 18 moves in the opposite direction, equal to the distance moved by the bending of the guide rail 2A. Therefore, the distance between the recording head and the recording medium held by the vertical movement unit 18 is kept constant.

Further, when recording on a thick recording medium, a predetermined switch on an operation panel (not shown) on the main body of the recording apparatus is pressed to instruct the processing means to perform recording on the thick recording medium. In the processing means, in order to correct the decrease in the distance between the print head and the print medium due to the thick print medium, the pulse motor 28 is driven to move the vertical movement unit 18 by a predetermined amount. By the above operation, the distance between the recording head and the recording medium is corrected to an appropriate range.

(3) Third Embodiment FIG. 6 is an enlarged perspective view of an essential part of the third embodiment.

The present embodiment is different from the second embodiment in that a solenoid is used as the drive means for the vertical moving part.

As shown in FIG. 6, similarly to the second embodiment, the signal detected by the vertical sensor 27 is input to the control unit (not shown) of the recording apparatus main body. In the control unit, when the movement is detected, the solenoid 31 on the carriage is
Generate a signal to drive.

The vertical moving part 18 is coupled to the movable core 32 of the solenoid 31 via a lever 33. Therefore,
The vertical movement unit 18 moves in the vertical direction by driving the solenoid 31.

Next, the operation will be described.

As described above, by moving the carriage C2,
The guide rail 2A bends due to the weight of the guide rail 2A itself and the weight of the carriage C2. When the guide rail 2A is bent, the carriage body 12 is lowered and the distance between the recording head and the recording medium is narrowed.

Then, the vertical direction sensor 27 is used as described above.
Detects that the carriage body 12 has moved in the vertical direction, and generates a detection pulse signal. Based on this detection pulse signal, the control unit outputs a drive signal to the solenoid 31,
The solenoid 31 is driven by the drive signal to move the movable core 32. Since the movable core 32 is connected to the lever 33 of the vertical movement unit 18, when the movable core 32 moves, the vertical movement unit 18 moves accordingly.

As shown in FIG. 7, the solenoid 31 is set to operate when the distance between the recording head and the recording medium becomes narrow due to the deflection amount 21 of the guide rail 2A at the position of the carriage C2 on the guide rail 2A. There is. As shown by the reference numeral 35, the operation amount becomes stepwise according to the on / off state of the solenoid. Therefore, as shown in FIG. 8, the distance 22 between the recording head and the recording medium held by the vertical movement unit 18 is maintained within the allowable range.

In this embodiment, the case where the recording medium is placed and conveyed horizontally has been described, but the present invention can be applied to the case where the recording medium is arranged in a state other than horizontal (for example, vertical). Of course.

[0053]

As described above, according to the invention described in each claim, in the recording apparatus for recording on the recording medium while the recording head supported by the recording head supporting means moves on the recording medium, A recording head moving means for moving the recording head in accordance with a variation amount of the recording head supporting means, wherein the recording head moving means is interlocked with the movement of the recording head supporting means; Since the recording head moving means is driven according to the fluctuation amount of the recording head supporting means detected by the fluctuation amount detecting means, the recording head and the recording medium are It is possible to keep the interval within a certain range, for example, without increasing the cost of the guide rail, and without making complicated adjustments during manufacturing, with sufficient accuracy without adjustment. One it becomes possible, it is possible to prevent a decrease in image quality.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a first embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the deflection of the rail and the operation amount of the cam in the first embodiment.

FIG. 3 is a perspective view of a main part of a second embodiment of the present invention.

FIG. 4 is an enlarged view of a conventional linear scale.

FIG. 5 is an enlarged view of a linear scale used in the second embodiment.

FIG. 6 is a perspective view of a main part of a third embodiment of the present invention.

FIG. 7 is a diagram showing a relationship between bending of a rail and ON / OFF of a solenoid in the third embodiment.

FIG. 8 is a diagram showing the relationship between the deflection of the rail and the operation amount of the solenoid in the third embodiment.

FIG. 9 is a plan view of a main part of a conventional inkjet recording device.

FIG. 10 is a diagram showing the deviation of the ink landing position according to the distance between the recording head and the recording material in the conventional inkjet recording apparatus.

FIG. 11 is an explanatory diagram of a problem of the conventional example.

[Explanation of symbols]

 C Carriage 2, 2A Guide rail 12 Carriage body 17 Cam 18 Vertical movement part 19 Guide groove 23 Linear scale 26 Vertical pulse generating means 27 Vertical direction sensor 28 Pulse motor 29 Pinion gear 30 Rack 31 Solenoid 33 Lever 34 Stopper

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Komichi Someya 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo Copier Co., Ltd. (72) Inventor Kazunori Ikai 6-3-3 Shimorenjaku, Mitaka-shi, Tokyo Copy A Incorporated company (72) Inventor Hiroyuki Kunii 6-3-3 Shimorenjaku, Mitaka City, Tokyo Inside Copier Co., Ltd.

Claims (3)

[Claims] 1. A recording apparatus for recording on a recording medium while the recording head supported by the recording head supporting means moves on the recording medium, wherein the recording head is moved according to a variation amount of the recording head supporting means. A recording apparatus, comprising: a recording head moving unit that allows the recording head to move. 2. The recording apparatus according to claim 1, wherein the recording head moving unit is interlocked with the movement of the recording head supporting unit. 3. A fluctuation amount detecting unit for detecting a fluctuation amount of the recording head supporting unit, and driving the recording head moving unit according to the fluctuation amount of the recording head supporting unit detected by the fluctuation amount detecting unit. The recording apparatus according to claim 1, wherein: