This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2008-187351, filed Jul. 18, 2008, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an image recording apparatus in which the space between a recording section and conveying section is adjustable.
2. Description of the Related Art
In recent years, inkjet printers have become widely used on account of their low recording noise and high print quality, in general. In these inkjet printers, the distance between a recording head that ejects ink and a conveying section for conveying a recording medium is set to a predetermined value for high-quality image recording.
In an image recording apparatus described in Jpn. Pat. Appln. KOKAI Publication No. 2005-14334, for example, a platen is raised by a platen moving mechanism to a position in which image recording can be performed, and a positioning hole in the platen is caused to engage with the a positioning lug on a support portion that supports a recording head. Thus, a distance from a recording medium supported on the platen to a nozzle surface of the recording head is adjusted to a predetermined value, whereby high-quality image recording can be performed.
Accordingly, an object of the present invention is to provide an image recording apparatus, capable of performing high-quality image recording without causing deformation of any components by the moving force of a moving mechanism, in adjusting a space between a recording section and conveying section by contact with space adjustment members.
According to an aspect of the invention, there is provided an image recording apparatus, which comprises a conveying section including a platen which conveys a recording medium, an image recording section which ejects an ink onto the recording medium conveyed by the conveying section, thereby performing image recording, a moving mechanism which moves at least, one of the image recording section and the conveying section to change the space between the image recording section and the conveying section, and enables a movement between a recording position in which the image recording is performed and a non-recording position in which the image recording is not performed, a positioning section which permits the space between the image recording section and the conveying section to have a predetermined value at the recording position,
wherein a point of application of a force with which at least one of the image recording section and the conveying section is moved by the moving mechanism is substantially coincident with the positioning section.
According to another aspect of the invention, there is provided an image recording apparatus, which comprises a conveying section including a platen which conveys a recording medium, an image recording section including a line-type head unit which ejects an ink onto the recording medium conveyed by the conveying section, thereby performing image recording, and a head holding section which holds the head unit, a moving mechanism which moves at least one of the image recording section and the conveying section to change the space between the image recording section and the conveying section, and enables a movement between a recording position in which the image recording is performed and a non-recording position in which the image recording is not performed, a positioning section including (i) a space adjustment member which is provided for one of the head holding section and the platen and adjusts the space between the image recording section and the conveying section, and (ii) an contacting portion which is provided for a remaining one of the head holding section and the platen and
permits the space between the image recording section and the conveying section to have a predetermined value at the recording position, wherein a point of application of a force with which the moving mechanism is operated to cause the contacting portion to contact or be fitted with the space adjustment member is substantially coincident, with a spot where the contacting portion contacts or is fitted with the space adjusting member.
Advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.
Embodiments of the present invention will now be described with reference to the accompanying drawings.
First, one embodiment of the invention will be described with reference to
In the description of the present embodiment to follow, the conveying direction of a recording medium will be referred to as the X-direction; a direction perpendicular to the X-direction, as the Y- or width direction; and a direction perpendicular to the X- and Y-directions, as the Z- or vertical direction.
Roughly speaking, an image recording apparatus 10 is composed of a supply section 12, image recording section 14, conveying section 16, elevating section 16, and receiving section 20.
The supply section 12 includes a paper feed tray 32 that contains recording medium 30, a paper feed roller 34, and an alignment roller pair 36.
The paper feed roller 34, contacts each recording medium 30 in the paper feed tray 32 and delivers the medium 30 one after another. Further, the alignment roller pair 36 corrects a tilt (or skew) of the conveyed recording medium 30 with respect to the X-direction.
The alignment roller pair 36 comprises upper and lower alignment rollers 36a and 36b. Alignment roller 36b is located so that its upper surface is flush with an extension of a conveying path for the recording medium 30. Further, alignment roller 36a is disposed above alignment roller 36b. Alignment roller 36a is urged to press the lower alignment roller 36b downward by a spring (not shown).
The leading end of the recording medium 30 fed by the paper feed roller 34 is brought into contact with a nip portion of the alignment, roller pair 36. The alignment roller pair 36 first corrects the skew of the recording medium 30 with respect to the X-direction. Thereafter, the roller pair 36 conveys the recording medium 30 downstream in time with image recording by the image recording section 14, which will be described below.
The following is a description of the image recording section 14.
In the present embodiment, the image recording section 14 includes, for example, a head unit 42 (42C, 42K, 42M and 42Y) that ejects inks of four colors (cyan [C], black [B], magenta [M], and yellow [Y]), head holding member 44 that holds the head unit 42, and space adjustment members 46 (46a to 46d).
As shown in
In the present embodiment, six recording heads are arranged in the Y-direction to form the head unit 42 that is greater than or equal to the recording medium 30 in width. It should be understood that the number of recording heads is not limited to six and the head unit 42 may be composed of a single elongated recording head.
The head unit 42 (42C to 42Y) ejects inks of the
various colors supplied individually from ink supply systems (not shown) onto the recording medium 30, thereby forming an image. Further, the space adjustment members 46 are disposed on an opposite surface 44a of the head holding member 44 that is opposed to the conveying section 16, which will be described later. More specifically, space adjustment members 46a and 46c are arranged upstream of the opposite surface 44a with respect to the conveying direction, and space adjustment members 46b and 46d are arranged downstream; of the opposite surface 44a with respect to the conveying direction. The space adjustment members 46 and contacting portions (to be described later) jointly constitute positioning sections.
The space adjustment member 46 (46a to 46d) is, for example, a pin that projects toward the conveying section 16. The pin has a length such that it slightly projects from a nozzle surface of each recording head 50. In the present embodiment, the distal end of the space adjustment member 46 projects 1 mm from the nozzle surface of the recording head 50. The amount of projection of the space adjustment member 46 from the nozzle surface of the recording head 50 can be varied by means of a projection adjustment member (not shown),
As shown in
The following is a description of the conveying section 16.
The conveying section 16 is located downstream of the supply section 12 in the conveying direction and opposed to the image recording section 14. The conveying section 16 is composed of suction fans 62, conveyor belt 64, platen 66, driving roller 68, driven roller 70, tension rollers 72a and 72b, and conveyor frame 74.
The conveyor belt 64 is formed of an endless belt having a large number of holes in its surface. The belt 64 is held under tension by the driving roller 68, driven roller 70, and tension rollers 72a and 72b.
The driving roller 63, driven roller 70, and tension rollers 72a and 72b are held for rotation by the conveyor frame 74. A motor 76 is connected to the driving roller 68. The conveyor belt 64 rotates in a predetermined direction as the motor 76 is driven.
Further, the platen 66 is disposed below the conveyor belt 64. The platen 66 is also held by the conveyor frame 74.
The platen 66 is machined so that at least its region opposed to the image recording section 14 is flat and is formed with a large number of holes. As shown in
As shown in
As shown in
Since fixing portions 82b to 82d are constructed in the same manner as fixing portion 82a, their description is omitted.
As shown in
The way of fixing the other end of wire 86a is not limited to this method. For example, the other end of wire 86a may be fixed directly to the conveyor frame 74 provided that the conveying section 16 can be raised and lowered without disengagement.
Further, the suction fans 62 are located below the platen 66 and held by the conveyor frame 74. The fans 62 draw in air through the numerous holes in the conveyor belt 64 and platen 66. Thus, the recording medium 30 conveyed from the alignment roller pair 36 is drawn onto the conveyor belt 64 and conveyed downstream at a predetermined conveying speed.
The following is a description of the elevating section 18.
The elevating section 18 is a moving mechanism for
moving the conveying section 16 between the image recording position and non-recording position. As shown in
As shown in
While only v/ire 86a and space adjustment member 46a are shown in
When the take-up shaft 94 is rotated in a predetermined direction by the motor 90, in the elevating section 18 constructed in this manner, the take-up sections 92 (each including the pulley 96 and torque limiter 98) rotate correspondingly. Thereupon, wires 86a to 86d are simultaneously taken up by the pulleys 96. When this is done, the torque limiters 98 serve to prevent the wires 86 from being excessively tensioned. Thus, the wires 86 are prevented from being broken or elongated by an excessive force when they are taken up by the take-up sections 92.
The following is a description of the receiving section 20.
The receiving section 20 is located downstream of the conveying section 16 in the conveying direction. The receiving section 20 includes a paper exit roller pair 102 and a paper receiving tray 104. The exit roller pair 102 serves to discharge the recording medium 30 having undergone image recording from the conveying section 16. The paper receiving tray 104 serves to stock the image-recorded medium 30.
The following is a description of the operation of the image recording apparatus 10.
First, when the image recording apparatus 10 is switched on, the conveying section 16 is retracted to a non-recording position (or retracted position) shown in
Then, the elevating section 18 is driven when an instruction for image recording is input through a control panel (not shown) of the apparatus 10 or an instruction signal for image recording is input from a host apparatus (not shown) that is connected by a signal line. To be more specific, the motor 90 is driven, and the resulting driving force is transmitted to the take-up shaft 94. As a result, the take-up shaft 94 rotates, and wires 86a to 86a are taken up individually by the take-up sections 92. When this is done, spheres 86a1, 86b1, 86c1 and 86d1 at the other ends of wires 36a to 86d are fixed by fixing portions 82a to 82d of the conveying section 16. Thus, the conveying section 16 is raised toward the image recording section 14.
When the conveying section 16 is raised by the elevating section 18, contacting portions 80a to 80d on the platen 66 of the conveying section 16 abut space adjustment members 46a to 46d, respectively, on the head holding member 44 of the image recording section 14.
Wire 86a passes through the through-hole 52 in space adjustment member 46a. Specifically, the axial direction of space adjustment member 46a is substantially coincident with that of wire 86a. Accordingly, the point of application of a force with which contacting portion 80a abuts space adjustment member 46a can be made substantially coincident with a spot at which adjustment member 46a and contacting portion 80a contact (or abut) each other. Thus, the ability to deform the conveying section 16 (or platen 66) can be reduced by applying a force to raise the conveying section 16 to space adjustment member 46a.
Consequently, the platen 66 can maintain its flatness without being deformed. Further, the space between the image recording section 14 and conveying section 16 can be set to the predetermined value by means of space adjustment members 46a to 46d and contacting portions 80a to 80d.
Thus, the conveying section 16 is located in the recording position shown in
Thereafter, the paper feed roller 34 is driven after the alignment roller pair 36, driven roller 70, and exit roller pair 102 are driven. Thereupon, the top recording medium 30 is picked up from the paper feed tray 32 by the paper feed roller 34. Then, the recording medium 30 reaches the nip portion that is defined by the respective facing parts of alignment rollers 36a and 36b.
When this is done, the rotation of alignment rollers 36a and 36b is temporarily stopped by a resist clutch. Thus, the recording medium 30 conveyed toward the alignment roller pair 36 runs into the nip portion and is arrested thereby, whereupon its conveyed attitude is corrected. In other words, a skew, if any, is corrected.
The inhibition by the resist clutch is removed in a predetermined time, and the alignment roller pair 36 starts to rotate. Thereupon, the recording medium 30 is delivered onto the conveyor belt 64 of the conveying section 16 at a predetermined speed. A sucking force produced by the suction fans 62 acts on the conveyor belt 64 through the numerous holes in the platen 66 and conveyor belt 64.
Therefore, the recording medium 30 delivered onto the conveyor belt 64 by the alignment roller pair 36 is drawn by the sucking force onto the belt 64. As a result, the recording medium 30 on the conveyor belt 64 is conveyed in the X direction at a predetermined conveying speed.
The recording medium 30 passes through an area below each of the head units 42C, 42K, 42M and 42Y. At the time, ink drops are ejected from the head units 42C to 42Y onto the recording medium 30, whereby images are recorded on the medium 30.
The recording medium 30, having the recorded images thereon, is discharged from by the exit roller pair 102 and stored by paper receiving tray 104.
In the present embodiment, as described above, the platen is raised and lowered by means of the wires, which are passed through the space adjustment members for adjusting the space between the head and platen. In this way, the force with which the platen abuts the space adjustment members is applied within a plane on which the platen contacts the adjustment members. According to this arrangement, the force of abutment does not bend the platen, so that the platen cannot be deformed, and therefore, high-quality image recording can be performed.
(First Modification)
Although the head holding member and platen according to the foregoing embodiment are provided with the space adjustment members and contacting portions, respectively, the present invention is not limited to this arrangement. As shown in
(Second Modification)
As shown in
(Third Modification)
In connection with the foregoing embodiment, moreover, the head unit has been described as of a line type. Alternatively, however, the head unit may be of a serial type, as shown in
(Fourth Modification)
Although the wires are used in the elevating section according to the foregoing embodiment, furthermore, the present invention is not limited to this arrangement. For example, ball screws may be used in place of the wires.
In this modification, one end of each ball screw 124 is held for rotation by a space adjustment member 46. Specifically, the axial direction of the space adjustment member 46 is substantially coincident with that of the ball screw 124. Grooves (not shown) for threaded engagement with the screw 124 are formed in a fixing portion 82 and contacting portion 80, individually.
When the ball screw 124 is rotated in a predetermined direction, in this arrangement, the contacting portion 80 and fixing portion 82 in threaded engagement with the screw 124, along with a conveying section 16, ascend or descend.
Also in this arrangement, a force of abutment does not act to bend a platen. Therefore, the platen cannot be deformed, and high-quality image recording can be performed.
In this fourth modification, moreover, the conveying section is raised and lowered with respect to the image recording section. Alternatively, however, only the image recording section or both the image recording section and conveying section may be raised and lowered.
Although the one embodiment of the present invention has been described herein, it should be understood that the invention is not limited to the embodiment, and that various changes or modifications may be effected therein without departing from the scope or spirit of the invention.
Further, the embodiment described above includes inventions in various stages, and various inventions can be extracted from an appropriate combination of a plurality of disclosed constituent elements. For example, some of all the constituent elements described in connection with the embodiment may be eliminated without tailing to solve the problem to be solved by the invention. This arrangement can also be extracted as an invention provided that the effects described herein can be obtained.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
Number | Date | Country | Kind |
---|---|---|---|
2008-187351 | Jul 2008 | JP | national |