JP3009787B2 - Recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device (printer) as an information output device such as a computer, and an image forming device such as a copying machine and a facsimile, for example. Related to a recording device.

[0002]

2. Description of the Related Art Conventionally, a so-called serial type recording apparatus which performs recording by scanning a recording means and a recording medium in a main scanning direction and a sub-scanning direction, respectively, has a configuration as shown in FIGS. ing. FIG. 6 is a cross-sectional view of the printing apparatus viewed from the main scanning direction, and FIG. 7 is a top view illustrating a main part of a main scanning unit of the printing apparatus illustrated in FIG.

As shown in FIGS. 6 and 7, a recording head 1 performs recording by discharging ink onto a recording medium. The recording head 1 is mounted on a carriage 2. The columnar carriage shaft 3 supports the carriage 2 via a carriage bearing (not shown) described later. , Reference numeral 28 denotes a carriage driving motor, and the driving force of the carriage driving motor 28
The carriage 2 is transmitted to the carriage 2 by a carriage belt 27 connected to the
Are scanned along. Reference numeral 29 denotes the carriage belt 27
This is a pulley that gives a proper tension to the pulley. The recording head 1 is moved in the main scanning direction by driving the carriage 2 to move in the main scanning direction along the carriage axis 3. The ink tank 4 stores ink ejected by the recording head 1, and the ink in the ink tank 4 is supplied to the recording head 1 via an ink pipe 5. Reference numeral 6 denotes a transport roller that holds the recording medium and transports the recording medium in the sub-scanning direction, and reference numeral 7 denotes a first driven roller that generates a transport force by pressing the recording medium against the transport roller 6.
The first driven roller 7 is supported by a first holding member 13. The recorded recording medium is discharged from a recording position by a discharge roller 8. Reference numeral 9 denotes a second driven roller that generates a conveying force by pressing the recording medium against the paper discharge roller 8, and the second driven roller 9 is a second holding member 15.
It is supported by. Reference numeral 10 denotes a position where printing is performed on a recording medium by the recording head 1 (printing unit: sheet processing unit).
The recording head 1 is opposed to the surface of the paper guide 10 with a small gap, and moves in the main scanning direction along the surface of the paper guide 10. A reference numeral 11 is provided upstream from the pressure contact point of the transport roller 6 and the first driven roller 7 in the recording medium transport direction.
A recording medium sensor lever 11 for detecting the leading end and the rear end of the recording medium.
This is a photosensor that converts the operation of FIG.

The first spring 14 urges the first holding member 13 to press the first driven roller 7 against the conveying roller 6, and the second spring 16 urges the second holding member 15. Then, the second driven roller 9 is pressed against the transport roller 8. Reference numeral 17 denotes a half-moon-shaped paper feed roller that picks up a recording medium on the pressure plate 21 as a paper feed stacker during a paper feed operation. The paper feed roller 17 has a paper feed roller shaft 25. Sign 1
Reference numeral 8 denotes a sheet feeding roller 1 provided coaxially with the sheet feeding roller 17.
It is an idle roller having a diameter smaller than the diameter of 7. At the time of paper feeding, the friction piece 19 is pressed against the paper feeding roller 17 by the third spring 20, reference numeral 21 is a pressure plate for stacking the recording medium 22 to be printed, and reference numeral 23 is to stack the recording medium after printing is completed. Reference numeral 24 denotes a pressure plate spring for pressing the pressure plate 21 against the paper feed roller 17 during paper feeding.

FIG. 8 is a view showing the carriage 2, the carriage shaft 3 and the like as viewed from the direction of arrow A in FIG. As shown in FIG. 6, FIG. 7 and FIG.
Is mounted on the carriage 2 having a cylindrical shape.
The two carriage bearings 2 a are held through a carriage shaft 3. When printing is started by receiving a print signal from the host computer or the like, the recording medium 22 is picked up by the paper feed roller 17, and the recording medium 22 is set on the paper guide 10 at the recording position by the transport roller 6 or the like. You. Thereafter, the carriage drive motor 28 is driven to move the carriage 2 on the carriage shaft 3 in the main scanning direction. At this time, the recording head 1 performs recording on the recording medium 22.

[0006]

However, in the above-mentioned conventional recording apparatus, since the carriage shaft 3 passes through the carriage bearing 2a formed in the cylindrical shape of the carriage 2, the play shown in FIG. like,
There is a problem that the position of the carriage shaft 3 is not fixed with respect to the carriage bearing 2a. This means that it is difficult to form the carriage bearing in a perfect circle when the carriage is made of resin, and the play tends to increase. Therefore, as shown in FIG. 10 (a view as seen from the direction of arrow B in FIG. 6), a repulsive force against bending of the cable 30 connected to the carriage 2 to send an electric signal to the recording head 1 (see FIG. 8). And the pulling force of the carriage belt 27 (see FIG. 8) with respect to the carriage 2, the carriage 2 is inclined, and the nozzle straight line 1a of the recording head 1 is not perpendicular to the carriage axis 3a.
As a result, as shown in FIG. 11, for example, a straight line formed by one main scan and the next main scan is not smoothly connected, and a single vertical ruled line cannot be formed. When the carriage 2 has a plurality of recording heads, the straight line 2b connecting the recording head mounting surface of the carriage 2 is not parallel to the carriage axis 3a. As a result, for example, as shown in FIG. There has been a problem that a desired dot is shifted. In particular, in the case of color recording, this effect is serious, causing misregistration of colors, and causing white stripes in the connection of each color, which has been a factor of deteriorating the image quality. This becomes a bigger problem as the resolution of the recording apparatus increases as in today.

Further, not only in terms of functions but also in terms of assemblability, it is complicated to fix and assemble the carriage shaft 3 after assembling from one end of the long carriage shaft 3 through the carriage bearing 2a of the carriage 2. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a recording apparatus which can obtain a good recording result and has good assemblability between a carriage and a carriage shaft.

[0009]

According to the present invention, there is provided a carriage mounted with a recording head for forming an image on a recording medium scanned in a sub-scanning direction and scanning in a main scanning direction. In a recording apparatus having a columnar carriage guide shaft serving as a guide when the carriage slides in the main scanning direction, the carriage is slidably contacted with the peripheral surface of the carriage guide shaft. The carriage guide shaft having a plurality of portions and the carriage guide shaft cooperating with the two portions of the carriage bearing while slidably contacting the peripheral surface of the carriage guide shaft at one position. A holding member; and an elastic member that elastically urges the carriage guide shaft toward the two portions by elastically urging the member toward the peripheral surface of the carriage guide shaft. , The carriage guide shaft, by contact with the member and the carriage bearing, is characterized in that is slidably supported at three points on the axial section circumference.

Further, the carriage bearing is effective when the carriage has a substantially U-shaped shaft cross section which is detachable from the carriage shaft in the axial direction of the carriage shaft and in a direction orthogonal to the axial direction. .

The recording head may be an ink jet recording head that forms an image by discharging ink from a discharge port.

Further, the recording head may discharge ink using thermal energy, and may include an electrothermal converter for generating the thermal energy.

[0013]

In the invention constructed as described above, the member is urged to the carriage shaft by the elastic member,
Since the carriage shaft is pressed and held against the surface of the carriage bearing, the positional relationship between the carriage bearing and the carriage shaft is not determined as in the conventional example. Further, since the carriage bearing does not need to be formed in a perfect circle, and only the dimensions of the surface of the carriage bearing that the carriage shaft contacts, it is possible to easily manage the accuracy even in molding resin or the like. As described above, since the relationship between the mounting seat surface of the recording head and the axis of the carriage shaft is determined, the main scanning can be performed with high accuracy without occurrence of ruled line shift and color shift unlike the related art.

Further, by making the carriage bearing a substantially U-shaped open type, the carriage can be attached to and detached from the carriage axis in a direction perpendicular to the axis of the carriage axis.
It is possible to solve the problem of poor assemblability that the carriage can be attached and detached only from the conventional direction of the carriage shaft, and to achieve assembly and service with high working efficiency.

[0015]

Next, embodiments of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a top view showing a carriage and a recording head according to a first embodiment of the recording apparatus of the present invention.
FIG. 3 is a sectional view taken along line CC of FIG.

As shown in FIG. 1, similarly to the conventional example, four recording heads 1X are mounted on the carriage 2X, and the recording heads 1X are provided in rows as shown in FIG. In order to discharge the recording liquid from the plurality of discharge ports 4Y, an electrothermal converter 4X for generating thermal energy to which an applied voltage is supplied is provided for each liquid path. Then, by applying a drive signal, heat energy is generated in the electrothermal transducer 4X, thereby causing film boiling and forming bubbles in the ink liquid path. Then, an ink droplet is ejected from the ejection port 4Y by the growth of the bubble.

As shown in FIGS. 1 and 3 again, reference numeral 3
1X indicates a leaf spring as an elastic member, and the leaf spring 31X is attached to the carriage 2X with two screws 33X. Reference numeral 32X is a member to be described later such as a resin attached to the leaf spring 31X. 2 of carriage 2X
The two carriage bearings 2aX are substantially U-shaped as shown in FIG.
These two carriage bearings 2
aX, leaf spring 31X screwed to carriage 2X
The carriage 2X is attached to the carriage shaft 3X such that the carriage 2X is sandwiched between two members 32X attached to one end of the carriage shaft 3X. And two members 3
Since the 2X is urged against the carriage shaft 3X by the leaf spring 31X, the carriage shaft 3X is pressed and held against two substantially V-shaped surfaces of the two carriage bearings 2aX. The contact point between the carriage bearing 2aX and the carriage shaft 3X is at two points on the circumference of the shaft section, and the contact point between the member 32X and the carriage shaft 3X is at one point on the circumference of the shaft section.
Is a point. Therefore, as in the conventional example, the carriage bearing 2
The positional relationship between aX and the carriage shaft 3X will not be determined. Further, since the carriage bearing 2aX is not cylindrical, it is not necessary to form the carriage bearing 2a in a perfect circle, and only the dimensions of the V-shaped surface of the carriage bearing with which the carriage shaft 3X abuts need to be controlled. Can be managed. As described above, since the relationship between the nozzle straight line of the recording head, the mounting seat surface of the recording head, and the carriage axis is determined, it is possible to perform high-precision main scanning in which ruled line deviation and color deviation do not occur. Also,
Since the carriage bearing 2aX is an open type, as shown in FIG.
The V-shaped surface of X is exposed, and the carriage 2X can be attached to and detached from the carriage shaft 3X in a direction perpendicular to the axis of the carriage shaft 3X, and the carriage 2X can be attached and detached only from the conventional axis direction of the carriage shaft 3X. Badness is eliminated, and assembling and service with high work efficiency can be performed. (Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
This is an example in which the concept of the present invention is applied to a conventional carriage bearing 2aY and carriage shaft 3Y. The member 32Y is held so as to hit the carriage shaft 3Y at two points, and the carriage shaft 3Y is in contact with one point of the carriage bearing 2aY. The carriage shaft 3Y is 1 in the carriage bearing 2aY.
Since the contact is made only at the points, it is not necessary to form the carriage bearing in a perfect circle as in the related art, and the carriage can be easily formed. Thus, the same effect as in the first embodiment can be obtained in terms of printing accuracy.

If the carriage bearing is formed in a U-shape instead of a cylinder, it is needless to say that the same effect as in the first embodiment can be obtained in terms of assemblability.

The present invention provides an excellent effect in an ink jet recording head and a recording apparatus in which a flying droplet is formed by utilizing thermal energy among the ink jet recording methods and recording is performed.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling to an electrothermal transducer arranged corresponding to the sheet or liquid path in which This is effective because heat energy is generated in the electrothermal transducer, causing film boiling on the heat-acting surface of the recording head, and as a result, air bubbles in the liquid (ink) corresponding one-to-one to this drive signal can be formed. It is. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

As the pulse-shaped driving signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angle liquid flow path) as disclosed in the above-mentioned respective specifications, The present invention also includes a configuration using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which a heat acting portion is arranged in a bending region.

In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and absorbs pressure waves of thermal energy. The present invention is also effective as a configuration based on JP-A-59-138461, which discloses a configuration in which an opening corresponds to a discharge unit.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is determined by combining a plurality of recording heads as disclosed in the above-mentioned specification. The present invention can exhibit the above-mentioned effects more effectively, though it may be either a configuration that satisfies the above requirements or a configuration as a single recording head that is formed integrally.

In addition, the print head is exchangeable with a print head of a chip type, which is electrically connected to the main body of the apparatus and can supply ink from the main body of the apparatus, or is integrated with the print head itself. The present invention is also effective when a cartridge type recording head provided with an ink tank is used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like provided as components of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. If you list these specifically,
Capping means, cleaning means, pressurizing or suction means for the printhead, preheating means using an electrothermal transducer or another heating element or a combination thereof, and a preliminary ejection mode for performing ejection other than recording Is also effective for performing stable recording.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, and the recording head may be formed integrally or by combining a plurality of recording heads. The present invention is also extremely effective for an apparatus provided with at least one of full colors by color mixture.

In the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or below and which softens at room temperature, or which is liquid, In general, in the ink jet method, the temperature of the ink itself is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. What is necessary is just to be liquid.

In addition, the temperature rise due to thermal energy can be positively prevented by using it as energy for changing the state of the ink from a solid state to a liquid state, or solidified in a standing state for the purpose of preventing evaporation of the ink. Either ink may be used, or in any case, the ink may be liquefied by application of heat energy according to the recording signal and ejected as a liquid ink, or may already start to solidify when reaching the recording medium. The use of an ink having a property of being liquefied for the first time by thermal energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or Japanese Patent Application Laid-Open No. 60-71260, in which the porous sheet is opposed to the electrothermal converter while being held in a liquid or solid state in the concave portions or through holes of the porous sheet. It may be. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition to the above, the recording apparatus according to the present invention may be provided as an image output terminal of an information processing apparatus such as a word processor or a computer as an integrated or separate image output terminal, a copying apparatus combined with a reader, and the like. May take the form of a facsimile machine having a transmission / reception function.

[0031]

As described above, according to the present invention,
Since the positional relationship between the carriage bearing and the carriage shaft is determined, the relationship between the mounting seat surface of the recording head and the axis of the carriage shaft is also determined, and the main scanning with high accuracy without the occurrence of ruled line deviation and color deviation as in the conventional case is achieved. It is possible and good recording results can be obtained. Further, since the carriage bearing does not need to be formed in a perfect circle, and only the dimensions of the surface of the carriage bearing that the carriage shaft contacts, it is possible to easily manage the accuracy even in molding resin or the like. Further, in addition to the above effects, the carriage bearing has a substantially U-shape in which the carriage can be attached to and detached from the carriage shaft in the axial direction of the carriage shaft and in a direction orthogonal to the axial direction. It is possible to provide a recording device having good assemblability.

[Brief description of the drawings]

FIG. 1 is a top view illustrating a carriage and a recording head according to a first embodiment of the recording apparatus of the present invention.

FIG. 2 is a schematic perspective view of the recording head shown in FIG.

FIG. 3 is a cross-sectional view showing a characteristic portion of FIG. 1;

FIG. 4 is a sectional view when the carriage is attached to a carriage shaft in FIG. 3;

FIG. 5 is a sectional view similar to FIG. 3, showing a second embodiment of the recording apparatus of the present invention.

FIG. 6 is a cross-sectional view of a conventional recording apparatus viewed from a main scanning direction.

7 is a top view illustrating a main part of a main scanning unit of the printing apparatus illustrated in FIG.

8 is a diagram illustrating the carriage 2, the carriage shaft 3, and the like as viewed from the direction of arrow A in FIG.

FIG. 9 is a sectional view of a main part of FIG.

FIG. 10 is a view as seen from the direction of arrow B in FIG. 6;

FIG. 11 is a diagram illustrating a result of printing a ruled line by a conventional recording apparatus.

FIG. 12 is a diagram showing a dot printing result by a conventional recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head 1a Nozzle straight line 2 Carriage 2a Carriage bearing 2b Straight line 3 Carriage shaft 3a Carriage axis 4 Ink tank 5 Ink pipe 6 Conveyance roller 7 First driven roller 8 Discharge roller 9 Second driven roller 10 Paper guide 11 Recording Medium sensor lever 12 Photo sensor 13 First holding member 14 First spring 15 Second holding member 16 Second spring 17 Paper feed roller 18 Idle roller 19 Friction piece 20 Third spring 21 Pressure plate 22 Recording medium 23 Discharge stacker 24 Pressure plate spring 25 Feed roller shaft 27 Carriage belt 28 Carriage drive motor 29 Pulley 30 Cable 1X Recording head 2X Carriage 2aX, 2aY Carriage bearing 3X, 3Y Carriage shaft 4X Electrothermal transducer 4Y Discharge port 31X, 31 Leaf springs 32X, 32Y member 33X bis

────────────────────────────────────────────────── ─── Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B41J 19/20 B41J 2/01

Claims (4)

(57) [Claims] 1. A carriage that carries a recording head that forms an image on a recording medium that is scanned in a sub-scanning direction and scans in a main scanning direction, and serves as a guide when the carriage slides in the main scanning direction. In a recording apparatus including a columnar carriage guide shaft, the carriage includes a carriage bearing having two portions that are slidably contacted with a peripheral surface of the carriage guide shaft; A member that sandwiches the carriage guide shaft in cooperation with the two portions of the carriage bearing while slidably contacting the peripheral surface at one position; and moving the member to the peripheral surface of the carriage guide shaft. An elastic member that elastically urges the carriage guide shaft in the direction of the two portions by elastically urging the carriage guide shaft. A recording apparatus characterized in that the recording apparatus is slidably supported at three points on the circumference of a shaft cross section by contact between a bearing and the member. 2. The carriage bearing according to claim 1, wherein the carriage has a shaft section substantially U detachable from the carriage shaft in an axial direction of the carriage shaft and a direction orthogonal to the axial direction.
2. The recording apparatus according to claim 1, wherein the recording apparatus has a character shape. 3. The recording apparatus according to claim 1, wherein the recording head is an inkjet recording head that forms an image by discharging ink from a discharge port. 4. The recording apparatus according to claim 3, wherein said recording head ejects ink using thermal energy, and includes an electrothermal converter for generating said thermal energy. apparatus.