JPH09207408A - Image recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image recording apparatus wherein it is unnecessary to adjust a head gap during assembling and to extend uselessly the length of a carrying means in the width direction and it can be achieved to decrease cost and to record an image with high quality. SOLUTION: This image recording apparatus has a constitution with a recording head carrying means (a carriage) 2 which carries a recording head 1 and moves forth and back on a material P for recording, guiding means 3 and 4 for guiding the movement of the head carrying means, and a carrying means 5 (carrying roller) for carrying freely the material P for recording in one direction. In this case, both end parts (a roller shaft) of the carrying means as well as the guiding means 3 and 4 can be supported at the inside of the moving range 11c of the head carrying means 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus suitable for an inkjet recording system.

[0002]

2. Description of the Related Art An image recording apparatus records information such as characters and images on a recording material (hereinafter referred to as a recording sheet) such as paper, cloth and plastic. Among such image recording apparatuses, a low-noise non-impact recording method, which uses an ink jet recording method in which ink is ejected from an ink ejection port of a recording head to perform recording on a recording sheet, has high density and high speed recording. Therefore, it has been widely used in printers, copying machines, facsimiles, word processors and the like.

Particularly, in an image recording apparatus using such an ink jet recording system, in order to form a high quality recording image on a recording sheet, an ink flying distance from an ink ejection port (formation) surface of the recording head to the recording sheet (hereinafter , Head gap) must always be kept at a predetermined value within the optimum range. If the head gap is smaller than the predetermined value, the ink ejection port surface comes into contact with the recording sheet, which may disturb or stain the image, possibly impairing the recording function. Further, if the head gap is larger than the predetermined value, the accuracy with which ink is deposited on the recording sheet decreases, and the recording quality may deteriorate.

In order to solve the above-mentioned problems, it is generally necessary to make an adjustment at the time of assembly so as to keep the head gap at the predetermined value. If an adjusting mechanism is provided, the number of parts will increase and the cost will increase. , Leads to a decrease in reliability. Further, in order to carry out adjustment at the time of assembly, it is necessary to incorporate the steps of measuring, adjusting, and confirming the head gap in the assembly work, which causes a cost increase in terms of workability.

Therefore, in Japanese Patent Application No. 7-31260, a guide shaft and a guide rail for guiding scanning of a carriage equipped with a recording head are provided in order to obtain a predetermined head gap regardless of adjustment during assembly. There is disclosed a configuration in which a recording sheet is held at a recording position, and the conveying rollers involved in the sheet feeding / conveying are respectively positioned at predetermined positioning portions on the left and right side plates of the same frame. FIG. 6 shows an outline of the configuration.

In FIG. 6, 101 is an ink jet recording head, 101A is an ink ejection port surface thereof, and 102 is a carriage on which the recording head 101 is mounted and which reciprocates along a guide shaft 103 and a guide rail 104 arranged in parallel with each other. The carriage 102 reciprocates in the A direction via a timing belt or the like by a carriage drive motor (not shown). In the meantime, ink is ejected toward the recording sheet P from an ink ejection port (not shown) provided on the ink ejection port surface 101A, and image recording is performed on the recording sheet P. Reference numeral 105 denotes a roller for holding the recording sheet P at the recording position and for feeding and conveying the recording sheet P, 106, a roller gear coaxial with the roller 105, and 107, a motor gear which is driven by a drive motor 108 and meshes with the roller gear 106. .

Further, H _P is the maximum width of the recording sheet P can be used by the image recording apparatus, H _C the moving range of the carriage 2, H _G and the ink discharge port surface 101A recording sheet P
Is a predetermined head gap value to be maintained between the upper surface of the head and the upper surface of the head. The recording sheet P is sandwiched between the conveyance roller 105 and the conveyance roller 105 by a pressure contact roller (not shown) that is in pressure contact with the conveyance roller 105 so that the above head gap value H _C is maintained. Reference numeral 109 is a frame that holds the main part of the image recording apparatus, and 109A and 109B are side plates that rise from both sides of the frame 109.
03, the guide rail 104, and the conveyance roller 105 have frame side plates 109A and 1
By accurately supporting the positioning shaft on a predetermined support portion of 09B, no matter where the carriage 102 is in the carriage movement range H _C , there is a gap between the ink ejection port surface 101A of the head and the upper surface of the recording sheet P. The predetermined head gap value H _G is maintained. Therefore, it is not necessary to adjust the head gap for each device.

[0008]

However, in the conventional example as shown in FIG. 6, the guide shaft 103, the guide rail 104 and the conveying roller 105 are all supported by the left and right frame side plates 109A and 109B. , These must be made to have almost the same length, and the functionally required lengths for this are,
Sheet maximum width H _P when the transport roller 105, and for the guide shaft 103 and guide rail 104 may, if only corresponding to the carriage moving range H _C. Therefore, in the case of a relatively small image recording apparatus in which the width of the carriage 102 in the operation direction is relatively small and the maximum recording sheet width used is, for example, A4 vertical size (210 mm), the carriage movement range H _C and recording sheet The difference from the maximum width H _P is not so problematic and is suitable, but it is not always suitable in the case of a color image recording apparatus or the like.

This is because in a color image recording apparatus or the like in which a plurality of recording heads are mounted on the carriage in the moving direction for ejecting a plurality of inks, the moving range H _C of the carriage itself becomes large. However, the above difference also becomes large, and the cost of the transport roller is unnecessarily increased due to the lengthening of the transport roller. In particular, in the case of a large apparatus in which the maximum width of a recordable recording sheet is, for example, A3 vertical size (397 mm) or A3 horizontal size (420 mm), the length of the transport roller is further lengthened to prevent the bending of the thick shaft. Diameter is required, which causes an increase in cost.

The object of the present invention is to focus on these problems,
In order to solve the problem, regardless of the model, the head gap can be maintained at a predetermined value without adjustment, and unnecessary extension of the transport roller is not required, resulting in cost reduction and high-quality image recording. An object is to provide an image recording apparatus that can contribute to both achievement.

[0011]

In order to achieve the above object, the present invention comprises a recording head for recording an image on a recording material, a recording head mounted on the recording head, and reciprocating on the recording material. Recording head mounting means, guide means for guiding the recording head mounting means in a reciprocating manner, and a head gap between the recording head and the recording head are kept at a predetermined value, and the recording material intersects the moving direction of the guiding means. In the image recording apparatus having a conveying unit that can be conveyed in the direction, the both ends of the conveying unit are supported together with the guiding unit inside the moving range of the recording head mounting unit.

According to the present invention, the recording material is supported inside the moving range of the head mounting means at both ends of the conveying means which is capable of transporting the recording material in the direction intersecting with the moving direction of the guide means of the head mounting means. By similarly supporting the head mounting means in a form that does not hinder the movement of the head mounting means, it is not necessary to extend the span of the conveying means for keeping the recording material freely conveyable beyond the width of the recordable recording material. It contributes to weight reduction and cost reduction of the device. Further, the both ends are supported by the same support wall provided inside the moving range of the head mounting means of the support member integrally formed with the guide member, so that the head gap is set to a predetermined value without adjustment during assembly. can do. [Detailed Description of the Invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 and 2 show a first embodiment of the present invention. In the following examples, an image recording apparatus capable of color recording by an inkjet method will be described as a preferred example of the present invention. In FIGS. 1 and 2, reference numeral 1 denotes a head portion 1Bk for ejecting black (Bk) ink, a head portion 1C for ejecting cyan (C) ink,
Reference numeral 2 denotes a color recording head in which a head portion 1M for ejecting magenta (M) ink and a head portion 1Y for ejecting yellow (Y) ink are arranged in the scanning direction. Reference numeral 2 denotes the color recording head 1 mounted in the X direction. It is a carriage that moves back and forth. Further, 3 and 4 are guide shafts and guide rails for guiding the reciprocating movement of the carriage 2, and 5 is a conveyance roller involved in the conveyance of the recording sheet P.

[0015] Note Here, the conveying roller 5 as shown in FIG. 1, the maximum width H _P of the recording sheet P can be used in the apparatus
While it is required to have a length for holding the, H _C is necessary as the movement range of the carriage 2 to perform color recording on the recording sheet P such maximum width H _P. Therefore, the lengths of the guide shaft 3 and the guide rail 4 must extend further than both ends of the transport roller 5, as shown in FIG. Therefore, in this embodiment, the transport roller 5, the guide shaft 3 and the guide rail 4 are properly individually supported according to their lengths, and these supporting portions are integrally configured, and as a result, recording is performed in the assembled state. The ink ejection port surface 1A of the head 1 and the recording sheet P
The head gap H _G
Can be maintained.

That is, 11 and 12 are support base members each having a substantially U-shaped cross section as shown in FIG. 1, and 13 is a connecting member integrally combining these support base members 11 and 12. , 14 are grounding portions for mounting the entire apparatus on the grounding surface 15 via the coupling member 13.
The support base members 11 and 12 and the side plate portions 11A and 12A that pivotally support the conveying roller 5 at the facing position and the conveying roller 5 are provided.
It has side plate portions 11B and 12B capable of further supporting the both ends of the guide shaft 3 extending further. 6 is a conveyor roller pulley coaxial with the conveyor roller 5 axially supported by the side plate portion 11A, 7 is a motor pulley coaxial with the drive motor 8, and 9 is a timing belt stretched between the pulleys 6 and 7.

Here, the bearing portion 11C of the side plate portion 11A and the bearing portion 12C of the side plate portion 12A, which respectively support the roller shafts 5A at both ends of the conveying roller 5, are joined together by a coupling member 13.
Are provided at the same height from the upper surface of the. The guide rail 4 is fixed to the tops of the side plate portions 11A and 12A with screws 16, and the heights from the upper surface of the coupling member 13 to the tops of the side plate portions 11A and 12A are also matched. Furthermore, both ends of the guide shaft 3 are axially supported by the tops of the side plate portions 11B and 12B as shown in FIG. 2, and are biased toward the axial support portion by the spring force of the biasing member such as the spring 17 (see FIG. 1). However, here again the side plate 1
The heights of 1B and 12B from the upper surface of the coupling member 13 are matched. Thus, when the carriage 2 is movably supported by the guide shaft 3 and the guide rail 4, a predetermined head gap H _{G is formed} between the ink ejection port surface 1A of the recording head 1 and the recording sheet P held by the conveying roller 5.
So that the above-mentioned side plate portions 11A, 11B, 12A,
The support position in 12B is preset.

Next, with reference to FIG. 2, the details of the support state of the carriage 2 on the support base members 11 and 12 and the support state of the transport roller 5 on the support base members 11 and 12 will be supplemented. In FIG. 2, reference numeral 2A denotes a shaft receiving portion that is in sliding contact with the guide shaft 3 of the carriage 2.
B is a roller shaft protruding from the carriage 2 and 2C is a roller shaft 2.
A roller that is rotatably supported by B and rolls on the guide rail 4. Further, 5B is a driven roller which is biased from above toward the conveying roller 75 by the spring force of the spring 5C, holds the recording sheet P between the conveying roller 5 and the driven roller 5B, and forms an upper surface of the recording sheet P. A predetermined head gap H _G is maintained between the recording head and the ink ejection surface 1A, and the recording sheet P is fed in the direction of arrow Y for each recording by one scan of the recording head 1. After the recording is completed, the recording sheet P is conveyed in the same direction so as to be discharged. Here, in order to prevent the recorded ink from being transferred to the driven roller side on the driven roller 5B that is in contact with the transport roller 5 on the downstream side in the Y direction, a driven spur is generally used.

According to this embodiment, the guide shaft 3 and the guide rails 4 involved in the reciprocal movement of the carriage 2 and the recording roller P for holding the recording sheet P at the recording position and the conveying roller 5 for conveying the recording sheet P are integrally supported. Side plate portions 11A and 12A of the base members 11 and 12 and the side plate portion 11
B and 12B are supported by a supporting portion whose height position is accurately set, so that the conveying roller 5 does not extend more than necessary, and the head gap has a required dimension (H _G ) after assembling. Can be kept unadjusted (including tolerance). Further, by providing the ground portion 14 in accordance with the side plate portions 11A and 12A of the support base members 11 and 12 integrated by the joining member 13, the support base 11 due to its own weight when the image recording apparatus is placed on a desk or the like. , 1
It is possible to suppress the displacement between the two and the coupling member 13.

FIG. 3 shows the configuration according to the second embodiment of the present invention. In this embodiment, the arrangement of the conveying roller 5, the driven roller 5B and the spring 5C is opposite to that of the first embodiment shown in FIGS. It should be noted that although the roller shaft 5A of the transport roller 5 is axially supported by the bearing portions 11C and 12C provided on the side plate portions 11A and 12A of the support base members 11 and 12, respectively, the basics are the same as in the first embodiment, but According to the embodiment, even when the conveying roller 5 is in contact with the upper surface of the recording sheet P, a change in the thickness of the recording sheet P such as a postcard or an envelope having a different thickness is absorbed by the fine displacement of the driven roller 5B. By doing so, the head gap H _G is not affected by the change in the sheet thickness.

4 and 5 show a third embodiment of the present invention. In the first embodiment, both end portions of the guide shaft 3 are provided with side plate portions 11B, 1 located outside the support base members 11, 12.
2B is configured so as to be positioned, supported and fixed to the shaft support portion at the upper end. This embodiment is different from the above-mentioned first embodiment in that the guide shaft 5 is supported and fixed to the side plate portions 11A and 12A located inside the support base members 11 and 12. As shown in FIG. 5, the shaft receiving portion 2A supported by the guide shaft 3 of the carriage 2 is open at the lower portion thereof as in FIGS. Therefore, in this embodiment,
As shown in FIG. 4, shaft fixing flanges 11D and 12D are provided so as to protrude from the side plate portions 11A and 12A along the lower surface of the guide shaft 3 so as not to hinder the movement of the carriage 2. Screws 19 are formed on these flanges 11D and 12D.
The guide shaft 3 is fixed by.

According to this embodiment, the support base member 11,
Will be 12 to each other are coupled by the coupling member 13 and the guide rail 4 and the guide shaft 3 is prevented occurrence of deformation and displacement between each other, more across the sheet maximum width H _P held by the conveying roller 5 It can contribute to surely maintaining a predetermined head gap H _G.

Although the supporting base members 11 and 12 are integrally connected by the connecting member 13 in the above-described embodiments, each supporting base member has two parallel side plate portions from the beginning of assembly of the apparatus. The base members 11 and 12 may be integrally formed.

In addition, the guide rail 4 and the guide shaft 3
Is fixed to the side plate portions 11A and 12A of the support base members 11 and 12 with the screws 16 and 17, but the member for fixing is not limited to the screw or the like, and, for example, a fastening Of course, any fixing method may be used as long as the guide rail 4 and the guide shaft 3 are reliably positioned and fixed to the side plate portions 11A and 12A, for example, by crimping with a spring.

Further, in the above-mentioned embodiment, although it was not described in detail how to support the extending free end portion of the guide rail, it is extended from the side plate portions 11A and 12A of the guide rail 4 to the outside. When the portions are particularly long, these extending free ends may be further supported by the outer side plate portions 11B and 12B.

(Others) The present invention is particularly provided with a means (for example, an electrothermal converter or a laser beam) for generating heat energy as energy used for ejecting ink, even in the ink jet recording system. The present invention brings about excellent effects in a recording head and a recording apparatus of the type in which the state of ink is changed by the heat energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. 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 drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As for the structure of the recording head, US Pat. No. 4,558,333, US Pat. The structure using the specification of 4459600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters.
The effect of the present invention is effective even if it is based on Japanese Patent Laid-Open No. 59-138461, which discloses a structure in which an opening for absorbing a pressure wave of heat energy is made to correspond to a discharge portion.
That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

In addition, even in the case of the serial type as in the above example, a replaceable chip type recording head capable of supplying ink from the apparatus main body or the recording head itself is provided with an ink tank integrally. The present invention is also effective when a cartridge type recording head is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add ejection recovery means of the recording head, preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are provided. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change from the solid state of the ink to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying heat energy such as ink that is liquefied by applying heat energy according to the recording signal and liquid ink is ejected or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. 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, as a form of the ink jet recording apparatus of the present invention, other than the one used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function are provided. It may be a form or the like.

[0034]

As described above, according to the present invention, a recording head for recording an image on a recording material, a recording head mounting the recording head, and reciprocating on the recording material. Means, a guide means for guiding the recording head mounting means in a reciprocating manner, and a head gap between the recording head and the recording head, while maintaining the head gap at a predetermined value, the recording material in a direction intersecting the moving direction of the guide means. In an image recording apparatus having a transporting means capable of transporting, since both end portions of the transporting means are supported together with the guiding means inside the moving range of the recording head mounting means, the head gap can be provided without providing an adjusting means. Not only can be maintained accurately from the beginning to a predetermined value, at least within an allowable range, but multiple recording heads that require a wide width especially in the carriage movement direction can be used. Even in those mounting do not have to extend the span of unnecessarily conveying roller, it is possible to provide an image recording apparatus that can contribute to cost reduction compact.

[Brief description of drawings]

FIG. 1 is a side view showing an outline of a configuration according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a cross section of the configuration of the first embodiment shown in FIG.

FIG. 3 is an explanatory diagram showing a cross section of a structure according to a second embodiment of the present invention.

FIG. 4 is a side view showing the outline of the configuration according to the third embodiment of the present invention.

5 is an explanatory diagram showing a cross section of the configuration of the first embodiment shown in FIG. 4. FIG.

FIG. 6 is a side view showing an outline of a configuration according to a conventional example.

[Explanation of symbols]

1 (color) recording head 1Bk, 1C, 1M, 1Y head section 1A ink ejection surface 2 carriage 2A shaft receiving section 2B roller shaft 2C roller 3 guide shaft 4 guide rail 5 transport roller 5A roller shaft 5B driven roller 5C spring 8 drive motors 11 and 12 supporting the base member 11A, 11B, 12A, 12B side plate portions 11C, 12C bearing portion 13 coupling member 16, 19 bis 17 spring H _C carriage moving range H _P recording sheet maximum width H _G head gap P a recording material ( Recording sheet)

Claims (13)

[Claims] 1. A recording head for recording an image on a recording material, a recording head mounting means for mounting the recording head, and reciprocatingly moving on the recording material, and a reciprocating movement of the recording head mounting means. An image recording apparatus having guide means for guiding and a conveying means capable of conveying the recording material in a direction intersecting a moving direction of the guide means while maintaining a head gap between the recording head and the recording head at a predetermined value, An image recording apparatus, wherein both ends of the conveying means are supported together with the guiding means inside a moving range of the recording head mounting means. 2. The image recording apparatus according to claim 1, wherein both ends of the conveying unit are supported together with the guiding unit on the same supporting wall of a supporting member formed integrally. 3. The image recording apparatus according to claim 1, wherein the supporting member is supported on the mounting surface via a grounding member provided below the same supporting wall. 4. The image recording apparatus according to claim 1, wherein the guide unit is a guide shaft and / or a guide rail. 5. The image recording apparatus according to claim 1, wherein the conveying unit is a plurality of conveying rollers that are rotationally driven by a drive motor. 6. The recording material according to claim 5, wherein the recording material is sandwiched between the transport roller and a driven rolling element which is biased toward the transport roller and driven by the transport roller. The image recording apparatus described. 7. The image recording apparatus according to claim 6, wherein the driven rolling element is biased toward a recording surface of the recording material. 8. The image recording apparatus according to claim 6, wherein the driven rolling element is biased toward a non-recording surface of the recording material. 9. The image recording apparatus according to claim 1, wherein the guide unit is supported on the top of the support wall. 10. The image recording apparatus according to claim 9, wherein each of the guiding means is fixedly supported. 11. The ink jet recording head according to claim 1, wherein the recording head ejects ink onto the recording material to record an image.
The image recording apparatus described in any one of 1. 12. The recording head according to claim 11, wherein the recording head has an electrothermal converter that generates thermal energy that causes film boiling in the ink, as an element that generates energy for ejecting the ink. Image recording device. 13. The image recording apparatus according to claim 12, wherein the recording head includes a plurality of heads that eject different kinds of ink.