JPH054394A - Paper feeder and recording device with the same paper feeder - Google Patents

Abstract

PURPOSE:To improve the handling properties and reliability of a device by positively preventing a recording miss due to skew feeding, previously detecting skew feeding due to a defective paper-feed mechanism and conducting proper previous maintenance before an unusable state is brought. CONSTITUTION:A pair of bail rollers 10A, 10B are disposed at positions at a regular interval in the longitudinal direction of a platen while the surface of the platen 14 and the surfaces of each bail roller 10A, 10B are brought to a conductive state, the time difference of left and right continuity interruption at a time when the front end of recording paper 1 reaches the bail rollers 10A, 10B is measured, skew feeding is detected by time difference, and a fixed quantity of paper is carried reversely and carrying force on one side is lowered and paper is conveyed again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device for feeding a recording medium to a recording section and a recording device equipped with the sheet feeding device.

[0002]

2. Description of the Related Art A recording device having functions such as a printer, a copying machine and a facsimile, or a recording device used as an output device of a composite electronic device including a computer, a word processor, etc. An image is recorded on a recording medium (recording material) such as a plastic thin plate. The recording apparatus can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, etc., depending on the recording method.

In a serial type recording apparatus which employs a serial scan system in which main scanning is performed in a direction intersecting a conveyance direction (sub-scanning direction) of the recording medium, the recording medium is set at a predetermined recording position and then along the recording medium. The image is recorded (main scanning) by the recording means mounted on the moving carriage, and after the recording for one line is completed, the paper is fed by a predetermined amount (pitch conveyance), and then the recording medium is stopped again. Then, by repeating the operation of recording (main scanning) the image of the next row, the entire recording medium is recorded. On the other hand, in a line type printing apparatus that prints only by sub-scanning in the conveyance direction of the print medium, the print medium is set at a predetermined print position, one line of print is performed at a time, and then a predetermined amount of paper is printed. The entire recording medium is recorded by repeating the operation of feeding (pitch feeding) and then collectively recording the next row.

Among the above-mentioned recording apparatuses, the ink-jet recording apparatus (ink-jet recording apparatus) performs recording by ejecting ink from a recording unit (recording head) onto a recording medium, and it is easy to make the recording unit compact. And
High-definition images can be recorded at high speed, plain paper can be recorded without any special processing, running costs are low, and the non-impact method produces less noise and multicolor images. It has advantages such as easy recording of a color image using ink. Above all, a line type apparatus using a line type recording means in which a large number of ejection openings are arranged in the paper width direction can further speed up recording.

In particular, an ink jet type recording means (recording head) for ejecting ink by utilizing thermal energy
Is a high-density liquid channel arrangement (discharging) by forming the electrothermal converter, electrodes, liquid channel wall, top plate, etc. formed on the substrate through semiconductor manufacturing processes such as etching, vapor deposition, and sputtering. Those having an outlet arrangement) can be easily manufactured, and further downsizing can be achieved.
On the other hand, there are various requirements for the material of the recording medium, and in recent years, paper and resin thin plate (O
In addition to HP, etc., thin paper and processed paper (paper with punched holes for filing, paper with perforations, paper of arbitrary shape, etc.) have been required to be used.

In the above recording apparatus or image reading apparatus, there is provided a paper feeding apparatus for supplying a recording medium (including original document) to the recording section. In the paper feeding device, when the recording medium is set in the recording unit, double feeding or skewing of the recording medium occurs due to the close contact of the recording mediums or the jamming of the cut portion of the recording medium, which causes the recording medium to be caught. Sometimes. In the conventional paper feeding device, in order to prevent the double feeding and the skew feeding, when the recording media are set on the paper feeding table or the paper feeding cassette, the recording media are bundled and squeezed to reduce the adhesion between the recording media. Operation to
That is, an operation commonly called "paper sabaki" is performed.

[0007]

However, in the conventional paper feeding device, it is difficult to completely wipe the recording medium even by the above-mentioned paper feeding device, and the skew feeding of the recording medium is caused by the incomplete paper feeding device. When it occurs, there is no control method, so it was simply discarded as a misprint.
Even if the accuracy of the paper feeding / conveying system of the printing apparatus is improved, it is not possible to fundamentally eliminate the skew due to the lack of the paper sacrifice despite the increase in the cost of the mechanical parts, and the printing time due to misprinting and There is a problem to be solved that the recording medium is wasted.

The present invention has been made in view of the above technical problems, and an object of the present invention is to reliably prevent a recording error due to skewing and to feed (convey) paper.
It is possible to detect in advance skewing due to mechanical failure due to wear of the mechanism, etc., and it is possible to detect mechanical failure before the paper feeding device fails and become unusable, and perform appropriate preliminary maintenance. It is an object of the present invention to provide a paper feeding device that can improve the reliability of the paper and a recording device that uses the paper feeding device.

[0009]

SUMMARY OF THE INVENTION According to the present invention, in a paper feeding device for feeding a recording medium, a pair of paper pressing rollers are arranged at predetermined intervals in the length direction of a platen facing the recording means, and a surface of the platen is provided. Also, the paper pressing roller is made conductive, and the time difference between the left and right paper pressing rollers when the leading edge of the recording medium reaches the paper pressing roller is cut off, and the skew of the recording medium is detected by this time difference. By doing so, the above object is achieved.
In addition to the above-described configuration, another aspect of the present invention has a configuration in which, when skew of the recording medium is detected, the skew of the recording medium is corrected by changing the left and right paper feeding force by a brake of the paper feeding system. Thus, the above object can be achieved more efficiently.

Further, according to the present invention, in a recording apparatus provided with recording means for recording on a recording medium based on image information and a paper feeding device for feeding the recording medium, the paper feeding device is opposed to the platen. A pair of paper pressing rollers are arranged at predetermined intervals in the length direction of the platen, and the surface of the platen and the paper pressing roller are made electrically conductive, so that the leading end of the recording medium reaches the paper pressing roller and A configuration that measures the time difference between power interruptions and detects skew of the recording medium based on this time difference, or in addition to this configuration, when skew of the recording medium is detected, the left and right paper feed forces are fed by the brakes of the paper feed system. The above-mentioned object is achieved by changing the above-mentioned condition to correct skew.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an embodiment of a recording apparatus provided with a sheet feeding device to which the invention is applied. The embodiment of FIG. 1 illustrates the case of a serial recording device using an inkjet recording means (recording head). In FIG. 1, 1 is a recording medium (recording material) such as recording paper or a plastic thin plate, 2 is a paper feed drive motor, and 3 is one for feeding the recording media 1 loaded in a cassette or on a paper feed tray one by one. A paper feed roller 4, a platen (a platen roller in the illustrated example) for guiding and supporting the supplied recording medium 1, 5 a feed roller for giving a conveying force to the recording medium 1, and 6 for the recording medium 1. A paper sensor for monitoring the head position, a recording means (recording head) 7 for recording on the recording medium 1, and 8 for recording medium 1 along two guide rails 9 arranged in parallel. A carriage movable in the width direction, 10 is a paper pressing roller for bringing the recording medium 1 into close contact with the platen 4, and 11 is a control circuit board for controlling the entire recording apparatus. The recording unit 7 is mounted on a carriage 8, and the main scanning of the recording medium 1 is performed by the movement of the carriage 8.

The recording means (recording head) 7 is an ink jet recording means for ejecting ink by utilizing heat energy, and is provided with an electrothermal converter for generating heat energy. Further, the recording means 7 performs recording by ejecting ink from an ejection port by utilizing a pressure change caused by growth and contraction of bubbles due to film boiling caused by thermal energy applied by the electrothermal converter. Is.

FIG. 2 is a partial perspective view schematically showing the structure of the ink ejection portion of the recording means (recording head) 7.
In FIG. 2, a plurality of ejection openings 52 are formed at a predetermined pitch on an ejection opening formation surface 51 that faces the recording material 1 with a predetermined gap (for example, about 0.5 to 2.0 mm). Each liquid path 5 that connects the common liquid chamber 53 and each discharge port 52
An electrothermal converter (heat generating resistor, etc.) 55 for generating energy for ejecting ink is disposed along the wall surface of No. 4. In this example, the recording head 7 is mounted on the carriage 8 in such a positional relationship that the ejection ports 52 are arranged in a direction intersecting the scanning direction of the carriage 8. In this manner, the corresponding electrothermal converter 55 is driven (energized) based on the image signal or the ejection signal to cause the ink in the liquid path 54 to film-boil, and the pressure generated at that time causes the ink to be ejected from the ejection port 52. The recording head 7 is configured.

FIG. 3 is a plan perspective view showing the arrangement of the paper pressing roller 10 and the platen (platen roller) 4 in the width direction, and FIG. 4 is a front perspective view showing the arrangement of the feed roller 5 and the platen 4 in the width direction. FIG. 5 is a block diagram showing a main configuration of an electric circuit of the recording apparatus. As shown in FIG. 3, the paper pressing roller 10 is composed of two left and right paper pressing rollers 10A and 10B. The pair of paper pressing rollers 10A and 10B are arranged at positions spaced apart from the width of the recording medium 1 so as to be capable of abutting (pressing) on the surface of the platen 4. The outer peripheral surface of the platen 4 has conductivity by being coated with a conductive material or molded with a conductive material. In addition, each of the paper pressing rollers 10
A and 10B also have conductivity by coating the outer periphery thereof with a conductive material or by molding with a conductive material. Therefore, as shown in the electric circuit of FIG. 5, by energizing between the platen 4 and each of the paper pressing rollers 10A and 10B, when the recording medium 1 is not present, electricity is applied through the contact portion, but the recording medium 1 is present. In some cases, the power supply is cut off. The presence or absence of this energization is detected by the CPU 12 (FIG. 5) of the control circuit 11.

In FIGS. 1 and 4, the feed roller 5 is pressed against the peripheral surface of the platen 4 by setting springs 15A and 15B provided on both sides of the feed roller 5. Further, magnets 14A and 14B are disposed on both sides of the feed roller 5, and by individually energizing (energizing) these magnets 14A and 14B, the springs 15A and 15B are overcome and corresponding. Adjust the pressure contact force of the feed roller 5 on the side (release or decrease)
By doing so, it is possible to cause a predetermined difference between the left and right conveyance forces (paper feed force). That is, the magnet 14 and the spring 15 function as a brake mechanism that can change the left-right conveyance force of the recording medium 1.

Next, the operation of the recording apparatus having the above configuration will be described. First, in the paper feed mechanism section, when the paper feed drive motor 2 drives the paper feed roller 3, one sheet of the recording medium 1 reaches between the platen (platen roller) 4 and the feed roller 5 and further passes. Then, the paper sensor 6 is reached. When the input port PC of the circuit board 11 is changed by the detection signal of the paper sensor 6, the CP of the circuit board 11 is changed.
U12 detects the head position of the recording medium 1. By continuously feeding the paper, the recording medium 1 reaches a position where its head is bited into the paper pressing rollers 10A and 10B near the recording head 7, that is, a predetermined recording start position for the recording head 7.

The top of the recording medium 1 is the paper pressing roller 10.
When biting into A and 10B, the energization state between the paper pressing roller and the platen 4 changes to the cutoff state.
The U12 detects that the left end or the right end of the recording medium 1 has reached the corresponding paper pressing roller 10 by the input port PA or PB (FIG. 5).
Corresponds to the skew reference amount (allowable limit) stored in the ROM 13 on the control circuit board 11 that stores the control program and fixed data after either the left or right tip reaches and the one changes to the cutoff state. The paper feed is further performed by the amount to be performed, and when the paper pressing roller that has not been blocked by the paper feed at this time also changes to the blocking state, it is determined that the skew feeding is within the allowable limit. When the skew feeding is less than the reference amount, the paper feed drive motor 2 is reversely rotated to return the recording medium 1 to the recording start position corresponding to the recording head 7, and recording is started from there.

If the remaining paper pressing roller 10 does not change to the cutoff state within the above-mentioned reference amount of paper feeding, the CPU
12 determines that skew has occurred, and the paper feed drive motor 2
The paper pressing roller 10 that has been cut off by reversing
Is returned to the energized state, and a fixed amount of return feed is further performed from the energized state returning position. Next, paper feed (conveyance of the recording medium) is performed for a fixed time while the magnet 14A or 14B on the side where the interruption occurs is activated. In this case, the operation of the magnet 14A or 14B overcomes the spring force of the spring 15A or 15B on the corresponding side, and the corresponding side of the feed roller 5 is moved to the platen 4.
Therefore, the conveying force (paper feeding force) on the corresponding side of the recording medium 1 is weakened, and a difference occurs between the left and right conveying forces. By carrying with a difference in the left and right carrying forces,
Skew occurs in the opposite direction to the previous one, and the skew is corrected.
In addition, one of the magnets 14A or 14
The above-mentioned certain time for carrying the sheet in the state where B is operated is
It is regulated by the data stored in 13.

The recording medium 1 is transported by the above-mentioned fixed time.
Reaches the paper pressing roller 10 again, and the conduction between the paper pressing roller 10 and the platen 4 is cut off. At this time, CP
Similarly to the above, the time difference between the interruption occurrence timings of the left and right paper pressing rollers 10A and 10B is measured by U12, and if skew exists, the same operation as described above is repeated. By repeating the above series of operations, the skew of the recording medium 1 can be accommodated (converged) within the standard.

That is, according to the above-described embodiment, when the head position of the conveyed recording medium 1 is detected and the cue is performed before recording, the difference (deviation) between the left and right detection times of the recording medium 1 is detected. When the skew is detected, reverse feeding (returning direction feeding) is performed, and when the sheet is fed again (feeding), the preceding feeding mechanism (feed roller 5) is braked (feeding force). It is configured to eliminate the inclination (skew) on the left and right by applying the effect of (lowering).

In a more specific operation of the recording apparatus, the CPU 12 detects the energization state between the platen (platen roller in the illustrated example) 4 and the left and right paper pressing rollers 10A and 10B, and at the time of cueing, recording is performed. When the front end of the medium 1 passes through the feed roller 5 and reaches the paper sensor 6, the CPU 12 detects the front end position of the recording medium 1 and continues feeding the paper to the recording position corresponding to the recording head 7. When the paper is further fed through the recording position, the head of the recording medium 1 reaches the paper pressing roller 10 arranged at the left and right positions in the vicinity of the recording head 7, and the recording medium 1 and the plate pressing roller 10 and the platen. When the recording medium 1 is caught between the paper pressing roller 10 and the platen, the electric conduction between the paper pressing roller and the platen becomes an insulating (blocking) state.
It detects that it has reached.

At this time, if there is a difference between the left and right of the recording medium 1 in the progress of paper feeding (if skew occurs), the delayed side of the left and right paper pressing rollers 10A and 10B remains in the short-circuited state. Therefore, it is detected that the sheet is conveyed in the skewed state. Therefore, if the remaining paper pressing rollers are not interrupted within a fixed time after further carrying, it is detected that the skew feeding exceeds the reference amount. If such skewing that requires correction occurs, a certain amount of reverse conveyance (returning feed) is performed until the paper pressing roller that has been cut off by reversing the conveyance mechanism returns to the energized state. To do.

Next, of the magnets 14A and 14B provided on the left and right of the feed roller 5, the magnet on the side where the paper pressing roller is interrupted is actuated so that the interrupted side of the feed roller 5 is moved to the platen. Float from 4 to reduce the carrying force and put the brakes. The left and right leading positions of the recording medium 1 are adjusted by feeding (conveying) the recording medium 1 for a certain period of time with the brake applied, that is, with the conveying force on the leading side of the recording medium 1 weakened. Left and right paper pressing rollers 10A,
The skew of the recording medium 1 is corrected by repeating the above-described operation until the difference in the shutoff timing of 10B is within the specified time. After making this skew correction, recording is started.

According to the embodiment described above, the platen 4
Of the left and right paper pressing rollers 10A and 10B are made of conductive material.
By energizing between A and 10B and the platen 4, the energized state is detected by the CPU 12, and a brake is provided in the conveying system to control the left and right conveying forces, so that there is no recording error due to skewing of the recording medium 1. In addition, it is possible to detect in advance the occurrence of a large skew due to a defective transport mechanism such as wear, and it will be possible to detect before a device fails and becomes unusable. As a result, a paper feeding device and a recording device equipped with the paper feeding device, which can be easily maintained in advance and have high reliability, are obtained.

In the above embodiment, the platen 4
Although the platen roller is used as the platen, it may be a platen having various other structures such as a plate-shaped fixed platen.
Further, in the above-described embodiment, the leading edge of the recording medium 1 is detected by the combination of the platen roller 4 and the paper pressing roller 10. However, since skewing of the recording medium often occurs in the initial stage of the transport mechanism, The leading edge may be detected by a member different from the paper pressing roller 10 such as a pair of rollers provided at a position near the end of the transport system.

In the above embodiment, the recording means (recording head) 7 is mounted on the carriage 8 and the serial type recording apparatus for performing the main scanning along the recording medium 1 is described as an example. Can be similarly applied to a line type recording apparatus using a line type recording means corresponding to the whole or a part of the recording width of a recording medium, and the same effect can be achieved. . Further, in the above-mentioned embodiment, the case of recording by one recording means 7 is illustrated, but
The present invention provides recording means (recording means) such as a color recording apparatus having a plurality of recording means for recording in different colors, or a recording apparatus for gradation recording using a plurality of recording means for recording with the same color but different densities. The same can be applied regardless of the number of heads), and the same effect can be achieved.

Further, as the recording means, other recording heads such as a cartridge type recording means (head cartridge) in which a recording head and an ink tank are integrated, or a structure in which the recording head and the ink tank are separately provided The same can be applied to the recording device having the configuration of the ink tank and the ink tank, and the same effect can be obtained.

When the recording apparatus is an ink jet recording apparatus, the present invention can be applied to, for example, a recording means (recording head) using an electromechanical transducer such as a piezo element. The present invention brings about an excellent effect in an ink jet recording apparatus using a recording means of a type that ejects ink by utilizing thermal energy. This is because such a system can achieve high density recording and high definition recording.

With regard to its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
This is preferably done using the basic principles disclosed in 796. This method can be applied to both the so-called on-demand type and the continuous type, but particularly in the case of the on-demand type, a liquid (ink) is used.
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path in which is stored, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling. Since the electrothermal converter generates heat energy to cause film boiling on the heat acting surface of the recording means (recording head), as a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal. It is valid.

By the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection openings to form at least one droplet. It is more preferable to make the driving signal into a pulse shape because bubbles can be grown and contracted immediately and appropriately, and thus a liquid (ink) with excellent responsiveness can be ejected. As this pulse-shaped drive signal, US Pat.
Those described in US Pat. Nos. 4,633,359 and 4,345,262 are suitable. Incidentally, US Pat. No. 43131 of the invention relating to the rate of temperature rise of the heat acting surface.
If the conditions described in the specification of No. 24 are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of No. 459600 is also included in the present invention. In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective as a structure based on Japanese Patent Laid-Open No. 138461/1984, which discloses a structure in which the discharge section is associated with the discharge section. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed. In addition, even with the serial type as in the above example, it is possible to electrically connect to the device body and supply ink from the device body by mounting it on the recording head fixed to the device body or the device body. The present invention is also effective when a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided in the present invention as a configuration of the recording apparatus, because the effects of the present invention can be further stabilized. If you list these specifically,
Capping means, cleaning means, pressurizing or suctioning means, electrothermal converter or other heating element or preheating means by a combination thereof, and ejection different from recording are applied to the recording head. Performing the preliminary ejection mode is also effective for stable recording.

Regarding the type or 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 supported. And a plurality of them may be provided. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode only for mainstream colors such as black,
The recording head may be integrally configured or a combination of a plurality of recording heads may be used, but the present invention is also extremely effective for an apparatus provided with at least one of a mixed color of different colors or a full color by mixing colors.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature, or an ink jet. In the method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. It may be in a liquid form. in addition,
Whether the temperature rise due to thermal energy is positively used as the energy for changing the state of the ink from the solid state to the liquid state, or the ink that solidifies when left standing for the purpose of preventing evaporation of the ink is used. In any case, the ink is liquefied by applying the thermal energy according to the recording signal and the liquid ink is ejected,
The present invention is also applicable to the case of using an ink that has a property of being liquefied only by thermal energy, such as one that has already started to solidify when it reaches the recording medium.

The ink in such a case is disclosed in JP-A-54-
As described in JP-A-56847 or JP-A-60-71260, a mode in which it is held as a liquid or a solid in the recesses or through holes of the porous sheet and faces the electrothermal converter. 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, as the form of the ink jet recording apparatus according to the present invention, in addition to 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 transmitting / receiving function. And the like may be used.

[0038]

As is apparent from the above description, according to the present invention, in the paper feeding device for feeding the recording medium, the pair of paper pressing rollers are arranged at predetermined intervals in the length direction of the platen facing the recording means. In addition, the platen surface and the paper pressure roller are made conductive, and the time difference between the left and right paper pressure roller power interruptions due to the leading edge of the recording medium reaching the paper pressure roller is measured. Since it is configured to detect lines, recording errors due to skewing can be reliably prevented, and skewing due to mechanical failure due to wear of the paper feed (conveyance) mechanism can also be detected in advance. Provided is a paper feeding device which can detect a mechanical failure before the paper feeding device fails and becomes unusable and can perform appropriate pre-maintenance, thereby improving the reliability of the device. According to another paper feeding device of the present invention,
In addition to the above configuration, when skew of the recording medium is detected, the skew of the recording medium is corrected by changing the left and right paper feeding force by the brake of the paper feeding system, so that the above effect is achieved more efficiently. A paper feeding device is provided.

Further, according to another aspect of the present invention, in a recording apparatus including recording means for recording on a recording medium based on image information and a paper feeding device for supplying the recording medium, the paper feeding device is a recording means. A pair of paper pressing rollers are arranged at predetermined intervals in the length direction of the platen opposite to the platen, and the surface of the platen and the paper pressing roller are made conductive so that the front end of the recording medium reaches the paper pressing roller. Since the time difference between power interruptions of the paper pressing roller is measured and the skew of the recording medium is detected by this time difference,
Recording mistakes due to skewing can be reliably prevented, and skewing due to mechanical failure due to wear of the paper feed (conveyance) mechanism can be detected in advance, and the paper feeding device fails and cannot be used. There is provided a recording apparatus capable of detecting a mechanical failure before the occurrence of the above and performing appropriate pre-maintenance and improving the reliability of the apparatus. Further, according to another recording apparatus of the present invention, in addition to the above configuration, when skew of the recording medium is detected, the skew of the recording medium is corrected by changing the left and right paper feeding forces by the brake of the paper feeding system. With this configuration, a recording device that can achieve the above effect more efficiently is provided.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a configuration of an embodiment of a recording apparatus to which the present invention is applied.

FIG. 2 is a partial perspective view schematically showing the structure of an ink ejection portion of the recording means in FIG.

3 is a plan view showing a platen and a paper pressing roller in FIG.

4 is an elevation view showing a platen and a feed roller in FIG. 1. FIG.

FIG. 5 is a block diagram showing a main part of a control system of a recording apparatus including a sheet feeding device according to the present invention.

[Explanation of symbols]

1 recording medium 2 Paper feed drive motor (conveyor motor) 3 paper feed rollers 4 Platen 5 Feed roller 6 Paper sensor 7 Recording means (recording head) 8 carriage 10 Paper pressing roller 11 Control circuit board 12 CPU 13 ROM 14 magnets 15 spring 51 Discharge port forming surface 52 Discharge port 55 Electrothermal converter

Claims (6)

[Claims] 1. In a paper feeding device for feeding a recording medium, a pair of paper pressing rollers are arranged at predetermined intervals in the length direction of a platen facing the recording means, and the surface of the platen and the paper pressing roller are made electrically conductive. A paper feeding device, characterized in that the time difference between the left and right paper pressing rollers when the leading edge of the recording medium reaches the paper pressing roller is cut off and the skew of the recording medium is detected. 2. The sheet feeding device according to claim 1, wherein when the skew of the recording medium is detected, the skew of the recording medium is corrected by changing the left and right sheet feeding forces by a brake of the sheet feeding system. 3. A recording apparatus comprising a recording means for recording on a recording medium based on image information and a paper feeding device for feeding the recording medium, wherein the paper feeding device is in a longitudinal direction of a platen facing the recording means. A pair of paper pressing rollers are arranged at predetermined intervals, the surface of the platen and the paper pressing roller are made electrically conductive, and the time difference between the power interruption of the left and right paper pressing rollers when the leading edge of the recording medium reaches the paper pressing roller And a skew of the recording medium is detected by the time difference. 4. The recording apparatus according to claim 3, wherein when the skew of the recording medium is detected, the skew of the recording medium is corrected by changing the left and right sheet feeding forces by a brake of the sheet feeding system. 5. The ink jet recording means, wherein the recording means comprises an electrothermal converter for generating thermal energy for ejecting ink.
Recording device. 6. The recording apparatus according to claim 5, wherein the recording unit ejects the ink from the ejection port by utilizing film boiling generated in the ink by the thermal energy applied by the electrothermal converter. .