JPH0692521A - Sheet conveyor device and recording device using the same - Google Patents

Abstract

PURPOSE:To obtain stable sheet converying accuracy regardless of the eccentricity of a carrier rotor in a device for conveying a sheet by the rotation of the carrier rotor by setting the peripheral length of the carrier rotor in such a way as to satisfy the specific relation to the basic sheet conveyance quantity. CONSTITUTION:A sheet conveyor device in a recording device with a serial type recording means rotatory-drives a carrier roller 11, a carrier rotor, in a direction (a) and nips a recording sheet 1 by a pinch roller 12 rotated following the rotation of the carrier roller 11a for upward conveyance. In this case, the basic conveyance quantity (one line part conveyance quantity) M of the recording sheet 1 is set in such a way as to coincide with recording width N by a recording head 3. Each line is thereby recorded without a gap and overlap. The basic conveyance quantity M is also set in such a way as no be sufficiently longer by the X-part than the peripheral length L of the carrier roller 11. Accordingly, even if the carrier roller 11 is decentered, the dispersion of conveyance can be suppressed to heighten the accuracy of sheet conveyance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device with improved sheet conveying accuracy and a recording apparatus using the sheet conveying device.

[0002]

2. Description of the Related Art Today, as shown in FIG. 5, the structure of a recording apparatus is such that a recording head 50 is moved in the front-back direction of the paper to record one line on a recording sheet 51, and the recording sheet 51 is moved upward one line. A so-called serial type recording apparatus that carries the next minute and performs the next line recording is widely used.

In such a recording apparatus, a recording sheet
51 is a conveyance roller for transmitting the driving force of the motor 52 via a transmission gear 53.
The recording sheet 51 is transmitted to the sheet 54 and is rotated upward by the rotation of the sheet feeding roller 54. Incidentally, reference numeral 55 in the drawing denotes a pinch roller which presses the recording sheet 51 against the conveying roller 54 and rotates following it.

[0004]

In the above-described sheet conveying structure, the conveying roller 54 is provided even if the precision of the transmission gear 53 and the like is increased.
Due to the eccentricity, the sheet conveyance accuracy becomes unstable, and white streaks or black streaks may occur during recording.

To explain this concretely, the recording sheet 51
The recording sheet 51 is conveyed by the conveyance roller 54 having a perimeter L (L = 4M) for four times of the basic conveyance amount M of 4
When recording lines, the transport roller 54 (L = M ₁ + M ₂ + M ₃ + M ₄ ) in which the roller shaft 54a is eccentric as shown in FIG.
FIG. 7 shows the result of recording four lines using. That is, after the first one-line recording, the conveyance roller 54 is rotated by ¼ rotation and each line recording is performed, and it is assumed that the conveyance at this time is performed in the order of M ₁ → M ₂ → M ₃ → M _4. At the first carrying amounts M ₁ and M ₂ , the carrying amount becomes large due to the eccentricity of the carrying roller 54, so that a gap occurs between the recording lines and a white streak occurs. Also, carry amount M ₃ , M
_{In the case of 4} , the carry amount becomes small, and as a result, the recording lines overlap and black streaks occur.

An object of the present invention is to solve the above-mentioned conventional problems,
The sheet conveyance accuracy is stable even if the conveyance rotator is eccentric,
An object of the present invention is to provide a sheet conveying device capable of accurately conveying a sheet and capable of high-quality recording, and a recording device using the sheet conveying device.

[0007]

A typical structure according to the present invention for achieving the above-mentioned object is a peripheral length L of a conveying rotary member.
With respect to the basic sheet conveyance amount M, L≈M or L <M
It is characterized by being configured in.

[0008]

In the above structure, even if the rotary shaft of the transport rotary body is eccentric, since the circumferential length of the transport rotary body is constant, there is almost no transport error when L≈M. become. Further, when the transport rotary body is eccentric, if the transport rotary body is rotated once or more to transport the sheet by the basic amount, the error rate becomes small even if the transport error occurs due to the eccentricity, and the transport accuracy is improved. .

[0009]

【Example】

[First Embodiment] Next, a preferred first embodiment of the present invention will be described with reference to FIGS. 1 is an explanatory view of a recording head and a conveyance roller portion, and FIG. 2 is a perspective explanatory view of the entire recording apparatus.

First, the overall structure of the recording apparatus will be described with reference to FIG. This recording apparatus has a serial type recording means and performs predetermined recording on the recording sheet 1 conveyed by the conveying means which is a sheet conveying device.

The recording means presses the recording sheet 1 conveyed by the conveying means against the platen 2 and performs recording by the recording head 3. The recording head 3 is mounted on a carriage 5 which can reciprocate along a guide rail 4, and the carriage 5 has left and right side walls 6a, 6 of the apparatus frame.
A timing belt 8 spanning between pulleys 7a and 7b provided near b is connected. A carriage motor 9 is connected to the pulley 7a, and the carriage 5 reciprocates along the guide rail 4 by the forward and reverse driving of the motor 9.

The recording head 3 in this embodiment is an ink jet recording head which ejects ink for recording. That is, the recording head 3 has a fine liquid discharge port (orifice), a liquid passage, and an energy acting portion provided in a part of the liquid passage, and energy for generating droplet forming energy that acts on the liquid in the acting portion. Equipped with generating means.

As an energy generating means for generating such energy, a recording method using an electromechanical transducer such as a piezo element, electromagnetic waves such as a laser are irradiated to generate heat, and droplets are ejected by the action of the heat generation. There are a recording method using an energy generating means, a recording method using an energy generating means for heating a liquid and discharging the liquid by an electrothermal converter such as a heating element having a heating resistor.

Among them, a recording head used in an ink jet recording method for ejecting a liquid by thermal energy has a high density of liquid ejection ports (orifices) for ejecting recording liquid droplets to form ejection liquid droplets. Since they can be arranged, high resolution recording is possible. Among them, the recording head using the electrothermal converter as the energy generating means can easily be made compact, and has the advantages of the IC technology and the microfabrication technology, which have been remarkably improved in technology and reliability in the recent semiconductor field. This is advantageous because it can be used in two parts, high-density mounting is easy, and the manufacturing cost is low.

Next, the structure of the sheet conveying means is the recording apparatus P.
The recording sheet 1 fed from the detachable automatic feeding device S or the recording sheet 1 manually fed from the manual feed port 10 is conveyed. That is, the conveying roller 11, which is a conveying rotating body, is driven to rotate in the direction of arrow a in FIG.
Are nipped and conveyed upward.

Both ends of the conveying roller 11 have left and right side walls 6a,
The roller shaft 11a is rotatably attached to the roller shaft 6a and is divided into a plurality of portions and attached to the roller shaft 11a. This roller shaft 11
A conveyance gear 13a is attached to a, and a transmission gear 13b is sequentially meshed with the gear 13a to be connected to the conveyance motor 14. Therefore, the rotational force of the carry motor 14 is transmitted to the carry roller 11 via the gear train, and the roller 11 rotates to carry the recording sheet 1 upward. The transmission gear 11
The gear 15 attached to the roller shaft 15a of the discharge roller 15 is shown in b.
b is meshed, and a gear 16b attached to the roller shaft 16a of the automatic feeder S is meshed via a clutch mechanism (not shown), and is rotated by the drive of the carry motor 14.

Here, the carrying roller 11 in the carrying means
The relationship between the peripheral length L of the recording head 3 and the recording width N of the recording head 3 will be described with reference to FIG.

In this embodiment, the basic conveyance amount M (conveyance amount for one line) M of the recording sheet 1 in the sheet conveying means is set so as to match the recording width N of the recording head 3.
As a result, recording of each line can be performed without gaps and without overlapping. The basic carry amount M is set to be X longer than the circumferential length L of the carry roller 11 (L <M). That is, in order to carry the recording sheet 1 by the basic carry amount, the carry roller 11 rotates once and further rotates by the circumference length X.

Here, the error of the carry amount when the roller shaft 11a is eccentric to the carry roller 11 as shown in FIG. 1 will be described. First, even if the roller shaft 11a is eccentric, there is no error in the carry amount when the roller 11 makes one rotation. Therefore, the error of the transport amount due to the eccentricity is the length X
Caused by the transport of minutes. If this error is ΔX, the error rate that occurs when the recording sheet 1 is fed by the basic carry amount M is ΔX / (L + X).

On the other hand, in the case of the conventional example shown in FIG. 6, the error rate of the basic carry amount M ₁ with respect to the carry error ΔM ₁ is ΔM ₁ / M ₁ . Therefore, as in this embodiment, the basic carry amount M is equal to the peripheral length L + X (M ₁ <L +) of the carry roller 11.
The configuration X) reduces the transport error rate due to the eccentricity of the roller shaft 11a, reduces the transport error, and enables high-quality image recording.

Since the conveyance error rate decreases as the length X with respect to the basic conveyance amount M decreases, the conveyance roller 11 is rotated twice or more to convey the recording sheet 1 by the basic conveyance amount M, and M = nL + X ( If n is an integer, the transport error rate can be further reduced.

[Second Embodiment] In the above-described first embodiment, an example in which the peripheral length L of the transport roller 11 with respect to the basic transport amount M of the recording sheet 1 is set to L <M, is shown in FIG. Thus, the basic carry amount M and the circumferential length L of the carry roller 11 match (L =
M) may be configured.

For example, when the recording head 3 having 256 dots of nozzles at a pitch of 1/360 inch is used, the recording head 3
Thus, the recording width N = the basic transport amount of the recording sheet 1 = the peripheral length L of the transport roller 11 = 256/360 inches. Therefore, it suffices to use a conveyance roller having a diameter of 5.75 mm. Similarly, in the case of the recording head 3 having a 1/300 inch pitch and 256-dot nozzles, the conveyance roller 11 having a diameter of 6.9 mm may be used.

With this arrangement, the roller shaft of the transport roller 11
Even if 11a is eccentric, there is no conveyance error due to this eccentricity. The peripheral length L of the transport roller 11 is set to L = M / n with respect to the basic transport amount M (n is an integer), and the transport roller 11 is rotated a plurality of times to transport the recording sheet 1 by the basic transport amount M. Even if it does, the same effect can be obtained.

The settings of L = M and L = M / n are substantially equal (L≈M, L≈M / n) even if they are not exactly equal.
If it is set so that there is almost no error in conveyance due to the eccentricity of the roller shaft 11a, there is no problem.

[Third Embodiment] Next, an embodiment in consideration of the reduction ratio when the driving force is transmitted from the carry motor 14 to the carry roller 11 will be described with reference to FIG.

The drive transmission structure shown in FIG.
Motor gear 14a meshes with input gear 13b1 of transmission gear 13b, and output gear 13b2 that rotates integrally with input gear 13b1 meshes with transport gear 13a. And the motor gear 14a
From the transmission gear 13b to the input gear 13b1 is set to 1: 2, and the reduction ratio from the output gear 13b2 to the transport gear 13a is set to 1: 3.

Therefore, the transport gear for the motor gear 14a
The reduction ratio of 13a is 1: 6. As a result, the transport motor 14
After 6 rotations, the transmission gear 13b rotates 3 times and the conveying roller 11 rotates 1 rotation. In this way, the rotation reduction ratio of the transport roller 11 to the transport motor 14 is set to 1: n (n is an integer), and the transport motor and the transmission gear 13b are rotated many times to rotate the transport roller 11 once. For example, the transport roller
11 not only the eccentric component of the roller shaft 11a but also the transport motor 14
It is possible to cancel even the eccentric component of the transmission gear 13b.

[Other Embodiments] In the above-described embodiments, the ink jet recording method is used as the recording means. However, the electrothermal converter is energized according to a recording signal and the thermal energy applied by the electrothermal converter is changed. It is more preferable that the recording is performed by ejecting the ink from the ejection port due to the growth and contraction of the bubbles generated in the ink by utilizing the film boiling generated in the ink.

With regard to its typical structure and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4740796. This method can be applied to both the so-called on-demand type and continuous type, but in the case of the on-demand type in particular, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal to the electrothermal transducer, which corresponds to the recorded information and gives a rapid temperature rise beyond nucleate boiling,
This is effective because heat energy is generated in the electrothermal converter to cause film boiling on the heat acting surface of the recording head, and as a result, bubbles in the liquid can be formed in a one-to-one correspondence with this drive signal. Due to the growth and contraction of the bubbles, the liquid is ejected through the ejection openings to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be grown and contracted immediately and appropriately, so that particularly excellent liquid ejection can be achieved.

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 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. The present invention also includes configurations using US Pat. Nos. 4,558,333 and 4,459,600, which disclose configurations in which the heat acting portion is arranged in a bending region.

Further, JP-A-59-123670 discloses a structure 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. Japanese Patent Laid-Open Publication No.
The effect of the present invention is effective even if the configuration is based on Japanese Patent Laid-Open No. 59-138461. That is, according to the present invention, recording can be surely 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 structure that satisfies the length by combining a plurality of recording heads or a structure as one recording head integrally formed.

In addition, even in the case of the serial type described above, when it is mounted on the recording head fixed to the carriage or the carriage, it is possible to electrically connect to the apparatus main body and supply ink from the apparatus main body. 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 may be used.

Further, it is preferable to add a recovery means for the recording head, a preliminary auxiliary means, etc., which are provided as a constituent of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. Specifically, these are capping means, cleaning means, pressurizing or suctioning means for the recording head, preheating means by electrothermal conversion type or other heating element or a combination thereof, and recording. It is also effective to perform a stable recording by performing a preliminary discharge mode in which another discharge is performed.

Regarding the type and number of recording heads mounted on the carriage, 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 of only the mainstream color such as black, but may be a combination of a plurality of recording heads integrally formed, but a mixed color of different colors or a mixed color It is also applicable to a device with at least one of the full colors according to

In addition, although the ink is described as a liquid in the above-described embodiments, it is an ink that solidifies at room temperature or lower and softens or liquefies at room temperature, or in the ink jet recording system. 30 inks
Generally, the temperature is controlled in the range of ℃ to 70 ℃ to control the temperature of the ink so that the viscosity of the ink is within the stable ejection range. good. In addition, it is possible to prevent the temperature rise due to thermal energy from being positively used as the energy for changing the state of the ink from the solid state to the liquid state, or to use ink that solidifies when left standing for the purpose of preventing ink evaporation. However, in any case, when heat ink is liquefied by applying heat energy according to the recording signal and liquid ink is ejected, or when the ink reaches the recording sheet, it begins to solidify. It is also applicable when using an ink that has the property of being liquefied for the first time by energy.

The ink in such a case is disclosed in JP-A-54-5.
As described in Japanese Patent No. 6847 or Japanese Patent Laid-Open No. 60-71260, a mode in which it is opposed to the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or through hole of the porous sheet. Also good. The most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

Further, as the form of the above-mentioned ink jet recording apparatus, in addition to the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, or a facsimile apparatus having a transmitting / receiving function is used. It may take a form or the like.

Although an example using the ink jet recording system as the above-mentioned recording means has been described, the present invention need not be limited to the ink jet recording system, and other thermal transfer recording systems, thermal recording systems, and the like. Can also be applied to an impact recording method such as a wire dot recording method or another recording method. Further, it is not necessary to limit to the serial recording method, and a so-called line recording method may be used.

Further, in the above-mentioned embodiment, the recording apparatus for conveying the recording sheet is exemplified as the apparatus using the sheet conveying apparatus, but a scanner is mounted on the carriage 5 instead of the recording head 3 of the above-mentioned first embodiment, and the carriage It is also possible to use the serial-type document reading device for reading the document description information line by line as the document is moved.

[0043]

As described above, according to the present invention, by making the peripheral length of the transport roller substantially equal to or smaller than the basic transport amount of the sheet, variation in transport is suppressed even if the transport rotating body is eccentric. Can be done. Therefore, it is possible to increase the sheet conveyance accuracy and record a high-quality image in the recording apparatus using the sheet.

Further, since the diameter of the carrier rotating body is reduced to downsize the apparatus, and the accuracy of the carrier rotating body against eccentricity is low, there is no problem, so that the manufacturing can be facilitated and the cost can be reduced. Is.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a recording width and a peripheral length of a conveyance roller.

FIG. 2 is an overall perspective explanatory diagram of a recording apparatus.

FIG. 3 is an explanatory diagram of a peripheral length of a conveyance roller and a sheet conveyance amount.

FIG. 4 is an explanatory diagram showing a relationship between a drive transmission speed reduction ratio from a carry motor to a carry roller and a circumferential length of the carry roller.

FIG. 5 is an explanatory diagram of a sheet conveying device and a recording device according to a conventional technique.

FIG. 6 is an explanatory diagram showing a relationship between a conventional sheet basic carry amount and a carry roller circumferential length.

FIG. 7 is an explanatory diagram of a recording sheet in which white lines and black lines are generated.

[Explanation of symbols]

 P ... Recording device S Automatic feeding device 1 ... Recording sheet 2 ... Platen 3 ... Recording head 4 ... Guide rail 5 ... Carriage 6a, 6b ... Side walls 7a, 7b ... Pulley 8 ... Belt 9 ... Carriage motor 10 ... Manual insertion port 11 ... Transport roller 11a ... Roller shaft 12 ... Pinch roller 13a ... Transport gear 13b ... Transmission gear 14 ... Transport motor 15 ... Discharge roller 15a ... Roller shaft 15b ... Gear 16 ... Roller shaft 16a ... Gear

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B65H 27/00 Z 2124-3F

Claims (9)

[Claims] 1. A sheet conveying device for conveying a sheet by rotation of a conveying rotating body, wherein a peripheral length L of the conveying rotating body is set to L≈M or L <M with respect to a basic sheet conveying amount M. A sheet conveying device characterized by being configured. 2. A sheet conveying device for conveying a sheet by rotation of a conveying rotating body, wherein a peripheral length L of the conveying rotating body is L≈M / n (n is an integer) with respect to a basic conveying amount M of the sheet. ), The sheet conveying device. 3. The reduction ratio of the transport motor with respect to the transport motor that rotates the transport rotary member is set to 1: n (n is an integer).
The sheet conveying device described. 4. A recording apparatus which records on a sheet with a predetermined recording width by a recording means and conveys a sheet in a direction perpendicular to the recording direction by rotation of a conveying rotary body, wherein a peripheral length L of the conveying rotary body is For recording width N, L≈N,
Alternatively, the recording device is configured such that L <N. 5. A recording apparatus which records on a sheet with a predetermined recording width by a recording means and conveys a sheet in a direction perpendicular to the recording direction by rotation of a conveying rotary body, wherein a peripheral length L of the conveying rotary body is For recording width N, L≈N /
A recording device having a configuration of n (n is an integer). 6. A recording apparatus for recording a sheet with a predetermined recording width by a recording means and conveying the sheet in a direction perpendicular to the recording direction by rotation of the conveying rotary body, in which the conveying rotary body is rotated. The recording apparatus according to claim 4 or 5, wherein the reduction ratio of the motor to the conveying rotary member is set to 1: n (n is an integer). 7. The recording apparatus according to claim 4, wherein the recording apparatus is an inkjet recording method in which recording means ejects ink in response to a signal to perform recording. 8. The recording device according to claim 4, wherein the recording device is provided with an electrothermal converter for generating thermal energy for ejecting ink by the recording means. 9. The recording device according to claim 4, wherein the recording means ejects the ink from the ejection port by utilizing the film boiling generated in the ink by the thermal energy applied by the electrothermal converter. The recording device described.