Drive mechanism for conveying print media for printer having plurality of printheads

Abstract

The utility model relates to a driving mechanism for conveying a printing medium, which is used by a printer with a plurality of printing heads, can effectively ensure that the printing medium is not easy to arch and is excessively stretched in the whole printing process, and can effectively reduce the waste of the first-section material of the printing medium during the first printing. Comprising a paper feeding rubber roller arranged on the side of a paper inlet and an nth printing rubber roller arranged on the side of a paper outlet and corresponding to an nth printing head, and the linear speed of the paper feeding rubber roller is smaller than that of the nth printing rubber roller. A printing medium can be in a stretched state all the time in the printing process, and arching or wrinkling of the printing medium is effectively avoided. Furthermore, the printing rubber roller is arranged to rotate in a one-way mode, the problem that the printing medium is excessively stretched or wrinkled in the printing process due to the fact that the linear speed difference value is large can be solved, and waste of blank section printing materials generated in the initial printing process can be effectively reduced when first-time printing is carried out.

Description

Technical Field

[0001] The utility model relates to a printing device, in particular to a paper feeding driving mechanism applied to a printer with multiple printing heads. Background Art

[0002] In the market, there are two types of drive structures for driving the movement of printing media in printers that are equipped with multiple printing mechanisms and can complete printing work at the same time:

[0003] The first type is to set a driving mechanism at the front end of the first printing mechanism in multiple printing mechanisms (the paper feeding end of the printing medium is the front end, and the delivery end of the printing medium after printing is the rear end, the printing mechanism at the front end is the first printing mechanism, and the printing mechanism at the rear end is the last printing mechanism) and the rear end of the last printing mechanism. The driving mechanism set at the rear end of the last printing mechanism is usually a double roller pressed up and down. During the printing process, the printing medium is tightly pressed between the double rollers. After printing is completed, the double rollers deliver the printed printing medium under the action of the driving force. A damping device or a tension device is set at the front end of the first printing mechanism, which provides a force to the printing medium in the opposite direction of the printing medium moving out after printing is completed, so as to ensure that the printing medium maintains a certain tension state under all printing mechanisms. In this case, the printing rubber roller corresponding to each print head in the printing mechanism (the printing rubber roller is located directly below the print head) is in a state of no power drive.

[0004] During the printing process, the print medium is dragged out of the printer by the double rollers, and the print rollers corresponding to each print head in the printing mechanism also passively rotate with the movement of the print medium. This structure has the following two shortcomings:

[0005] 1) Since double rollers are provided at the material outlet end after the printing medium is printed, the structural complexity is increased, which increases the cost of the printer and the size of the printer, and also increases the maintenance cost and difficulty.

[0006] 2) Since the print medium is moved by the double rollers during the printing process, the rubber rollers at each print head in the printing mechanism also passively rotate with the print medium. Therefore, each time the first print medium is printed, the print medium must be passed through each printing mechanism in turn and inserted between the double rollers. In this way, the print medium from the first group of printing mechanisms to the double rollers cannot be used for printing, resulting in a waste of this section of print medium.

[0007] The second method is to set the printing rollers corresponding to the print heads of the multiple printing mechanisms as driving rollers. Under the action of the driving force, all the rollers rotate together. During the printing process, the printing medium moves under the drive of all the printing rollers. This structure also has the following shortcomings:

[0008] 1) In order to achieve an ideal printing effect, all rubber rollers are required to have the same linear speed during the printing process. Due to processing errors, this goal is basically impossible to achieve. If the linear speeds of all rubber rollers are inconsistent, the printing medium will be arched or over-stretched during the printing process, which may easily cause the problem of misalignment of printed content lines.

[0009] 2) Since the linear speeds of all printing rollers are inconsistent, the printing media may arch during printing and may also cause the printing media to block the printing channel, increasing the possibility of paper jams in the machine.

[0010] 3) Since the linear speeds of all printing rollers are inconsistent, the printing medium may be over-stretched during the printing process. The printing medium on some printing rollers may be pulled by the larger rollers with higher linear speeds to generate sliding friction, thereby causing damage to the drive structure. Utility Model Content

[0011] The technical problem to be solved by the utility model is to provide a driving mechanism for conveying printing media used in a printer with multiple print heads, wherein the driving mechanism can effectively ensure that the printing media is not prone to arching and excessive stretching during the entire printing process, and at the same time, it can also effectively reduce the waste of the first section of printing media material when performing the first printing.

[0012] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0013] The utility model discloses a driving mechanism for conveying printing media used in a printer with multiple print heads, comprising a paper feed roller arranged on a paper feed side and an nth print roller corresponding to an nth print head arranged on a paper outlet side, characterized in that a linear speed of the paper feed roller is less than a linear speed of the nth print roller, and a ratio of the linear speed of the paper feed roller to the linear speed of the nth print roller is between 0.84 and 0.99.

[0014] The paper feed rubber roller rotates at the same angular velocity as the nth printing rubber roller, and the roller diameter of the paper feed rubber roller is smaller than the roller diameter of the nth printing rubber roller, and the difference is between 2.0 mm and 8 mm.

[0015] The roller diameter of the paper feed roller is the same as the roller diameter of the nth printing roller, and the angular velocity of the paper feed roller is smaller than the angular velocity of the nth printing roller, and the difference is between 2% and 10%.

[0016] The roller diameter and angular velocity of the paper feed roller are different from the roller diameter and angular velocity of the nth printing roller. The relevant parameters of the paper feed roller and the nth printing roller are calculated according to ω O r O / ω n r n= k calculation, where

[0017] ω O - Angular velocity of the paper feed roller, r O -Roller diameter of the paper feed roller;

[0018] ω n - Angular velocity of the nth printing roller, r n -Roller diameter of the nth printing roller;

[0019] K-factor, its value range is 0.85-0.98.

[0020] The paper feeding rubber roller is connected to the nth printing rubber roller by a synchronous belt drive, a chain drive or a gear drive mechanism.

[0021] Among the printing rubber rollers corresponding to the other printing heads arranged between the nth printing head and the paper feed rubber roller, at least one printing rubber roller is dynamically connected to the nth printing rubber roller through a synchronous belt drive, a chain drive or a gear drive mechanism. This printing rubber roller is called a middle printing rubber roller, and a one-way bearing is arranged on it.

[0022] The linear speed of the middle printing rubber roller is less than the linear speed of the nth printing rubber roller, and greater than the linear speed of the paper feeding rubber roller.

[0023] The output end of the driving motor driving each printing rubber roller to operate is connected to the nth printing rubber roller or the paper feeding rubber roller.

[0024] The printing rubber rollers corresponding to the other printing heads arranged between the nth printing head and the paper feeding rubber roller are freely rotatable rubber rollers.

[0025] The output end of the driving motor driving each printing rubber roller to operate is connected to the nth printing rubber roller or the paper feeding rubber roller.

[0026] In the printer having a plurality of print head assemblies arranged in sequence from front to back, the utility model designs the linear speed of the power-driven printing rubber roller corresponding to the previous print head to be smaller than the linear speed of the power-driven printing rubber roller corresponding to the next print head, and designs the linear speed of the paper feed rubber roller to be smaller than the linear speed of the first power-driven printing rubber roller, so that the printing medium is always in a stretched state during the printing process, effectively avoiding the printing medium from being arched or wrinkled. Furthermore, the middle printing rubber roller is set to rotate in one direction, which can not only solve the problem of excessive stretching or wrinkling of the printing medium during the printing process caused by the large linear speed difference, but also effectively reduce the waste of blank section printing materials generated during the initial printing when the first printing is performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is a schematic diagram of the driving mechanism of the utility model.

[0028] Figure 2 for Figure 1 Schematic diagram from another perspective.

[0029] Figure 3 for Figure 1 A plan view from the front view.

[0030] The reference numerals are as follows:

[0031] A paper feeding rubber roller 1, a middle printing rubber roller 2, a one-way power rubber roller 21, a tail printing rubber roller 3, a synchronous power connection mechanism 4, and a power driving source 5. DETAILED DESCRIPTION

[0032] like Figure 1-Figure 3 As shown, the drive mechanism for conveying printing media used in the printer with multiple printing heads of the utility model is applied to a printer in which multiple printing head assemblies are sequentially arranged between a paper inlet for the medium to be printed and a paper outlet after printing.

[0033] 1. Features of the utility model solution

[0034] The printing rubber rollers corresponding to each print head in the multiple print head assemblies can all be powered, or only a part of them can be powered [the other powered printing rubber rollers between the paper feed rubber roller 1 and the last powered printing rubber roller (this printing rubber roller is called the tail printing rubber roller 3) can be called the middle printing rubber roller 2], and the rest can be in a free-rotating state without power drive.

[0035] The characteristic of the scheme of the utility model is that the linear speed of the paper feed rubber roller 1 arranged on the paper feed side is smaller than the linear speed of the first powered printing rubber roller. Similarly, among the several powered printing rubber rollers in the printer, the linear speed of the front powered printing rubber roller is smaller than the linear speed of the rear powered printing rubber roller (the paper feed side of the printer is the front, and the paper outlet side of the printer is the rear). In this way, when the rear powered printing rubber roller is rolled, the printing medium between it and the front powered printing rubber roller is always in a stretched state (that is, the speed at which the rear printing rubber roller pulls the printing medium is faster, and the speed at which the front printing rubber roller conveys the printing medium is slightly slower, thereby preventing the printing medium from being arched due to the speed at which the front printing rubber roller conveys the printing medium being greater than the speed at which the rear printing rubber roller pulls the printing medium, which is also called the medium wrinkling phenomenon).

[0036] In order to avoid the excessive stretching or breaking of the printing medium in the forward direction (moving from the paper inlet to the paper outlet is the forward movement) due to the large positive difference (positive difference refers to the difference between the linear speed of the rear printing rubber roller 3 or the rear middle printing rubber roller 2 and the linear speed of the front middle printing rubber roller 2) , the utility model sets the front middle printing rubber roller 2 with a one-way bearing (this type of rubber roller is called a one-way power rubber roller 21), that is, when the printing medium moves forward, the middle printing rubber roller 2 rotates under the action of the driving force. When the above-mentioned positive difference in linear speed is too large, the middle printing rubber roller 2 idles in the forward rotation direction due to the setting of the one-way bearing. Reasonably controlling the positive difference between two adjacent driven printing rubber rollers will prevent the printing medium from wrinkling or excessive stretching during the forward movement.

[0037] The utility model preferably has a ratio of the linear speed of the front powered printing rubber roller to the linear speed of the rear powered printing rubber roller within a range of 0.85-0.99.

[0038] The above design can not only effectively solve the problem of unevenness or arching of the printing medium between two adjacent powered printing rollers due to the negative difference in linear speed between the front and rear printing rollers (that is, the linear speed of the rear printing roller is less than the linear speed of the front printing roller), but also solve the problem of excessive waste of printing medium (that is, when printing the first printing medium, the above design of the utility model does not need to pull the leading end of the printing medium to the double rollers arranged near the paper outlet of the printer before starting to instruct the first print head to print as in the prior art. The above design only needs to pull the leading end of the printing medium to the first powered printing roller for printing, and it can be considered that it will not cause waste of printing medium).

[0039] In order to reduce the size of the printer, the manufacturing cost and the speed control of each power-driven printing rubber roller, in the scheme of the present invention, each power-driven printing rubber roller and the paper feeding rubber roller 1 preferably share a power driving source 5 through a synchronous belt drive, a chain drive or a gear drive mechanism (referred to as a synchronous power connection mechanism 4), and the present invention preferably arranges the power driving source 5 at the rear printing rubber roller 3. The power driving source 5 is the output end of the driving motor, and the output end can be connected to the power of the last power-driven printing rubber roller through gear meshing, male and female matching or other conventional transmission mechanisms.

[0040] In the above design, if at least one non-powered printing rubber roller is provided between the first powered printing rubber roller and the paper feed rubber roller 1 (that is, a print head is provided above the printing rubber roller), since there is a linear speed difference between the first powered printing rubber roller and the paper feed rubber roller 1, it can be theoretically considered that among these non-powered printing rubber rollers, the linear speed of the preceding printing rubber roller is slightly less than or equal to the linear speed of the succeeding printing rubber roller. This can be summarized as follows: the linear speed of the paper feed rubber roller 1 is less than the linear speed of the nth printing rubber roller corresponding to the nth print head.

[0041] 2. Methods of implementing the utility model

[0042] In order to make the linear speed of the paper feeding rubber roller 1 smaller than the linear speed of the first powered printing rubber roller and the linear speed of the first powered printing rubber roller smaller than the linear speed of the second powered printing rubber roller, the utility model is implemented by the following structures:

[0043] 1. When the paper feed roller 1 is connected to the first powered printing roller at the same angular velocity, the roller diameter of the paper feed roller 1 should be smaller than the roller diameter of the first powered printing roller, and the difference is between 0.1 mm and 8 mm.

[0044] When the front powered printing roller is connected to the rear powered printing roller at the same angular velocity, the roller diameter of the front powered printing roller should be smaller than the roller diameter of the rear powered printing roller, and the difference is 0.1mm-8mm.

[0045] 2. When the roller diameter of the paper feed roller 1 is the same as the roller diameter of the first powered printing roller, the angular velocity of the paper feed roller 1 should be smaller than the angular velocity of the first powered printing roller, and the difference is preferably 2%-10% of the angular velocity of the first powered printing roller.

[0046] When the roller diameter of the previous powered printing rubber roller is the same as the roller diameter of the next powered printing rubber roller, the angular velocity of the previous powered printing rubber roller should be smaller than the angular velocity of the next powered printing rubber roller, and the difference is preferably 2%-10% of the angular velocity of the next powered printing rubber roller.

[0047] 3. When the roller diameter and angular velocity of the paper feed roller 1 are different from the roller diameter and angular velocity of the first powered printing roller, the correlation between the roller diameter and angular velocity between the paper feed roller 1 and the first powered printing roller is calculated according to ω O r O / ω1r1=k1 calculation, where

[0048] ωO - Angular velocity of paper feed roller 1, r O -Roller diameter of paper feed roller 1;

[0049] ω1-angular velocity of the first powered printing roller, r1-roller diameter of the first powered printing roller;

[0050] K1-coefficient, its value range is 0.85-0.99.

[0051] When the roller diameter and angular velocity of the first power-driven printing rubber roller are different from the roller diameter and angular velocity of the second power-driven printing rubber roller, the correlation relationship between the roller diameter and angular velocity of the first power-driven printing rubber roller and the second power-driven printing rubber roller is calculated according to ω m r m / ω n r n =k n Calculate, where

[0052] ω m - angular velocity of the previous powered printing roller, r m - the roller diameter of the previous powered printing roller;

[0053] ω n - angular velocity of the next powered printing roller, r n - the roller diameter of the rear powered printing roller;

[0054] K n - coefficient, its value range is 0.85-0.99.

[0055] Both m and n are integers.

[0056] 3. Reverse transmission of printing media

[0057] In the prior art, for a printer with multiple print heads, when the last print head finishes printing, a section of print media between the last print head and the previous one or several print heads is blank media (i.e., has no printed content). Usually, the printer then enters the second round of printing, and the section of blank media continues to move forward and out of the printer, so that the section of blank media is wasted.

[0058] In order to save printing media, the utility model moves the blank media in reverse to the bottom of the print head that needs to be printed after the last print head finishes printing, thus reducing the waste of printing media. The utility model sets the middle printing rubber roller 2 corresponding to the first one or several print heads to the aforementioned one-way power rubber roller 21. The function of this design is: when the printing medium needs to be reversed, it moves in reverse under the traction of the paper feed rubber roller 1. At the same time, the driving mechanism of the one-way power rubber roller 21 also applies a reverse rotation force to the one-way power rubber roller 21. Due to the setting of the one-way bearing, the reverse rotation force cannot generate a reverse driving force for the one-way power rubber roller 21. At this time, the one-way power rubber roller 21 is relatively inert to the printing medium moving in reverse. It is in a free rotation state, so the printing medium can be reversely sent back to the designated middle printing rubber roller 2 under the control of the control board under the traction of the paper feeding rubber roller 1; when printing starts again, the driving mechanism of the middle printing rubber roller 2 where the printing medium is located drives it to rotate forward and makes the middle printing rubber roller 2 have a driving force and drives the printing medium to move forward. Since the linear speed of the middle printing rubber roller 2 driving the printing medium to move forward is greater than the linear speed of the paper feeding rubber roller 1, the printing medium between the middle printing rubber roller 2 and the paper feeding rubber roller 1 still remains in a stretched state.

Claims

1. A drive mechanism for conveying print media used in a printer having multiple print heads, comprising a paper feed roller (1) arranged on the paper feed side and an nth print roller corresponding to the nth print head arranged on the paper outlet side, characterized in that: The linear speed of the paper feeding rubber roller (1) is less than the linear speed of the nth printing rubber roller, and the ratio of the linear speed of the paper feeding rubber roller (1) to the linear speed of the nth printing rubber roller is between 0.84 and 0.

99.

2. The driving mechanism for conveying printing medium used in a printer having multiple print heads according to claim 1, characterized in that: The paper feed rubber roller (1) rotates at the same angular speed as the nth printing rubber roller, and the roller diameter of the paper feed rubber roller (1) is smaller than the roller diameter of the nth printing rubber roller, and the difference is between 2.0 mm and 8 mm.

3. The driving mechanism for conveying printing medium used in a printer with multiple print heads according to claim 1, characterized in that: The roller diameter of the paper feed rubber roller (1) is the same as the roller diameter of the nth printing rubber roller, and the angular velocity of the paper feed rubber roller (1) is smaller than the angular velocity of the nth printing rubber roller, and the difference is between 2% and 10%.

4. The driving mechanism for conveying printing medium used in a printer with multiple print heads according to claim 1, characterized in that: The roller diameter and angular velocity of the paper feed roller (1) are different from the roller diameter and angular velocity of the nth printing roller. The relevant parameters of the paper feed roller (1) and the nth printing roller are calculated according to ω O r O / ω n r n = k calculation, where ω O - Angular velocity of the paper feed roller (1), r O - roller diameter of the paper feed roller (1); ω n - Angular velocity of the nth printing roller, r n -Roller diameter of the nth printing roller; K-factor, its value range is 0.85-0.

98.

5. A drive mechanism for conveying printing media used in a printer with multiple print heads according to any one of claims 1 to 4, characterized in that: The paper feeding rubber roller (1) is connected to the nth printing rubber roller by means of a synchronous belt drive, a chain drive or a gear drive mechanism.

6. The driving mechanism for conveying printing medium used in a printer with multiple print heads according to claim 5, characterized in that: Among the printing rubber rollers corresponding to the other printing heads arranged between the nth printing head and the paper feeding rubber roller (1), at least one printing rubber roller is connected to the nth printing rubber roller through a synchronous belt drive, a chain drive or a gear drive mechanism. This printing rubber roller is called a middle printing rubber roller (2) and is provided with a one-way bearing.

7. The driving mechanism for conveying printing medium used in a printer with multiple print heads according to claim 6, characterized in that: The linear speed of the middle printing rubber roller (2) is less than the linear speed of the nth printing rubber roller, and greater than the linear speed of the paper feeding rubber roller (1).

8. The driving mechanism for conveying printing medium used in a printer with multiple print heads according to claim 7, characterized in that: The output end of the driving motor for driving each printing rubber roller to operate is connected to the nth printing rubber roller or the paper feeding rubber roller (1) in power connection.

9. The driving mechanism for conveying printing medium used in a printer with multiple print heads according to claim 5, characterized in that: The printing rubber rollers corresponding to the other printing heads arranged between the nth printing head and the paper feeding rubber roller (1) are freely rotatable rubber rollers.

10. The driving mechanism for conveying printing medium used in a printer with multiple print heads according to claim 9, characterized in that: The output end of the driving motor for driving each printing rubber roller to operate is connected to the nth printing rubber roller or the paper feeding rubber roller (1) in power connection.

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