JP2004210472A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of stably supplying the recording material. <P>SOLUTION: This image forming device includes a drawing roller 45, to which a sheet roll 2 formed by winding a label sheet into a roll can be fitted and which is brought in contact with the sheet roll 2 in a separation point wherein the sheet is separated from the sheet roll 2. Position of the sheet roll 2 is controlled by moving a lift roller 46 in response to a change of the outside diameter of the sheet roll 2 so that a drawing direction of the sheet separated from the separation point and the normal direction connecting the center of the drawer roller 45 and the center of the sheet roll 2 form the predetermined angle or less. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus to which a sheet roll can be attached and detached, and more particularly to an image forming apparatus that moves a mounted sheet roll according to an outer diameter of the sheet roll.
[0002]
[Prior art]
Conventionally, an image forming apparatus to which a sheet roll can be attached and detached has been known. For example, in a thermal transfer printer disclosed in Patent Document 1, a roll paper holder is mounted on a roll paper feed shaft and a roll paper mounting roller.
[0003]
[Patent Document 1]
JP 10-44481 A
[Problems to be solved by the invention]
However, in the conventional image forming apparatus, the separation point at which the recording material separates from the sheet roll is free. Therefore, as the recording material is consumed, the separation point moves, the drawing direction of the recording material changes, and there is a case where stable supply of the recording material cannot be performed. In addition, since the tension of the recording material is directly applied to the sheet roll, if the pulling force is strong, the sheet density of the sheet roll is reduced, and the rotation of the sheet roll is not proportional to the amount of the pulled out recording material. Was.
[0005]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the related art, and has as its object to provide an image forming apparatus capable of stably supplying a recording material.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an apparatus according to the present invention comprises:
A sheet roll in which the recording material is wound in a roll shape is detachable,
A drawing mechanism that pulls out the recording material from the sheet roll;
A support mechanism for supporting the sheet roll,
An image forming mechanism for forming an image on the recording material pulled out from the sheet roll,
An image forming apparatus comprising:
The drawer mechanism,
Including a drawing roller contacting the sheet roll at a separation point where the recording material is separated from the sheet roll,
The support mechanism,
The drawing direction of the recording material separated from the separation point, and the normal direction connecting the center of the drawing roller and the center of the sheet roll are set to a predetermined angle or less, according to the change in the outer diameter of the sheet roll. And moving the sheet roll.
[0007]
The support mechanism may include a support roller that follows the sheet roll while supporting the outer diameter of the sheet roll, and moves the sheet roll.
[0008]
A rotation force is applied to the sheet roll by rotating the pull-out roller.
[0009]
The support roller may move the sheet roll upward as the recording material is pulled out from the sheet roll and the outer diameter of the sheet roll decreases.
[0010]
The support roller is attached to a swing member centered on the pull-out roller,
The apparatus further comprises a mechanism for swinging the swing member.
[0011]
The support roller is attached to a movable member that approaches and separates from the pull-out roller,
It is characterized by further comprising a mechanism for moving the movable member horizontally.
[0012]
In order to achieve the above object, another device according to the present invention includes:
A sheet roll in which the recording material is wound in a roll shape is detachable,
First and second support rollers having an axis substantially parallel to the axis of the sheet roll and supporting the sheet roll;
An image forming mechanism for forming an image on the recording material pulled out from the sheet roll,
An image forming apparatus comprising:
A normal direction connecting the center of the first support roller and the center of the sheet roll disposed closer to the image forming mechanism than the second support roller, and a drawing direction of the recording material from the sheet roll. , Wherein the second support roller is moved in accordance with a change in the outer diameter of the sheet roll so that the angle formed by the second support roller is within a predetermined range.
[0013]
The second support roller is driven by the sheet roll while supporting the outer diameter of the sheet roll, and moves the sheet roll.
[0014]
A rotation force is applied to the sheet roll by rotating the first support roller.
[0015]
The second support roller moves the sheet roll upward as the recording material is pulled out from the sheet roll and the outer diameter of the sheet roll decreases.
[0016]
The first support roller and the second support roller are attached to a swing member that swings around the first support roller,
The apparatus further comprises a mechanism for swinging the swing member.
[0017]
The second support roller is attached to a movable member that approaches and separates from the pull-out roller,
It is characterized by further comprising a mechanism for moving the movable member horizontally.
[0018]
It is further characterized by further comprising a sensor for detecting a change in the outer diameter of the sheet roll.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be illustratively described in detail with reference to the drawings. However, the components described in this embodiment are merely examples, and are not intended to limit the scope of the present invention only thereto.
[0020]
(1st Embodiment)
FIG. 1 is a schematic configuration diagram showing an internal configuration of a label printer 1 as a first embodiment of the present invention.
[0021]
The printer 1 is connected to a computer or the like (not shown), receives print data transmitted from the computer or the like, and performs printing based on the print data.
[0022]
The printer 1 has a roller pair of a sheet roller 45 and a lift roller 46 arranged substantially in parallel. The sheet roll 2 can be placed on the sheet roller 45 and the lift roller 46. The sheet roll 2 is obtained by winding a label sheet as a recording material into a roll.
[0023]
As a label sheet, for example, a long sheet in which an adhesive layer is adhered to the back surface and the adhesive layer is further covered with a release tape, or a die-cut in which a plurality of labels are attached at regular intervals to a long mount. Labels and the like can be used. Also, the printer 1
A plurality of label sheets having different width dimensions can be used.
[0024]
The sheet roller 45 and the lift roller 46 have a structure in which a surface layer having high sliding resistance such as rubber is provided on a metal cored bar. The sheet roller 45 receives a driving force from a motor (not shown) and rotates to pull out the sheet from the roll 2.
[0025]
The sheet pulled out by the sheet roller 45 is sandwiched between the transport roller 42 and the roller 41. The transport roller 42 is rotated forward and backward at a predetermined speed by a motor (not shown). Therefore, the sheet is sent in the printing direction or the reverse direction according to the rotation of the transport roller 42. In addition, a sheet sensor 51 is provided between the sheet roller 45 and the transport roller 42, and determines whether the sheet pulled out from the roll 2 is held by the transport roller 42 and the roller 41 or not.
[0026]
The printer 1 is provided with a cover 12 that can be freely opened and closed, and a print head 13 is attached to the cover 12. The sheet sandwiched between the transport rollers 42 and the rollers 41 is sent to the print head 13.
[0027]
The ink ribbon cassette 3 is detachably attached to the cover 12. When the ink ribbon cassette 3 is loaded on the cover 12, the ink ribbon 31 of the ink ribbon cassette 3 covers the print head 13.
[0028]
The ink ribbon cassette 3 has a cylindrical bobbin (not shown) on which an ink ribbon 31 is wound in an initial state, and a cylindrical bobbin (FIG. 1) for winding the ink ribbon 31 wound on the bobbin as printing is performed. (Not shown) are loaded into the cassette case 34. A pair of shaft members 32 and 33 are inserted into both sides of both bobbins. The shaft members 32 and 33 are exchanged for appropriate length so that they can be mounted on the ink ribbon cassette 3 according to the width of the ink ribbon 31.
[0029]
43 is a platen roller. When the cover 12 is closed, the print head 13 is located above the platen roller 43. The print head 13 can be moved up and down by the cam mechanism 43a. When printing is performed, the print head 13 is lowered by the pressure of the pressure spring 71, and the printing head 13 and the platen roller 43 hold the conveyed sheet, and convey the image onto the sheet surface while conveying. Form. When printing is not performed, the print head 13 is pushed up by the cam mechanism 43a and separates from the platen roller 43.
[0030]
Reference numeral 52 denotes a leading end detection sensor that is located downstream of the print head 13 with the cover 12 closed, and is a reflection-type optical sensor attached to the upper surface of the roll 2. In addition to the position of the leading end of the roll 2, when a die-cut label is set as the roll 2, the leading end of the label affixed to the backing sheet, or the trailing end depending on the print mode, is detected.
[0031]
A front panel 14 is attached to the front of the printer 1 so that the front panel 14 can be opened so as to fall forward. The front panel 14 has discharge ports 15 and 16 opened in two upper and lower stages. When printing on a sheet with the printer 1, the printed sheet is discharged from the upper discharge port 15. The sheet is automatically cut by the cutter 17 for each predetermined size defined by the print content and the setting of the margin amount and the like. The cutter 17 is disk-shaped and has a cutting edge formed all around. Then, the cutter 17 is moved by a motor (not shown) to cut the sheet.
[0032]
When printing on a die-cut label and performing label peeling processing, the path of the backing sheet is bent downward immediately before the upper discharge port 15, and is sandwiched between a pair of rollers 18 a and 18 b located in the front panel 14 to discharge the lower sheet. Send out from the outlet 16 to the outside. The roller 18a is attached to the main body of the printer 1 and freely rotates. On the other hand, the roller 18b is mounted on the front panel 14, and the gear 18c is mounted on the rotation shaft of the roller 18b. When the front panel 14 is closed, the gear 18c meshes with a gear (not shown) exposed on the main body side, and the mount can be sent in the forward and reverse directions. Since the path of the mount is bent downward immediately before the upper discharge port 15 as described above, the label attached to the mount is peeled off from the mount and discharged forward through the upper discharge port 15.
[0033]
Reference numeral 53 denotes a peel sensor. When a die-cut label is set as a roll, the printed label is peeled off from the backing sheet while leaving a fixed length, and is discharged forward through the upper discharge port 15. It detects labels. Reference numeral 54 denotes a backing sheet sensor for detecting that the backing sheet transported between the rollers 18a and 18b is discharged from the lower discharge port 16.
[0034]
Next, problems that may occur in such a printer 1 will be described.
[0035]
FIG. 2 is a model diagram showing a relationship between the set roll 2 and a pair of rollers 45 and 46 supporting the roll 2.
[0036]
The sheet roller 45 is in contact with the roll 2 at a separation point where the sheet separates from the roll 2. Then, the sheet separated from the roll 2 is wound around the sheet roller 45 by a minute distance, and is pulled out at a different angle.
[0037]
When a sufficient number of sheets are wound on the set roll 2, the sheet separated from the roll 2 is pulled out at an angle θL as shown in the figure.
[0038]
However, when the sheet is pulled out from the roll 2 and the outer diameter of the roll 2 is reduced, assuming that the relative position between the sheet roller 45 and the lift roller 46 is fixed, the center thereof is lowered to the position indicated by the roll 2S. Would. When the center of the roll is lowered in this way, the sheet separated from the roll 2S changes its direction by the angle θS by the sheet roller 45.
[0039]
When the sheet changes its direction with a large curvature in this manner, there is a problem in that the sheet may bend or the label 2b may be separated from the mount 2a as shown in FIG.
[0040]
Thus, in the present embodiment, the drawing direction of the sheet separated from the separation point and the tangential direction at the contact point between the sheet roller 45 and the roll 2 are maintained near θL, and the roll is moved so as not to become excessive as θS. The roll is moved according to the change in the outer diameter. In other words, the lift roller 46 is moved so that the angle between the normal line connecting the center of the sheet roller 45 and the center of the roll 2 and the drawing direction is within a predetermined range (for example, between 100 degrees and 140 degrees). , The position of the roll 2 is controlled.
[0041]
Therefore, as shown in FIG. 1, the outer circumference of the set roll 2 is detected by the roll outer circumference detection sensor 55. The roll outer periphery detection sensor 55 uses a push-type switch, and detects the position in the height direction of the roll by detecting the outer periphery of the roll when the switch is turned on and off.
[0042]
Further, a lift roller 46 that is driven by the roll while supporting the outer diameter of the roll is rotatably attached to a swing member 47 centering on the sheet roller 45. The swing member 47 swings when the roll lift cam 48 rotates in the rotation direction r, whereby the lift roller 46 moves up and down.
[0043]
As a result, as shown in FIG. 4, the sensor 55 detects the roller 2S from which the sheet is pulled out and the outer diameter of which is reduced, rotates the roll lift cam 48, moves the lift roller 46 upward, and 2S is moved to an optimal position according to the outer diameter.
[0044]
FIG. 5 is a perspective view showing the appearance of the printer 1 with the cover 12 opened. This figure shows a state where the roll 2 is not mounted.
[0045]
In FIG. 5, reference numeral 11 denotes a position where the roll 2 is set, and a sensor 55 is provided substantially at the center thereof. The sensor 55 has a configuration in which the tip protrudes from a hole formed substantially in the center of the swinging member 47.
[0046]
When a narrow roll is set at the roll setting position 11, the pair of pressing members 11a are moved inward so that the roll is positioned at the center.
[0047]
FIG. 6 is a schematic cross-sectional view of the printer 1 with the cover 12 opened.
[0048]
Reference numeral 6 denotes an ink ribbon sensor for detecting the presence or absence and color type of the ink ribbon 31. A roller 41 that can rotate freely is attached to the ink ribbon sensor 6. When the cover 12 is closed, the roller 41 presses the sheet drawn from the roll 2 against the transport roller 42 from above.
[0049]
<Operation>
The operation of printing on the roll 2 by the printer 1 having the above configuration will be described below with reference to FIG.
[0050]
First, when print data including settings such as margins is received from a computer or the like (not shown), a sensor (not shown) determines whether the cover 12 is open. If the cover 12 is open, a message to that effect is displayed and the system waits for the cover 12 to be closed.
[0051]
When the cover 12 is closed, the sheet sensor 51 determines whether the sheet is set properly. If a sheet is not set, a message indicating that there is no sheet is displayed, and the printing operation is stopped. If the sheet is set properly, the outer circumference of the roll 2 set is subsequently detected by the roll outer circumference detection sensor 55. When the roll outer circumference detection sensor 55 detects the outer circumference of the roll 2, a motor (not shown) rotates the roll lift cam 48 and moves the lift roller 46 to an optimum position according to the outer diameter of the roll 2.
[0052]
When the roll outer diameter is large and the switch of the roll outer periphery detection sensor 55 is off, the lift roller 46 is moved downward, and the roll 2 is lowered until the switch of the roll outer periphery detection sensor 55 is pressed by the roll 2 (on). Let it. Thereafter, the lift roller 46 is raised again, and immediately after the roll outer peripheral detection sensor 55 is turned off, the lift roller 46 stops lifting.
[0053]
Here, when the roll outer periphery detection sensor 55 is off, the lift roller 46 is moved downward until the sensor 55 is turned on. However, when the roll outer periphery detection sensor 55 is off, the lift roller 46 is moved. It may be controlled so as not to exist. That is, even if the roll outer periphery detection sensor 55 is turned off at the time when the print data is received, the problem described with reference to FIGS. 2 and 3 does not occur, and the lift roller does not need to be moved in that state. In this case, it is sufficient to control the lift roller 46 to move only after the sheet is consumed and the outer diameter of the roll is reduced and the sensor 55 is turned on.
[0054]
Conversely, when the roll outer diameter is small and the switch of the roll outer periphery detection sensor 55 is pressed, the lift roller 46 is raised, and immediately after the roll outer periphery detection sensor 55 is turned off, the lifting of the lift roller 46 is stopped. I do.
[0055]
Subsequently, it is checked by the ribbon presence / absence detection sensor 8 of the ink ribbon sensor 6 whether the ink ribbon 31 is set. When the ink ribbon cassette 3 is not loaded, or when the ink ribbon 31 wound around the bobbin (not shown) is completely wound around the bobbin (not shown) even if the ink ribbon cassette 3 is loaded, no ink ribbon is present. Further printing operations are stopped as an error.
[0056]
If there is no abnormality in each of the above steps, the bobbin (not shown) is rotated in the forward direction to apply a constant tension to eliminate the slack of the ink ribbon 31.
[0057]
Next, the color type of the ink ribbon 31 is determined by the ink ribbon sensor 6. Compared with the color type data included in the print data received from the computer or the like, if the color type of the actually loaded ink ribbon 31 does not match the color type data, the wrong type of ink ribbon is set. Therefore, the user is notified and the printing operation is stopped.
[0058]
When the color type of the ink ribbon 31 matches the color type data, it is checked whether or not the label is detected by the peel sensor 53. At the start of printing, since no label has been printed yet, if the peel sensor 53 detects a label, it determines that an error has occurred and stops the printing operation.
[0059]
If the above-described pre-print check is completed and there is no error, printing is started. As described above, the printer 1 can perform printing on a sheet and printing on a die-cut label. Therefore, the print mode is read from the print data received from the computer, and a sheet print process is performed for printing on a sheet, and a die cut label printing process is performed for printing on a die cut label.
[0060]
When the sheet printing process is selected, first, it is checked whether or not the mount sensor 54 is in the detection state. If the mount sensor 54 is in the detection state, there is a possibility that the die-cut label is set by mistake or the sheet is set in the die-cut label mode.
[0061]
Next, the tip detection sensor 52 is checked. If the leading edge detection sensor 52 is on, the sheet that is the roll 2 is pulled out from the roll, and the sheet covers the leading edge detection sensor 52. Then, the conveying roller 42 is rotated backward until the leading edge detection sensor 52 is turned off, and the sheet is fed backward. When the leading edge detection sensor 52 is turned off, the leading edge of the sheet is located at the position where the leading edge detection sensor 52 is installed. Therefore, the reverse feeding of the sheet is stopped and the printing process is started.
[0062]
When printing a sheet, there are a cutting mode in which the sheet is cut by the cutter 17 at predetermined lengths and a non-cutting mode in which the sheet is not cut. If the non-cut mode is set, printing is continued until all the received print data is printed. Then, after printing all the print data, the label is transported until the last printed portion passes through the cutter 17, and the label is cut by the cutter 17, thereby completing the printing process.
[0063]
On the other hand, if the cutting mode is set in which the cutting is performed for each length of one page according to the print data input in units of a page, the portion printed for one page is sent until it passes through the cutter 17, and the cutting is performed. After cutting at 17, the sheet is reversed, the next page is printed again, and then sent to the cutter 17 for cutting, and the cycle of cutting is continued for the specified number of pages. Then, when printing for the specified number of pages is completed, the last page is conveyed until the printed portion passes through the cutter 17, cut by the cutter 17, and the printing process ends.
[0064]
When performing die-cut label printing, it is first checked whether or not label peeling processing is to be performed. The label peeling process is a process in which the mount is discharged from the lower discharge port 16, the label is peeled from the mount, and the label is discharged from the upper discharge port 15. In the label peeling process, the label is not completely discharged from the upper discharge port 15, and the printing process is temporarily stopped while a fixed length of the rear end portion is adhered to the backing paper. The label ejected leaving a certain length from the upper outlet 15 is picked up with a finger, and when the label is taken out, the printing process is restarted, and the next label is ejected leaving a certain length from the outlet 15 again. The printing process stops temporarily.
[0065]
If the label peeling process is not selected, the printed label is discharged from the upper discharge port 15 while being stuck to the backing paper. Further, it is possible to set a mount-sheet non-cutting mode in which the mount is discharged in a continuous state without cutting, or a mount-cut mode in which the mount is cut between the labels and the labels are discharged one by one.
[0066]
In the mount cutting mode, after printing on the first label is completed, the mount is conveyed, and the leading end position sensor 52 detects the trailing end position of the printed label and the leading end position of the second label. Based on the detected position, the conveyance is stopped when the cutter 17 comes to the middle between the printed label and the second label, and the mount is cut. The cut first label is discharged from the upper discharge port 15. When the cutting is completed, the backing paper is fed back, and the second label is conveyed to the printing position based on the leading edge position of the second label detected by the leading edge detection sensor 52 during the backward feeding. Then, a series of operations such as printing on the second label is repeated. In addition, when the mount sheet non-cutting mode or the mount sheet cutting mode is set, if the mount sensor 54 is in the detection state, the printing process is not started as a roll set error.
[0067]
The die-cut labels are attached to the mount at a fixed pitch.In the mount non-cutting mode, the pitch is input, and the mount is transported and printed at each input pitch. It is possible to set a high-accuracy transport mode in which the leading edge is detected for each label and printing is performed based on the leading edge position.
[0068]
In the mode of detecting the leading edge of each label, when the die-cut label as the roll 2 is pulled out and set, the die-cut label is transported until the leading edge of the leading label is detected by the leading edge detection sensor 52. Since the leading edge detection sensor 52 is located downstream of the print head 13, when the leading edge detection sensor 52 detects the leading edge, the label has passed through the print head 13. When the leading edge position is detected, the backing sheet is fed back with reference to the leading edge position, and the label is returned to the printing position. Then, when the printing on the label is completed, the mount is conveyed until the leading edge of the next label is detected by the leading edge detection sensor 52. When the leading edge is detected, the backing paper is fed back, the second label is returned to the printing position, and printing is performed.
[0069]
In the case of the peel mode in which the label peeling process is selected, after printing on the first label is completed, the label is conveyed by a predetermined distance while detecting the states of the mount sensor 54 and the peel sensor 53. Stop. The predetermined distance is determined by detecting the rear end position of the label by the leading edge detection sensor 52 and sending a set distance from the detected position, so that the label has a fixed length regardless of the label length when stopped. Is set to a position that remains on the backing paper. At this time, it is confirmed that the peel sensor 53 is turned on. When the label peeling process is selected, the mount is sandwiched between the rollers 18a and 18b, is discharged from the lower discharge port 16, and it is previously determined that the discharge path of the mount has been changed to the rollers 18a and 18b. It is detected by the sensor 54.
[0070]
When the printed label is removed from the backing paper, the peel sensor 53 is turned off. Since the distance between the peel sensor 53 and the tip detection sensor 52 is large, at this point, the tip of at least the second unprinted label has passed through the tip detection sensor 52. When the peel sensor 53 is turned off, the transport roller 42 is rotated in the reverse direction, and after the printing of the first label is completed, the backing paper is transported by the same distance as the predetermined distance to which the label has been fed. During the reverse feeding, the leading edge of the label detected last by the leading edge detection sensor 52 is detected as the leading edge of the second label, and the second unprinted label is transported to the printing position based on the leading edge position. Then, after printing on the unprinted label, a series of operations including the operation of transporting the backing paper by a predetermined distance as in the case of the first label described above are repeated.
[0071]
In any case, since the outer diameter of the roll 2 decreases as printing is performed, the roll 2 descends between the sheet roller 45 and the lift roller 46. At this time, if the roll outer circumference detection sensor 55 is turned on even during printing, the lift roller 46 is moved upward to raise the roll 2 to a position where the roll outer diameter detection sensor 55 is turned off.
[0072]
As described above, since the sheet roll is moved in the vertical direction in accordance with the change in the outer diameter of the sheet roll, it is possible to pull out the sheet while substantially maintaining the position of the contact point between the sheet roll and the drive roller. Accordingly, it is possible to prevent the sheet from being bent and the die cut label from being peeled off from the long backing paper, and to prevent image defects and stagnant jams.
[0073]
(2nd Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. FIGS. 7 and 8 are schematic cross-sectional views of a printer according to a second embodiment of the present invention. The second embodiment differs from the first embodiment only in the method of driving the lift roller 46. Other configurations and operations are the same as those in the first embodiment, and thus, the same components are denoted by the same reference numerals and description thereof will be omitted.
[0074]
The lift roller 46 is rotatably attached to a moving member 49 that moves horizontally. The moving member 49 can reciprocate horizontally between the state shown in FIG. 7 and the state shown in FIG. 8 by the rotation of the roll lift cam 48 whose drive is transmitted by a motor (not shown). Thus, the roll lift cam 48 moves the set roll 2 to an optimum position according to its outer diameter by moving the lift roller 49 via the moving member 49.
[0075]
In the present embodiment, substantially the same operation as in the first embodiment is performed. That is, when print data is received from a computer or the like (not shown), the outer circumference of the set roll 2 is detected by the roll outer circumference detection sensor 55. Then, the roll lift cam 48 is rotated, and the lift roller 46 is horizontally moved to a position optimal for the roll outer diameter of the set roll 2. When the outer diameter of the roll is large and the switch of the roll outer periphery detection sensor 55 is not pressed, the lift roller 46 is once moved in a direction away from the sheet roller 45, and the switch of the roll outer periphery detection sensor 55 is pressed by the roll 2. Roll 2 is lowered until it is turned on. Thereafter, the lift roller 46 is moved again in a direction to approach the sheet roller 45, and the movement of the lift roller 46 is stopped immediately after the roll outer periphery detection sensor 55 is turned off.
[0076]
Conversely, the roll outer diameter is small like the roll 2s, the switch of the roll outer circumference detection sensor 55 is pressed (ON), and the lift roller 46 is moved in a direction to approach the sheet roller 45, and the roll outer diameter detection sensor 55 Immediately after being turned off, the movement of the lift roller 46 is stopped. The roll outer periphery detection sensor 55 uses a push-type switch, and detects the outer periphery of the roll when the switch is turned on or off.
[0077]
After performing a pre-printing check such as the presence or absence of a roll or a ribbon and the identification of the ribbon color, if there is no error, printing is started.
[0078]
(Other embodiments)
The present invention is not limited to the first embodiment and the second embodiment, and can take various forms without departing from the gist of the present invention. In the present embodiment, a thermal printer using an ink ribbon has been described. However, other printers such as ink jet and dot impact may be used. Further, in the present embodiment, the lift roller for raising and lowering the roll is configured by providing a rubber surface layer on a metal cored bar. However, a roller made of resin or metal, or a metal shaft alone may be used. Good. The movement of the lift roller is not performed by the cam, but may be performed by another mechanism such as using a gear and a rack. The change in the outer diameter of the roll is also detected by another detection means such as a photo sensor. The position of the detection means may be any position as long as the change in the outer diameter of the roll can be detected.
[0079]
Further, in the above embodiment, the sheet roller 45 and the lift roller 46 are configured to directly contact the sheet, but the present invention is not limited to this, and disk-shaped flanges are provided on both sides of the axis of the sheet roll. A configuration may be adopted in which at least one of these roller pairs is in contact with the flange. In this case, taking into account the difference between the flange diameter and the roll outer diameter, for example, the position of the roll outer diameter is detected, and the lift roller is moved so as to lower the sheet roll as the sheet roll outer diameter decreases.
[0080]
Furthermore, a support roller for rotatably supporting the roll may be provided near the center of the roll, and a sensor or cam may be omitted by providing a groove for the support roller to move in the housing of the printer. That is, the roll is supported only by the supporting roller and the sheet roller near the axis, and the rollers are arranged such that the roll is pressed by the sheet roller by its own weight or the weight of the supporting roller. When the outer diameter of the roll decreases, the support roller moves toward the sheet roller due to the weight of the roll or the weight of the support roller. As a result, the sheet is consumed in a state where the drawing direction of the sheet separated from the separation point and the tangential direction at the contact point between the sheet roller and the roll are substantially maintained.
[0081]
In the above-described embodiment, the thermal label printer has been described as an example. However, the image forming apparatus according to the present invention is not limited to this, and any printer, facsimile, copier, This is a concept that includes a multifunction peripheral having the functions described above. Further, the recording material according to the present invention is not limited to a label sheet, but is a concept including all printable rolls such as a recording sheet, a plastic sheet, and a metal sheet.
[0082]
【The invention's effect】
As is apparent from the above description, the present invention can provide an image forming apparatus capable of stably supplying a recording material.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic cross section of a printer as a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a problem that may occur in a printer in which a sheet roll can be attached and detached.
FIG. 3 is a diagram illustrating a problem that may occur in a printer in which a sheet roll can be attached and detached.
FIG. 4 is a diagram showing a schematic cross section of the printer as the first embodiment of the present invention.
FIG. 5 is a perspective view of the printer according to the first embodiment of the present invention when a cover is released.
FIG. 6 is a cross-sectional view of the printer according to the first embodiment of the present invention when a cover is released.
FIG. 7 is a diagram illustrating a schematic cross section of a printer as a second embodiment of the invention.
FIG. 8 is a diagram illustrating a schematic cross section of a printer according to a second embodiment of the invention.
[Explanation of symbols]
1 Printer 2 Roll 45 Sheet Roller 46 Lift Roller 47 Swinging Member 48 Roll Lift Cam 49 Moving Member 55 Roll Outer Edge Detection Sensor

Claims (13)

A sheet roll in which the recording material is wound in a roll shape is detachable,
A drawing mechanism that pulls out the recording material from the sheet roll;
A support mechanism for supporting the sheet roll,
An image forming mechanism for forming an image on the recording material pulled out from the sheet roll,
An image forming apparatus comprising:
The drawer mechanism,
Including a drawing roller contacting the sheet roll at a separation point where the recording material is separated from the sheet roll,
The support mechanism,
The drawing direction of the recording material separated from the separation point, and the normal direction connecting the center of the drawing roller and the center of the sheet roll are set to a predetermined angle or less, according to the change in the outer diameter of the sheet roll. An image forming apparatus, wherein the sheet roll is moved. The image forming apparatus according to claim 1, wherein the support mechanism includes a support roller that follows the sheet roll while supporting an outer diameter of the sheet roll and moves the sheet roll. The image forming apparatus according to claim 1, wherein a rotation force is applied to the sheet roll by rotating the drawing roller. 3. The image forming apparatus according to claim 2, wherein the support roller moves the sheet roll upward as the recording material is pulled out from the sheet roll and the outer diameter of the sheet roll decreases. . The support roller is attached to a swing member centered on the pull-out roller,
The image forming apparatus according to claim 3, further comprising a mechanism that swings the swing member. The support roller is attached to a movable member that approaches and separates from the pull-out roller,
The image forming apparatus according to claim 1, further comprising a mechanism that horizontally moves the movable member. A sheet roll in which the recording material is wound in a roll shape is detachable,
First and second support rollers having an axis substantially parallel to the axis of the sheet roll and supporting the sheet roll;
An image forming mechanism for forming an image on the recording material pulled out from the sheet roll,
An image forming apparatus comprising:
A normal direction connecting the center of the first support roller and the center of the sheet roll disposed closer to the image forming mechanism than the second support roller, and a drawing direction of the recording material from the sheet roll. Wherein the second support roller is moved in accordance with a change in the outer diameter of the sheet roll so that the angle between the second support roller and the second support roller is within a predetermined range. The image forming apparatus according to claim 7, wherein the second support roller is driven by the sheet roll while supporting an outer diameter of the sheet roll, and moves the sheet roll. The image forming apparatus according to claim 7, wherein a rotation force is applied to the sheet roll by rotating the first support roller. The image according to claim 8, wherein the second support roller moves the sheet roll upward as the recording material is pulled out from the sheet roll and the outer diameter of the sheet roll decreases. Forming equipment. The first support roller and the second support roller are attached to a swing member that swings around the first support roller,
The image forming apparatus according to claim 7, further comprising a mechanism that swings the swing member. The second support roller is attached to a movable member that approaches and separates from the pull-out roller,
The image forming apparatus according to claim 7, further comprising a mechanism that horizontally moves the movable member. The image forming apparatus according to claim 1, further comprising a sensor that detects a change in an outer diameter of the sheet roll.

Images