JP3642541B2 - Recording paper guide device for thermal printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording paper guide device for a thermal printer. More specifically, the recording paper is nipped, the recording paper is sent out to the thermal head side and pulled back, and this sending and pulling are alternately performed to record a full color image. The present invention relates to a recording paper guide device for a thermal printer.
[0002]
[Prior art]
In a color thermal printer, for example, a color thermal printer, color thermal recording paper is used, and a full color image is recorded in three-color plane order. This color thermosensitive recording paper has a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer sequentially arranged on the base. The yellow thermosensitive coloring layer, which is the uppermost layer, has the highest thermal sensitivity and the lowest layer. The thermal sensitivity of the cyan thermosensitive coloring layer is the lowest. Each thermosensitive coloring layer is recorded in order from the top layer, but when recording the magenta thermosensitive coloring layer, a purple visible of 420 nm is visible after recording the yellow image so that the uncolored components in the yellow thermosensitive coloring layer do not color. Light fixing by irradiation with light. Similarly, after recording on the magenta thermosensitive coloring layer, the magenta thermosensitive coloring layer is photofixed by irradiating with 365 nm ultraviolet rays. In such a color thermal printer, a pair of conveying rollers composed of a capstan roller and a nip roller is used to increase the feeding accuracy of the color thermal recording paper, and a full color image is recorded by feeding or pulling back the recording paper three times. . When the leading edge of the recording paper is guided to the thermal head, the thermal head and the platen roller are released from pressure contact so that the leading edge of the recording paper passes smoothly between the thermal head and the platen roller.
[0003]
[Problems to be solved by the invention]
In the conventional color thermal printer, the platen roller is fixed and the thermal head is moved up and down, so that the heating element array of the thermal head is pressed against the recording paper for thermal recording. In this method, the thermal head is moved up and down, so the thermal head is retracted from the recording paper path at the retracted position, so there is a possibility that the leading edge of the recording paper will be locked due to gaps or steps in the thermal head and a paper jam will occur. There is an advantage that it decreases. On the other hand, the conveyance load fluctuation due to the vertical movement of the thermal head is larger than that due to the vertical movement of the platen roller, and there is a problem that uneven printing tends to occur. On the other hand, as shown in FIG. 7, the thermal head 2 is fixed and the platen roller 3 is moved up and down by the roller shift mechanism 4.
[0004]
However, when the thermal head 2 is fixed and the platen roller 3 is moved up and down, there is a gap 5a, a step 5b, etc. between the thermal head body 2a and the cover 2b that protects the wiring portion and the like below the thermal head body 2a. When the recording paper 6 is fed by the conveying roller pair 7, there is a problem that the recording paper leading edge 6a is locked by the gap 5a or the step 5b. On the other hand, it is conceivable to create a thermal head without the gap 5a or the step 5b. However, in this case, there is a problem that the manufacturing cost increases.
[0005]
The present invention has been made to solve the above problems, and a thermal printer in which the leading edge of the recording paper is not locked to a gap or a step between the thermal head and the protective cover even when the thermal head is fixed. An object of the present invention is to provide a recording paper guide apparatus.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a recording paper guide device for a thermal printer according to claim 1 is disposed between a pair of transport rollers and a thermal head, and guides the recording paper from the pair of transport rollers to a position below the thermal head. A movable guide that is mounted so as to be freely displaceable between a guide position and a retracted position that retracts from the recording paper path during recording of the thermal head, and a platen displacement member that is provided to switch from the retracted position of the platen to the crimping position. And a guide displacement member that displaces the movable guide from the guide position to the retracted position due to the displacement at this time. According to a second aspect of the present invention, the movable guide is displaced from the retracted position to the guide position by a guide displacement member when the platen is switched from the crimping position to the retracted position. In addition, it is preferable to provide a guide plate urging means for urging the movable guide on the opposite side to the displacement direction of the movable guide by the guide displacement member. Further, it is preferable that the movable guide is constituted by a guide plate and a holding plate, and at the guide position, the guide plate is inserted obliquely with respect to the recording paper path. Further, it is preferable that the holding plate is made of a member having a spring property and the guide plate urging means is constituted by the holding plate. The pair of conveying rollers performs feeding and withdrawal of the recording paper by changing the rotation direction. When feeding the recording paper, the platen roller is moved to the retracted position and the leading edge of the recording paper is guided to the thermal head side to perform recording. It is preferable to perform thermal recording with the platen roller placed in the pressure-bonding position when the paper is pulled back.
[0007]
[Action]
The leading edge of the recording paper is fed to the thermal head side by the pair of conveying rollers. When the recording paper is fed, the movable guide is set at the guide position, and the platen roller is at the retracted position away from the heating element array of the thermal head. Therefore, when the recording paper is fed to the thermal head side, the tip of the recording paper comes into contact with the guide surface of the movable guide at an angle, and the recording paper is guided downward of the thermal head by this guide surface. Accordingly, the leading edge of the recording paper is not locked by a gap or a step between the thermal head main body and the protective cover, and paper jam is prevented. When the recording area of the recording paper passes the heating element array, the feeding of the recording paper is finished and the recording paper is pulled back. At the time of this pull back, the platen displacement member is displaced and the platen roller is switched from the retracted position to the crimping position. Further, the guide displacement member switches the movable guide from the guide position to the retracted position by the displacement of the platen displacement member. At the retracted position, since the guide surface of the movable guide is retracted from the recording paper path, the recording paper does not come into contact with the movable guide, and the recording paper is smoothly pulled back. While the recording paper is pulled back, for example, a yellow image is thermally recorded on the recording paper. When the recording of the yellow image is finished and the leading edge of the recording paper approaches the pair of conveyance rollers, the drawing back of the recording paper is finished. After the recording paper is pulled back, the platen roller is displaced from the pressure bonding position to the retracted position by the platen displacement member. Since the guide displacement member is displaced by the displacement of the platen displacement member, the movable guide is switched from the retracted position to the guide position. Thereafter, the recording paper is sent out and pulled back in the same manner.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
In the side view shown in FIG. 2, the recording paper roll 10 is housed in the roll housing chamber 9 in a roll form by being attached to the attachment shaft 8. The conveying roller pair 11 pulls out the color thermal recording paper 12 from the recording paper roll 10 and sends it to the thermal head 13. The conveyance roller pair 11 includes a capstan roller 11a, a nip roller 11b disposed above the capstan roller 11a, an auxiliary nip roller 11c disposed obliquely above the capstan roller 11a, and a roller shift mechanism 11d. The nip roller 11b and the auxiliary nip roller 11c are moved up and down by the roller shift mechanism 11d and enter the nip state of the recording paper 12 when lowered, and the nip release state of the recording paper 12 when raised.
[0009]
The auxiliary nip roller 11c is disposed at a position rotated by, for example, 60 degrees counterclockwise from the nip roller 11b with the capstan roller 11a as a center. Accordingly, the recording paper 12 is always wound around the capstan roller 11a by the nip roller 11b and the auxiliary nip roller 11c at 60 degrees. As a result, the curl is removed by curving the recording paper 12 on the side opposite to the roll form of the recording paper 12. Note that the winding angle is not limited to 60 degrees, and can be appropriately changed depending on the thickness of the recording paper 12 and the like.
[0010]
As is well known, the recording paper 12 is provided with a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer in this order on the support, and the uppermost yellow thermosensitive coloring layer has the highest thermal sensitivity. The yellow thermosensitive coloring layer loses its coloring ability by violet visible light of 420 nm, and the magenta thermosensitive coloring layer loses its coloring ability by 365 nm ultraviolet light.
[0011]
A thermal head 13 and a platen roller 14 are disposed on the downstream side of the conveyance roller pair 11 in the recording paper feed direction. The thermal head 13 is attached and fixed to a machine frame (not shown). The platen roller 14 is made of hard rubber and is rotatable. The platen roller 14 is mounted so as to be movable up and down by an up / down mechanism 15 and is displaced between a crimping position and a retracted position. As shown in FIG. 1B, during thermal recording, the platen roller 14 is displaced upward to a pressure-bonding position, and the recording paper 12 is pressed against the heating element array 13a of the thermal head 13. Further, as shown in FIG. 1A, when the recording paper 12 is sent out, the platen roller 14 is displaced downward to the retracted position, and the recording paper 12 passes between the thermal head 13 and the platen roller 14. A gap is formed.
[0012]
The up / down mechanism 15 includes a pair of roller displacement levers 16 and a solenoid 17. The pair of roller displacement levers 16 are rotatably attached to a machine frame (not shown) via an attachment shaft 18. In addition, a platen roller 14 is rotatably attached to the roller displacement lever 16 via an attachment shaft 14a. Further, a push-up plate 19 as a guide displacement member is formed at the upper end of the roller displacement lever 16. The push-up plates 19 are arranged on both sides of the path avoiding the position where the recording paper 12 passes so as not to obstruct the conveyance of the recording paper 12.
[0013]
The heat generating element array 13a of the thermal head 13 has a large number of heat generating elements formed in a line in the axial direction of the platen roller 14, and each heat generating element is driven in accordance with image data during thermal recording. A full-color image is recorded in three color planes sequentially in 12 recording areas. The thermal head 13 includes a head substrate 20 that also serves as a mounting plate, a thermal head main body 21 in which a heating element array 13 a is formed, a heat radiating plate 22, and a protective cover 23. A thermal head main body 21 is attached to the head substrate 20 via a heat radiating plate 22, and the thermal head main body 21 is attached to the machine frame via the head substrate 20. The protective cover 23 is fixed to the head substrate 21 via mounting screws 24, and covers the lower portion of the thermal head main body 21 and the head substrate 20 to protect wiring and the like.
[0014]
As shown in FIG. 2, a cutter 25 is disposed on the downstream side of the thermal head 13. When the pair of movable blades 25a move up and down, the cutter 25 cuts the recording paper 12 from the planned cutting line (virtual line) and separates the recording area portion as a sheet-like print.
[0015]
A fixing device 30 is disposed on the downstream side of the cutter 25. The fixing device 30 includes a reflector 31, a yellow fixing lamp 32, and a magenta fixing lamp 33. The yellow fixing lamp 32 emits violet visible light having a wavelength of 420 nm to fix the yellow thermosensitive coloring layer, so that the yellow component does not color during the next magenta recording. The magenta fixing lamp 33 emits ultraviolet rays having a wavelength range of 365 nm to fix the magenta thermosensitive coloring layer so that the magenta component does not color during the next cyan recording.
[0016]
In order to form a path of the recording paper 12 from the recording paper roll 10 to the fixing device 30, a paper feed section guide plate 40, lower paper guide plates 41 and 42, a movable guide 43, and an upper paper guide plate 44 are provided. ing. The first lower paper guide plate 41 is disposed between the transport roller pair 11 and the platen roller 14. The second paper guide plate 42 is disposed between the platen roller 14 and the paper discharge port (not shown). The movable guide 43 is disposed above the first lower paper guide plate 41 between the transport roller pair 11 and the thermal head 13, and is attached to the upper surface of the thermal head 13 via an attachment screw 45. The upper paper guide plate 44 is disposed between the thermal head 13 and the paper discharge port. The second lower paper guide plate 42 and the upper paper guide plate 44 are paired. The second lower paper guide plate 42 is formed with openings for the cutter 25 and the discharge roller pair 46. Further, the upper paper guide plate 44 is formed with openings for the cutter 25, the fixing device 30, and the paper discharge roller pair 46.
[0017]
The movable guide 43 is configured by bending a thin plate having a spring property, and includes a guide plate main body 43a and a holding plate 43b. The holding plate 43 b is bent in an L shape, a guide plate main body 43 a is disposed at one end thereof, and the other end is fixed to the upper surface of the thermal head 13 by a mounting screw 45. The guide plate main body 43a is disposed obliquely with respect to the path of the recording paper 12 at the guide position, and the leading end of the recording paper 12 is in contact with the recording paper 12 at an angle so that the recording paper 12 is located below the thermal head 13. To guide you. Therefore, the leading edge of the recording paper 12 can be smoothly guided below the thermal head 13 without the leading edge of the recording paper 12 being locked to a gap or a step between the thermal head main body 21 and the protective cover 23. .
[0018]
Both side portions of the guide plate main body 43a are pushed up by the push-up plate 19 when the platen displacement lever 16 is in the crimping position. As a result, the guide plate body 43a is moved to the retracted position as shown in FIG. Further, as shown in FIG. 1A, when the platen roller 14 is in the retracted position, the push-up plate 19 is also displaced downward and does not contact both side portions of the guide plate main body 43a. The plate body 43a is set to the guide position by the spring property of the holding plate 43b. Thus, in conjunction with the displacement of the platen roller 14, the guide plate body 43a of the movable guide 43 is automatically set to the guide position and the retracted position. In addition, since it is not necessary to provide a special shift mechanism for the movable guide 43, the overall configuration can be simplified.
[0019]
As shown in FIG. 2, the paper discharge roller pair 46 is moved away from the path of the recording paper 12 except for paper discharge by the roller shift mechanism 46c shown in FIG. , And ejects this from the paper exit.
[0020]
FIG. 3 is a block diagram showing the electrical configuration of the color thermal printer. The operation unit 50 includes a print start key and sends various commands to the controller 51. The controller 51 controls the driver 52, the cutter driving unit 53, the up / down mechanism 15, the print control unit 55, the lamp control unit 56, the roller shift mechanisms 11 d and 46 c, and the counter 57.
[0021]
The controller 51 sends a rotation direction signal and a drive pulse to the driver 52. The driver 52 rotates the pulse motor 60 in the normal direction or the reverse direction, and rotates the capstan roller 11a of the conveying roller pair 11 and the driving roller of the paper discharge roller pair 46 in the normal direction or reverse direction. The counter 57 starts a count operation when the tip detection signal of the tip sensor 61 is input, counts up when the pulse motor 60 rotates forward, and counts down when it reverses. The tip sensor 61 is disposed between the conveying roller pair 11 and the thermal head 13 as shown in FIG.
[0022]
The cutter driving unit 53 moves the movable blades 25a of the cutter 25 up and down, cuts the recording paper 12 from the planned cutting line, and separates the printed portion as a sheet-like print. The up / down mechanism 15 includes a platen displacement lever 16 and a solenoid 17, and as shown in FIG. 1B, the platen roller 14 is lifted at the pressure-bonding position to bring the recording paper 12 into the heating element array 13 a of the thermal head 13. Press. Further, as shown in FIG. 1A, the platen roller 14 is lowered at the retracted position so that the recording paper 12 is separated from the heating element array 13a. The print control unit 55 includes a memory storing three-color image data for one frame and a head driver, and drives each heating element of the thermal head 13 according to the image data of each color. These heating elements generate heat according to the image data and the color to be recorded, and develop the recording paper 12 to a desired density.
[0023]
The lamp controller 56 controls light emission from the yellow fixing lamp 32 and the magenta fixing lamp 33. The roller shift mechanisms 11d and 46c are composed of solenoids or the like, and bring the conveyance roller pair 11 and the discharge roller pair 46 into a nip state or a nip release state.
[0024]
Next, the operation of the above embodiment will be described based on the flowchart shown in FIG. After the image data to be printed is captured, if the operation unit 50 is operated to indicate printing, the controller 51 first rotates the pulse motor 60 forward via the driver 52 and the recording paper roll 10 by the transport roller pair 11. Then, the recording paper 12 is pulled out from the recording head 12 and sent to the thermal head 13. As shown in FIG. 1A, when the recording paper 12 is fed, the platen roller 14 is set at the retracted position by the up / down mechanism 15. At this retracted position, the push-up plate 19 is also displaced downward, so that the push-up plate 19 and the guide plate main body 43a do not come into contact with each other, and the guide plate main body 43a is brought to the guide position by the spring property of the holding plate 43b. ing. Therefore, since the leading end of the recording paper 12 is guided below the thermal head 13 by the guide plate main body 43a, the leading end of the recording paper 12 may be locked in a gap or a step between the head main body 21 and the protective cover 23. The leading edge of the recording paper 12 can be smoothly fed to the thermal head 13 side.
[0025]
When the leading edge of the recording paper 12 passes through the leading edge sensor 61, the controller 51 starts the count up of the counter 57 from the leading edge detection time. Based on the up-count value, the controller 51 detects that the recording area has passed through the heating element array 13a of the thermal head 13, and ends the sending of the recording paper 12.
[0026]
Next, the controller 51 reverses the motor 60 and pulls back the recording paper 12, and counts down the counter 57 during the pull-back. The controller 51 identifies a recording area based on the downcount value, and records a yellow image line by line with the thermal head 13 in the recording area. Prior to this thermal recording, as shown in FIG. 1B, the controller 51 operates the up / down mechanism 15 to rotate the platen displacement lever 16 to bring the platen roller 14 into the crimping position. As the platen displacement lever 16 is displaced, the push-up plate 19 pushes the guide plate main body 43a upward, so that the guide plate main body 43a is switched from the guide position to the retracted position. Therefore, the guide plate main body 43a is retracted from the passage of the recording paper 12 during recording, so that the recording paper 12 can be smoothly pulled back without contacting the recording paper 12. When the recording paper 12 is pulled back, the recording paper 12 pulled back by the conveying roller pair 11 is wound and loosened in the gap between the recording paper roll 10 and the roll storage chamber 9 as indicated by a two-dot chain line in FIG. Stored.
[0027]
When the leading edge sensor 61 detects that the leading edge of the recording paper 12 has passed after the recording of the yellow image is finished, the pulling back of the recording paper 12 is terminated. Further, the controller 51 resets the count value of the counter 57 based on the tip detection signal. Further, the controller 51 operates the up / down mechanism 15 to rotate the platen displacement lever 16 to displace the platen roller 14 from the crimping position in FIG. 1 (B) to the retracted position in FIG. 1 (A). In conjunction with this displacement, the push-up plate 19 is also separated from the guide plate main body 43a, so that the guide plate main body 43a is displaced downward by the spring property of the holding plate 43b and set to the guide position in FIG.
[0028]
Next, the controller 51 rotates the conveyance roller pair 11 in the normal direction to send out the recording paper 12, and irradiates the recording area with a violet visible ray by the yellow fixing lamp 32 to fix the yellow image. When the light fixing of the yellow image is completed, the controller 51 reverses the conveying roller pair 11 and pulls back the recording paper 12, and at this time, the magenta image is printed on the recording area in the same manner as the yellow image recording. Record.
[0029]
Thereafter, in the same manner as the fixing of the yellow image, after the magenta image is recorded, the magenta image is fixed by feeding the recording paper 12. When fixing a magenta image, the magenta fixing lamp 33 emits light and irradiates the recording area with ultraviolet rays. Since the magenta fixing lamp 33 is disposed in front of the yellow fixing lamp 32, the feeding amount of the recording paper 12 at the time of magenta fixing is made smaller than the feeding amount of the recording paper 12 at the time of yellow fixing. Yes. Similarly, a cyan image is recorded by pulling back the recording paper 12. Note that the cyan thermosensitive coloring layer does not need to be fixed because it does not have photofixability like the yellow or magenta coloring layer, but the unrecorded white and blank areas in the recording area are pale yellow. When this portion is irradiated with magenta fixing light, light yellow can be bleached to white, so that the magenta fixing lamp 33 is turned on and the recording area is bleached in the same manner as magenta fixing.
[0030]
During the bleaching, the controller 51 stops the feeding of the recording paper 12 when the cut line of the recording paper 12 is positioned at the cutter 25, cuts the recording paper 12 at the planned cutting line, and prints the sheet-like print on the recording paper. Disconnect from 12. After this cutting, the controller 51 places the discharge roller pair 46 in the nip state by the roller shift mechanism 46c, and discharges only the sheet-like print from the discharge port to a discharge tray (not shown).
[0031]
In the above embodiment, the movable guide 43 is attached to the thermal head 13 side. However, as shown in FIG. 5, the movable guide 67 is attached to the stay 65 on the machine frame side with an attachment screw 66. Also good. Also in this case, the push-down plate 69 provided integrally with the platen displacement lever 68 is configured to push down the guide plate body 67a of the movable guide 67 to the guide position in FIG. 5A via the engagement piece 67c. . The guide plate main body 67a is attached to the stay 65 by a holding plate 67b. Since the holding plate 67b has a spring property, the platen displacement lever 68 is displaced upward as shown in FIG. When the platen is pressed, the guide plate body 67a is automatically set at the retracted position. In addition, the same code | symbol is attached | subjected to the same structural member as what is shown in FIG.1 (B).
[0032]
Moreover, in the said embodiment, although the movable guide 43 was comprised with the thin board which has spring property, it was not necessary to provide an urging means separately, In addition to this, by spring members, such as a coil spring provided separately, The movable guide may be biased to either the guide position or the retracted position.
[0033]
In the above embodiment, the platen roller 14 is displaced to the crimping position and the retracted position by using the platen displacement lever 16, but the platen roller 14 can be rotated to the slider 70 as shown in FIG. It may be attached to and lifted by the lifting mechanism 71. The elevating mechanism 71 may be configured by a combination of a motor and a cam in addition to using a solenoid. Also in this case, the push-up plate 72 is formed on a part of the slider 70 that holds the platen roller 14, and the push-up plate 72 pushes up the guide plate body 43 a of the movable guide 43 upward.
[0034]
In the above embodiment, the wrapping angle of the recording paper 12 around the capstan roller 11a is always kept constant by using the nip roller 11b and the auxiliary nip roller 11c. A pair of conveying rollers may be configured by the stun roller 11a and the nip roller 11b.
[0035]
In the above embodiment, the recording paper roll 10 is used. However, the present invention may be implemented when a cut sheet type recording paper is used. In the above embodiment, the recording paper 12 pulled back by the conveying roller pair 11 is wound and stored in the gap around the recording paper roll 10, but the recording paper roll 10 is taken up in addition to this. The recording paper 12 rotated in the direction and retracted may be stored. Further, the recording paper 12 pulled back by forming a free loop between the recording paper roll 10 and the conveying roller pair 11 may be temporarily stored.
[0036]
In addition, when the fixing light irradiation area of the optical fixing device 30 is long in the recording paper feeding direction and uneven fixing occurs at the leading edge and the trailing edge of the recording area, the recording paper is within the fixing light irradiation area. It is preferable to provide a shutter that moves in the feeding direction and blocks the fixing light. In this case, the shutter is opened and closed in conjunction with the feeding of the recording paper, and the integrated fixing light amount distribution in the light fixing area is made uniform. In addition to fixing unevenness by the shutter, the recording paper 12 is fed so that all areas of the recording area pass through the fixing light irradiation area. When the recording area passes through the fixing light irradiation area, the shutter is used by the shutter. By shading the unrecorded area adjacent to the recording area, it is possible to prevent the occurrence of uneven fixing and to prevent the unrecorded area from being fixed.
[0037]
Further, instead of the platen roller 14, a fixed plastic template may be used. Further, the positions of the cutter 25 and the optical fixing device 30 may be changed as appropriate. In the above embodiment, the present invention is applied to a color thermal printer. However, the present invention may be applied to a sublimation type or melt type color thermal transfer printer. In this case, the recording paper is also related to the thermal head. The recording paper can be smoothly fed to the thermal head without stopping.
[0038]
Further, the conveyance roller pair 11 in FIG. 2 is used as a paper feed roller pair, another conveyance roller pair is provided between the thermal head 13 and the cutter 16, and the direction of the thermal head 13 is opposite to that in FIG. Thus, recording may be performed when the recording paper 12 is sent out. Also in this case, a movable guide is provided between the conveying roller pair and the thermal head 13, and this movable guide is displaced between the retracted position and the guide position in conjunction with the displacement of the platen displacement lever. Also good.
[0039]
【The invention's effect】
According to the present invention, a movable guide is provided between the conveying roller pair and the thermal head, and the movable guide is displaced between the guide position and the retracted position in conjunction with the displacement of the platen displacement member. For example, the movable guide can be changed from the guide position to the retracted position by simply switching the movable platen from the retracted position to the print position. Therefore, when feeding the recording paper to the thermal head, the platen roller is set at the retracted position and the movable guide is set at the guide position, so that the recording paper can be smoothly fed to the thermal head side. In addition, since the leading edge of the recording paper is guided below the thermal head by the movable guide at the time of feeding, the leading edge of the recording paper is not locked in the gap or step between the thermal head body and the cover, and the paper is jammed. Can be prevented.
[0040]
Further, since the guide plate urging means for urging the movable guide is provided on the side opposite to the displacement direction of the movable guide by the guide displacement member, the return of the displacement of the movable guide by the guide displacement member can be easily performed.
[0041]
At the guide position, the guide plate is inserted obliquely with respect to the recording paper path so that the leading edge of the recording paper is guided below the thermal head. The end of the paper is not locked, and paper jams can be reliably prevented.
[0042]
By constituting the holding plate from a member having spring properties and constituting the guide plate urging means by this holding plate, it is not necessary to separately provide a spring member such as a coil spring, and the configuration can be simplified.
[0043]
The conveyance roller pair changes the rotation direction to feed and pull back the recording paper. When feeding the recording paper, the platen roller is moved to the retracted position to guide the leading edge of the recording paper to the thermal head side. In the case of a thermal head that is fixed in a full-color printer that alternately feeds and pulls back the recording paper by performing thermal recording with the platen roller in the pressure-bonding position when pulling back, the leading edge of the recording paper is related to the thermal head. It is no longer stopped and paper jams can be prevented.
[Brief description of the drawings]
FIGS. 1A and 1B are schematic views showing a main part of a color thermal printer embodying the present invention, in which FIG. 1A shows a state in which the leading edge of a recording sheet is fed to the thermal head side, and FIG. This shows the state of performing thermal recording.
FIG. 2 is a side view showing an outline of the entire color thermal printer.
FIG. 3 is a block diagram illustrating an electrical configuration of a color thermal printer.
FIG. 4 is a flowchart showing a processing procedure in a color thermal printer.
FIGS. 5A and 5B are schematic views showing a main part of a color thermal printer using another movable guide, in which FIG. 5A shows a state in which the leading edge of the recording paper is fed to the thermal head side, and FIG. This shows a state where the thermal recording is performed by pulling back.
FIGS. 6A and 6B are schematic views showing a main part of a color thermal printer using a slider, in which FIG. 6A shows a state in which the leading edge of the recording paper is fed to the thermal head side, and FIG. The state where thermal recording is performed is shown.
FIG. 7 is a schematic view showing a main part of a color thermal printer in which a thermal head is fixed and a platen roller is moved up and down by a roller shift mechanism.
[Explanation of symbols]
10 Recording paper roll
11 Transport roller pair
11a Capstan Roller
11b Nip roller
11c Auxiliary nip roller
11d Roller shift mechanism
12 Recording paper
13 Thermal head
14 Platen roller
16 Platen displacement lever
19,72 Push-up plate
25 cutters
30 Fixing device
32 Fixing lamp for yellow
33 Fixing lamp for magenta
43, 67 Movable guide
43a, 67a Guide plate body
43b, 67b Holding plate
69 Push-down plate
70 slider

Claims (6)

A platen that is freely displaceable between a crimping position where the recording paper is crimped to the heating element array of the thermal head and a retracting position away from the heating element array, and a platen displacement that selectively displaces the platen to the crimping position and the retracting position. A recording paper guide device of a thermal printer that includes a member, nips recording paper by a pair of conveyance rollers, and performs thermal recording by sending it to a thermal head,
Between the conveyance roller pair and the thermal head, between the guide position for guiding the recording paper from the conveyance roller pair below the thermal head and the retreat position for retreating from the recording paper path during recording of the thermal head A movable guide that can be freely displaced by
And a guide displacement member that is provided on the platen displacement member and that displaces the movable guide from the guide position to the retracted position when the platen is switched from the retracted position to the crimping position. Printer recording paper guide device. A platen that is freely displaceable between a crimping position where the recording paper is crimped to the heating element array of the thermal head and a retracting position away from the heating element array, and a platen displacement that selectively displaces the platen to the crimping position and the retracting position. A recording paper guide device of a thermal printer that includes a member, nips recording paper by a pair of conveyance rollers, and performs thermal recording by sending it to a thermal head,
Between the conveyance roller pair and the thermal head, between the guide position for guiding the recording paper from the conveyance roller pair below the thermal head and the retreat position for retreating from the recording paper path during recording of the thermal head A movable guide that is mounted to be freely displaceable with
And a guide displacement member that is provided on the platen displacement member and that displaces the movable guide from the retracted position to the guide position when the platen is switched from the crimping position to the retracted position. Printer recording paper guide device. In the recording paper guide device of the thermal printer according to claim 1 or 2,
A recording paper guide device for a thermal printer, comprising a guide plate urging means for urging the movable guide on a side opposite to a displacement direction of the movable guide by the guide displacement member. In the recording paper guide device of the thermal printer according to claim 3,
A thermal printer characterized in that the movable guide is composed of a guide plate and a holding plate for holding the guide plate, and the guide plate is inserted obliquely with respect to the path of the recording paper at the guide position. Recording paper guide device. In the thermal paper recording paper guide device according to claim 4,
A recording paper guide device for a thermal printer, wherein the holding plate is constituted by a member having spring properties, and the guide plate urging means is constituted by the holding plate. In the recording paper guide device of the thermal printer according to any one of claims 1 to 5,
The conveying roller pair performs feeding and withdrawal of the recording paper by changing the rotation direction. When feeding the recording paper, the platen roller is moved to the retracted position to guide the leading edge of the recording paper to the thermal head side. A recording paper guide device for a thermal printer, which performs thermal recording with the platen roller in a pressure-bonding position when the sheet is pulled back.

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