JP4338301B2 - Printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printer that conveys and prints paper.
[0002]
[Prior art]
Conventionally, in order to detect the presence or absence of paper, a paper sensor has been provided in the paper transport path. In addition, the vertical direction of the paper transport path is usually regulated by a guide plate or the like. Furthermore, in order to increase the detection accuracy of the paper by the paper sensor, it has been necessary to make the distance between the paper sensor and the paper constant to some extent.
[0003]
Therefore, a protrusion is provided in the paper transport path to keep the distance between the paper sensor and the paper constant, and the paper is pushed toward the paper sensor. However, the provision of the protrusions narrows the sheet conveyance path, causing a problem in jamming and paper replacement. Further, when the printer is in a standby state and the paper stays at the same place for a long time, there has been a problem that the paper is bent and wrinkled by the protrusion.
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a so-called clamshell type printer capable of opening a conveyance path and capable of keeping a sheet conveyance path at a fixed position.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, a printer according to the present invention includes a main body frame having a print head and a sensor for detecting paper on a conveyance path, and a cover frame that supports the platen. And the print head are configured to be movable between a mounting position for printing while transporting the paper and a non-mounting position for retracting the platen from the print head to form a space for mounting the paper. In the case where the cover frame is in the mounting position, a restriction member for restricting the sheet to a predetermined distance from the sensor is provided on the upstream side of the platen in the sheet conveyance direction. In the clamshell type printer, a regulating member is provided on the cover frame side to regulate the sheet conveyance path so that the distance between the sensor and the sheet is always kept substantially constant.
[0006]
Moreover, it is preferable that the regulating member is provided at a position facing at least the sensor when the cover frame is in the mounting position.
Further, it is preferable that the restricting member is provided over almost the entire width of the sheet when the cover frame is in the mounting position.
Further, the restricting member preferably has an opening at a position facing the sensor when the cover frame is in the mounting position.
[0007]
Further, it is preferable that the restricting member has a substantially flat portion on the upstream side of the platen in the sheet conveying direction when the cover frame is in the mounting position, and the sensor is provided in the flat portion.
Furthermore, the sensor preferably includes a light emitting element and a light receiving element.
Furthermore, the print head is preferably a line thermal head.
[0008]
Further, the paper is preferably thermal paper.
Furthermore, it is preferable that the platen is rotatably supported by the cover frame.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The printer according to the present invention will be described below.
FIG. 1 is a schematic central sectional view of a printer according to the present invention. Here, the thermal roll 1 has a shaft 2. In addition, the state of the thermal roll 1 in which the thermal paper P is used and the roll diameter is reduced is indicated as 3 (indicated by a two-dot chain line). Further, FIG. 1 shows a base 10, a platen cover 20, and a cutter unit 30.
[0010]
The base 10 is provided with a first holding member 11, a bearing member 13, a guide member 14, and a plate holding member 15. The first holding member 11 holds the cover frame 20 rotatably about the shaft 12. Further, the bearing member 13 holds the shaft 2 of the thermal roll 1 in a rotatable manner.
The guide member 14 has a function of always transporting the thermal paper P fed from the thermal roll 1 toward the later-described line thermal head 43 at a substantially constant height. When the diameter of the thermal roll 1 is reduced, the position where the thermal paper P is fed out changes. Therefore, the guide member 14 functions so as to be always conveyed from the same height in the direction of the line thermal head 43 by bending the conveyance direction of the thermal paper P. Therefore, it is preferable that the height of the guide member 14 is equal to or higher than the position of the lowest point of the central axis 2 of the thermal roll paper 1.
[0011]
The cover frame 20 includes a regulating member 21, a platen roller 22, a platen roller shaft 23, a first engagement member 24, a fixed blade 25, a dome-shaped plate member 26, and the like.
The cutter unit 30 includes a movable blade 31, a second engagement member 32, a swing support member 33, a protrusion 34, a stopper 35, and the like.
[0012]
The plate 40 is fixed on the plate holding member 15, and a guide plate 41, a sensor 42, a line thermal head 43, an elastic member 44, a second holding member 45, and the like are provided above the plate 40. The second holding member 45 is provided with a groove 46 and a third engagement member 47. Therefore, the swing support member 33 of the cutter unit 30 is inserted into a groove 46 provided in the second holding member 45, and the cutter unit 30 swings up and down with the swing support member 33 as a fulcrum as a whole. It is held by the holding member 45 as possible.
[0013]
The sensor 42 is attached below the guide plate 41 in order to detect the presence or absence of the thermal paper P. Further, as the sensor 42, a reflection type sensor composed of a light emitting element and a light receiving element is used. When the thermal paper P is not detected at the position of the sensor 42, a no-paper signal is transmitted from the sensor 42 to a control circuit (not shown). In the reflection type sensor, the light from the light emitting element is emitted toward the conveyance path, and the light reflected from the paper is incident on the light receiving element, thereby detecting the presence or absence of the paper. Therefore, in particular, in the reflective sensor, it is preferable that the distance between the sensor and the paper is substantially constant. In the present embodiment, a reflective sensor is used, but other types of sensors can also be used.
[0014]
Reference numeral 50 denotes an elastic member (a helical spring) provided between the protrusion 34 of the cutter unit 30 and the second holding member 45, and an urging force for rotating the cutter unit 30 in the clockwise direction in FIG. 1. Is always given to the cutter unit 30.
Hereinafter, the base 10 and the plate 40, and various members provided on the base 10 and the plate 40 are collectively referred to as a main body frame. In FIG. 1, the platen roller shaft 23 is held on the main body frame by a lock member 60 (not shown), whereby the cover frame 20 is maintained in the state shown in FIG. 20 is in the mounting position. Furthermore, the state in which the holding of the platen roller shaft 23 is released, for example, the state of FIG. 2 is referred to as the cover frame being in the non-attached position.
[0015]
In response to the cover frame 20 being held in the state of FIG. 1, the first engagement member 24 of the cover frame 20 is engaged with the second engagement member 32 of the cutter unit 30, and the cutter unit 30 is moved counterclockwise. The cutter unit 30 is held at the position shown in FIG. 1 while being pressed around and opposed to the urging force of the elastic member 50. Further, at this time, both side protrusions 31a and 31b of the movable blade 31 of the cutter unit 30 press the fixed blade 25 on the cover frame 20 side from the top to the bottom in the drawing, and thereby the movable blade is placed on the fixed blade 25. The both side protrusions 31a and 31b of 31 are positioned so as to contact each other. From the state of FIG. 1, the movable blade 31 is moved by sliding on the fixed blade 25 to the cover frame 20 side by a drive mechanism (not shown) so that the thermal paper P can be cut. Yes.
[0016]
The elastic member 44 urges the line thermal head 43 toward the platen roller 23, and is configured so that the thermal paper P is sandwiched between the platen roller 23 and the line thermal head 43. When the platen roller 23 rotates in the state of FIG. 1, the thermal paper P is unwound from the thermal roll 1 and conveyed upward in the drawing.
[0017]
The line thermal head 43 is provided with a plurality of heating elements in a row in the longitudinal direction of the platen roller 23, and the heating elements generate heat by a drive circuit (not shown), whereby printing or the like is performed on the thermal paper P. It is comprised so that. Therefore, as the platen roller 22 rotates, printing is performed on the thermal paper P while the thermal paper P is being conveyed, and is discharged outside the printer. In the present embodiment, the platen is configured in a roller shape. However, the platen is not limited to the roller shape as long as the positional relationship between the print head and the sheet can be regulated. It is also possible to use a shape. Further, when a roller-shaped platen is not used, a separate transport mechanism for transporting paper is required.
[0018]
FIG. 2 shows a case where the cover frame 20 is in the non-attached position. The state of FIG. 2 shows a state where the holding of the platen roller shaft 23 is released. In the state of FIG. 2, since the first engagement member 24 of the cover frame 20 is engaged with the second engagement member of the cutter unit 30 and does not press the cutter unit 30, the cutter unit 30 has an elastic member 50. Thus, an urging force is applied so as to rotate in the clockwise direction in the figure with the swing support member 33 as a fulcrum. However, the stopper 35 of the cutter unit 30 is configured not to rotate in the clockwise direction beyond the position of FIG. 2 by engaging with the third engaging member 47 provided on the frame 40. In FIG. 2, the line thermal head 43 is held at a position retracted from the platen roller 23 side against the urging force of the elastic member 44 by a lock member 60 (not shown).
[0019]
FIG. 3 is a top view of the state of FIG. 1 viewed from above in FIG. In FIG. 3, 24 a and 24 b are projecting portions on both sides of the first engaging member 24 provided on the cover frame 20. Reference numeral 27 denotes a gear provided on the platen roller shaft 23. Further, 48 is a gear provided on the plate 40. The gear 48 receives a driving force from a motor (not shown), engages with the gear 27, and rotates the platen roller shaft 23. Reference numeral 60 denotes a lock member for holding the cover frame 20 at the position shown in FIG. As can be understood from FIG. 3, the thermal paper P passes between the cover frame 20 and the cutter unit 30 and between the protruding portions 24 a and b of the first engagement member 24.
[0020]
4 is a top view of the state of FIG. 2 viewed from above in FIG. In FIG. 4, 31 a and 31 b are projecting portions on both sides of the movable blade 31. Moreover, 32a and 32b have shown the both-ends tip part of the 2nd engagement member. FIG. 4 shows a state where the stopper 35 of the cutter unit 30 and the third engagement member 47 provided on the plate 40 are engaged.
[0021]
FIG. 5 is a view showing the front end portion of the cover frame 20. Reference numeral 28 denotes an opening provided in the regulating member 21. The opening 28 is provided corresponding to the position where the sensor 42 is provided. Reference numerals 203 and 205 denote bearing portions that rotatably support the platen roller shaft 23. Reference numerals 201 and 204 denote sheet metal frame pairs provided with bearing portions 203 and 205. Reference numeral 202 denotes a pressing portion provided on the sheet metal frame 201.
[0022]
The regulating member 21 is disposed upstream of the platen roller 22 in the conveying direction of the thermal paper P, and has a width that can regulate the thermal paper P over almost the entire width of the thermal paper P. The distance between P and the sensor 42 is kept substantially constant, and a malfunction of detection of the sensor 42 is prevented. The restricting member has a substantially flat portion, and is arranged so that the flat portion faces the sensor 42. Further, the opening 28 is provided almost directly above the sensor 42 in a state where the cover frame 20 of FIG. 1 is in the mounting position, and the light from the light emitting element of the sensor 42 is reflected on the regulation plate 21, and is heat sensitive. Although there is no paper P, it is prevented that the thermal paper P is misidentified. In this embodiment, the regulating member is provided over almost the entire width of the thermal paper P. However, if the distance between the thermal paper P and the sensor 42 can be maintained substantially constant in the vicinity of the sensor 42, the regulating member is not necessarily provided. It is not necessary to provide a regulating member over the entire width of the thermal paper P.
[0023]
As described above, the thermal paper P is fed out from the thermal roller 1, the conveyance direction is slightly bent by the guide member 14, and then conveyed while contacting the substantially flat portion of the lower end portion of the regulating member 21 of the cover frame 20. Then, while being sandwiched between the platen roller 22 and the line thermal head 43, it is discharged upward in FIG.
[0024]
In the present embodiment, the case where the thermal paper P is used as the paper has been described as an example. However, paper other than the thermal paper can be used. For example, it is possible to use plain paper and use an inkjet head or the like instead of a line thermal head.
[0025]
【The invention's effect】
According to the present invention, in a so-called clamshell type printer capable of opening the conveyance path, the sheet conveyance path can be maintained at a substantially constant position.
In addition, since the sheet conveyance path can be maintained at a substantially constant position, malfunction of the sheet detection sensor can be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic central sectional view of a printer according to the present invention when a cover frame is in a mounting position.
FIG. 2 is a schematic central sectional view of the printer according to the present invention when the cover frame is in a non-attached position.
FIG. 3 is a schematic top view of the printer according to the present invention when a cover frame is in a mounting position.
FIG. 4 is a schematic top view of the printer according to the present invention when the cover frame is in a non-mounted position.
FIG. 5 is a diagram showing a front end portion of a cover frame in the printer according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Thermal roll 10 ... Base 11 ... 1st holding member 13 ... Bearing member 14 ... Guide member 20 ... Cover frame 21 ... Restricting member 22 ... Platen roller 23 ... Platen roller shaft 24 ... 1st engaging member 25 ... Fixed blade 28 ... Opening 30 ... Cutter unit 31 ... Movable blade 32 ... Second system coupling member 33 ... Swing support member 35 ... Stopper 40 ... Plate 42 ... Sensor 43 ... Line thermal head 44 ... Elastic member 45 ... Second holding member 47 ... 3rd engagement member 50 ... Elastic member

Claims (8)

A main body frame having a sensor composed of a light-emitting element and a light-receiving element for detecting a print head and a paper on a conveyance path; and a cover frame supporting a platen, wherein the cover frame is formed between the platen and the print head. In a printer configured to be movable between a mounting position where printing is performed while transporting paper in cooperation and a non-mounting position where the platen is retracted from the print head to form a space for mounting paper,
The cover frame regulates the paper at a predetermined distance from a sensor composed of the light emitting element and the light receiving element on the upstream side in the paper transport direction of the platen when the cover frame is in the mounting position, and the print head And a regulating member for guiding the paper to a position where the platen is opposed to the platen ,
A printer characterized by that.   The printer according to claim 1, wherein the restricting member is provided at a position facing at least the sensor when the cover frame is in the mounting position.   The printer according to claim 1, wherein the restricting member is provided over substantially the entire width of the sheet when the cover frame is in the mounting position.   The printer according to claim 2, wherein the restricting member has an opening at a position facing the sensor when the cover frame is in the mounting position.   The restricting member has a substantially flat portion on the upstream side of the platen in the sheet conveying direction when the cover frame is in the mounting position, and the sensor is provided to face the flat portion. The printer according to any one of claims 1 to 4, wherein: 6. The apparatus according to claim 1, further comprising a guide member that maintains a position of the fed paper at a constant height so that the paper is conveyed from substantially the same height toward the print head. The printer described.   The printer according to claim 1, wherein the print head is a line thermal head. The platen printer according to any one of claim 1 to 7, characterized in that it is rotatably supported by the cover frame.

Images