JP2002192779A - Recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To preferably determine a recording starting position in a sheet. SOLUTION: In a recording apparatus comprising a recording head 11 on a carriage 16 running along a flat surface shaped platen 17 with the platen supported elastically movably in the direction approaching to or moving away from the recording head using a forcing spring 26, for recording an image on the sheet by the recording head at the time a sheet S of different thicknesses is conveyed between the recording head and the platen and the platen is moved in the sheet thickness direction, a pressuring roller 27 for adjusting the platen gap, pivoted on the recording head serves as a conductive contact point member, with the roller provided capable of contacting with a conductive part 31 of the platen such that existence or absence of the sheet between the recording head and the platen is judged by detecting the conduction state between the roller and the conductive part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for recording an image on a sheet conveyed between a platen and a recording head, and more particularly to a recording apparatus in which the platen has a planar shape and at least one of the platen and the recording head. The present invention relates to a recording apparatus which is elastically supported so as to be movable toward and away from each other.

[0002]

2. Description of the Related Art In a recording apparatus, as shown in FIG. 4, a recording head 103 is mounted on a carriage 102 running along the longitudinal direction of a platen 101 having a planar shape. When the sheet S having a different thickness is conveyed by the conveying roller 106 between the recording head 103 and the platen 101, the platen 101 is elastically supported so as to be movable toward and away from the recording head 103. Moves in the thickness direction of the sheet S in a direction away from the recording head 103, and the recording head 103
Of the recording sheet (not shown)
There is a dot impact printer 100 for recording an image.

In the dot impact printer 100, a pressing roller 105 is rotatably supported by a recording head 103, and the pressing roller 105 sandwiches a sheet S between the pressing roller 105 and a platen 101. Then, the pressing roller 10
5 ensures a constant platen gap between the surface of the sheet S and the recording head 103 irrespective of the sheet thickness of the sheet S.

Further, the recording head 103 is provided with a reflection type optical sensor 107. This optical sensor 107
Detects the left and right side edge positions of the sheet S by running the carriage 102. Based on this detection result, the recording start position on the sheet S by the recording head 103 is determined.

[0005]

In the dot impact printer 100 as described above, a dedicated optical sensor 107 is used to determine the recording start position on the sheet S in a favorable manner. This is one of the factors that increase the cost of the impact printer 100.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording apparatus capable of satisfactorily determining a recording start position on a sheet in view of the above circumstances.

[0007]

According to a first aspect of the present invention, there is provided a recording apparatus in which a recording head mounted on a carriage traveling along a platen records an image on a sheet conveyed between the carriage and the platen. , A conductive contact member is provided on the recording head, and the contact member is provided so as to be able to contact a conductive portion of the platen or a conductive portion disposed near the platen. The present invention is characterized in that it is configured to detect a conduction state between the sets and determine the presence or absence of a sheet between the recording head and the platen.

According to a second aspect of the present invention, a recording head is mounted on a carriage that travels along a planar platen, and at least one of the recording head and the platen is elastically movable in a direction in which the recording head and the platen come into contact with or separate from each other. When a sheet having a different thickness is conveyed between the recording head and the platen supported by the recording head, at least one of the recording head and the platen moves in the sheet thickness direction, and the recording head In a recording apparatus for recording an image, a conductive contact member is disposed on the recording head, and the contact member is provided so as to be able to contact a conductive portion of the platen, or a conductive portion disposed near the platen. Detecting the presence or absence of a sheet between the recording head and the platen by detecting a conduction state between these contact members and the conductive portion. It is characterized in that it was.

According to a third aspect of the present invention, in the first or second aspect, the contact member is rotatably supported by a recording head and is conveyed between the recording head and a platen. It is characterized by comprising rollers for ensuring a constant platen gap between the sheet and the recording head.

[0010] The invention described in claim 4 is the first to third aspects of the present invention.
In the invention described in any one of the above, the platen is characterized in that a portion facing the recording head is formed of a shock absorbing member.

The invention according to claim 1 or 2 has the following operation.

[0012] A conductive contact member is provided on the recording head, and the contact member is provided so as to be able to contact a conductive portion of a platen or a conductive portion disposed near the platen.
Since the conductive state between the contact member and the conductive part is detected to determine the presence or absence of a sheet between the recording head and the platen, the conductive state between the contact member and the conductive part of the platen or the like is established. If it is secured, it can be determined that there is no sheet between the recording head and the platen, and if the conduction state is cut off between the contact member and the conductive part of the platen, etc., it is possible to determine between the recording head and the platen. It can be determined that there is a sheet. Therefore, the recording start position on the sheet can be favorably determined based on the determination result of the presence or absence of the sheet.

The third aspect of the invention has the following operation.

Since the contact member is constituted by a roller for ensuring a constant platen gap between the sheet conveyed between the recording head and the platen and the recording head, the roller comprises a platen. Since the member for ensuring the gap and the member for determining the presence or absence of the sheet are also used, the number of components of the recording apparatus can be reduced. As a result, the recording start position on the sheet can be determined at low cost.

The invention described in claim 4 has the following operation.

In the platen, the portion facing the recording head is made of a shock absorbing member, so that the shock absorbing member absorbs the impact of the recording wire projecting from the recording head. Noise can be reduced, and the life of the ink ribbon provided between the sheet and the recording head can be extended.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing a printer main body of a dot impact printer to which an embodiment of a recording apparatus according to the present invention is applied. FIG. 2 is a side sectional view showing a state in which a sheet is conveyed to the printer main body of FIG.

The printer 10 as a recording apparatus shown in FIGS. 1 and 2 connects a plurality of recording wires 12 of a recording head 11 to a sheet S (FIG. 2) via an ink ribbon 13.
This is a dot impact printer that records an image including a character by recording a dot by hitting the dot. The printer 10 includes a printer main body 1 as a recording apparatus main body.
4 and an upper case and a lower case (both not shown) which cover the upper and lower portions of the printer main body 14, respectively.

The sheets include a cut sheet cut to a predetermined length and a continuous sheet formed by connecting a plurality of sheets. The cut sheet includes, for example, a cut sheet, a copy sheet, a passbook or a cut film, and the continuous sheet includes a continuous sheet.

The printer main body 14 includes a main body frame 1
5, a recording head 11, a carriage 16, and a platen 17 as a recording mechanism, a sheet guide 18, a first transport roller 21, and a second transport roller 2 as a sheet transport mechanism.
2, a third transport roller 23 and a fourth transport roller 24.

A carriage shaft 25 is bridged over the main body frame 15 and a sheet guide 18 is fixedly provided. Further, the platen 17 is formed in a planar shape, is elastically supported by the main body frame 15 via a biasing spring 26, and is configured to be movable in a direction of coming into contact with and separating from the recording head 11.

The above-mentioned sheet conveying mechanism section includes a first conveying roller 21 and a second conveying roller 22 with respect to the platen 17 in front of the printer main body 14, and a third conveying roller 23 and a fourth conveying roller 24 with the printer main body 14. Are arranged on the rear side of the vehicle. Further, the first transport roller 21 and the second transport roller 22 are connected to each other.
The transport rollers 24 are arranged vertically and form a pair.

The first transport roller 21 and the third transport roller 23 are, together with the platen 17, a sheet guide 18.
, And the second conveyance roller 22 and the fourth conveyance roller 24 are arranged above the sheet guide 18. First transport roller 21, second transport roller 22, third transport roller 2
The third and fourth conveying rollers 24 are driven to rotate clockwise (CW) or counterclockwise (CCW) in FIGS. 1 and 2 by a sheet conveying motor and a drive train (not shown).

As shown in FIG. 2, after the sheet is manually supplied from the front side of the printer main body 14, the first conveying roller 21 and the third conveying roller 23 are rotated clockwise, and the second conveying roller 22 and the second conveying roller 22 are rotated clockwise. Due to the counterclockwise rotation of the fourth conveyance roller 24, the paper is conveyed from the front to the rear of the printer body 14, and the first conveyance roller 21 and the third conveyance roller 23 are rotated counterclockwise, and the second conveyance is performed. By the clockwise rotation of the roller 22 and the fourth transport roller 24, the printer body 14 is transported from the rear to the front. As a result, the sheet S is conveyed in the sub-scanning direction orthogonal to the main scanning direction of the carriage 16 described later.

The carriage 16 has a carriage shaft 25
The recording head 11 is mounted slidably on the recording medium 11 and has a pressing roller 27 for adjusting a platen gap.

The carriage 16 is connected to a timing belt 28 which is reciprocated by forward or reverse rotation of a carriage drive motor (not shown). Accordingly, the carriage 16 is guided by the carriage shaft 25 via the timing belt 28 by the forward or reverse rotation of the carriage drive motor, and travels in the main scanning direction coinciding with the axial direction of the carriage shaft 25 and the longitudinal direction of the platen 17. (Scan).

The pressing roller 27 is rotatably supported by the recording head 11 and rolls in contact with the surface of the platen 17 or the surface of the sheet S when the carriage 16 travels in the main scanning direction. As shown in FIG. 2, when the sheet S is carried in between the recording head 11 and the platen 17, the pressing roller 27 presses the platen 17 via the sheet S and presses the platen 17 by the urging force of the urging spring 26. In the thickness direction of the sheet S, the sheet S is moved away from the recording head 11 (ie, downward in FIG. 2). This allows
Even when a sheet S having a different thickness is carried in between the recording head 11 and the platen 17, or when the thickness of the sheet S changes in the middle such as a passbook, the recording head 11 and the sheet S The platen gap between the platen 17 and the platen 17 is always kept constant irrespective of the sheet thickness, and the pressing roller 27 sandwiches the sheet S with the platen 17.

Here, the upper limit of the spring constant of the urging spring 26 is set so that the platen gap between the sheet S and the recording head 11 can be sufficiently secured by being easily pressed by the pressing roller 27 as described above. You. The lower limit of the spring constant is such that the platen 17 is excessively pressed by the impact force of the recording wire 12 during the recording operation on the sheet S by the recording wire 12 of the recording head 11 and the recording quality on the sheet S is deteriorated. Not set.

The recording head 11 has a large number of recording wires 12, and an ink ribbon 13 is located in front of the recording wires 12 in the protruding direction. This ink ribbon 13
Is folded and stored in a ribbon cartridge mounted on the carriage 16 or the main body frame 15. The recording head 11 projects the recording wire 12 and strikes the ink ribbon 13 while traveling in the main scanning direction together with the carriage 16, and applies the ink of the ink ribbon 13 between the platen 17 and the recording head 11. An image including characters is recorded on the conveyed sheet.

The recording operation by the recording head 11 is such that one line of recording is performed by the recording wire 12 of the recording head 11 while the recording head 11 is traveling leftward or rightward in the main scanning direction. Every time is done, the first
The conveyance is performed by the conveyance roller 21, the second conveyance roller 22, the third conveyance roller 23, and the fourth conveyance roller 24 conveying the sheet S by a predetermined length (normal line spacing), and these operations are repeated.

The pressing roller 27 is made of a conductive material, for example, metal and functions as a contact member. In the platen 17, a portion of the recording head 11 facing the recording wire 12 is made of an impact absorbing material, for example, rubber, and the other portion is made of a conductive material, for example, metal. The portion made of the shock absorbing material becomes the shock absorbing portion 30 of the platen 17, and the portion made of the metal becomes the conductive portion 31 of the platen 17. The impact absorbing section 30 of the platen 17 absorbs an impact caused by the recording head 11 projecting from the recording wire 12. Further, the pressing roller 27 is provided so as to be able to contact the conductive portion 31 of the platen 17.

As shown in FIG. 3, a voltage (for example, a voltage of +5 V) is applied between the pressing roller 27 and the conductive portion 31 of the platen 17, and the pressing roller 27 or the conductive portion 31 presses these voltages. A sensor 32 such as a current sensor for detecting a current flowing between the roller 27 and the conductive portion 31 or a voltage sensor for detecting a voltage between the pressing roller 27 and the conductive portion 31 is attached. This sensor 32
Detects the ON state (conductive state) when the sheet S is not present between the recording head 11 and the platen 17,
The sheet S is placed between the pressing roller 27 and the platen 17.
When the sheet S exists, the OFF state (non-conduction state) is detected, and the sheet S between the pressing roller 27 and the platen 17 is detected.
Is detected.

More specifically, the operation of the first transport roller 21, the second transport roller 22, the third transport roller 23, and the fourth transport roller 24 causes the recording head 11 and the platen 17 to move.
At the stage when the sheet S is carried in between the
Is moved in the main scanning direction, so that the pressing roller 2
7. The positions of the left and right side edges Sa of the sheet S are detected by the operation of the conductive portion 31 of the platen 17 and the sensor 32. From this detection information, the recording start position on the sheet S by the recording head 11 is determined.

Therefore, according to the above embodiment, the following effects are obtained.

The recording head 11 is provided with a pressing roller 27 functioning as a conductive contact member. The pressing roller 27 is provided so as to be in contact with the conductive portion 31 of the platen 17. The sensor 32 detects the conduction state between the recording head 11 and the platen 1.
7, the presence or absence of the sheet S between the recording head 11 and the recording head 11 is ensured if a conductive state is secured between the pressing roller 27 and the conductive portion 31 of the platen 17.
If there is no sheet S between the recording head 1 and the platen 17, and if the conduction state is cut off (ON state) between the pressing roller 27 and the conductive portion 31 of the platen 17, the recording head 1
It can be determined that there is a sheet S between the platen 1 and the platen 17. Therefore, the position of the side edge Sa of the sheet S can be detected based on the determination result of the presence or absence of the sheet S, and the recording start position of the recording head 11 on the sheet S can be determined favorably.

The contact member is a sheet S conveyed between the recording head 11 and the platen 17 and the recording head 11
And a pressure roller 27 for ensuring a constant platen gap between the pressure roller 2 and the pressure roller 2.
Since the member 7 also serves as a member for securing the platen gap and a member for determining the presence or absence of the sheet S, the number of parts of the printer 10 can be reduced. As a result, the recording start position of the recording head 11 on the sheet S can be determined at low cost.

Since the platen 17 has a portion facing the recording head 11 as an impact absorbing portion 30 made of an impact absorbing material, the impact absorbing portion 30 absorbs the impact of the recording wire 12 protruding from the recording head 11. Accordingly, noise during the recording operation by the recording head 11 can be reduced, and the life of the ink ribbon 13 positioned between the sheet S and the recording head 11 can be extended.

As described above, the present invention has been described based on the above embodiment, but the present invention is not limited to this.

For example, in the above-described embodiment, the pressing roller 27 is arranged upstream of the recording wire 12 of the recording head 11 in the sheet S carrying direction. May also be located downstream.

In the above embodiment, the contact member is also used as the pressing roller 27 for adjusting the platen gap. However, the contact member is made of a conductive metal piece and recorded separately from the pressing roller 27. It may be installed on the head 11.

Further, in the above-described embodiment, the pressing roller 27 as the contact member is described as being in contact with the conductive portion 31 of the platen 17. It may be configured to be able to contact the conductive part near the platen 17.

Further, in the above embodiment, the platen 17
Is biased by a biasing spring 26 in the direction in which
The recording head 11 is movably and elastically supported by using the platen 17, but instead of or together with the platen 17, the recording head 11 can be elastically supported by a spring or the like so that the recording head 11 can be moved toward and away from the platen 17. May be done.

In the above embodiment, the platen 17
Although the printer 10 is provided with a so-called flat platen formed in a planar shape, a dot impact printer having a so-called round platen that has a cylindrical platen and is supported by the main body frame 15 may be used. In this case,
The conductive portion with which the contact member comes into contact is provided on a sheet guide or the like near the platen.

In the above embodiment, the printer 10
Has been described as a dot impact printer, but the present invention can also be applied to an ink jet printer or a page printer.

[0046]

As described above, according to the recording apparatus of the first aspect of the present invention, the recording head mounted on the carriage traveling along the platen moves the sheet conveyed between the recording head and the platen. In the recording apparatus for recording an image on the recording head, a conductive contact member is provided on the recording head, and the contact member is provided so as to be able to contact a conductive portion of the platen, or a conductive portion disposed near the platen. Since the state of conduction between these contact members and the conductive portion is detected to determine the presence or absence of a sheet between the recording head and the platen, the recording start position on the sheet can be determined favorably. .

According to the recording apparatus of the present invention, the recording head is mounted on the carriage that travels along the planar platen, and at least one of the recording head and the platen comes into contact with and separate from each other. Elastically movably in the direction, when a sheet having a different thickness is conveyed between the recording head and the platen, at least one of the recording head and the platen moves in the sheet thickness direction, In a recording apparatus in which the recording head records an image on the sheet, a conductive contact member is disposed on the recording head, and the contact member is a conductive portion of the platen or a conductive portion disposed near the platen. The contact state between the contact member and the conductive portion is detected, and the presence or absence of a sheet between the recording head and the platen is detected. Since configured to determine, it can be favorably determining the recording start position in the sheet.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a printer main body of a dot impact printer to which an embodiment of a recording apparatus according to the present invention is applied.

FIG. 2 is a side sectional view showing a state in which a sheet is conveyed to the printer main body of FIG. 1;

FIG. 3A is a schematic view taken along the arrow III in FIG.
(B) is a graph which shows the detection state by the sensor of FIG. 3 (A).

FIG. 4 is a side sectional view showing a printer main body of a conventional dot impact printer.

[Description of Signs] 10 Printer (recording apparatus) 11 Recording head 16 Carriage 17 Platen 26 Urging spring 27 Press roller (Contact member) 30 Shock absorbing part 31 Conductive part 32 Sensor S Sheet Sa Side edge

Claims (4)

[Claims] A recording head mounted on a carriage traveling along a platen for recording an image on a sheet conveyed between the recording head and the platen, wherein a conductive contact member is disposed on the recording head. The contact member is provided so as to be able to contact a conductive portion of the platen or a conductive portion disposed near the platen, and detects a conduction state between the contact member and the conductive portion, thereby detecting the recording head. A recording apparatus configured to determine the presence or absence of a sheet between the sheet and the platen. 2. A recording head is mounted on a carriage that travels along a platen having a planar shape, and at least one of the recording head and the platen is elastically supported so as to be movable in a direction in which the recording head and the platen move toward and away from each other. When a sheet having a different thickness is conveyed between the recording head and the platen, at least one of the recording head and the platen moves in the sheet thickness direction, and the recording head records an image on the sheet. Wherein a conductive contact member is provided on the recording head, and the contact member is provided so as to be able to contact a conductive portion of the platen or a conductive portion disposed near the platen. And detecting the presence or absence of a sheet between the recording head and the platen by detecting a conduction state between the units. Recording apparatus. 3. The printing apparatus according to claim 1, wherein the contact member is rotatably supported by a recording head, and a platen gap between the sheet conveyed between the recording head and the platen and the recording head is kept constant. The recording apparatus according to claim 1, wherein the recording apparatus includes a roller. 4. The recording apparatus according to claim 1, wherein a portion of the platen facing the recording head is formed of a shock absorbing member.