Information
-
Patent Grant
-
6690909
-
Patent Number
6,690,909
-
Date Filed
Monday, August 12, 200222 years ago
-
Date Issued
Tuesday, February 10, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Birch, Stewart, Kolasch & Birch, LLP
-
CPC
-
US Classifications
Field of Search
US
- 399 16
- 399 364
- 399 401
- 271 186
- 271 225
- 271 902
- 101 229
- 101 230
- 101 234
- 101 262
- 101 296
- 355 24
- 400 624
-
International Classifications
-
Abstract
A double-sided printing device for paper handling is proposed by the invention to allow users to print on both sides of a sheet of paper. The double-sided printing device employs the interaction between the switches, the obstructing unit and the turning unit to allow a sheet of paper to enter the turning unit and be turned over so that its back side will be directed to the printing unit.
Description
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a printing device for paper handling applied to print data and/or records on paper, and especially relates to a double-sided printing device for paper handling.
2. Related Art
Conventional printing apparatuses are fax machines, printers and photocopiers, and printers can be furthermore classified as dot matrix, ink jet and laser printers. In accordance with the mechanisms of paper-picking, they can also be classified as front and back input tray printers.
Recycled paper is often used with printers, and it is preferable to use both sides of a sheet of paper when printing. But because the papers are re-used, they often become jammed inside the printer during the process of paper-picking, which wastes time and can damage the printer. If both sides of a sheet of paper are used for printing less paper is wasted.
In order to overcome the above problems some inventions have been proposed, such as U.S. Pat. Nos. 6,167,231 and 6,332,068. Although by these two inventions double-sided printing is achieved, some problems still occur and are described as follows:
1. The designs of the double-sided printing devices of the previous inventions are only useful for the front input tray printers but not for the back input tray printers.
2. The designs of the double-sided printing devices of the previous inventions are oriented externally. The production cost for these devices is increased.
SUMMARY OF THE INVENTION
The object of the invention is to provide a double-sided printing device in order to overcome the above problems. The device of the invention is designed internally and is driven by a single drive so that the production cost can be decreased.
The double-sided printing device proposed by the invention comprises a holding unit, a first switch, a drive, a printing unit, a turning unit, an obstructing unit and a second switch. Some papers are placed in the holding unit, the first switch is driven by the reverse rotation of the drive to couple with the holding unit such that a sheet of paper placed in the holding unit is pulled out and by the ordinary rotation of the drive is fed into the printing unit so that printed data can be printed on its front side.
After completing the printing on the front side of the sheet of paper, the second switch is driven by another reverse rotation of the drive to couple with the turning unit such that the sheet of paper is guided into the turning unit and turned over. At this time the obstruction unit is applied to stop the first switch from coupling with the holding unit to prevent it from feeding papers repeatedly. Finally the drive rotates normally to pull the second switch to free from the turning unit so that the sheet of paper can be fed into the printing unit and the printed data can be printed on the back side of the sheet of paper.
A page sensor can also be applied to actuate the obstructing unit to reduce control problems. The page sensor is set on the path for paper handing and when a sheet of paper goes through it, it is initiated to push the obstructing unit to function normally.
Further scope of applicability of the invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1
is a schematic drawing of the invention;
FIG. 2
is a schematic drawing of the paper-picking mechanism of the invention;
FIG. 3
is a schematic drawing of the page sensor used to drive papers of the invention;
FIG. 4
is a schematic drawing of the first switch in the original position of the invention;
FIG. 5
is a schematic drawing of the printing status of the invention;
FIGS. 6A-6B
are schematic drawings of the invention after completing the printing;
FIG. 7
is a schematic drawing of a sheet of paper entering the turning unit of the invention;
FIGS. 8A-8B
are schematic drawings of a sheet of paper entering the printing unit of the invention;
FIG. 9
is a schematic drawing of the invention for a sheet of paper with printed data on its reverse side;
FIG. 10
is a schematic drawing of the first embodiment of the page sensor of the invention;
FIG. 11
is a schematic drawing of the second embodiment of the page sensor of the invention; and
FIGS. 12 and 13
are schematic actuating drawings of the second embodiment of the paper sensor of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring firstly to
FIG. 1
, the double-sided printing device of the invention comprises a holding unit
10
, a first switch
20
, a drive
30
, a printing unit
40
, a turning unit
50
, a second switch
60
, an obstructing unit
70
and a page sensor
80
. The holding unit
10
possesses a reservoir
12
in which papers are placed while the first switch
20
is set on the bottom of the holding unit
10
and the passive gear
21
on the first switch
20
can be coupled selectively with the holding unit
10
. A sheet of paper
11
placed inside the holding unit
10
is fed to the printing unit
40
by a supplying roller
13
such that printed data can be printed on the sheet of paper
11
. Between the first switch
20
and the supplying roller
13
some gears are set and the numbers of gears is dependent upon the length of the sheet of paper
11
and the types of the printers.
The drive
30
is coupled with the gear
26
by a feeding roller
31
, and the numbers of gears set between the feeding roller
31
and the gear
26
depends upon the types and designs of the printers. Naturally the drive
30
can also be directly coupled with the gear
26
. Above the feeding roller
31
a printing unit
40
is set which can be applied to print data on the sheet of paper
11
that is fed by the feeding roller
31
. In the back of the printing unit
40
a turning unit
50
coupled with the second switch
60
is set. It is applied to turn over the sheet of paper
11
such that the reverse side
112
of the sheet of paper
11
can be printed upon by the printing unit
40
after the front side
111
of the sheet of paper
11
has been used. The method of paper-handing for the sheet of paper
11
and the actuations of the first and second switches
20
and
60
are described together with the drawings as follows.
As shown in
FIG. 2
, the gear
26
coupled with the drive
30
is initiated to rotate by the reverse rotation of the drive
30
. The rotation of the gear
26
causes the first switch
20
to rotate due to friction. The rotation direction of the first switch
20
shown in
FIG. 2
is counterclockwise such that the passive gear
21
on the first switch
20
swings upward and couples with the gear
14
set on the bottom of the holding unit
10
. Hence the feeding roller
13
rotates and a sheet of paper
11
placed in the holding unit
10
is pulled out then the front of the sheet of paper
11
reaches the rear
82
of the page sensor
80
. As shown in
FIG. 3
, the middle of the page sensor
80
is pinned to the printing device of the invention (see also FIG.
10
). Therefore when the sheet of paper
11
goes through the page sensor, the rear
82
of the page sensor
80
is pushed to swing upward such that the page sensor
80
rotates around the pin set in the middle of it. Consequently the obstructing unit
70
and the sensing flag
81
on the top of the page sensor
80
is driven to swing downward. The downward flag
81
makes the sensors (not shown in the figure) set on the both sides of the sensing flag
81
sense that the sheet of paper
11
is in position. Accordingly the drive
30
is about to change rotating direction and the printing unit
40
is ready to start the printing job.
Next, as shown in
FIG. 4
, the drive
30
rotates normally to drive the feeding roller
31
to pull the sheet of paper
11
into the bottom of the printing unit
40
so that the front side
111
of the sheet of paper
11
can be printed on. Meanwhile the first switch
20
is driven to rotate clockwise by the ordinary rotation of the drive
30
to let the passive gear
21
swings downward such that the first switch
20
separates from the holding unit
10
and is finally stopped by the dead point
25
. Simultaneously the hook
22
pinned on first switch
20
is brought to close with the obstructing lever
71
of the obstruction unit
70
and then rotates around the obstructing lever to pass through it by the downward swing of the first switch
20
. Eventually the hook
22
on first switch
20
is again in its original position through the action of the spring
23
(see FIG.
5
).
Finally, the feeding roller rotates continuously until the printing for the front side
111
of the sheet of paper
11
has been completed (see FIGS.
6
A and
6
B). Next it has to wait for some time until the ink dries or the toner adheres on the paper, then the drive
30
rotates once again in reverse to push the feeding roller
31
to fed the sheet of paper
11
into the turning unit
50
. The first switch
20
rotates counterclockwise by the reverse rotation of the drive
30
, but the obstruction unit
70
is pushed by the sheet of paper
11
to swing downward so that the hook
22
on the first switch
20
is confined by the obstructing lever
71
of the obstructing unit
70
so as not to be able to couple with the holding unit
10
, as shown in FIG.
7
. The hook
22
is also confined simultaneously by the obstructing block
24
and acts consequently as a one-way hook and is confined in the present position to prevent the holding unit
10
from feeding the papers repeatedly. Guiding elements
53
associated with the turning unit
50
guide the sheet of paper
11
to enter the turning unit
50
but not the holding unit
10
(see FIG.
10
).
The turning unit
50
has a space in which turning rollers
51
and idler rollers
54
with flexible positions are set. The sheet of paper
11
is pressed by the idler rollers
54
to be in contact with the turning rollers
51
and is driven by them to be turned over by the guidance of the frame
52
of the turning rollers. Similarly the turning rollers
51
do not need to be directly coupled with the first switch
20
and their position dependents upon the length of the sheet of paper
11
and the types of the printers. The sheet of paper
11
being fed by turning rollers
51
continuously and then reenters the feeding roller
31
. After the sheet of paper
11
enters the feeding roller
31
, the drive
30
rotates once again normally to pull the sheet of paper
11
into the printing unit
40
, now the back side
112
of the sheet of paper
11
can be directed to the printing unit
40
so that printed data can be printed on it, as shown in
FIGS. 8A and 8B
. The turning unit
50
can also be selectively coupled with the turning rollers
51
by the second switch
60
. When the drive
30
rotates reversely, the second switch
60
can rotate counterclockwise due to friction so that the passive gear
61
is brought to swing upward and couple with the turning rollers
51
. The passive gear
61
can also be brought to swing downward to separate from the turning rollers
51
and prevent the turning rollers
51
from pulling the sheet of paper
11
back when the drive
30
rotates normally, as shown in FIG.
9
.
However, the design described above has two disadvantages, the first is, it is not possible to apply the page sensor
80
to detect whether the rear edge of sheet of paper
11
is close to the feeding roller
31
while printing unit
40
is printing on the front side
111
. The second is, while the back side
112
of the sheet of paper
11
is facing to the printing unit
40
and about to enter the feeding roller
31
, the page sensor
80
can't detect whether the sheet of paper
11
is in position because the obstructing lever
71
is caught by the hook
22
. Therefore, as shown in
FIG. 11
, the second embodiment of the invention is to separate the page sensor
80
from the obstructing unit
70
and let the rear
72
of the obstructing unit
70
be larger than the rear
82
of the page sensor
80
. In this way the rear
82
of the page sensor
80
can separate from the rear
72
of the obstructing unit
70
to make the sensing part
81
of the page sensor
80
swing upward to sense that the rear edge of sheet of paper
11
is close to the feeding roller
31
. But the rear
72
of the obstructing unit
70
is still pushed by the sheet of paper
11
, as shown in
FIG. 12
, so that the obstructing unit
70
can be applied to prevent the first switch
20
from coupling with the holding unit
10
. In order to make sure that the sheet of paper
11
can enter the turning unit
50
freely, a movable part
83
which can be applied to allow the sheet of paper
11
to pass through it is also designed and associated with the page sensor
80
(shown in FIG.
13
). Similarly, by the separated page sensor
80
and the obstructing unit
70
, the page sensor
80
is in neutral position and free to detect whether the sheet of paper
11
is in position while the back side
112
of the sheet of paper
11
is facing to the printing unit
40
and about to enter the feeding roller
31
.
The invention relates to a double-sided printing device in which the switches are driven by a drive to swing and couple with the holding and turning units selectively such that the path for paper-picking of the sheet of paper can be controlled and the sheet of paper can be guided and turned over inside the turning unit to reenter the printing unit. The double-sided printing device is designed as a built-in turning mechanism and is driven only by a single drive so that its production cost can be greatly reduced.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Claims
- 1. A double-sided printing device for paper handling applied to print data on a sheet having a first and a second side for printing, said printing device comprising:a holding unit applied to store and supply said sheet; a first switch selectively coupling with said holding unit; a drive connected with said first switch for supplying power to said first switch; a printing unit settled on one side of said first switch, said first switch is driven by said drive to provide power to said holding unit to feed said sheet into said printing unit to allow said first side of said sheet to be printed; a turning unit coupled with said first switch possessing an space for the circumrotation of said sheet; and an obstructing unit settled beside said first switch and confining selectively said first switch to couple with said holding unit; wherein said first switch is confined not to couple with said holding unit by said obstructing unit after said printing unit has finished the printing on said first side of said sheet, said sheet is guided by said turning unit into said space for circumrotation to be turned over and then reenters said printing unit for the printing on said second side of said sheet of paper.
- 2. The double-sided printing device for paper handling in accordance with claim 1, wherein said holding unit further comprises a reservoir for placing a plurality of sheets.
- 3. The double-sided printing device for paper handling in accordance with claim 2, wherein said drive rotates reversely to push said first switch to couple with said holding unit so that said holding unit feeds said sheet placed in said reservoir of said holding unit to said printing unit while by the ordinary rotation of said drive, said first switch is pushed to escape from said holding unit to feed said sheet to said printing unit to print data on said first side of said sheet of paper and simultaneously to prevent said holding unit to feed papers repeatedly.
- 4. The double-sided printing device for paper handling in accordance with claim 3, wherein said drive rotates once again reversely to drive a medium to push said obstructing unit to confine the first switch not to couple with said holding unit to prevent said holding unit to feed sheets, and said turning unit is pushed by said first switch to turn over said sheet which front side has been printed previously and to feed said sheet of paper again to said printing unit.
- 5. The double-sided printing device for paper handling in accordance with claim 4, wherein said turning unit utilizes a turning roller settled inside said space for circumrotation to turn over said sheet of paper which front side has been printed previously.
- 6. The double-sided printing device for paper handling in accordance with claim 5, wherein said turning unit is coupled with said first switch by a second switch and by another reverse rotation of said drive, said second switch is pushed to couple with said turning roller by said first switch such that said turning roller turns over said sheet which first side has been printed previously and then by the ordinary rotation of said drive, said second switch is pushed to escape from said turning roller by said first switching to feed said sheet to said printing unit.
- 7. The double-sided printing device for paper handling in accordance with claim 1, wherein said drive is coupled with said first switch by a feeding roller and by said feeding roller said sheet is fed to said printing unit.
- 8. The double-sided printing device for paper handling in accordance with claim 7, further comprises a page sensor settled beside said feeding roller, and said page sensor is actuated when said sheet goes through and enters or leaves said printing unit.
- 9. The double-sided printing device for paper handling in accordance with claim 8, wherein a rear of said page sensor stretches across the path for paper-handling of said sheet and the middle of said page sensor is pined to said printing device such that when said sheet of paper goes through said page sensor, said rear of said page sensor is pushed upward to make the top of said page sensor swing downward to sense that said sheet of paper has passed.
- 10. The double-sided printing device for paper handling in accordance with claim 9, wherein said obstructing unit is connected with one side of said page sensor and when said sheet goes through and pushes said page sensor, said obstructing unit simultaneously is driven to swing downward to produce obstruction for papers.
- 11. The double-sided printing device for paper handling in accordance with claim 10, wherein said first switch possesses a one-way hook corresponding with said obstructing unit and when said obstructing unit in position of obstruction, said one-way hook only confines the motions of said first switch in one-way.
- 12. The double-sided printing device for paper handling in accordance with claim 9, wherein said page sensor stretches similarly above said path for paper-advance of said sheet as a rear of said obstructing unit and the stretching length of said obstructing unit is larger than the one of said page sensor such that said obstructing unit still produces obstruction for papers after a front side of said sheet has been printed and said sheet of paper has escaped from said rear of said page sensor.
- 13. The double-sided printing device for paper handling in accordance with claim 12, wherein said rear of said page sensor is pined with said page sensor so that said sheet which first side has been printed still goes through said page sensor and enter said turning unit.
- 14. The double-sided printing device for paper handling in accordance with claim 12, wherein said first switch having a one-way hook corresponding with said obstructing unit, when said obstructing unit produces obstruction for papers, said one-way hook confines the motions of said first switch in one-way.
- 15. The double-sided printing device for paper handling in accordance with claim 1, wherein said turning unit further comprises a guiding element applied to prevent said sheet which the first side has been printed to enter said holding unit.
Priority Claims (1)
Number |
Date |
Country |
Kind |
91203175 U |
Mar 2002 |
TW |
|
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A |
6290410 |
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B1 |
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