Incremental printing of symbolic information – Ink jet – Controller
Reexamination Certificate
2002-03-07
2004-05-11
Meier, Stephen D. (Department: 2853)
Incremental printing of symbolic information
Ink jet
Controller
C347S018000
Reexamination Certificate
active
06733103
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-070811, filed Mar. 13, 2001, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a print apparatus such as a printer, and the like, and more particularly, to a printer such as an inkjet printer, and the like arranged such that inkjet heads are mounted on a carriage and power is supplied from a printer main body side to the carriage through cables.
2. Description of the Related Art
Conventionally, it is sometimes a case that inkjet printers have a plurality of print heads mounted thereon to eject inks having a different color for the purpose of making multi-color print, and so on.
In this case, a power supply having a sufficient electric power is disposed to the printer main body side to perform recording by driving the plurality of print heads at the same time. The plurality of print heads are connected to the printer main body side through many power supply lines and control signal lines.
An example of an arrangement of an inkjet printer according the conventional art will be described here with reference to
FIG. 1
showing the example.
FIG. 1
shows the arrangement of the inkjet printer which performes recording by driving a plurality of print heads
111
-
1
to
111
-
6
at the same time. That is, a main power supply
104
is mounted on a printer main body
101
side. The main power supply
104
is connected to a plurality of voltage converters
109
-
1
to
109
-
6
.
The outputs of the voltage converters
109
-
1
to
109
-
6
are connected to the inputs of head drive units
110
-
1
to
110
-
6
, respectively. Further, a CPU
105
is mounted on the main body
101
to control the inkjet printer in its entirety. The control signal lines of the CPU
105
are connected to a head voltage controller
108
, an image data processing unit
106
, and a head drive controller
107
, respectively. The printer main body
101
arranged as described above is connected to a carriage
103
side through a cable
102
so as to freely communicate therewith.
The plurality of print heads
111
-
1
to
111
-
6
are mounted on the carriage
103
. The power supply lines and control signal lines are connected to the print heads
111
-
1
to
111
-
6
, respectively. Further, the outputs from temperature detectors (not shown) included in the print heads
111
-
1
to
111
-
6
are fed back to the CPU
105
on the printer main body
101
side (hereinafter, this arrangement is referred to as prior art
1
).
Nowadays, there have been also developed printers having a head voltage generation circuit disposed in each of print heads to generate a drive voltage for driving each print head. It is also contemplated to dispose the head voltage generation circuits the print heads, as described above (hereinafter, this arrangement is referred to as prior art
2
).
Jpn. Pat. Appln. KOKAI Publication No. 7-25038, for example, discloses a technology of an inkjet recording apparatus that is roughly divided into a recording device section (mainly composed of print heads, and a carriage on which the print heads are mounted) and a machine main body (mainly composed of a power supply, respective control circuits, and respective head drive circuits) in which the drive of the recording apparatus section is controlled from the machine main body side. In this technology, the print heads are driven and controlled by electrically connecting the machine main body side to the recording device section through cables so as not to interfere with the movement of the carriage.
In this technology, a cable for connecting the machine main body side to the carriage side contains a control signal line and a power supply line for one set of the print heads, and it further contains a print head selection signal line. Therefore the number of control signal lines and voltage supply lines is reduced. That is, machine main body select one of the plurality of recording heads which is used for recording by using the the print head selection line, and a control signal and a drive voltage are supplied only to the selected print head (hereinafter, this arrangement is referred to as prior art
3
).
Jpn. Pat. Appln. KOKAI Publication No. 2000-203014 discloses a technology of an inkjet printer having a head, a carriage, and a head drive circuit, wherein the head drive circuit has a plurality of selection units, which are connected to respective piezo electric elements and can receive drive signals, a controller which controls the selection units, and a plurality of voltage/current amplifiers which amplify the drive signals that are supplied to the piezo electric elements (hereinafter, this arrangement is referred to as prior art
4
).
However, the prior art
1
has a problem in that while it is provided with the plurality of print heads to realize multi-gradation recording, when the print heads are driven at the same time, the number of the control signal lines and the power supply lines of the cable
102
increases as the number of the print heads
111
-
1
to
111
-
6
increases.
That is, since the print heads
111
-
1
to
111
-
6
must be individually controlled, it is necessary to provide the control signal lines according to the number of the print heads, which results in an increase in the number of the control signal lines. Further, when a different drive voltage is supplied to each drive head, the power supply lines must be provided according to the number of the print heads, which results in an increase in the number of the power supply lines.
Further, while the length of the cable
102
is determined according to the moving range of the carriage
103
, the length thereof must be increased in a printer which prints a larger image because the carriage
103
moves in a wider range. In this case, a predetermined drive voltage cannot be supplied to the print heads
111
-
1
to
111
-
6
because the drive voltage generated on the printer main body
101
side is dropped by the resistance component and the inductance component of the cable
102
itself before it is supplied to the print heads
111
-
1
to
111
-
6
through the cable
102
.
To solve this problem, it is contemplated to generate the drive voltage on the machine main body side at a higher level in consideration of the drop thereof.
However, this is against a today's requirement for reducing power consumption.
Further, when it is desired to abruptly apply a large drive voltage is to the print heads, the long cable interfere contribute to make the rise time of the drive voltage longer. Accordingly, there is a possibility that the print heads cannot be driven at predetermined timing.
In the arrangement of the prior art
2
, the temperature of the print heads themselves is excessively increased by the heat generated by the head voltage generating circuits disposed in the print heads. Thus, there is a possibility that ink ejection characteristics are made abnormal when inks are ejected and the quality of a recorded image is deteriorated thereby.
Further, each print head is not designed specifically for a particular ink but has versatility such that it can cope with a plurality of ink colors. With this design, a voltage generate circuit that constitutes a part of the head voltage generation circuit disposed in each print head also has versatility.
Therefore, when it is desired to differently control a voltage for each color, means for externally supplying ink color information, and the like to the voltage control circuit is necessary. Without this means, it is impossible the control the voltage for each ink color.
That is, when it is desired to differently control the voltage for each ink, it is necessary to separately supply ink color information to the voltage control circuit in each print head.
According to the arrangement as shown in the prior art
3
, it is impossible to execute simultaneous print by the plurality of print he
Dudding Alfred
Meier Stephen D.
Olympus Optical Co,. Ltd.
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