Incremental printing of symbolic information – Light or beam marking apparatus or processes – Scan of light
Reexamination Certificate
1995-04-26
2002-04-16
Yockey, David F. (Department: 2861)
Incremental printing of symbolic information
Light or beam marking apparatus or processes
Scan of light
C358S001900, C358S296000
Reexamination Certificate
active
06373513
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a non-impact printer, and more particularly to a printer improved in printing quality to provide a natural printing image for a curve, a slash or the like.
2. Description of the Prior Art
Hitherto, in a non-impact printer such as an electrophotographic printer, an electrically charged photoconductor drum is illuminated with a light source to form an electrostatic latent image on a surface thereof, a developing is performed upon adhesion of a toner to the electrostatic latent image, to form a toner image, and then the thus obtained toner image is transferred to a recording material to be fixed thereon.
FIG. 2
is a block diagram of a printer control circuit for use in a conventional non-impact printer. In the figure, a printing control unit
1
transmits, at the time point that a sheet arrives at a printing ready point, a timing signal
12
, including a line and a raster timing signal, to a host or another controller, and receives video data
11
which has been edited on each page in a host or another controller. The received video data
11
in the printing control unit
1
is transmitted to an LED (Light Emitting Diode) head
19
in the form of a real printing data signal
18
. Upon receipt of a line of video data
11
, the control unit
1
transmits a latch signal
17
to the LED head
19
so as to hold the real printing data signal
18
therein. Before receiving the subsequent data from a host or another controller, the thus held real printing data signal
18
is visualized in print when the print head
19
receives a printing drive signal
13
. The real printing data signal
18
is transmitted to the LED head
19
in synchronism with a clock signal
18
a.
Transmission and receipt operation of the video data
11
is performed in the unit of print lines.
FIG. 3
is an operational time chart of the conventional non-impact printer as mentioned above.
However, according to the conventional non-impact printer as mentioned above, the printing is performed in accordance with image data or video data
11
transmitted from the host controller as it is, or depending on resolution of the LED head
19
which is determined by an arrangement of the LED devices at regular intervals in a raster direction. Thus, there will be retained a serrated edge-like image on a slash portion of the printed image due to the resolution.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention, in view of the foregoing problems, to provide an improved printer.
It is another object of the present invention to provide a non-impact printer capable of printing with a resolution higher than that of video data received from another controller or a host controller.
It is still another object of the present invention to provide a non-impact printer capable of reducing a serrated edge-like image on a slash portion of the printed image, thereby improving a printing quality.
In accordance with a preferred embodiment of the present invention, there is disclosed a non-impact printer provided with control means for providing a sequence control for the printer in its entirety in response to a control signal and a video data from another controller, comprising: means for generating line timing signals for printing on basic raster lines, and additional line timing signals each for printing on a sub-raster line during an interval of basic raster lines; line buffer means adapted for storing the received video datas in units of lines at predetermined continuous-line correspondence; means responsive to the line timing signals for causing the video data to be sequentially stored in said line buffer means; logical operation circuit means for taking out the video data stored in said line buffer in units of columns, performing a logical operation for the obtained video data in accordance with function groups each previously defined, and outputting a first correction output data for printing on the basic raster line and at least one second correction output data for printing on the sub-raster line; and means for transmitting the first and second correction output data to a print head in the form of a real printing data signal in synchronism with the line timing signal and the additional line timing signal, respectively; wherein said control means includes means for setting a print head drive energy for printing on the basic raster lines and a print head drive energy for printing on the additional raster lines independently of each other.
In accordance with another preferred embodiment of the invention, there is disclosed a non-impact printer provided with control means for providing a sequence control for the printer in its entirety in response to a control signal and a video signal from another controller, comprising: means for generating line timing signals for printing on basic raster lines, and additional line timing signals each for printing on a sub-raster line during an interval of a receiving timing of the line timing signals; line buffer means adapted for storing the received video data in units of lines at predetermined continuous-line correspondence; means responsive to the line timing signals for causing the video data to be sequentially stored in said line buffer means; means for taking out the video data stored in said line buffer in units of dots, and performing a logical operation for location of the center of gravity of the peripheral dots in the center the obtained dot; and a table conversion logical operation circuit for converting location information obtained by the logical operation into the corresponding output patterns, and transmitting the thus obtained output patterns to a print head in the form of a real printing data signal in synchronism with the line timing signal and the additional line timing signal, respectively; wherein said control means includes means for setting a print head drive energy for printing on the basic raster lines and a print head drive energy for printing on the additional raster lines independently of each other.
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patent: 4437122 (1984-03-01), Walsh et al.
patent: 4703323 (1987-10-01), Troupes et al.
patent: 4837587 (1989-06-01), Ng
patent: 4843408 (1989-06-01), Tanaka
patent: 5025322 (1991-06-01), Ng
patent: 5050227 (1991-09-01), Furusawa et al.
patent: 5130821 (1992-07-01), Ng
patent: 5134495 (1992-07-01), Frazier et al.
patent: 5193008 (1993-03-01), Frazier et al.
patent: 0 132 415 (1985-01-01), None
patent: 416886 (1991-03-01), None
Ito Katsuyuki
Katakura Shinichi
Nagumo Akira
Tanuma Jiro
Oki Data Corporation
Sartori Michael A.
Venable
Yockey David F.
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