Printer having circuit for providing improved printing quality

Claim 2

A non-impact printer according to claim 1, CHARACTERIZED IN THAT the other data sequence of the second signal is obtained in such a manner that each of the remaining bit data of the received video signal not converted into the first signal is converted correspondingly to the adjacent two resolution positions of the LED head.

Claim 3

A non-impact printer according to claim 1, CHARACTERIZED IN THAT said LED head comprises a plurality of LED devices, and the first LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head sufficiently exceeds a sensitivity of a photoconductor drum, and the second LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head is less than the sensitivity of the photoconductor drum, but if there happens the simultaneous light emission at the adjacent light emission points, synthesized light emission intensity exceeds the sensitivity of the photoconductor drum.

Claim 4

A non-impact printer provided with an LED head for printing and 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, said control means including a print data receiving circuit adapted to receive the video signal from the other controller and transmit a timing signal to the other controller, CHARACTERIZED IN THAT said print data receiving circuit (R) comprises: means (60 in FIG. 16) for generating line timing signals defining printing on an additional raster line during an interval of a receiving timing of the line timing signals; means (61 in FIG. 16) for generating additional line timing signals each defining printing on basic raster lines; a line buffer (82 in FIG. 16) for storing the received video signal; first conversion means (81, 96, 97 in FIG. 16) for reading out the video signal stored in said line buffer, converting bit data of the read out video signal into a first signal representative of a data sequence corresponding to a resolution of the LED head (19 in FIG. 1. 1), so that a resolution in a raster direction is converted into that in a sheet transfer direction; means (95, 96 in FIG. 16) for transmitting the first signal to the LED head in the form of a real printing data signal to be printed on the basic raster line in synchronism with the line timing signal; second conversion means (89, 90, 92, in FIG. 16) for performing a logical operation based on the current video signal entered and the previous video signal on the preceding line stored in the line buffer to generate a second signal representative of another data sequence, so that the resolution in the raster direction is converted into that in the sheet transfer direction; means (93, 95 in FIG. 16) for transmitting the second signal generated from said second conversion means to the LED head in the form of a real printing data signal to be printed on the additional raster line in synchronism with the additional line timing signal, wherein said control means further includes means (S in FIG. 1; FIG. 28) for setting first LED head drive energy with which the basic raster lines are printed and second LED head drive energy with which the additional raster lines are printed independently of each other.

Claim 5

A non-impact printer according to claim 4, CHARACTERIZED IN THAT the logical operation is performed in accordance with the following logical expression representing bit data on an additional raster data line of the sheet: where A m, n represents bit data on the m-th and n-th lines of the received 600 DPI video signal with n representing, if it is an even number, an LED head resolution position and, if it is an odd number, an intermediate position of an LED head resolution position.

Claim 6

A non-impact printer according to claim 4, CHARACTERIZED IN THAT said LED head comprises a plurality of LED devices, and the first LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head sufficiently exceeds a sensitivity of a photoconductor drum, and the second LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head is less than the sensitivity of the photoconductor drum, but if there happens the simultaneous light emission at the adjacent light emission points, the synthesized light emission intensity exceeds the sensitivity of the photoconductor drum.

Claim 7

A non-impact printer provided with an LED head for printing and 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, said control means including a print data receiving circuit adapted to receive the video signal from the other controller and transmit a timing signal to the other controller, CHARACTERIZED IN THAT said print data receiving circuit (R) comprises: means (60 in FIG. 20) for generating line timing signals defining printing on basic raster lines, and additional line timing signals each defining printing on an additional raster line; and resolution conversion means (100 in FIG. 20) adapted to receive repeatedly twice bit data on the same line of the video signal corresponding to the line timing signal and the additional line timing signal, respectively, said resolution conversion means providing such a control that bit data corresponding to a resolution of the LED head is extracted from either one of the bit data to be repeatedly received to generate a first signal representative of data sequence, and then the first signal is transmitted to the LED head in the form of a real printing data signal to be printed on the basic raster line in synchronism with the line timing signal, and bit data not corresponding to the resolution of the LED head is extracted from another of the bit data to be repeatedly received to generate a second signal representative of another data sequence, and then the second signal is transmitted to the LED head in the form of a real printing data signal to be printed on the additional raster line in synchronism with the additional line timing signal, wherein said control means further includes means (S in FIG. 1; FIG. 28) for setting first LED head drive energy with which the basic raster lines are printed and second LED head drive energy with which the additional raster lines are printed independently of each other.

Claim 8

A non-impact printer according to claim 7, CHARACTERIZED IN THAT said LED head comprises a plurality of LED devices, and the first LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head sufficiently exceeds a sensitivity of a photoconductor drum, and the second LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head is less than the sensitivity of the photoconductor drum, but if there happens the simultaneous light emission at the adjacent light emission points, the synthesized light emission intensity exceeds the sensitivity of the photoconductor drum.

Claim 9

A non-impact printer provided with am LED head for printing and 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, CHARACTERIZED IN THAT said LED head (30 in FIG. 22) includes: a shift register (30a in FIG. 23) comprising a plurality of line buffers (1-n in FIG. 23 ) adapted for storing data sequence corresponding to a resolution of the LED head, which is extracted from bit data of a printing data signal transmitted from the control unit (301 in FIG. 22); and resolution conversion means (30e in FIG. 23, 41-45 in FIG. 24) for converting the remaining bit data not corresponding to the resolution of the LED head into at least one another data sequence corresponding to the resolution of the LED head, and for providing such a control that the at least one other data sequence is also stored in said line buffers, and the data sequence and the at least one other data sequence are alternately read out from said line buffers, so as to print the data sequence corresponding to the resolution of the LED head on a basic raster line and print the at least one other data sequence on at least one additional raster line, wherein said control means includes means (S in FIG. 22; FIG. 28) for setting first LED head drive energy with which the basic raster lines are printed and second LED head drive energy wich which the additional raster lines are printed independently of each other.

Claim 10

A non-impact printer according to claim 9, CHARACTERIZED IN THAT said LED head comprises a plurality of LED devices (30c in FIG. 24) and the first LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head sufficiently exceeds a sensitivity of a photoconductor drum, and the second LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head is less than the sensitivity of the photoconductor drum, but if there happens the simultaneous light emission at the adjacent light emission points, the synthesized light emission intensity exceeds the sensitivity of the photoconductor drum.

Claim 11

A non-impact printer provided with an LED head for printing and 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, CHARACTERIZED IN THAT said LED head (30 in FIG. 22) includes: a buffer (30f in FIG. 26) for storing a printing data signal on a preceding line transmitted from the control unit (301 in FIG. 22); a logical operation circuit (65-74 in FIG. 26) for performing a logical operation of the printing data signal on the preceding line stored in said buffer (30f) and the printing data signal now transmitted to generate a real printing data signal for printing on additional raster lines; storage means (30a in FIG. 26) for storing the real printing data signal from said logical operation circuit and another real printing data signal for printing on basic raster lines; and means (72 in FIG. 26) for taking out alternately the real printing data signal and the other real printing data signal from said storage means, wherein said control means includes means (S in FIG. 22; FIG. 28) for setting first LED head drive energy with which the basic raster lines are printed and second LED head drive energy with which the additional raster lines are printed independently of each other.

Claim 12

A non-impact printer according to claim 11, CHARACTERIZED IN THAT the logical operation is performed in accordance with the following logical expression representing bit data on an additional raster data line: where A m, n represents bit data on the m-th and n-th lines of the received 600 DPI video signal with n representing, if it is an even number, an LED head resolution position and, if it is an odd number, an intermediate position of an LED head resolution position.

Claim 13

A non-impact printer according to claim 11, CHARACTERIZED IN THAT said LED head comprises a plurality of LED devices (30c in FIG. 26), and the first LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head sufficiently exceeds a sensitivity of the photoconductor drum, and the second LED head drive energy is predetermined in such a manner that light emission intensity at the light emission point of the respective LED devices of the LED head is less than the sensitivity of the photoconductor drum, but if there happens the simultaneous light emission at the adjacent light emission points, the synthesized light emission intensity exceeds the sensitivity of the photoconductor drum.

Claim 14

A non-impact printer according to claim 11, CHARACTERIZED IN THAT said storage means comprises a shift register (30a in FIG. 26) having a first stage of storage unit (32a in FIG. 26) and a second stage of storage unit (32b in FIG. 26) each adapted to store a half of bit data corresponding to the number of a raster line of dots.