CN100436144C

CN100436144C - Thermal accumulative process method for thermal transfer printer

Info

Publication number: CN100436144C
Application number: CNB2005101181607A
Authority: CN
Inventors: 谢文鸿
Original assignee: Hiti Digital Inc
Current assignee: Hiti Digital Inc
Priority date: 2005-10-26
Filing date: 2005-10-26
Publication date: 2008-11-26
Anticipated expiration: 2025-10-26
Also published as: CN1955006A

Abstract

A method for treating the heat accumulation in thermal transfer printer in order to eliminate the ink trailing features that in the ink trailing region the grayscale value of the printed pixel is updated to make the actual grayscale value lower than predefined one, and the normal grayscale value is gradually restored with the increasement of printed distance, resulting in high print quality.

Description

Be applied to the heat history processing method of a thermal transfer printer

Technical field

The present invention is about a kind of heat history processing method, particularly a kind of heat history processing method that is applied to a thermal transfer printer.

Background technology

The main difference of thermal transfer printer and general printer is that thermal transfer printer can print the image than high image quality, for example the photograph of high image quality.Please refer to Fig. 1, Fig. 1 is the schematic diagram of the printing paper feed mode of thermal transfer printer 10 in the prior art.Including a plurality of heaters 22 that are linear and equidistant arrangement on the thermal printer head 12 is used for to colour band 14 heating, so that the coloured dye on the colour band 14 is attached on the photo paper 16 by the mode of heat sublimation, wherein, when thermal printer head 12 is used for to photo paper 16 heating, each heater 22 of thermal printer head 12 can and produce a plurality of corresponding print point X1 and forms a linear image Y1 colour band 14 heating on photo paper 16, afterwards, photo paper 16 can move along this predetermined direction with a predetermined speed by roller set, so that thermal printer head 12 is able to print another linear image Y2 on photo paper 16.So, can print many linear images constantly on the photo paper 16, till being filled up by linear image on the photo paper 16, promptly finish the print routine of photo paper 16.

From the above, the number of thermal printer head 12 upper heaters 22 has determined the number of every print point X1 on the linear image.In addition, 22 pairs of colour band 14 heating-up temperatures of each heater determine the color depth of 22 corresponding print point X1 of each heater on photo paper 16, and this color depth is so-called GTG.Generally speaking, each print point X1 has different GTGs, and a plurality of print point X1 with different GTGs of all kinds have then constituted a striograph.Yet even each heater 22 all drives according to the image data that desire is printed, the actual gray of each print point X1 still might depart from the image gray scale of desire output, and reason just is to have on the thermal printer head 12 phenomenon of heat history.

Please refer to Fig. 2, Fig. 2 is the schematic diagram that drags black phenomenon that the heat history phenomenon of thermal transfer printer 10 in the prior art is caused.Since printhead 12 see through heating colour band 14 with the dye transfer on the colour band 14 to photo paper 16, and the high more required heating-up temperature of color of GTG value is high more.Therefore, if on the photo paper 16 of Fig. 2, have the lower regional Z1 of pixel gray level value, among the higher regional Z2 of Z3 and pixel gray level value, only need lower heating-up temperature when desiring the lower regional Z1 of first print pixel GTG value, when the higher regional Z2 of the print pixel GTG value of desiring to continue, 12 of printheads need to continue to improve the pixel that temperature can print high gray, therefore the border L1 that has clear and definite gray scale variation between regional Z1 and Z2.Yet if printhead 12 (this moment, heater 22 temperature were higher) after the higher regional Z2 of print pixel GTG value, when then being the lower regional Z3 of print pixel GTG value, because the temperature of heater 22 can't be reduced to the required temperature of regional Z3 at once, therefore heater 22 can with the heating-up temperature that is higher than regional Z3 GTG value correspondence with the dye transfer of colour band 14 to regional Z3, cause the GTG value of the region S that is connected with regional Z2 among the regional Z3 (by the border L2 among Fig. 2 to border L3) to be higher than the required GTG value in former S zone, and return to the GTG value (the border L3 among Fig. 2) of regional Z3 gradually along Print direction, this be the heat history phenomenon cause drag black phenomenon.

Because the heat history phenomenon of thermal transfer printer 10 makes the output finished product produce between high gray and low GTG and drags black phenomenon, the quality that influence is printed.

Summary of the invention

Therefore, main purpose of the present invention is providing a kind of heat history processing method of a thermal transfer printer that is applied to address the above problem.

The invention provides a kind of heat history processing method that is applied to a thermal transfer printer, this method includes that the first average GTG value according to a dozen printing elements deducts and the second average GTG value of these a dozen printing elements produces a GTG difference; When this GTG difference is timing, upgrade the GTG value of these a dozen printing elements some print pixels afterwards according to this GTG difference, wherein, the first average GTG value is the average GTG value of a plurality of print pixels before these a dozen printing elements, and the second average GTG value is the average GTG value of a plurality of print pixels after these a dozen printing elements.

Description of drawings

Fig. 1 is the schematic diagram of the printing paper feed mode of thermal transfer printer in the prior art.

The schematic diagram that drags black phenomenon that Fig. 2 causes for thermal transfer printer heat history phenomenon in the prior art.

Fig. 3 is applied to the flow chart of the heat history processing method of a thermal transfer printer for the present invention.

Fig. 4 is corresponding to the curve distribution figure of the GTG difference H of print pixel P.

Fig. 5 is for making the schematic diagram of GTG correction at a plurality of print pixel P that revise pixel O and continue according to an experience function.

The primary clustering symbol description

10 thermal transfer printers, 12 thermal printer heads

14 colour bands, 16 photo papers

22 heaters, 100～200 steps

X1 print point Y1, the Y2 image

Z1, Z2, Z3, S area L 1, L2, L3 border

G GTG updating value D GTG upgrades distance

C fair curve O revises pixel

The specific embodiment

Please refer to Fig. 3, Fig. 3 is applied to the flow chart of the heat history processing method of a thermal transfer printer for the present invention.Use method of the present invention as follows with the step of the heat history phenomenon of solution thermal transfer printer:

Step 100: determine the average GTG value W2 of w print pixel behind the average GTG value W1 of w print pixel before the plain P of a dozen printing and the print pixel P along the printer prints direction, wherein w is the integer greater than 1, determines a suitable numerical value by experiment;

Step 120: deduct W2 to obtain to correspond to the GTG difference H of print pixel P, wherein H=W1-W2 by the W1 in the step 100;

Step 140: repeating step 100～step 120 is set up the curve map of plain P of a dozen printing and GTG difference H relation behind the GTG difference H that obtains all print pixel P;

Step 160: in the curve map that step 140 is set up, find out the correction pixel O that GTG difference H is local maximum M, wherein revise pixel O and can be a plurality of according to the GTG difference H of a plurality of continuous print pixel P;

Step 180: will revise the pairing GTG difference of pixel O H according to an experience function and be converted to a GTG updating value G and a GTG and upgrade distance D, wherein to upgrade distance D be to revise after the pixel O continuously the print pixel P number that the GTG value of a print pixel P need be updated to GTG; And

Step 200: GTG updating value G and GTG according to step 180 gained upgrade the GTG value that distance D is upgraded the afterwards a plurality of print pixel P desires outputs of correction pixel O.

Method of the present invention is to do the processing of heat history problem according to the characteristic whether each print pixel P has an obvious gray scale variation to judge whether needs.At first as described in step 100 and the step 120, with the gray-scale distribution of each w adjacent print pixel before and after each print pixel P gray scale variation basis as print pixel P.The average GTG value W1 of w print pixel before the print pixel P is deducted the average GTG value W2 of w print pixel behind the print pixel P, the GTG difference H (H=W1-W2) of the plain P of 0 printing that must fall out, this GTG difference H can be positive number or negative.GTG difference H is the zone that high gray is changed to low GTG for " just " expression print pixel P zone of living in, and promptly heat history drags black phenomenon generation area in the prior art; GTG difference H is that " bearing " expression print pixel P zone of living in is the zone of low gray scale variation to high gray.In view of the above, what method desire of the present invention was handled is that GTG difference H is positive print pixel P, to solve the problem that heat history drags China ink.And if GTG difference H is big more, it is strong to represent the high gray in the zone at print pixel P place to be changed to the degree Shaoxing opera of low GTG, that causes drags black phenomenon obvious more, therefore can set up the curve distribution figure of a GTG difference H in step 140 according to the GTG difference H of all print pixel P.

Please refer to Fig. 4, Fig. 4 is corresponding to the curve distribution figure of the GTG difference H of print pixel P.Because each heater 22 representative printable print point (being print pixel P) of thermal transfer printer 10, so a plurality of print pixel P that each heater 22 is printed in photo paper 16 upper edge Print directions all can produce the curve distribution figure as Fig. 4 by method of the present invention.As previously mentioned, the black problem of dragging that thermal transfer printer 10 heat history phenomenons are caused in the prior art betides the zone of GTG difference H for " just ", in order to make heat history processing method of the present invention be easy to real work, a preferred embodiment of heat history processing method of the present invention is directly to handle to have print pixel P and the adjacent domain thereof that local maximum gray changes among all print pixel P.As described in step 160, in the curve distribution figure of Fig. 4, take out the correction pixel O1 that GTG difference H has local maximum, O2 and O3, its corresponding GTG difference is respectively H1, (owing to revise pixel O4 and O5 pairing GTG difference H4 and H5 is negative value for H2 and H3, need not use method of the present invention to handle, therefore not in the discussion scope), therefore in step 180 directly at revising pixel O1, O2 and O3 and a plurality of print pixels that continue thereof are done the GTG correction, to simplify heat history processing method of the present invention, only heat history processing method of the present invention is not limited to only determine in the above described manner the correction pixel O of desire correction.

Please refer to Fig. 5, Fig. 5 is for making the schematic diagram of GTG correction at a plurality of print pixel P that revise pixel O and continue according to an experience function.As described in step 180, when Fig. 4 determines to revise pixel O1, O2, O3 and corresponding GTG difference H1, H2 is behind the H3, each is revised the pairing GTG difference of pixel H substitution one experience function F (H) upgrades distance D to draw a GTG updating value G and a GTG, wherein F (H)=(G, D).The preferred embodiment of heat history method of the present invention is then at revising pixel O1, O2, and O3 and a plurality of print pixel P that continue separately do the GTG correction.

For example, if will revise the pairing GTG difference of pixel O1 H1 substitution this empirical function F (H), draw F (H1)=(G1, D1), then when reality is printed, review one's lessons by oneself the GTG value of upgrading correction pixel O1 in positive pixel O1 place and lack the new GTG value of G1 GTG value, as the actual printing GTG value of revising pixel O1 for revising the former GTG value of pixel O1.D1 is then for reviewing one's lessons by oneself the number of the print pixel P that needs to upgrade the GTG value behind the positive pixel O1.Therefore reviewing one's lessons by oneself positive pixel O1 all can upgrade via method of the present invention to the actual printing GTG value of a plurality of print pixel P between print pixel (O1+D1).As for review one's lessons by oneself positive pixel O1 to the correction of the GTG value of a plurality of print pixel P between print pixel (O1+D1) then as shown in Figure 5, revise pixel O1 and have downward GTG updating value G1, print pixel (O1+D1) is then no longer done the GTG correction afterwards, therefore the GTG correction degree that is begun by correction pixel O1 will be decremented to 0 by GTG updating value G1, shown in the curve C of Fig. 5, what the heat history phenomenon caused in the also realistic print procedure of these modification methods drags black problem with printing the characteristic that distance reduces gradually.The correction pixel O2 that other finds, O3 also handle according to revising pixel O1.

The present invention is applied to the heat history processing method of a thermal transfer printer and is easily dragging the zone of black phenomenon to drag the print pixel of black phenomenon to upgrade its GTG value at meeting, make the GTG value of actual output be lower than default GTG value, pyrogenic high gray when before printing the high gray zone to diminish drags China ink, makes the output quality of thermal transfer printer more be tending towards perfect.

The above only is the preferred embodiments of the present invention, and is all according to equalization variation and modification that the present invention did, all should belong to covering scope of the present invention.

Claims

1. heat history processing method that is applied to a thermal transfer printer comprises:

The second average GTG value that deducts these a dozen printing elements according to the first average GTG value of a dozen printing elements produces a GTG difference; When this GTG difference is timing, upgrade the GTG value of the some print pixels after these a dozen printing elements according to this GTG difference,

Wherein, the first average GTG value is the average GTG value of a plurality of print pixels before these a dozen printing elements, and the second average GTG value is the average GTG value of a plurality of print pixels after these a dozen printing elements.

2. method according to claim 1 is characterized in that, produces the number of the print pixel of these a dozen printing elements needs renewal afterwards according to the GTG difference of described a dozen printing elements.

3. heat history processing method that is applied to a thermal transfer printer comprises:

Produce a GTG difference according to first average GTG value of a dozen printing elements and the second average GTG value of these a dozen printing elements;

A plurality of continuous print pixels are as above operated and obtained a plurality of GTG differences, and utilizing these a plurality of GTG differences to find the GTG difference is the print pixel of positive local maximum;

According to the GTG value that is the some print pixels after the more new-found print pixel of GTG difference of positive local maximum,

4. method according to claim 3 is characterized in that, produces the number of the print pixel of the print pixel needs renewal of finding afterwards according to the GTG difference for positive local maximum.