# US 2019/0168503 A1 · Indirect inkjet printing system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0168503 A1 - Document ID: US20190168503A1 - Status: Published application - Kind: A1 - Application number: 16/244,145 - Filed: 2019-01-10 - Published: 2019-06-06 - Earliest claimed: 2015-07-10 - Assignees: Landa Corporation Ltd. - Applicants: Landa Corporation Ltd. - Inventors: Haggai KARLINSKI; Alon SIMAN-TOV; Yehoshua SHEINMAN; Aharon SHMAISER; Daniel ALKHANATI; Elad PUR BUCHRAY - Web page: https://patentgrep.com/patent/US20190168503A1 ## CPC - B41J 2/0057: {where an intermediate transfer member receives the ink before transferring it on the printing material} - B41J 2/01: Ink jet - B41J 2/165: Prevention {or detection} of nozzle clogging, e.g. cleaning, capping or moistening for nozzles - B41J 2/1714: {Conditioning of the outside of ink supply systems, e.g. inkjet collector cleaning, ink mist removal (B41J2/08, B41J2/16517, B41J2/18 take precedence)} - B41J 2002/012: {with intermediate transfer member} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract An indirect printing system comprising an intermediate transfer member (ITM) and an image forming station at which droplets of ink are applied to the ITM to form ink images thereon, the image forming station including a first print bar including a first plurality of print heads and having mounted thereon a first blowing mechanism for introducing a first gas flow, having a first flow rate, into a gap between the first plurality of print heads and the ITM, and a second print bar including a second plurality of print heads and having mounted thereon a second blowing mechanism for introducing a second gas flow, having a second flow rate, into a gap between the second plurality of print heads and the ITM, the second print bar being disposed downstream of the first print bar, the second flow rate being greater than the first flow rate. ## Claims ### Claim 1 An indirect printing system comprising: a. an intermediate transfer member (ITM); b. an image forming station at which droplets of ink are applied to an outer surface of said ITM to form ink images thereon, the image forming station including: a first print bar including a first plurality of print heads spaced from said ITM by a first gap and having mounted thereon a first blowing mechanism, configured for blowing a first gas flow into said first gap in a print direction, said first gas flow having a first flow rate; and a second print bar including a second plurality of print heads spaced from said ITM by a second gap and having mounted thereon a second blowing mechanism, configured for blowing a second gas flow into said second gap in said print direction, said second gas flow having a second flow rate, said second print bar being disposed downstream of said first print bar; c. an impression station for transfer of the ink images from said ITM onto a printing substrate; and d. a guiding system for guiding said ITM along said image forming station, and from said image forming station to said impression station, wherein said second flow rate is different from said first flow rate. ### Claim 2 (depends on 1) The indirect printing system of claim 1, wherein said second flow rate is greater than said first flow rate. ### Claim 3 (depends on 1) The indirect printing system of claim 1, wherein said first flow rate is sufficient to prevent condensation on said first plurality of print heads, and said second flow rate is sufficient to prevent condensation on said second plurality of print heads. ### Claim 4 (depends on 1) The indirect printing system of claim 1, wherein said image forming station further includes: a third print bar including a third plurality of print heads spaced from said ITM by a third gap and having mounted thereon a third blowing mechanism, configured for blowing a third gas flow into said third gap in said print direction, said third gas flow having a third flow rate, said third print bar being disposed downstream of said second print bar; and a fourth print bar including a fourth plurality of print heads spaced from said ITM by a fourth gap and having mounted thereon a fourth blowing mechanism, configure for blowing a fourth gas flow into said fourth gap in said print direction, said fourth gas flow having a fourth flow rate, said fourth print bar being disposed downstream of said third print bar, wherein at least one of the following is true: said third flow rate is different from said second flow rate, and said fourth flow rate is different from said third flow rate. ### Claim 5 (depends on 4) The indirect printing system of claim 4, wherein at least one of the following is true: said third flow rate is greater than said second flow rate; and said fourth flow rate is greater than said third flow rate. ### Claim 6 (depends on 4) The indirect printing system of claim 4, wherein none of said first flow rate, said second flow rate, said third flow rate, and said fourth flow rate, exceeds a pre-determined threshold. ### Claim 7 (depends on 1) The indirect printing system of claim 1, wherein at least one of the following is true: at least one print head of said first plurality of print heads emits a droplet onto the ITM followed by a satellite droplet, and said first flow rate is sufficient to cause said satellite droplet to merge with said parent droplet on said ITM; and at least one print head of said second plurality of print heads emits a droplet onto the ITM followed by a satellite droplet, and said second flow rate is sufficient to cause said satellite droplet to merge with said parent droplet on said ITM. ### Claim 8 (depends on 1) The indirect printing system of claim 1, wherein said first blowing mechanism is further adapted to introduce into said first gap a first high speed gas flow blowing in said print direction, said first high speed gas flow having at least one of a higher speed and a higher pressure than said first gas flow. ### Claim 9 (depends on 8) The indirect printing system of claim 8, wherein said first gas flow and said first high speed gas flow are emitted from a single outlet of said first blowing mechanism. ### Claim 10 (depends on 8) The indirect printing system of claim 8, wherein said first gas flow and said first high speed gas flow are emitted from two separate outlets of said first blowing mechanism. ### Claim 11 (depends on 1) The indirect printing system of claim 1, wherein said second blowing mechanism is further adapted to introduce into said second gap a second high speed gas flow blowing in said print direction, said second high speed gas flow having at least one of a higher speed and a higher pressure than said second gas flow. ### Claim 12 (depends on 11) The indirect printing system of claim 11, wherein said second gas flow and said second high speed gas flow are emitted from a single outlet of said second blowing mechanism. ### Claim 13 (depends on 11) The indirect printing system of claim 11, wherein said second gas flow and said second high speed gas flow are emitted from two separate outlets of said second blowing mechanism. ### Claim 14 (depends on 1) The indirect printing system of claim 1, wherein each of said first and second blowing mechanisms includes a main body defining a first chamber and a first gas flow outlet in fluid connection with said first chamber, said first chamber including at least two compartment connected by at least one slot, and at least one perforated baffle plate, such that gas flow exiting said first gas flow outlet has an even pressure along a length of a corresponding said blowing mechanism. ### Claim 15 (depends on 14) The indirect printing system of claim 14, wherein said main body of each of said first and second blowing mechanisms includes a second chamber fluidly connected to a third chamber and a second gas flow outlet in fluid communication with said third chamber, the second chamber, third chamber and second gas flow outlet form a second flow path separate from a flow path formed by said first chamber and said first gas flow outlet. ### Claim 16 (depends on 15) The indirect printing system of claim 15, wherein said second gas flow outlet of said first blowing mechanism is adapted to provide, into said first gap and in said print direction, a first stream of gas having at least one of a higher speed and a higher pressure than said first gas flow. ### Claim 17 (depends on 15) The indirect printing system of claim 15, wherein said second gas flow outlet of said second blowing mechanism is adapted to provide, into said second gap and in said print direction, a second stream of gas having at least one of a higher speed and a higher pressure than said second gas flow. ### Claim 18 A method for preventing condensation on print heads of print bars in a printing system comprising an intermediate transfer member (ITM), a first print bar including a first plurality of print heads spaced from said ITM by a first gap and having mounted thereon a first blowing mechanism, and a second print bar including a second plurality of print heads spaced from said ITM by a second gap and having mounted thereon a second blowing mechanism said second print bar being disposed downstream of said first print bar, the method comprising: blowing, from said first blowing mechanism into said first gap in a print direction, a first gas flow having a first flow rate, thereby to prevent condensation on said first plurality of print heads; and blowing, from said second blowing mechanism into said second gap in said print direction, a second gas flow having a second flow rate, said second flow rate being different from said first flow rate, thereby to prevent condensation on said second plurality of print heads. ### Claim 19 (depends on 18) The method of claim 18, wherein said second flow rate is greater than said first flow rate. ### Claim 20 (depends on 18) The method of claim 18, wherein said printing system further includes a third print bar including a third plurality of print heads spaced from said ITM by a third gap and having mounted thereon a third blowing mechanism, said third print bar being disposed downstream of said second print bar, and a fourth print bar including a fourth plurality of print heads spaced from said ITM by a fourth gap and having mounted thereon a fourth blowing mechanism, said fourth print bar being disposed downstream of said third print bar, and wherein said method further comprises: blowing, from said third blowing mechanism into said third gap in said print direction, a third gas flow having a third flow rate, said third flow rate being different from said second flow rate, thereby to prevent condensation on said third plurality of print heads; and blowing, from said fourth blowing mechanism into said fourth gap in said print direction, a fourth gas flow having a fourth flow rate, said fourth flow rate being different from said third flow rate, thereby to prevent condensation on said fourth plurality of print heads. ### Claim 21 (depends on 20) The method of claim 20, wherein at least one of the following is true: said third flow rate is greater than said second flow rate; and said fourth flow rate is greater than said third flow rate.